A Comparative Analysis of Metabolic and Urinary Microbiome Profiles in Patients with Staghorn versus Non-Staghorn Infectious Renal Stones
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Abstract Objective To investigate the risk factors associated with staghorn calculus formation and the distribution differences in urine microbiota in patients with infectious renal stones. Methods A retrospective analysis was conducted on the clinical data of 201 patients hospitalized in our center from January 2020 to December 2024, who underwent upper urinary tract stone surgery and whose postoperative stone composition analysis indicated the main component was infectious stones. The patients were divided into two groups based on the presence or absence of staghorn calculi. General data, serum biochemical parameters, 24-hour urine metabolic parameters, and urine culture results were collected and compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for staghorn calculus formation. Results There were no significant differences between the two groups in terms of gender, age, or comorbidities. Serum calcium levels and estimated glomerular filtration rate (eGFR) were significantly higher in the non-staghorn stone group (P < 0.05), and the 24-hour urinary calcium level was also significantly higher than in the staghorn stone group (P = 0.003). Multivariate logistic regression analysis showed that low serum calcium level was a risk factor associated with staghorn calculus formation (P = 0.017, OR 0.016, 95% CI [0.001, 0.473]). Microbiota analysis revealed that the detection rate of Proteus mirabilis was significantly higher in the staghorn stone group compared to the non-staghorn stone group (31.5% vs. 2.4%, P = 0.001). Conclusion Low serum calcium levels and Proteus mirabilis are key factors in the formation of staghorn calculi. Clinically, attention should be paid to monitoring blood calcium levels and controlling urinary tract infections in patients with infectious stones to prevent the occurrence and progression of staghorn calculi and to protect renal function.
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A Comparative Analysis of Metabolic and Urinary Microbiome Profiles in Patients with Staghorn versus Non-Staghorn Infectious Renal Stones | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article A Comparative Analysis of Metabolic and Urinary Microbiome Profiles in Patients with Staghorn versus Non-Staghorn Infectious Renal Stones Endi Zhang, Zhichao Chi, Xuming Zhang, Jianxing Li, Chaoyue Ji, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9213702/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Objective To investigate the risk factors associated with staghorn calculus formation and the distribution differences in urine microbiota in patients with infectious renal stones. Methods A retrospective analysis was conducted on the clinical data of 201 patients hospitalized in our center from January 2020 to December 2024, who underwent upper urinary tract stone surgery and whose postoperative stone composition analysis indicated the main component was infectious stones. The patients were divided into two groups based on the presence or absence of staghorn calculi. General data, serum biochemical parameters, 24-hour urine metabolic parameters, and urine culture results were collected and compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for staghorn calculus formation. Results There were no significant differences between the two groups in terms of gender, age, or comorbidities. Serum calcium levels and estimated glomerular filtration rate (eGFR) were significantly higher in the non-staghorn stone group (P < 0.05), and the 24-hour urinary calcium level was also significantly higher than in the staghorn stone group (P = 0.003). Multivariate logistic regression analysis showed that low serum calcium level was a risk factor associated with staghorn calculus formation (P = 0.017, OR 0.016, 95% CI [0.001, 0.473]). Microbiota analysis revealed that the detection rate of Proteus mirabilis was significantly higher in the staghorn stone group compared to the non-staghorn stone group (31.5% vs. 2.4%, P = 0.001). Conclusion Low serum calcium levels and Proteus mirabilis are key factors in the formation of staghorn calculi. Clinically, attention should be paid to monitoring blood calcium levels and controlling urinary tract infections in patients with infectious stones to prevent the occurrence and progression of staghorn calculi and to protect renal function. Infectious stones Staghorn calculi Serum calcium Metabolic analysis 24-hour urine Microorganisms Introduction Kidney stones are a common urological disorder, whose incidence has been steadily increasing over the past three decades, currently affecting approximately 10% of the global population [ 1 , 2 ]. Characterized by high incidence, high recurrence rates, and high hospitalization rates, kidney stones impose a substantial burden on global healthcare systems [ 3 ]. Reports indicate that healthcare expenditure on urolithiasis in the United States alone reached $ 5.3 billion as early as 2014. Given the ongoing trends in the disease's prevalence, this will undoubtedly continue to strain local healthcare systems [ 4 ]. Infectious stones are a specific type of urinary calculus, accounting for about 15% of all cases. Their composition primarily includes struvite (magnesium ammonium phosphate hexahydrate), carbonate apatite, and ammonium acid urate [ 5 , 6 ]. The formation of infectious stones is closely related to urinary tract infections caused by urease-producing bacteria [ 7 , 8 ]. Under the action of the enzyme urease, urea is hydrolyzed into ammonia and carbon dioxide. This leads to the formation of ammonium ions and an increase in urine pH, creating alkaline conditions. These two conditions promote the crystallization of struvite and carbonate apatite [ 5 , 9 ]. A notable characteristic of infectious stones is their rapid growth, which readily leads to the formation of staghorn calculi [ 10 ]. Depending on the extent of involvement of the renal calyces, staghorn calculi can be classified as complete or partial. Literature indicates that staghorn calculi are typically associated with infection and progressive renal impairment¹¹, and often require prolonged surgical procedures with a high risk of multiple postoperative complications, making their management particularly challenging¹¹. Although numerous studies have investigated staghorn calculi, few have compared the metabolic profiles and urinary microbiome distributions between patients with infectious staghorn stones and those with non-staghorn infectious stones. Furthermore, while infectious stones are prone to form staghorn calculi, some patients do not develop this characteristic morphology. This suggests potential differences in underlying pathogenesis and metabolic factors, which may ultimately influence clinical treatment and prevention strategies. Therefore, this study retrospectively analyzed data from patients with infectious stones hospitalized in our center between January 2020 and December 2024. We compared general characteristics, serum biochemical parameters, and 24-hour urine metabolic indicators between staghorn and non-staghorn stone groups to identify factors influencing staghorn stone formation in patients with infectious stones, aiming to provide a theoretical basis for preventing staghorn calculus formation in this population. Materials and Methods Study patients A retrospective analysis was conducted on the clinical data of patients diagnosed with infectious stones who underwent upper urinary tract stone surgery at our center between January 2020 and December 2024. The composition of all stones was determined using Fourier transform infrared spectroscopy. Cases were included in this study only if the infectious stone components (magnesium ammonium phosphate hexahydrate, carbonate apatite) accounted for ≥ 50% of the total stone composition. Exclusion criteria included: (1) concurrent urinary tract anatomical abnormalities (e.g., horseshoe kidney, ectopic kidney, transplanted kidney) or dysfunction (e.g., neurogenic bladder); (2) patients on dialysis; (3) history of antibiotic use within 7 days prior to admission. This study was approved by the Ethics Committee of Beijing Tsinghua Changgung Hospital, Tsinghua University. Research Method Collect and organize baseline data (gender, age), blood pressure, body mass index (BMI), past comorbidities (hypertension, diabetes), preoperative laboratory test data (serum biochemistry, 24-hour urine, urine culture), and related imaging diagnostic data. The diagnostic criteria for comorbidities are as follows: hypertension is diagnosed according to the 2020 International Society of Hypertension Guidelines for the Practice of Hypertension Management [ 12 ], and diabetes is diagnosed according to the 2021 American Diabetes Association Classification and Diagnosis Criteria for Diabetes [ 13 ]. Based on the results of computed tomography (CT), plain radiography of the kidney, ureter, and bladder (KUB), and renal ultrasound, patients were divided into two groups: staghorn calculi and non-staghorn calculi. If patients had multiple medical records, only the data from their first visit were included for statistical analysis. Midstream urine specimen collection Upon hospital admission, 10 mL of random midstream urine should be