Utility of Urinary Netrin-1 in Patients With Type 2 Diabetic Nephropathy and Its Correlation With Renal Function

Utility of Urinary Netrin-1 in Patients With Type 2 Diabetic Nephropathy and Its Correlation With Renal Function | 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 Utility of Urinary Netrin-1 in Patients With Type 2 Diabetic Nephropathy and Its Correlation With Renal Function Rahul Kumar Tomar, Vadivelan Mehalingam, Prashant Adole This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6801534/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Nov, 2025 Read the published version in BMC Endocrine Disorders → Version 1 posted 23 You are reading this latest preprint version Abstract Purpose -Netrin-1 is a urinary protein that may help in the diagnosis of diabetic nephropathy. The objectives of this study were to assess urinary netrin-1 levels in patients with type 2 diabetic nephropathy and to determine its correlation with renal function among them. Methodology - This cross-sectional analytical study was conducted at a tertiary care teaching hospital in south India for 18 months. Study subjects were divided into four groups: non-diabetics, diabetics with normal to mildly increased albuminuria, moderately increased albuminuria, and severely increased albuminuria. Urinary albumin was quantified by nephelometry for all study subjects. The ELISA technique estimated urinary netrin-1 levels in all groups. Results- Urinary netrin-1 levels were higher in diabetic subjects with normal to mildly increased and severely increased albuminuria than in the control group. Correlation analysis showed that there was a positive correlation of urinary netrin-1 with urinary albumin-creatinine ratio (UACR) and no correlation with estimated glomerular filtration rate (eGFR). Urinary netrin-1 showed a sensitivity of 88.3% and specificity of 75% at a cut-off value of 889.74 pg/mg creatinine for diagnosing diabetic nephropathy. Conclusion -Urinary netrin-1 levels were elevated in diabetic subjects with moderately and severely increased albuminuria as compared to non-diabetic subjects. It showed a positive correlation with the urinary albumin-creatinine ratio and no correlation with eGFR in diabetic subjects. Urinary netrin-1 diabetic nephropathy albuminuria Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Diabetic nephropathy (DN) is a microvascular complication that occurs in 30-40% of diabetic patients 1 . Proteinuria is the hallmark of diabetic nephropathy. The natural course of diabetic nephropathy progresses from normoalbuminuria to microalbuminuria and then to macroalbuminuria 2 . Microalbuminuria (urine albumin 30-300 mg/day or urine albumin-creatinine ratio 30-300 mg/gm creatinine) is the currently accepted marker for early diagnosis and indicates the beginning of established diabetic nephropathy 3 . Although diabetic nephropathy is believed to affect the glomerulus primarily, recent studies have shown that tubulointerstitial injury can precede glomerulopathy and hence, normoalbuminuric diabetic patients can have significant renal damage 4 . Netrins were first recognized as axonal guidance molecules and belong to a class of laminin-like proteins 5 . Netrin-1 is mainly expressed in the endothelial cells of healthy kidneys. Following renal injury, its expression increases in proximal tubular epithelial cells and is down-regulated in vascular endothelial cells 6 . Netrin-1 is an indicator of tubulointerstitial damage, which in diabetic patients may happen even prior to glomerular injury. Urinary netrin-1 has been found to have diagnostic utility as a biomarker for identifying diabetic nephropathy in a few studies 7, 8 . The aims of this study were to evaluate the diagnostic utility of urinary netrin-1 levels in patients with and without type 2 diabetic nephropathy and determine its correlation with renal function among them. Methodology This cross-sectional analytical study was conducted at Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry, over 18 months. The Institute Ethics Committee (Observational Studies), JIPMER, Puducherry, approved the study. ( Approval number - JIP/IEC-OS/2022/304 ) The study was conducted in accordance with the Declaration of Helsinki. Patients with type 2 diabetes mellitus above 18 years attending Medicine OPD with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/minute/1.73 m 2 (calculated by the CKD-EPI equation) were recruited as study subjects. Healthy individuals above 18 years without any symptoms of diabetes with a random blood sugar less than 200 mg/dL along with a serum creatinine below 1.3 mg/dL (males) and below 1.1 mg/dL (females) and urine protein-creatinine ratio (PCR) less than 0.20 were recruited as control subjects. Patients on angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), those with urinary tract infections, autoimmune disease, malignancy, chronic liver disease, congestive cardiac failure and renal impairment due to a cause other than diabetes were excluded from the study. Subjects were divided into four groups for this study. The control group was composed of non-diabetic patients without any renal disease. Diabetic patients were divided into 3 groups based on urine albumin creatinine ratio (UACR). Patients with UACR of 0-30 mg/g were classified as diabetics with normal to mildly increased albuminuria, and those with UACR between 30-300 mg/g were grouped as diabetics with moderately increased albuminuria. Diabetic patients with UACR above 300 mg/g were grouped as those with severely increased albuminuria. Convenience sampling technique was used in this study. Patients with type 2 diabetes mellitus attending Medicine OPD at JIPMER hospital and control subjects attending OPD for minor ailments were recruited over 18 months. 