collected using a sterile collection tube before antibiotic administration and immediately sent for microbiological culture testing. If immediate testing is not possible, the specimen should be refrigerated at 4°C and sent for analysis within 8 hours. Blood biochemistry and 24-hour urine collection To ensure testing accuracy, patients must complete fasting before morning venous blood collection. Routine biochemical tests include blood electrolytes, urea nitrogen, creatinine, uric acid, parathyroid hormone (PTH), and estimated glomerular filtration rate (eGFR). The 24-hour urine collection is performed from 8:00 AM on the second day of hospitalization until 8:00 AM the following day. During the initial collection, hydrochloric acid is added as a preservative to stabilize urine components. Urine analysis is conducted using certified automated analyzers following standardized methods, with tested parameters including urine pH, total urine volume, calcium, phosphorus, sodium, potassium, chloride, and uric acid excretion rate. Throughout the collection period, patients are instructed to avoid strenuous physical activity and maintain detailed dietary records. Statistical Methods Statistical analysis was performed using SPSS software version 27.0. Categorical data were expressed as number of cases (N) and percentage (%). Normally distributed continuous data were presented as mean ± standard deviation (SD), and comparisons between groups were conducted using the Chi-square test, t-test, and Fisher's exact test. Non-normally distributed continuous data were expressed as median (Q1, Q3), and the Mann-Whitney U test was used for intergroup comparisons. Multivariate logistic regression analysis was employed to identify independent risk factors promoting staghorn calculus formation in patients with infectious stones. A P-value < 0.05 was considered statistically significant. Results Patient Demographic and Baseline Characteristics A total of 201 patients with infectious stones were included in this study (Table 1 ). Among them, the staghorn calculi group comprised 130 cases (64.7%), including 41 males (20.4%) and 89 females (44.3%), with a mean age of 52.1 ± 11.4 years. The non-staghorn calculi group consisted of 71 cases (35.3%), including 22 males (10.9%) and 49 females (24.4%), with a mean age of 49.1 ± 13.6 years. No statistically significant differences were observed between the two groups in terms of gender, age, BMI, or comorbidities (diabetes, hypertension) (P > 0.05). Table 1 General Characteristics of the Patients General Data Non-staghorn Group Staghorn Group \(\:\varvec{x}\) 2 /t P-value N 71(35.3) 130(64.7) Gender 0.007 0.936 Male 22(10.9) 41(20.4) Female 49(24.4) 89(44.3) Age 49.11 ± 13.58 52.14 ± 11.38 -1.681 0.094 Hypertension 21(34.4) 40(65.6) 0.031 0.861 Diabetes 10(40.0) 15(60.0) 0.273 0.601 BMI 24.89 ± 3.49 25.44 ± 5.27 -0.797 0.427 Comparison of Metabolic Characteristics Regarding serum biomarkers, patients in the staghorn calculi group exhibited significantly lower blood calcium levels compared to the non-staghorn calculi group (2.27 ± 0.11 mmol/L vs. 2.31 ± 0.11 mmol/L, P = 0.013). Furthermore, the estimated glomerular filtration rate (eGFR) was significantly lower in the staghorn calculi group than in the non-staghorn calculi group (74.79 ± 30.50 vs. 87.19 ± 33.94 mL/min, P = 0.009). No significant differences were observed between the two groups in serum levels of magnesium, phosphorus, potassium, chloride, sodium, blood urea nitrogen (BUN), creatinine, uric acid, or parathyroid hormone (PTH) (P > 0.05). In the analysis of 24-hour urinary metabolic parameters, urinary calcium excretion was significantly lower in patients with staghorn calculi than in those with non-staghorn calculi (3.20 ± 2.19 vs. 4.26 ± 2.70 mmol/d, P = 0.003). Conversely, no statistically significant differences were found between the groups regarding urinary pH, sodium, potassium, phosphorus, chloride, uric acid excretion, or total urine volume (P > 0.05) (Table 2 ). Table 2 Metabolic Profiles of the Patients Metabolic indicators Group P-value Non-staghorn Group(n = 71) Staghorn Group (n = 130) Serum Biochemistry Calcium (mmol/L) 2.31 ± 0.11 2.27 ± 0.11 0.017 Magnesium (mmol/L) 0.89 ± 0.08 0.88 ± 0.08 0.349 Phosphorus (mmol/L) 1.18 ± 0.21 1.19 ± 0.16 0.748 Potassium (mmol/L) 4.00 ± 0.42 3.94 ± 0.37 0.270 Chloride (mmol/L) 106.34 ± 2.79 106.97 ± 3.40 0.186 Sodium (mmol/L) 141.49 ± 2.08 141.51 ± 2.62 0.950 BUN (mmol/L) 5.78 ± 3.08 6.79 ± 4.33 0.083 Creatinine (umol/L) 89.03 ± 58.74 103.78 ± 66.50 0.119 eGFR (mL/min) 87.19 ± 33.94 74.79 ± 30.50 0.009 Uric acid (µmol/L) 328.56 ± 102.31 358.39 ± 102.80 0.050 PTH (ng/mL) 52.44 ± 27.52 56.67 ± 47.80 0.494 24-Hour Urine pH (urine) 6.51 ± 0.63 6.54 ± 0.63 0.736 Calcium (mmol/d) 4.26 ± 2.70 3.20 ± 2.19 0.003 Sodium (mmol/d) 148.60 ± 66.85 154.02 ± 68.84 0.591 Potassium (mmol/d) 30.95 ± 12.65 29.17 ± 11.21 0.306 Phosphorus (mmol/d) 16.28 ± 10.05 15.53 ± 6.82 0.530 Chloride (mmol/d) 126.42 ± 56.19 127.43 ± 56.61 0.903 Uric Acid (µmol/d) 2523.39 ± 1056.46 2630.82 ± 1119.62 0.508 Volume (L/d) 2.10 ± 0.78 2.17 ± 0.84 0.532 Univariate and Multivariate Logistic Regression Analyses The univariate logistic regression analysis indicated that serum calcium, eGFR, and urinary calcium were influencing factors for staghorn calculus formation (P 0.05) (Table 3 ). Table 3 Univariate Logistic Regression Analysis Metabolic Indicator Group P-value Non-staghorn Group (n = 71) Staghorn Group (n = 130) Age 49.1 ± 13.6 52.1 ± 11.4 0.093 Serum calcium (mmol/L) 2.31 ± 0.11 2.27 ± 0.11 0.017 Serum Chloride (mmol/L) 106.34 ± 2.79 106.97 ± 3.40 0.184 Serum BUN (mmol/L) 5.78 ± 3.08 6.79 ± 4.33 0.082 Serum Creatinine (umol/L) 89.03 ± 58.74 103.78 ± 66.50 0.118 eGFR(mL/min) 87.19 ± 33.94 74.79 ± 30.50 0.009 Serum Uric acid (µmol/L) 328.56 ± 102.31 358.39 ± 102.80 0.050 Urinary calcium (mmol/d) 4.26 ± 2.70 3.20 ± 2.19 0.003 To investigate the independent influencing factors for staghorn calculus formation in the included cases, a multivariate logistic regression analysis was further performed, incorporating variables such as age, serum calcium, serum chloride, BUN, serum creatinine, eGFR, serum uric acid, and urinary calcium. The results demonstrated that only serum calcium was an independent influencing factor for whether infectious stones formed staghorn calculi (P = 0.017, OR 0.016, 95% CI [0.001, 0.473]). A lower serum calcium level was significantly associated with the formation of staghorn calculi (Table 4 ). Table 4 Multivariate Logistic Regression Analysis of Independent Risk Factors for Infection Stone Formation Parameter Regression Coefficient Standard Error Wald P-Value OR (95%CI) Age 0.010 0.017 0.344 0.557 1.010(0.976,1.045) Serum calcium -4.165 1.743 5.707 0.017 0.016(0.001,0.473) Serum Chloride -0.022 0.061 0.135 0.713 0.978(0.867,1.102) Serum BUN 0.078 0.096 0.654 0.419 1.081(0.895,1.306) Serum Creatinine -0.010 0.006 2.749 0.097 0.990(0.978,1.002) eGFR -0.013 0.011 1.472 0.225 0.987(0.967,1.008) Serum Uric acid 0.002 0.002 1.860 0.173 1.002(0.999,1.006) Urinary calcium -0.128 0.072 3.171 0.075 0.880(0.765,1.013) Microbial Distribution Characteristics Of the 201 infectious stone patient samples included, 124 cases showed positive midstream urine culture results. The two most frequently detected urease-producing bacteria were Proteus mirabilis (42 cases, 33.9%) and Klebsiella pneumoniae (10 cases, 8.1%). The two most prevalent non-urease-producing bacteria were Escherichia coli (41 cases, 33.1%) and Enterococcus faecalis (8 cases, 6.5%). Comparative analysis of the microbial distribution between the staghorn calculi group and the non-staghorn calculi group revealed a significantly higher detection rate of Proteus mirabilis in patients from the staghorn calculi group (31.5% vs. 2.4%, P = 0.001) (Table 5 ). Table 5 Microbial Distribution Microbiota Group (%) \(\:\varvec{x}\) 2 \Fisher P-value Non-staghorn Group Staghorn Group Total Proteus mirabilis 3(2.4) 39(31.5) 42(33.9) 10.801 0.001 Escherichia coli 14(11.3) 27(21.8) 41(33.1) 2.733 0.098 Klebsiella pneumoniae 5(4.0) 5(4.0) 10(8.1) 3.626 0.057 Enterococcus faecalis 4(3.2) 4(3.2) 8(6.5) 2.851 0.091 Pseudomonas aeruginosa 2(1.6) 3(2.4) 5(4.0) 0.625 0.429 Ureaplasma 0(0.0) 6(4.8) 6(4.8) 2.102 0.147 Morganella morganii 0(0.0) 2(1.6) 2(1.6) 0.678 0.410 Staphylococcus saprophyticus 0(0.0) 2(1.6) 2(1.6) 0.678 0.410 Candida albicans 1(0.8) 1(0.8) 2(1.6) 0.678 0.410 Mycoplasma hominis 1(0.8) 1(0.8) 2(1.6) 0.678 0.410 Providencia rettger Proteus vulgaris 0(0.0) 0(0.0) 1(0.8) 1(0.8) 1(0.8) 1(0.8) 0.336 0.336 0.562 0.562 Streptococcus agalactiae 0(0.0) 1(0.8) 1(0.8) 0.336 0.562 Haemophilus parainfluenzae 1(0.8) 0(0.0) 1(0.8) 3.024 0.082 Total 31(25) 93(75) 124(100) - - Discussion Urinary tract stones represent a global health issue, affecting 5%-10% of the world's population, and their incidence continues to rise due to changes in diet, lifestyle, and metabolic factors [ 14 ]. Infectious stones, a specific type of urinary tract stone, are the primary component of staghorn calculi [ 15 ]. Staghorn calculi, characterized by their complex structure and large stone burden, can lead to severe complications such as pyonephrosis, perinephric abscess, and pyelonephritis if not treated promptly, potentially resulting in renal failure [ 16 ]. Current research on staghorn calculi predominantly focuses on treatment strategies, while studies investigating their serum and urinary metabolic characteristics, particularly within the context of infectious stones, remain relatively limited [ 17 ]. To address this, our study strictly adhered to inclusion and exclusion criteria, enrolling 201 patients with infectious stones to compare differences in metabolic parameters and urinary microbial distribution between those with staghorn and non-staghorn calculi. The results demonstrated that patients in the staghorn calculi group had significantly lower serum and urinary calcium levels, along with a lower eGFR, suggesting that staghorn calculi may cause greater renal impairment. Urine culture analysis further revealed a significantly higher prevalence of Proteus mirabilis in the staghorn calculi group. Multivariate logistic regression analysis confirmed that low serum calcium level is an independent influencing factor for the formation of infectious staghorn calculi. These findings collectively indicate that metabolic abnormalities and infection with specific pathogens may jointly contribute to the formation process of staghorn calculi. Due to their large volume and frequent involvement of multiple calyces, staghorn calculi readily cause urinary tract obstruction and persistent infection. Long-term, this can lead to progressive deterioration of renal function, potentially advancing to end-stage renal disease or life-threatening uremia [ 18 , 19 ]. International studies have further confirmed that staghorn calculi are not only associated with declining renal function but may also induce systemic uremia [ 20 ]. An analysis of over 1,000 patients with xanthogranulomatous pyelonephritis revealed that approximately 69% had concurrent renal or ureteral stones, among whom 48% presented with staghorn calculi [ 21 ]. The conventional view holds that struvite stones themselves can lead to a reduced glomerular filtration rate [ 22 ]. The findings of our study further support this conclusion, emphasizing the significant importance of preventing staghorn calculi for the preservation of renal function. Numerous previous studies have confirmed a close relationship between the formation of urinary tract stones and metabolic abnormalities. For instance, the most common calcium oxalate stones are associated with hypercalciuria and hyperoxaluria, while hyperuricemia is a significant risk factor for the formation of uric acid stones [ 23 ]. However, metabolic studies focusing specifically on patients with infectious staghorn calculi remain relatively scarce. This study found that among patients with infectious stones, those with staghorn calculi exhibited lower serum and urinary calcium levels. The kidneys play a central role in calcium homeostasis, with approximately 98% of calcium ions being reabsorbed in the renal glomeruli [ 24 ]. When serum calcium decreases, to maintain systemic calcium balance, renal tubular reabsorption of calcium is enhanced, leading to a corresponding reduction in urinary calcium excretion and consequently lower urinary calcium levels. From the perspective of calcium-phosphorus metabolism, a decrease in serum ionized calcium can stimulate increased parathyroid hormone secretion, which promotes urinary phosphate excretion. In the context of renal insufficiency, phosphate reabsorption is further diminished, thereby predisposing to the formation of phosphate crystals [ 25 ]. The literature confirms that the formation of infectious stones is closely linked to recurrent infection with urease-producing bacteria [ 26 ]. Common urease-producing pathogens include Proteus species, Klebsiella species, and Pseudomonas species [ 19 ]. Although these pathogens are all urease-producers, their urease activity levels vary. Previous research has suggested that Proteus mirabilis possesses particularly high urease activity [ 27 ], a view supported indirectly by the findings of our study. Our microbial distribution results demonstrated a significant enrichment of Proteus mirabilis in the staghorn calculi group, indicating that this bacterium may play a key promotive role in the formation of staghorn calculi. The mechanism of infectious stone formation is well-established: firstly, bacterial urease enzymatically hydrolyzes urea into ammonia and carbon dioxide, which subsequently generate ammonium ions and bicarbonate. These then combine with cations present in the urine to form carbonate apatite and magnesium ammonium phosphate (struvite). Carbonate apatite begins to crystallize at a urine pH ≥ 6.8, while struvite only precipitates at a pH > 7.2. The alkaline environment created by urease-mediated urea hydrolysis accelerates the precipitation of calcium and magnesium ions (thereby reducing urinary calcium levels). Concurrently, renal impairment caused by bacterial infection disrupts calcium and phosphorus metabolism (reducing urinary phosphate reabsorption). This dual process provides accelerating conditions for the growth of infectious stones and the formation of staghorn calculi, establishing a vicious cycle of "infection-stone formation." This study is the first to identify hypocalcemia as an independent risk factor for the formation of infectious staghorn calculi. The underlying mechanism may involve hypocalcemia creating a lithogenic condition characterized by elevated urinary phosphate through the calcium-phosphorus metabolism pathway, while simultaneously leading to low urinary calcium levels via enhanced renal tubular reabsorption, thereby reducing the physicochemical stability of urine (such as the stone-inhibitory effect of citrate). When such patients are infected with urease-producing bacteria, the metabolic background created by hypocalcemia and the alkaline urinary environment and renal impairment caused by urease-producing bacterial infection exert a synergistic effect. This accelerates the precipitation and aggregation of magnesium ammonium phosphate crystals, predisposing to the formation of staghorn calculi. This finding suggests the potential importance of monitoring and maintaining serum calcium levels in patients with infectious stones in clinical practice, offering a novel therapeutic strategy for controlling the growth of infectious calculi. This study has several limitations. First, due to the inherent constraints of its retrospective design, the findings require further validation through multicenter prospective studies. Second, negative urine culture results in some patients may be attributed to detection errors caused by low bacterial load. Furthermore, the analysis was based solely on urine cultures without incorporating microbiological cultures of the stones themselves, thereby limiting a comprehensive characterization of the intrinsic microbial composition within the calculi. In summary, this study suggests that low serum calcium levels and Proteus mirabilis infection may serve as key influencing factors in the formation of infectious staghorn calculi. In clinical practice, monitoring and adjusting patients' serum calcium levels, along with proactive management of urinary tract infections, could potentially help prevent the formation and progression of staghorn calculi. Particularly for patients with pre-existing renal impairment, such interventional strategies should be emphasized to preserve renal function. Abbreviations eGFR, estimated glomerular filtration rate BUN, blood urea nitrogen PTH, parathyroid hormone BMI, body mass index Declarations Acknowledgements None. Ethics approval and consent to participate This study was approved by the Ethics Committee of Beijing Tsinghua Changgung Hospital, affiliated with Tsinghua University (Approval No. 26513-6-01), and was conducted in strict accordance with the ethical principles of the Declaration of Helsinki (1964) and its subsequent amendments. All subjects in this study met the criteria for exemption from informed consent, and none of the participating subjects signed an informed consent form. Conflicts of Interest The authors declare no conflicts of interest. FUNDING NONE Data availability The datasets used and analyzed during the current study are available from the corresponding author on reasonable request. Consent for publication Not applicable. References Chen Y, Liao X. Kidney stone disease increases the risk of cardiovascular events. PLoS ONE. 2025;20:e0330069. https://doi.org/10.1371/journal.pone.0330069 . Liu S, et al. 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BJU Int. 2023;131:395–407. https://doi.org/10.1111/bju.15878 . Kristensen C, Parks JH, Lindheimer M, Coe FL. Reduced glomerular filtration rate and hypercalciuria in primary struvite nephrolithiasis. Kidney Int. 1987;32:749–53. https://doi.org/10.1038/ki.1987.270 . Siener R. Nutrition and Kidney Stone Disease. Nutrients. 2021;13. https://doi.org/10.3390/nu13061917 . Staruschenko A, Alexander RT, Caplan MJ, Ilatovskaya DV. Calcium signalling and transport in the kidney. Nat Rev Nephrol. 2024;20:541–55. https://doi.org/10.1038/s41581-024-00835-z . Blaine J, Chonchol M, Levi M. Renal control of calcium, phosphate, and magnesium homeostasis. Clin J Am Soc Nephrol. 2015;10:1257–72. https://doi.org/10.2215/cjn.09750913 . Zheng Z, et al. A study of the difference in biochemical metabolism between patients with unilateral and bilateral upper urinary tract stones. Sci Rep. 2024;14:30154. https://doi.org/10.1038/s41598-024-81454-3 . Duran Ramirez JM, Gomez J, Obernuefemann CLP, Gualberto NC, Walker JN. Semi-Quantitative Assay to Measure Urease Activity by Urinary Catheter-Associated Uropathogens. Front Cell Infect Microbiol. 