30 subjects were recruited in each group. The sample size was estimated using the results of sensitivity and specificity of a previous study on urinary netrin-1 in predicting diabetic nephropathy in patients with type 2 diabetes, which were 83.3 and 85%, respectively, with an absolute precision of 12% using nMASTER V2.0 7 . Informed written consent was obtained from all study subjects after screening them with the inclusion and exclusion criteria. Diabetic patients self-reported their duration of diabetes. Weight, height and blood pressure were recorded for all subjects. The estimated glomerular filtration rate (eGFR) was calculated using the 2021 CKD-EPI equation. A 5 mL of spot urine sample from the study subjects was centrifuged at 2000 rotations per minute (rpm) for 5 minutes. Nephelometry (Siemens model) was used to estimate urinary albumin levels for all study subjects. Urinary creatinine levels were assessed by spectrophotometry technique. The ratio of albumin to creatinine in urine (urinary albumin-creatinine ratio) was then calculated. Diabetic patients were classified as having normal to mildly increased albuminuria, moderately increased albuminuria, or severely increased albuminuria based on the urine albumin-creatinine ratio. Urinary netrin-1 levels were measured using quantitative ELISA kits supplied by Abbkine Ltd. The detection range of the kit was 75-1500 pg/mL, as provided by the manufacturer. STATA version 14, a statistical software package developed by StataCorp for statistics, data processing, visualization and automated reporting, was used to analyze the collected data. Continuous data were reported as mean with standard deviation (SD) or median with interquartile range (IQR) based on the normality of data, which was assessed using the Shapiro-Wilk test. Categorical variables were summarized as frequencies or percentages. A comparison of urinary netrin-1 levels between diabetic subjects and controls was done using the Kruskal-Wallis test. Correlation between urinary netrin-1 level, urinary albumin-creatinine ratio and eGFR were tested using Spearman’s correlation coefficient. All statistical analysis was carried out at a 5% significance level, and a p-value of less than 0.05 was considered statistically significant. Results Baseline characteristics of the study population are shown in table 1. Table 1 -Baseline characteristics of study subjects Parameter Controls (n = 30) Normal to mildly increased albuminuria (n = 30) Moderately increased albuminuria (n = 30) Severely increased albuminuria (n = 30) p value Age (years) Mean ± SD 38.36 ± 12.7 48.83 ± 10.26 51.7 ± 9.81 52.1 ± 6.05 - Gender (male) Frequency (%) 16 (53.3) 18 (60) 17 (56.67) 16 (53.3) - Body mass index (kg/m 2 ) Mean ± SD 20.01 ± 4.23 23.38 ± 4.27 22.79 ± 3.49 22.64 ± 3.78 0.06 Systolic blood pressure (mm Hg) Mean ± SD 120.8 ± 7.2 129.4 ± 13.1 131.5 ± 12.1 132.1 ± 15.9 0.003 Diastolic blood pressure (mm Hg) Mean ± SD 73.9 ± 6.1 76.9 ± 6.8 77.7 ± 7.3 77.9 ± 9.5 0.017 Serum creatinine (mg/dL) Mean ± SD 0.72 ± 0.21 0.77 ± 0.25 0.84 ± 0.28 0.92 ± 0.30 0.153 Table 2 shows the duration of diabetes in the diabetic sub-groups. Table 2 -Duration of diabetes in diabetic sub-groups Duration of diabetes Normal to mildly increased albuminuria (n=30) Moderately increased albuminuria (n=30) Severely increased albuminuria (n=30) Less than 1 year 4 (13.5%) 5 (16.7%) 3 (10%) 1-5 years 11 (36.5%) 12 (40%) 12 (40%) More than 5 years 15 (50%) 13 (43.3%) 15 (50%) CKD-EPI 2021 equation was used to calculate eGFR in all study subjects. 74.1% of study subjects had an eGFR above 90 mL/minute/1.73 m 2 . 31 subjects (25.9%) had an eGFR below 90 mL/minute/1.73 m 2 . Table 3 shows the eGFR in the different study groups. Table 3 -eGFR in various groups eGFR (mL/minute/1.73 m 2 ) Controls (n=30) Normal to mildly increased albuminuria (n=30) Moderately increased albuminuria (n=30) Severely increased albuminuria (n=30) ≥ 90 26 (86.7%) 23 (76.7%) 21 (70%) 19 (63.3%) 60-89 4 (13.3%) 7 (23.3%) 9 (30%) 11 (36.6%) < 60 0 0 0 0 The levels of urinary albumin-creatinine ratio (ACR) in different groups are shown in table 4. Table 4 -Urinary albumin-creatinine ratio in various groups Group Median urinary albumin-creatinine ratio (ACR) Quartile (Q1, Q3) Controls 17.55 14.64, 19.12 Normal to mildly increased albuminuria 25.83 22.16, 28.87 Moderately increased albuminuria 128.54 110.42, 221.82 Severely increased albuminuria 1310.6 915, 1856.7 Urinary netrin-1 levels in controls and diabetic subjects are shown in table 5. Table 5 -Urinary netrin-1 level in various groups Group Median urinary netrin-1 value (pg/mg creatinine) Quartile (Q1, Q3) P value Controls 670.1 545.1, 852.1 - Normal to mildly increased albuminuria 685.7 551.5, 943.4 0.433 Moderately increased albuminuria 1010.1 884.9, 1116.9 < 0.001 Severely increased albuminuria 1177.8 1071.5, 1284.9 < 0.001 Urinary netrin-1 values were non-normally distributed. There was a significant difference in the median values of urinary netrin-1 between controls and diabetic subjects in the moderately increased albuminuria and severely increased albuminuria groups. Figure 1 shows the distribution of urinary netrin-1 levels in all four groups on its five-number summary (minimum, first quartile (Q1), median, third quartile (Q3) & maximum). Here, the minimum is calculated as Q1-1.5 IQR and the maximum is calculated as Q3+1.5 IQR. X-axis: 4 groups 0-controls/ 1-normal to mildly increased albuminuria/ 2-moderately increased albuminuria/ 3-severely increased albuminuria Y-axis: Urinary netrin-1 (pg/mg creatinine) levels Figure 2 shows the scatter plot between urinary ACR and netrin-1 levels. There was a positive correlation between urinary ACR and netrin-1 levels with Spearman’s correlation coefficient r=0.6432 (p < 0.01). Figure 3 shows the scatter plot between urinary netrin-1 and eGFR values. There was no significant correlation between urinary netrin-1 and eGFR. Here, Spearman’s correlation coefficient r=-0.0811 (p=0.378). Figure 4 shows the scatter plot between urinary netrin-1 and serum creatinine levels. There was no significant correlation between urinary netrin-1 and serum creatinine; Spearman’s correlation coefficient was r=0.0827 (p=0.369). The receiver operator characteristic (ROC) curve was plotted to assess the utility of urinary netrin-1 as a marker of diabetic nephropathy