2022;12:859093. https://doi.org/10.3389/fcimb.2022.859093 . Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9213702","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":614097197,"identity":"7eebae0c-ead8-4b5f-b13a-3cff782d1e30","order_by":0,"name":"Endi Zhang","email":"","orcid":"","institution":"Beijing Tsinghua Changgung Hospital, School of Clinical Medicine , Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Endi","middleName":"","lastName":"Zhang","suffix":""},{"id":614097198,"identity":"fdae0b0d-20a1-4669-8b20-aa590c6fe6ae","order_by":1,"name":"Zhichao Chi","email":"","orcid":"","institution":"Beijing Tsinghua Changgung Hospital, School of Clinical Medicine , Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Zhichao","middleName":"","lastName":"Chi","suffix":""},{"id":614097199,"identity":"bba7badd-f1a9-4a81-b6cd-c76b60a7e61e","order_by":2,"name":"Xuming Zhang","email":"","orcid":"","institution":"Beijing Tsinghua Changgung Hospital, School of Clinical Medicine , Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Xuming","middleName":"","lastName":"Zhang","suffix":""},{"id":614097200,"identity":"c2dd9ecc-3132-4797-b69d-5be1405b410c","order_by":3,"name":"Jianxing Li","email":"","orcid":"","institution":"Beijing Tsinghua Changgung Hospital, School of Clinical Medicine , Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Jianxing","middleName":"","lastName":"Li","suffix":""},{"id":614097201,"identity":"6b52aef9-2047-4755-aff6-d59422f56a27","order_by":4,"name":"Chaoyue Ji","email":"","orcid":"","institution":"Beijing Tsinghua Changgung Hospital, School of Clinical Medicine , Tsinghua University","correspondingAuthor":false,"prefix":"","firstName":"Chaoyue","middleName":"","lastName":"Ji","suffix":""},{"id":614097202,"identity":"a157d204-81f6-4156-b3f2-2d1f2208ee6b","order_by":5,"name":"Weiguo Hu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7ElEQVRIiWNgGAWjYFACxgYgcYCBn5n5gMEHAxs74rVItrclFM4oSEsm1qoDDAZnzhh85vlwCGwCXmBwvLn5NU/FncSGGwmGm20MDjAzsB8+ugGvljMH26x5zjxLbJyRkGycY3CHj4EnLe0GPi1mNxLbjHnbDic2SyQcA2p5xswgwWOGX8v9hxAtbRKJ7b8tDA4zNhDUcoOx+TFISw/PYQZjBmK02J9JbGOcc+aw8Qz2NgbDHoO0ZDZCfpFsP/74w5uKw7L7D/N/MPjxx8aOn/3wMbxagIBNApVLQDkIMH8gQtEoGAWjYBSMZAAAJC9VJQUK1GgAAAAASUVORK5CYII=","orcid":"","institution":"Beijing Tsinghua Changgung Hospital, School of Clinical Medicine , Tsinghua University","correspondingAuthor":true,"prefix":"","firstName":"Weiguo","middleName":"","lastName":"Hu","suffix":""}],"badges":[],"createdAt":"2026-03-24 15:08:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9213702/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9213702/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106094870,"identity":"857f947c-3dbb-4ae6-91d0-6b4172cd6959","added_by":"auto","created_at":"2026-04-03 11:43:30","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":968070,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9213702/v1/3308f1c1-ac42-453d-aaa2-e9d4b6e1513b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Comparative Analysis of Metabolic and Urinary Microbiome Profiles in Patients with Staghorn versus Non-Staghorn Infectious Renal Stones","fulltext":[{"header":"Introduction","content":"\u003cp\u003eKidney stones are a common urological disorder, whose incidence has been steadily increasing over the past three decades, currently affecting approximately 10% of the global population [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Characterized by high incidence, high recurrence rates, and high hospitalization rates, kidney stones impose a substantial burden on global healthcare systems [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Reports indicate that healthcare expenditure on urolithiasis in the United States alone reached \u003cspan\u003e$\u003c/span\u003e5.3\u0026nbsp;billion as early as 2014. Given the ongoing trends in the disease's prevalence, this will undoubtedly continue to strain local healthcare systems [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eInfectious stones are a specific type of urinary calculus, accounting for about 15% of all cases. Their composition primarily includes struvite (magnesium ammonium phosphate hexahydrate), carbonate apatite, and ammonium acid urate [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The formation of infectious stones is closely related to urinary tract infections caused by urease-producing bacteria [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Under the action of the enzyme urease, urea is hydrolyzed into ammonia and carbon dioxide. This leads to the formation of ammonium ions and an increase in urine pH, creating alkaline conditions. These two conditions promote the crystallization of struvite and carbonate apatite [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. A notable characteristic of infectious stones is their rapid growth, which readily leads to the formation of staghorn calculi [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Depending on the extent of involvement of the renal calyces, staghorn calculi can be classified as complete or partial.\u003c/p\u003e \u003cp\u003eLiterature indicates that staghorn calculi are typically associated with infection and progressive renal impairment\u0026sup1;\u0026sup1;, and often require prolonged surgical procedures with a high risk of multiple postoperative complications, making their management particularly challenging\u0026sup1;\u0026sup1;. Although numerous studies have investigated staghorn calculi, few have compared the metabolic profiles and urinary microbiome distributions between patients with infectious staghorn stones and those with non-staghorn infectious stones. Furthermore, while infectious stones are prone to form staghorn calculi, some patients do not develop this characteristic morphology. This suggests potential differences in underlying pathogenesis and metabolic factors, which may ultimately influence clinical treatment and prevention strategies. Therefore, this study retrospectively analyzed data from patients with infectious stones hospitalized in our center between January 2020 and December 2024. We compared general characteristics, serum biochemical parameters, and 24-hour urine metabolic indicators between staghorn and non-staghorn stone groups to identify factors influencing staghorn stone formation in patients with infectious stones, aiming to provide a theoretical basis for preventing staghorn calculus formation in this population.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy patients\u003c/h2\u003e \u003cp\u003eA retrospective analysis was conducted on the clinical data of patients diagnosed with infectious stones who underwent upper urinary tract stone surgery at our center between January 2020 and December 2024. The composition of all stones was determined using Fourier transform infrared spectroscopy. Cases were included in this study only if the infectious stone components (magnesium ammonium phosphate hexahydrate, carbonate apatite) accounted for \u0026ge;\u0026thinsp;50% of the total stone composition. Exclusion criteria included: (1) concurrent urinary tract anatomical abnormalities (e.g., horseshoe kidney, ectopic kidney, transplanted kidney) or dysfunction (e.g., neurogenic bladder); (2) patients on dialysis; (3) history of antibiotic use within 7 days prior to admission. This study was approved by the Ethics Committee of Beijing Tsinghua Changgung Hospital, Tsinghua University.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eResearch Method\u003c/h3\u003e\n\u003cp\u003eCollect and organize baseline data (gender, age), blood pressure, body mass index (BMI), past comorbidities (hypertension, diabetes), preoperative laboratory test data (serum biochemistry, 24-hour urine, urine culture), and related imaging diagnostic data. The diagnostic criteria for comorbidities are as follows: hypertension is diagnosed according to the 2020 International Society of Hypertension Guidelines for the Practice of Hypertension Management [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], and diabetes is diagnosed according to the 2021 American Diabetes Association Classification and Diagnosis Criteria for Diabetes [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Based on the results of computed tomography (CT), plain radiography of the kidney, ureter, and bladder (KUB), and renal ultrasound, patients were divided into two groups: staghorn calculi and non-staghorn calculi. If patients had multiple medical records, only the data from their first visit were included for statistical analysis.\u003c/p\u003e\n\u003ch3\u003eMidstream urine specimen collection\u003c/h3\u003e\n\u003cp\u003eUpon hospital admission, 10 mL of random midstream urine should be collected using a sterile collection tube before antibiotic administration and immediately sent for microbiological culture testing. If immediate testing is not possible, the specimen should be refrigerated at 4\u0026deg;C and sent for analysis within 8 hours.