in relation to urinary ACR. This is shown in figure 5. The area under the curve to diagnose diabetic nephropathy using urinary netrin-1 was 0.820 (95% CI, 0.75 to 0.89). A cut-off value of 889.74 pg/mg creatinine for urinary netrin-1 had a sensitivity of 88.3% and a specificity of 75%. The positive predictive value of urinary netrin-1 for diabetic nephropathy was 77.9% (95% CI, 66.2% to 87.1%), while the negative predictive value was 86.5% (95% CI, 74.2% to 94.4%). Discussion The hallmark of diabetic kidney disease (DKD) is worsening of glomerular function and tubulointerstitial injury with loss of functional nephrons. Conventionally, DKD has been recognized as glomerular dysfunction. However, studies have revealed that tubulointerstitial injury can precede glomerular pathology. The presence of albumin in the urine (UACR > 30 mg/g) and a decline in eGFR are the accepted markers for diabetic kidney disease. Current research has given an indication that renal impairment can be present in 30-60% of diabetic patients before the onset of moderately increased albuminuria. Hence, tubular biomarkers are being studied to detect nephropathy in non-albuminuric diabetic subjects. Netrin-1 is primarily released into the urine when the proximal renal tubule is affected. In renal tissue, diabetic nephropathy results from inflammation and glomerular and tubulointerstitial damage that increases the secretion of netrin-1 from damaged tubular epithelial cells 9 . Inflammation has a major role in the pathogenesis of diabetic nephropathy 11 . Netrin-1, through the UNC5B receptor, suppresses vascular inflammation and angiogenesis through interaction with vascular endothelial growth factor (VEGF). Thus, it has an anti-inflammatory effect, and hence, urinary excretion of netrin-1 is increased in patients with diabetic nephropathy 12 . Urinary excretion of netrin-1 increases tubulointerstitial damage that may precede apparent glomerular dysfunction in patients with diabetic nephropathy. Netrin-1 promotes the uptake of albumin in proximal tubular epithelial cells. In patients with diabetic nephropathy, tubular epithelial cells generate netrin-1 due to an increase in albumin excretion. This study investigated the diagnostic utility of urinary netrin-1, a tubular biomarker for diagnosing DKD relative to urinary ACR. Our study found no statistically significant difference in urinary netrin-1 levels between controls and diabetic subjects with normal to mildly increased albuminuria. This finding was in contrast to a study done by Mohammed EM et al. Their study showed that urinary netrin-1 levels in controls were significantly less compared to type 2 diabetic patients with normoalbuminuria [7]. Another study done by Jayakumar C et al, found similar results [8]. A study done by Elkholy RA et al, also found that there was a significant difference in urinary netrin-1 levels between controls and diabetic subjects with normoalbuminuria 10 . In our study, urinary netrin-1 showed a sensitivity of 88.3% (CI 77.4-95.2) and a specificity of 75% (CI 62.1-85.3) for the detection of diabetic nephropathy at a cut-off value of 889.74 pg/mg creatinine. Mohammed EM et al., in their study, found after performing ROC analysis that urinary netrin-1 had 82% sensitivity and 86% specificity for the prediction of diabetic nephropathy at a cut-off value of 630.7 pg/mg creatinine. Our study had a few limitations. First, the sample size was small, and selection bias was likely to be present since convenience sampling was performed. Second, our study used only a single spot urine albumin test (urinary albumin-creatinine ratio) instead of a 24-hour urinary albumin level to determine group entry among the subjects. Third, the study’s cross-sectional design did not allow the temporal association between elevated urinary netrin-1 levels and the onset of diabetic kidney disease to be determined. Conclusion Urinary netrin-1 levels were elevated in type 2 diabetic subjects with moderately increased albuminuria and severely increased albuminuria compared to non-diabetic subjects. However, compared to non-diabetic subjects, urinary netrin-1 levels were not significantly elevated in diabetic subjects with normal to mildly increased albuminuria. Urinary netrin-1 levels showed a strong positive correlation with urinary albumin-creatinine ratio (ACR) and no significant correlation with eGFR and serum creatinine in diabetic subjects. Statements & declarations 1. Ethical considerations-The study was approved by the Institutional Ethics Committee for Observational Studies, JIPMER, Puducherry on 06.10.2022. Approval number- JIP/IEC-OS/2022/304 . 2. Human ethics and consent to participate in the study-Informed, written consent was obtained from all subjects for participation in the study. All subjects gave written consent to participate in the study. 3. Consent to publish declaration-Not applicable 4. Declaration of conflicting interest-The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. 5. Funding statement-The study was funded by an Intramural Research Grant from Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry-605006. India 6. Data availability declaration-Data of this study is available with the corresponding author and can be provided when needed, for review. 7. Competing interests-All authors declare that they have no competing interests to declare. Acknowledgement -The authors gratefully acknowledge the financial support provided for the study by Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry. Author contributions statement - 1. Rahul Kumar Tomar-Formal analysis, investigation, writing-original draft preparation 2. Vadivelan Mehalingam-Conceptualization, writing-original draft preparation & editing 3. Prashant S Adole-Methodology, writing-review References Gross JL, de Azevedo MJ, Silveiro SP, Canani LH, Caramori ML, Zelmanovitz T. Diabetic nephropathy: diagnosis, prevention, and treatment. Diabetes Care. 2005;28:164-76. Gheith O, Farouk N, Nampoory N, Halim MA, Al-Otaibi T. Diabetic kidney disease: world wide difference of prevalence and risk factors. J Nephropharmacol. 