\u003c/p\u003e\n\u003ch3\u003eBlood biochemistry and 24-hour urine collection\u003c/h3\u003e\n\u003cp\u003eTo ensure testing accuracy, patients must complete fasting before morning venous blood collection. Routine biochemical tests include blood electrolytes, urea nitrogen, creatinine, uric acid, parathyroid hormone (PTH), and estimated glomerular filtration rate (eGFR). The 24-hour urine collection is performed from 8:00 AM on the second day of hospitalization until 8:00 AM the following day. During the initial collection, hydrochloric acid is added as a preservative to stabilize urine components. Urine analysis is conducted using certified automated analyzers following standardized methods, with tested parameters including urine pH, total urine volume, calcium, phosphorus, sodium, potassium, chloride, and uric acid excretion rate. Throughout the collection period, patients are instructed to avoid strenuous physical activity and maintain detailed dietary records.\u003c/p\u003e\n\u003ch3\u003eStatistical Methods\u003c/h3\u003e\n\u003cp\u003eStatistical analysis was performed using SPSS software version 27.0. Categorical data were expressed as number of cases (N) and percentage (%). Normally distributed continuous data were presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), and comparisons between groups were conducted using the Chi-square test, t-test, and Fisher's exact test. Non-normally distributed continuous data were expressed as median (Q1, Q3), and the Mann-Whitney U test was used for intergroup comparisons. Multivariate logistic regression analysis was employed to identify independent risk factors promoting staghorn calculus formation in patients with infectious stones. A P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003ePatient Demographic and Baseline Characteristics\u003c/h2\u003e \u003cp\u003eA total of 201 patients with infectious stones were included in this study (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Among them, the staghorn calculi group comprised 130 cases (64.7%), including 41 males (20.4%) and 89 females (44.3%), with a mean age of 52.1\u0026thinsp;\u0026plusmn;\u0026thinsp;11.4 years. The non-staghorn calculi group consisted of 71 cases (35.3%), including 22 males (10.9%) and 49 females (24.4%), with a mean age of 49.1\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6 years. No statistically significant differences were observed between the two groups in terms of gender, age, BMI, or comorbidities (diabetes, hypertension) (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGeneral Characteristics of the Patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGeneral Data\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-staghorn Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStaghorn Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\varvec{x}\\)\u003c/span\u003e\u003c/span\u003e\u003csup\u003e2\u003c/sup\u003e/t\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e71(35.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e130(64.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.936\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22(10.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e41(20.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e49(24.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e89(44.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e49.11\u0026thinsp;\u0026plusmn;\u0026thinsp;13.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e52.14\u0026thinsp;\u0026plusmn;\u0026thinsp;11.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-1.681\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.094\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21(34.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e40(65.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.031\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.861\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiabetes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10(40.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15(60.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.273\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.601\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24.89\u0026thinsp;\u0026plusmn;\u0026thinsp;3.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25.44\u0026thinsp;\u0026plusmn;\u0026thinsp;5.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.797\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.427\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eComparison of Metabolic Characteristics\u003c/h3\u003e\n\u003cp\u003eRegarding serum biomarkers, patients in the staghorn calculi group exhibited significantly lower blood calcium levels compared to the non-staghorn calculi group (2.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11 mmol/L vs. 2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11 mmol/L, P\u0026thinsp;=\u0026thinsp;0.013). Furthermore, the estimated glomerular filtration rate (eGFR) was significantly lower in the staghorn calculi group than in the non-staghorn calculi group (74.79\u0026thinsp;\u0026plusmn;\u0026thinsp;30.50 vs. 87.19\u0026thinsp;\u0026plusmn;\u0026thinsp;33.94 mL/min, P\u0026thinsp;=\u0026thinsp;0.009). No significant differences were observed between the two groups in serum levels of magnesium, phosphorus, potassium, chloride, sodium, blood urea nitrogen (BUN), creatinine, uric acid, or parathyroid hormone (PTH) (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In the analysis of 24-hour urinary metabolic parameters, urinary calcium excretion was significantly lower in patients with staghorn calculi than in those with non-staghorn calculi (3.20\u0026thinsp;\u0026plusmn;\u0026thinsp;2.19 vs. 4.26\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70 mmol/d, P\u0026thinsp;=\u0026thinsp;0.003). Conversely, no statistically significant differences were found between the groups regarding urinary pH, sodium, potassium, phosphorus, chloride, uric acid excretion, or total urine volume (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMetabolic Profiles of the Patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMetabolic indicators\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-staghorn Group(n\u0026thinsp;=\u0026thinsp;71)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStaghorn Group\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;130)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Biochemistry\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCalcium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.017\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMagnesium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e0.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.349\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePhosphorus (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.748\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.94\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.270\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChloride (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e106.34\u0026thinsp;\u0026plusmn;\u0026thinsp;2.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e106.97\u0026thinsp;\u0026plusmn;\u0026thinsp;3.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.186\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e141.49\u0026thinsp;\u0026plusmn;\u0026thinsp;2.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e141.51\u0026thinsp;\u0026plusmn;\u0026thinsp;2.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.950\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e5.78\u0026thinsp;\u0026plusmn;\u0026thinsp;3.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e6.79\u0026thinsp;\u0026plusmn;\u0026thinsp;4.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.083\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCreatinine (umol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e89.03\u0026thinsp;\u0026plusmn;\u0026thinsp;58.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e103.78\u0026thinsp;\u0026plusmn;\u0026thinsp;66.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.119\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eeGFR (mL/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e87.19\u0026thinsp;\u0026plusmn;\u0026thinsp;33.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e74.79\u0026thinsp;\u0026plusmn;\u0026thinsp;30.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.009\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUric acid (\u0026micro;mol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e328.56\u0026thinsp;\u0026plusmn;\u0026thinsp;102.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e358.39\u0026thinsp;\u0026plusmn;\u0026thinsp;102.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.050\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePTH (ng/mL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e52.44\u0026thinsp;\u0026plusmn;\u0026thinsp;27.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e56.67\u0026thinsp;\u0026plusmn;\u0026thinsp;47.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.494\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e24-Hour Urine\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH (urine)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e6.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e6.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.736\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCalcium (mmol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4.26\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.20\u0026thinsp;\u0026plusmn;\u0026thinsp;2.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium (mmol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e148.60\u0026thinsp;\u0026plusmn;\u0026thinsp;66.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e154.02\u0026thinsp;\u0026plusmn;\u0026thinsp;68.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.591\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mmol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e30.95\u0026thinsp;\u0026plusmn;\u0026thinsp;12.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e29.17\u0026thinsp;\u0026plusmn;\u0026thinsp;11.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.306\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePhosphorus (mmol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e16.28\u0026thinsp;\u0026plusmn;\u0026thinsp;10.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e15.53\u0026thinsp;\u0026plusmn;\u0026thinsp;6.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.530\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChloride (mmol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e126.42\u0026thinsp;\u0026plusmn;\u0026thinsp;56.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e127.43\u0026thinsp;\u0026plusmn;\u0026thinsp;56.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.903\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUric Acid (\u0026micro;mol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2523.39\u0026thinsp;\u0026plusmn;\u0026thinsp;1056.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2630.82\u0026thinsp;\u0026plusmn;\u0026thinsp;1119.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.508\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolume (L/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.532\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eUnivariate and Multivariate Logistic Regression Analyses\u003c/h2\u003e \u003cp\u003eThe univariate logistic regression analysis indicated that serum calcium, eGFR, and urinary calcium were influencing factors for staghorn calculus formation (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), whereas age, serum chloride, blood urea nitrogen (BUN), serum creatinine, and serum uric acid showed no statistical significance (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eUnivariate Logistic Regression Analysis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMetabolic Indicator\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-staghorn Group\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;71)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStaghorn Group\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;130)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e49.1\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e52.1\u0026thinsp;\u0026plusmn;\u0026thinsp;11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.093\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum calcium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.017\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Chloride (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e106.34\u0026thinsp;\u0026plusmn;\u0026thinsp;2.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e106.97\u0026thinsp;\u0026plusmn;\u0026thinsp;3.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.184\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum BUN (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e5.78\u0026thinsp;\u0026plusmn;\u0026thinsp;3.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e6.79\u0026thinsp;\u0026plusmn;\u0026thinsp;4.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.082\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Creatinine (umol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e89.03\u0026thinsp;\u0026plusmn;\u0026thinsp;58.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e103.78\u0026thinsp;\u0026plusmn;\u0026thinsp;66.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.118\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eeGFR(mL/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e87.19\u0026thinsp;\u0026plusmn;\u0026thinsp;33.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e74.79\u0026thinsp;\u0026plusmn;\u0026thinsp;30.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.009\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Uric acid (\u0026micro;mol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e328.56\u0026thinsp;\u0026plusmn;\u0026thinsp;102.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e358.39\u0026thinsp;\u0026plusmn;\u0026thinsp;102.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.050\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUrinary calcium (mmol/d)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e4.26\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e3.20\u0026thinsp;\u0026plusmn;\u0026thinsp;2.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTo investigate the independent influencing factors for staghorn calculus formation in the included cases, a multivariate logistic regression analysis was further performed, incorporating variables such as age, serum calcium, serum chloride, BUN, serum creatinine, eGFR, serum uric acid, and urinary calcium. The results demonstrated that only serum calcium was an independent influencing factor for whether infectious stones formed staghorn calculi (P\u0026thinsp;=\u0026thinsp;0.017, OR 0.016, 95% CI [0.001, 0.473]). A lower serum calcium level was significantly associated with the formation of staghorn calculi (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariate Logistic Regression Analysis of Independent Risk Factors for Infection Stone Formation\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eRegression Coefficient\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStandard Error\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWald\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP-Value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eOR (95%CI)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.344\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.557\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.010(0.976,1.045)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum calcium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-4.165\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e1.743\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.707\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.017\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e0.016(0.001,0.473)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Chloride\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.061\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.135\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.713\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.978(0.867,1.102)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum BUN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.078\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.096\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.654\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.419\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.081(0.895,1.306)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Creatinine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.010\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.749\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.097\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.990(0.978,1.002)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eeGFR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.011\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.472\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.225\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.987(0.967,1.008)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum Uric acid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.860\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.173\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.002(0.999,1.006)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUrinary calcium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.128\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e0.072\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.171\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.075\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.880(0.765,1.013)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eMicrobial Distribution Characteristics\u003c/h2\u003e \u003cp\u003eOf the 201 infectious stone patient samples included, 124 cases showed positive midstream urine culture results. The two most frequently detected urease-producing bacteria were \u003cem\u003eProteus mirabilis\u003c/em\u003e (42 cases, 33.9%) and \u003cem\u003eKlebsiella pneumoniae\u003c/em\u003e (10 cases, 8.1%). The two most prevalent non-urease-producing bacteria were \u003cem\u003eEscherichia coli\u003c/em\u003e (41 cases, 33.1%) and \u003cem\u003eEnterococcus faecalis\u003c/em\u003e (8 cases, 6.5%). Comparative analysis of the microbial distribution between the staghorn calculi group and the non-staghorn calculi group revealed a significantly higher detection rate of \u003cem\u003eProteus mirabilis\u003c/em\u003e in patients from the staghorn calculi group (31.5% vs. 2.4%, P\u0026thinsp;=\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMicrobial Distribution\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMicrobiota\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eGroup (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\varvec{x}\\)\u003c/span\u003e\u003c/span\u003e\u003csup\u003e2\u003c/sup\u003e\\Fisher\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP-value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-staghorn Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStaghorn Group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProteus mirabilis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3(2.