2015 9;5:49-56. Rico-Fontalvo J, Aroca-Martínez G, Daza-Arnedo R, Cabrales J, Rodríguez-Yanez T, Cardona-Blanco M, Montejo-Hernández J, Rodelo Barrios D, Patiño-Patiño J, Osorio Rodríguez E. Novel Biomarkers of Diabetic Kidney Disease. Biomolecules. 2023;13:633. Chang J, Yan J, Li X, Liu N, Zheng R, Zhong Y. Update on the Mechanisms of Tubular Cell Injury in Diabetic Kidney Disease. Front Med (Lausanne). 2021;8:661076. Boyer NP, Gupton SL. Revisiting Netrin-1: One Who Guides (Axons). Front Cell Neurosci. 2018;12:221. Wang W, Reeves WB, Ramesh G. Netrin-1 and kidney injury. I. Netrin-1 protects against ischemia-reperfusion injury of the kidney. Am J Physiol Renal Physiol. 2008;294:F739-47. Mohammed EM, El-Messallamy FA, Mazroue AM, Elsayed IA, Zidan AA. Urinary netrin-1 as an early marker for diabetic nephropathy. Egypt J Hosp Med. 2020;81:1924-30. Jayakumar C, Nauta FL, Bakker SJ, Bilo H, Gansevoort RT, Johnson MH, Ramesh G. Netrin-1, a urinary proximal tubular injury marker, is elevated early in the time course of human diabetes. J Nephrol. 2014;27:151-7. White JJ, Mohamed R, Jayakumar C, Ramesh G. Tubular injury marker netrin-1 is elevated early in experimental diabetes. J Nephrol. 2013;26:1055-64. Elkholy RA, Younis RL, Allam AA, Hagag RY, Abdel Ghafar MT. Diagnostic efficacy of serum and urinary netrin-1 in the early detection of diabetic nephropathy. J Investig Med. 2021;69:1189-95. Zheng Z, Zheng F. Immune Cells and Inflammation in Diabetic Nephropathy. J Diabetes Res. 2016;2016:1841690. Behnoush AH, Khalaji A, Shokri Varniab Z, Rahbarghazi A, Amini E, Klisic A. Urinary and circulatory netrin-1 as biomarker in diabetes and its related complications: a systematic review and meta-analysis. Endocrine. 2024;84:328-44. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 05 Nov, 2025 Read the published version in BMC Endocrine Disorders → Version 1 posted Editorial decision: Revision requested 05 Aug, 2025 Reviewers agreed at journal 05 Aug, 2025 Reviews received at journal 03 Aug, 2025 Reviewers agreed at journal 03 Aug, 2025 Reviews received at journal 03 Aug, 2025 Reviews received at journal 02 Aug, 2025 Reviewers agreed at journal 02 Aug, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviews received at journal 31 Jul, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviews received at journal 23 Jul, 2025 Reviews received at journal 20 Jul, 2025 Reviewers agreed at journal 18 Jul, 2025 Reviewers agreed at journal 13 Jul, 2025 Reviewers invited by journal 03 Jul, 2025 Editor invited by journal 10 Jun, 2025 Editor assigned by journal 09 Jun, 2025 Submission checks completed at journal 09 Jun, 2025 First submitted to journal 02 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-6801534","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":480103540,"identity":"6bb2dfd0-fcbe-4734-9c2f-3609cc242332","order_by":0,"name":"Rahul Kumar Tomar","email":"","orcid":"","institution":"Jawaharlal Institute of Post Graduate Medical Education and Research","correspondingAuthor":false,"prefix":"","firstName":"Rahul","middleName":"Kumar","lastName":"Tomar","suffix":""},{"id":480103541,"identity":"608757a6-7ab8-4839-808c-02bb1310d319","order_by":1,"name":"Vadivelan Mehalingam","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8ElEQVRIiWNgGAWjYLACHgMGBj4GBsbHYB4zcwNxWtiAao0ZGIAsZkZitDCAtbBJg7UwENCi295j+OFNwWE5Nvazx6oLKv5E87cDtfyo2IZTi9mZM8aScwwOG7Px5KXdnnHGIHfGYcYGxp4zt3FruZGWIM1jkJbYxpBjdpu3zSC3AaiFmbENj5b7z5J/A7XUt/G/MSsGaZlPUMsN5mNAW2wS2CRyzJhBWjYQ1HIm+ZjlHAMbwzaJN8bSPGeMczcCtRzE65fjB5tvvPkjIc/Pn2P4madCLnfe+cMHH/yowK0FOzhAovpRMApGwSgYBWgAAASCUs98tqaVAAAAAElFTkSuQmCC","orcid":"","institution":"Jawaharlal Institute of Post Graduate Medical Education and Research","correspondingAuthor":true,"prefix":"","firstName":"Vadivelan","middleName":"","lastName":"Mehalingam","suffix":""},{"id":480103542,"identity":"098928b3-d300-465f-8c6b-23517601b58e","order_by":2,"name":"Prashant Adole","email":"","orcid":"","institution":"Jawaharlal Institute of Post Graduate Medical Education and Research","correspondingAuthor":false,"prefix":"","firstName":"Prashant","middleName":"","lastName":"Adole","suffix":""}],"badges":[],"createdAt":"2025-06-02 11:08:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6801534/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6801534/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12902-025-02049-1","type":"published","date":"2025-11-05T15:57:38+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":86215872,"identity":"0cb2a3f1-42ee-479e-9bf6-9d4ad8890065","added_by":"auto","created_at":"2025-07-08 05:58:42","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":20358,"visible":true,"origin":"","legend":"\u003cp\u003eBox and whisker plot\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6801534/v1/0f34bddc48a4aa8ca636f647.png"},{"id":86215891,"identity":"92892651-3acc-43de-a0e3-e8d684de1125","added_by":"auto","created_at":"2025-07-08 05:58:59","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":33673,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation analysis of urinary ACR and netrin-1 levels\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6801534/v1/2f5eb18daf619e23edb4ae88.png"},{"id":86215887,"identity":"b7b2aa2b-ef73-4fcf-b399-ac50657036c0","added_by":"auto","created_at":"2025-07-08 05:58:43","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":40272,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation analysis of urinary netrin-1 and eGFR\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6801534/v1/3d92865d9078e0c0f9320fe4.png"},{"id":86216388,"identity":"8aec0bc5-39b9-467a-b215-335dc0f37e65","added_by":"auto","created_at":"2025-07-08 06:06:42","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":41231,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation analysis of urinary netrin-1 and serum creatinine\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6801534/v1/11201f87f8555d828020773b.png"},{"id":86215881,"identity":"dc7bc9b7-7960-4a01-aa13-fdbff388ca60","added_by":"auto","created_at":"2025-07-08 05:58:42","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":41381,"visible":true,"origin":"","legend":"\u003cp\u003eROC curve for urinary netrin-1\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6801534/v1/e8189198a177f0197534d74a.png"},{"id":95564265,"identity":"2f909f13-3064-4c27-8195-83283f8402b0","added_by":"auto","created_at":"2025-11-10 16:09:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":856098,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6801534/v1/9cdb997f-5e1a-494b-904e-9ed3815ba96f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eUtility of Urinary Netrin-1 in Patients With Type 2 Diabetic Nephropathy and Its Correlation With Renal Function\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDiabetic nephropathy (DN) is a microvascular complication that occurs in 30-40% of diabetic patients\u003csup\u003e1\u003c/sup\u003e. Proteinuria is the hallmark of diabetic nephropathy. The natural course of diabetic nephropathy progresses from normoalbuminuria to microalbuminuria and then to macroalbuminuria\u003csup\u003e2\u003c/sup\u003e. Microalbuminuria (urine albumin 30-300 mg/day or urine albumin-creatinine ratio 30-300 mg/gm creatinine) is the currently accepted marker for early diagnosis and indicates the beginning of established diabetic nephropathy\u003csup\u003e3\u003c/sup\u003e. Although diabetic nephropathy is believed to affect the glomerulus primarily, recent studies have shown that tubulointerstitial injury can precede glomerulopathy and hence, normoalbuminuric diabetic patients can have significant renal damage\u003csup\u003e4\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNetrins were first recognized as axonal guidance molecules and belong to a class of laminin-like proteins\u003csup\u003e5\u003c/sup\u003e. Netrin-1 is mainly expressed in the endothelial cells of healthy kidneys. Following renal injury, its expression increases in proximal tubular epithelial cells and is down-regulated in vascular endothelial cells\u003csup\u003e6\u003c/sup\u003e. Netrin-1 is an indicator of tubulointerstitial damage, which in diabetic patients may happen even prior to glomerular injury. Urinary netrin-1 has been found to have diagnostic utility as a biomarker for identifying diabetic nephropathy in a few studies\u003csup\u003e7, 8\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe aims of this study were to evaluate the diagnostic utility of urinary netrin-1 levels in patients with and without type 2 diabetic nephropathy and determine its correlation with renal function among them.\u0026nbsp;\u003c/p\u003e"},{"header":"Methodology","content":"\u003cp\u003eThis cross-sectional analytical study was conducted at Jawaharlal Institute of Postgraduate Medical Education \u0026amp; Research (JIPMER), Puducherry, over 18 months. The Institute Ethics Committee (Observational Studies), JIPMER, Puducherry, approved the study. (\u003cstrong\u003eApproval number\u003c/strong\u003e-\u003cstrong\u003eJIP/IEC-OS/2022/304\u003c/strong\u003e) The study was conducted in accordance with the Declaration of Helsinki.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePatients with type 2 diabetes mellitus above 18 years attending Medicine OPD with an estimated glomerular filtration rate (eGFR) \u0026ge; 60 mL/minute/1.73 m\u003csup\u003e2\u003c/sup\u003e (calculated by the CKD-EPI equation) were recruited as study subjects. Healthy individuals above 18 years without any symptoms of diabetes with a random blood sugar less than 200 mg/dL along with a serum creatinine below 1.3 mg/dL (males) and below 1.1 mg/dL (females) and urine protein-creatinine ratio (PCR) less than 0.20 were recruited as control subjects.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePatients on angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), those with urinary tract infections, autoimmune disease, malignancy, chronic liver disease, congestive cardiac failure and renal impairment due to a cause other than diabetes were excluded from the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSubjects were divided into four groups for this study. The control group was composed of non-diabetic patients without any renal disease. Diabetic patients were divided into 3 groups based on urine albumin creatinine ratio (UACR). Patients with UACR of 0-30 mg/g were classified as diabetics with normal to mildly increased albuminuria, and those with UACR between 30-300 mg/g were grouped as diabetics with moderately increased albuminuria. Diabetic patients with UACR above 300 mg/g were grouped as those with severely increased albuminuria.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConvenience sampling technique was used in this study. Patients with type 2 diabetes mellitus attending Medicine OPD at JIPMER hospital and control subjects attending OPD for minor ailments were recruited over 18 months.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e30 subjects were recruited in each group. The sample size was estimated using the results of sensitivity and specificity of a previous study on urinary netrin-1 in predicting diabetic nephropathy in patients with type 2 diabetes, which were 83.3 and 85%, respectively, with an absolute precision of 12% using nMASTER V2.0\u003csup\u003e7\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eInformed written consent was obtained from all study subjects after screening them with the inclusion and exclusion criteria. Diabetic patients self-reported their duration of diabetes. Weight, height and blood pressure were recorded for all subjects. The estimated glomerular filtration rate (eGFR) was calculated using the 2021 CKD-EPI equation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eA 5 mL of spot urine sample from the study subjects was centrifuged at 2000 rotations per minute (rpm) for 5 minutes. Nephelometry (Siemens model) was used to estimate urinary albumin levels for all study subjects. Urinary creatinine levels were assessed by spectrophotometry technique. The ratio of albumin to creatinine in urine (urinary albumin-creatinine ratio) was then calculated. Diabetic patients were classified as having normal to mildly increased albuminuria, moderately increased albuminuria, or severely increased albuminuria based on the urine albumin-creatinine ratio.