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39(31.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42(33.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.801\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEscherichia coli\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14(11.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27(21.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e41(33.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.733\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.098\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKlebsiella pneumoniae\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5(4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5(4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10(8.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.626\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.057\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnterococcus faecalis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4(3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8(6.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.851\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.091\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePseudomonas aeruginosa\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3(2.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5(4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.625\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.429\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUreaplasma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6(4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.147\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMorganella morganii\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.678\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.410\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStaphylococcus saprophyticus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.678\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.410\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCandida albicans\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.678\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.410\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMycoplasma hominis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.678\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.410\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProvidencia rettger\u003c/p\u003e \u003cp\u003eProteus vulgaris\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.336\u003c/p\u003e \u003cp\u003e0.336\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.562\u003c/p\u003e \u003cp\u003e0.562\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStreptococcus agalactiae\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.336\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.562\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHaemophilus parainfluenzae\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0(0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1(0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.024\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.082\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31(25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e93(75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e124(100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eUrinary tract stones represent a global health issue, affecting 5%-10% of the world's population, and their incidence continues to rise due to changes in diet, lifestyle, and metabolic factors [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Infectious stones, a specific type of urinary tract stone, are the primary component of staghorn calculi [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Staghorn calculi, characterized by their complex structure and large stone burden, can lead to severe complications such as pyonephrosis, perinephric abscess, and pyelonephritis if not treated promptly, potentially resulting in renal failure [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Current research on staghorn calculi predominantly focuses on treatment strategies, while studies investigating their serum and urinary metabolic characteristics, particularly within the context of infectious stones, remain relatively limited [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. To address this, our study strictly adhered to inclusion and exclusion criteria, enrolling 201 patients with infectious stones to compare differences in metabolic parameters and urinary microbial distribution between those with staghorn and non-staghorn calculi. The results demonstrated that patients in the staghorn calculi group had significantly lower serum and urinary calcium levels, along with a lower eGFR, suggesting that staghorn calculi may cause greater renal impairment. Urine culture analysis further revealed a significantly higher prevalence of \u003cem\u003eProteus mirabilis\u003c/em\u003e in the staghorn calculi group. Multivariate logistic regression analysis confirmed that low serum calcium level is an independent influencing factor for the formation of infectious staghorn calculi. These findings collectively indicate that metabolic abnormalities and infection with specific pathogens may jointly contribute to the formation process of staghorn calculi.\u003c/p\u003e \u003cp\u003eDue to their large volume and frequent involvement of multiple calyces, staghorn calculi readily cause urinary tract obstruction and persistent infection. Long-term, this can lead to progressive deterioration of renal function, potentially advancing to end-stage renal disease or life-threatening uremia [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. International studies have further confirmed that staghorn calculi are not only associated with declining renal function but may also induce systemic uremia [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. An analysis of over 1,000 patients with xanthogranulomatous pyelonephritis revealed that approximately 69% had concurrent renal or ureteral stones, among whom 48% presented with staghorn calculi [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The conventional view holds that struvite stones themselves can lead to a reduced glomerular filtration rate [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The findings of our study further support this conclusion, emphasizing the significant importance of preventing staghorn calculi for the preservation of renal function.\u003c/p\u003e \u003cp\u003eNumerous previous studies have confirmed a close relationship between the formation of urinary tract stones and metabolic abnormalities. For instance, the most common calcium oxalate stones are associated with hypercalciuria and hyperoxaluria, while hyperuricemia is a significant risk factor for the formation of uric acid stones [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. However, metabolic studies focusing specifically on patients with infectious staghorn calculi remain relatively scarce. This study found that among patients with infectious stones, those with staghorn calculi exhibited lower serum and urinary calcium levels. The kidneys play a central role in calcium homeostasis, with approximately 98% of calcium ions being reabsorbed in the renal glomeruli [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. When serum calcium decreases, to maintain systemic calcium balance, renal tubular reabsorption of calcium is enhanced, leading to a corresponding reduction in urinary calcium excretion and consequently lower urinary calcium levels. From the perspective of calcium-phosphorus metabolism, a decrease in serum ionized calcium can stimulate increased parathyroid hormone secretion, which promotes urinary phosphate excretion. In the context of renal insufficiency, phosphate reabsorption is further diminished, thereby predisposing to the formation of phosphate crystals [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe literature confirms that the formation of infectious stones is closely linked to recurrent infection with urease-producing bacteria [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Common urease-producing pathogens include \u003cem\u003eProteus\u003c/em\u003e species, \u003cem\u003eKlebsiella\u003c/em\u003e species, and \u003cem\u003ePseudomonas\u003c/em\u003e species [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Although these pathogens are all urease-producers, their urease activity levels vary. Previous research has suggested that \u003cem\u003eProteus mirabilis\u003c/em\u003e possesses particularly high urease activity [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], a view supported indirectly by the findings of our study. Our microbial distribution results demonstrated a significant enrichment of \u003cem\u003eProteus mirabilis\u003c/em\u003e in the staghorn calculi group, indicating that this bacterium may play a key promotive role in the formation of staghorn calculi.