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUrinary netrin-1 levels were measured using quantitative ELISA kits supplied by Abbkine Ltd. The detection range of the kit was 75-1500 pg/mL, as provided by the manufacturer.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSTATA version 14, a statistical software package developed by StataCorp for statistics, data processing, visualization and automated reporting, was used to analyze the collected data. Continuous data were reported as mean with standard deviation (SD) or median with interquartile range (IQR) based on the normality of data, which was assessed using the Shapiro-Wilk test. Categorical variables were summarized as frequencies or percentages. A comparison of urinary netrin-1 levels between diabetic subjects and controls was done using the Kruskal-Wallis test. Correlation between urinary netrin-1 level, urinary albumin-creatinine ratio and eGFR were tested using Spearman\u0026rsquo;s correlation coefficient.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll statistical analysis was carried out at a 5% significance level, and a p-value of less than 0.05 was considered statistically significant.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eBaseline characteristics of the study population are shown in table 1.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e-Baseline characteristics of study subjects\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"623\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eControls (n = 30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNormal to mildly increased albuminuria\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n = 30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eModerately increased albuminuria\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n = 30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSeverely increased albuminuria\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n = 30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003cp\u003eMean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e38.36 \u0026plusmn; 12.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e48.83 \u0026plusmn; 10.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e51.7 \u0026plusmn; 9.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e52.1 \u0026plusmn; 6.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eGender (male)\u003c/p\u003e\n \u003cp\u003eFrequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e16 (53.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e18 (60)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e17 (56.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e16 (53.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eBody mass index (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003cp\u003eMean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e20.01 \u0026plusmn; 4.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e23.38 \u0026plusmn; 4.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e22.79 \u0026plusmn; 3.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e22.64 \u0026plusmn; 3.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eSystolic blood pressure (mm Hg)\u003c/p\u003e\n \u003cp\u003eMean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e120.8 \u0026plusmn; 7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e129.4 \u0026plusmn; 13.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e131.5 \u0026plusmn; 12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e132.1 \u0026plusmn; 15.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eDiastolic blood pressure (mm Hg)\u003c/p\u003e\n \u003cp\u003eMean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e73.9 \u0026plusmn; 6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e76.9 \u0026plusmn; 6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e77.7 \u0026plusmn; 7.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e77.9 \u0026plusmn; 9.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e0.017\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eSerum creatinine (mg/dL)\u003c/p\u003e\n \u003cp\u003eMean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.72 \u0026plusmn; 0.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 137px;\"\u003e\n \u003cp\u003e0.77 \u0026plusmn; 0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e0.84 \u0026plusmn; 0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e0.92 \u0026plusmn; 0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e0.153\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 2 shows the duration of diabetes in the diabetic sub-groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e-Duration of diabetes in diabetic sub-groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDuration of diabetes\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNormal to mildly increased albuminuria\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eModerately increased albuminuria\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSeverely increased albuminuria\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003eLess than 1 year\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e4 (13.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e5 (16.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e3 (10%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e1-5 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e11 (36.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e12 (40%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e12 (40%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003eMore than 5 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e15 (50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e13 (43.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e15 (50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eCKD-EPI 2021 equation was used to calculate eGFR in all study subjects. 74.1% of study subjects had an eGFR above 90 mL/minute/1.73 m\u003csup\u003e2\u003c/sup\u003e. 31 subjects (25.9%) had an eGFR below 90 mL/minute/1.73 m\u003csup\u003e2\u003c/sup\u003e. Table 3 shows the eGFR in the different study groups.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e-eGFR in various groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"614\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eeGFR (mL/minute/1.73 m\u003csup\u003e2\u003c/sup\u003e)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eControls\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNormal to mildly increased albuminuria\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eModerately increased albuminuria\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSeverely increased albuminuria\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=30)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u0026ge; 90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e26 (86.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e23 (76.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e21 (70%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e19 (63.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e60-89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e4 (13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e7 (23.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e9 (30%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e11 (36.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u0026lt; 60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe levels of urinary albumin-creatinine ratio (ACR) in different groups are shown in table 4.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4\u003c/strong\u003e-Urinary albumin-creatinine ratio in various groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMedian urinary albumin-creatinine ratio (ACR)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eQuartile\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(Q1, Q3)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eControls\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e17.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e14.64, 19.12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eNormal to mildly increased albuminuria\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e25.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e22.16, 28.87\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eModerately increased albuminuria\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e128.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e110.42, 221.82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eSeverely increased albuminuria\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e1310.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e915, 1856.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eUrinary netrin-1 levels in controls and diabetic subjects are shown in table 5.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5\u003c/strong\u003e-Urinary netrin-1 level in various groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMedian urinary netrin-1 value (pg/mg creatinine)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eQuartile\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(Q1, Q3)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003eControls\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e670.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e545.1, 852.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003eNormal to mildly increased albuminuria\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e685.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e551.5, 943.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e0.433\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003eModerately increased albuminuria\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e1010.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e884.9, 1116.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003eSeverely increased albuminuria\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e1177.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e1071.5, 1284.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eUrinary netrin-1 values were non-normally distributed. There was a significant difference in the median values of urinary netrin-1 between controls and diabetic subjects in the moderately increased albuminuria and severely increased albuminuria groups.\u003c/p\u003e\n\u003cp\u003eFigure 1 shows the distribution of urinary netrin-1 levels in all four groups on its five-number summary (minimum, first quartile (Q1), median, third quartile (Q3) \u0026amp; maximum). Here, the minimum is calculated as Q1-1.5 IQR and the maximum is calculated as Q3+1.5 IQR.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eX-axis: 4 groups\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;0-controls/ 1-normal to mildly increased albuminuria/ 2-moderately increased albuminuria/ 3-severely increased albuminuria\u003c/p\u003e\n\u003cp\u003eY-axis: Urinary netrin-1 (pg/mg creatinine) levels\u003c/p\u003e\n\u003cp\u003eFigure 2 shows the scatter plot between urinary ACR and netrin-1 levels. There was a positive correlation between urinary ACR and netrin-1 levels with Spearman\u0026rsquo;s correlation coefficient r=0.6432 (p \u0026lt; 0.01).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFigure 3 shows the scatter plot between urinary netrin-1 and eGFR values. There was no significant correlation between urinary netrin-1 and eGFR. Here, Spearman\u0026rsquo;s correlation coefficient r=-0.0811 (p=0.378).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFigure 4 shows the scatter plot between urinary netrin-1 and serum creatinine levels. There was no significant correlation between urinary netrin-1 and serum creatinine; Spearman\u0026rsquo;s correlation coefficient was r=0.0827 (p=0.369).