\u003c/p\u003e \u003cp\u003eThe mechanism of infectious stone formation is well-established: firstly, bacterial urease enzymatically hydrolyzes urea into ammonia and carbon dioxide, which subsequently generate ammonium ions and bicarbonate. These then combine with cations present in the urine to form carbonate apatite and magnesium ammonium phosphate (struvite). Carbonate apatite begins to crystallize at a urine pH\u0026thinsp;\u0026ge;\u0026thinsp;6.8, while struvite only precipitates at a pH\u0026thinsp;\u0026gt;\u0026thinsp;7.2. The alkaline environment created by urease-mediated urea hydrolysis accelerates the precipitation of calcium and magnesium ions (thereby reducing urinary calcium levels). Concurrently, renal impairment caused by bacterial infection disrupts calcium and phosphorus metabolism (reducing urinary phosphate reabsorption). This dual process provides accelerating conditions for the growth of infectious stones and the formation of staghorn calculi, establishing a vicious cycle of \"infection-stone formation.\"\u003c/p\u003e \u003cp\u003eThis study is the first to identify hypocalcemia as an independent risk factor for the formation of infectious staghorn calculi. The underlying mechanism may involve hypocalcemia creating a lithogenic condition characterized by elevated urinary phosphate through the calcium-phosphorus metabolism pathway, while simultaneously leading to low urinary calcium levels via enhanced renal tubular reabsorption, thereby reducing the physicochemical stability of urine (such as the stone-inhibitory effect of citrate). When such patients are infected with urease-producing bacteria, the metabolic background created by hypocalcemia and the alkaline urinary environment and renal impairment caused by urease-producing bacterial infection exert a synergistic effect. This accelerates the precipitation and aggregation of magnesium ammonium phosphate crystals, predisposing to the formation of staghorn calculi. This finding suggests the potential importance of monitoring and maintaining serum calcium levels in patients with infectious stones in clinical practice, offering a novel therapeutic strategy for controlling the growth of infectious calculi.\u003c/p\u003e \u003cp\u003eThis study has several limitations. First, due to the inherent constraints of its retrospective design, the findings require further validation through multicenter prospective studies. Second, negative urine culture results in some patients may be attributed to detection errors caused by low bacterial load. Furthermore, the analysis was based solely on urine cultures without incorporating microbiological cultures of the stones themselves, thereby limiting a comprehensive characterization of the intrinsic microbial composition within the calculi.\u003c/p\u003e \u003cp\u003eIn summary, this study suggests that low serum calcium levels and \u003cem\u003eProteus mirabilis\u003c/em\u003e infection may serve as key influencing factors in the formation of infectious staghorn calculi. In clinical practice, monitoring and adjusting patients' serum calcium levels, along with proactive management of urinary tract infections, could potentially help prevent the formation and progression of staghorn calculi. Particularly for patients with pre-existing renal impairment, such interventional strategies should be emphasized to preserve renal function.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eeGFR, estimated glomerular filtration rate\u003c/p\u003e \u003cp\u003eBUN, blood urea nitrogen\u003c/p\u003e \u003cp\u003ePTH, parathyroid hormone\u003c/p\u003e \u003cp\u003eBMI, body mass index\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee of Beijing Tsinghua Changgung Hospital, affiliated with Tsinghua University (Approval No. 26513-6-01), and was conducted in strict accordance with the ethical principles of the Declaration of Helsinki (1964) and its subsequent amendments. All subjects in this study met the criteria for exemption from informed consent, and none of the participating subjects signed an informed consent form.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflicts of interest.\u003c/p\u003e\n\u003cp\u003eFUNDING \u0026nbsp;NONE\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eChen Y, Liao X. Kidney stone disease increases the risk of cardiovascular events. 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Semi-Quantitative Assay to Measure Urease Activity by Urinary Catheter-Associated Uropathogens. Front Cell Infect Microbiol. 2022;12:859093. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fcimb.2022.859093\u003c/span\u003e\u003cspan address=\"10.3389/fcimb.2022.859093\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-nephrology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bnep","sideBox":"Learn more about [BMC Nephrology](http://bmcnephrol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bnep/default.aspx","title":"BMC Nephrology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Infectious stones, Staghorn calculi, Serum calcium, Metabolic analysis, 24-hour urine, Microorganisms","lastPublishedDoi":"10.21203/rs.3.rs-9213702/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9213702/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eTo investigate the risk factors associated with staghorn calculus formation and the distribution differences in urine microbiota in patients with infectious renal stones.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective analysis was conducted on the clinical data of 201 patients hospitalized in our center from January 2020 to December 2024, who underwent upper urinary tract stone surgery and whose postoperative stone composition analysis indicated the main component was infectious stones. The patients were divided into two groups based on the presence or absence of staghorn calculi. General data, serum biochemical parameters, 24-hour urine metabolic parameters, and urine culture results were collected and compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for staghorn calculus formation.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThere were no significant differences between the two groups in terms of gender, age, or comorbidities. Serum calcium levels and estimated glomerular filtration rate (eGFR) were significantly higher in the non-staghorn stone group (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and the 24-hour urinary calcium level was also significantly higher than in the staghorn stone group (P\u0026thinsp;=\u0026thinsp;0.003). Multivariate logistic regression analysis showed that low serum calcium level was a risk factor associated with staghorn calculus formation (P\u0026thinsp;=\u0026thinsp;0.017, OR 0.016, 95% CI [0.001, 0.473]). Microbiota analysis revealed that the detection rate of \u003cem\u003eProteus mirabilis\u003c/em\u003e was significantly higher in the staghorn stone group compared to the non-staghorn stone group (31.5% vs. 2.4%, P\u0026thinsp;=\u0026thinsp;0.001).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eLow serum calcium levels and \u003cem\u003eProteus mirabilis\u003c/em\u003e are key factors in the formation of staghorn calculi. Clinically, attention should be paid to monitoring blood calcium levels and controlling urinary tract infections in patients with infectious stones to prevent the occurrence and progression of staghorn calculi and to protect renal function.\u003c/p\u003e","manuscriptTitle":"A Comparative Analysis of Metabolic and Urinary Microbiome Profiles in Patients with Staghorn versus Non-Staghorn Infectious Renal Stones","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-02 23:08:59","doi":"10.21203/rs.3.rs-9213702/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-28T06:19:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-26T17:49:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"249621776139439413035125440876201670434","date":"2026-04-05T23:26:06+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-02T09:09:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"145475690543344131513648008818562626281","date":"2026-03-29T17:02:45+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-29T16:07:51+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-29T16:05:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-27T16:07:45+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-27T14:57:55+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Nephrology","date":"2026-03-27T14:54:23+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-nephrology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bnep","sideBox":"Learn more about [BMC Nephrology](http://bmcnephrol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bnep/default.aspx","title":"BMC Nephrology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"62110776-0af8-4ab1-a880-9d19538d2727","owner":[],"postedDate":"April 2nd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-12T14:01:13+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-02 23:08:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9213702","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9213702","identity":"rs-9213702","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}
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