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe receiver operator characteristic (ROC) curve was plotted to assess the utility of urinary netrin-1 as a marker of diabetic nephropathy in relation to urinary ACR. This is shown in figure 5.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe area under the curve to diagnose diabetic nephropathy using urinary netrin-1 was 0.820 (95% CI, 0.75 to 0.89). A cut-off value of 889.74 pg/mg creatinine for urinary netrin-1 had a sensitivity of 88.3% and a specificity of 75%. The positive predictive value of urinary netrin-1 for diabetic nephropathy was 77.9% (95% CI, 66.2% to 87.1%), while the negative predictive value was 86.5% (95% CI, 74.2% to 94.4%).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe hallmark of diabetic kidney disease (DKD) is worsening of glomerular function and tubulointerstitial injury with loss of functional nephrons. Conventionally, DKD has been recognized as glomerular dysfunction. However, studies have revealed that tubulointerstitial injury can precede glomerular pathology. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe presence of albumin in the urine (UACR \u0026gt; 30 mg/g) and a decline in eGFR are the accepted markers for diabetic kidney disease. Current research has given an indication that renal impairment can be present in 30-60% of diabetic patients before the onset of moderately increased albuminuria. Hence, tubular biomarkers are being studied to detect nephropathy in non-albuminuric diabetic subjects.\u003c/p\u003e\n\u003cp\u003eNetrin-1 is primarily released into the urine when the proximal renal tubule is affected. In renal tissue, diabetic nephropathy results from inflammation and glomerular and tubulointerstitial damage that increases the secretion of netrin-1 from damaged tubular epithelial cells\u003csup\u003e9\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eInflammation has a major role in the pathogenesis of diabetic nephropathy\u003csup\u003e11\u003c/sup\u003e. Netrin-1, through the UNC5B receptor, suppresses vascular inflammation and angiogenesis through interaction with vascular endothelial growth factor (VEGF). Thus, it has an anti-inflammatory effect, and hence, urinary excretion of netrin-1 is increased in patients with diabetic nephropathy\u003csup\u003e12\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eUrinary excretion of netrin-1 increases tubulointerstitial damage that may precede apparent glomerular dysfunction in patients with diabetic nephropathy. Netrin-1 promotes the uptake of albumin in proximal tubular epithelial cells. In patients with diabetic nephropathy, tubular epithelial cells generate netrin-1 due to an increase in albumin excretion. \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis study investigated the diagnostic utility of urinary netrin-1, a tubular biomarker for diagnosing DKD relative to urinary ACR. Our study found no statistically significant difference in urinary netrin-1 levels between controls and diabetic subjects with normal to mildly increased albuminuria. This finding was in contrast to a study done by Mohammed EM et al. Their study showed that urinary netrin-1 levels in controls were significantly less compared to type 2 diabetic patients with normoalbuminuria [7]. Another study done by Jayakumar C et al, found similar results [8]. A study done by Elkholy RA et al, also found that there was a significant difference in urinary netrin-1 levels between controls and diabetic subjects with normoalbuminuria\u003csup\u003e10\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eIn our study, urinary netrin-1 showed a sensitivity of 88.3% (CI 77.4-95.2) and a specificity of 75% (CI 62.1-85.3) for the detection of diabetic nephropathy at a cut-off value of 889.74 pg/mg creatinine. Mohammed EM et al., in their study, found after performing ROC analysis that urinary netrin-1 had 82% sensitivity and 86% specificity for the prediction of diabetic nephropathy at a cut-off value of 630.7 pg/mg creatinine.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur study had a few limitations. First, the sample size was small, and selection bias was likely to be present since convenience sampling was performed. Second, our study used only a single spot urine albumin test (urinary albumin-creatinine ratio) instead of a 24-hour urinary albumin level to determine group entry among the subjects. Third, the study\u0026rsquo;s cross-sectional design did not allow the temporal association between elevated urinary netrin-1 levels and the onset of diabetic kidney disease to be determined.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eUrinary netrin-1 levels were elevated in type 2 diabetic subjects with moderately increased albuminuria and severely increased albuminuria compared to non-diabetic subjects. However, compared to non-diabetic subjects, urinary netrin-1 levels were not significantly elevated in diabetic subjects with normal to mildly increased albuminuria.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUrinary netrin-1 levels showed a strong positive correlation with urinary albumin-creatinine ratio (ACR) and no significant correlation with eGFR and serum creatinine in diabetic subjects.\u0026nbsp;\u003c/p\u003e"},{"header":"Statements \u0026 declarations","content":"\u003cp\u003e1. \u0026nbsp; Ethical considerations-The study was approved by the Institutional Ethics Committee for Observational Studies, JIPMER, Puducherry on 06.10.2022. Approval number-\u003cstrong\u003eJIP/IEC-OS/2022/304\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e2. \u0026nbsp; Human ethics and consent to participate in the study-Informed, written consent was obtained from all subjects for participation in the study. All subjects gave written consent to participate in the study.\u003c/p\u003e\n\u003cp\u003e3. \u0026nbsp; Consent to publish declaration-Not applicable\u003c/p\u003e\n\u003cp\u003e4. \u0026nbsp; Declaration of conflicting interest-The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.\u003c/p\u003e\n\u003cp\u003e5. \u0026nbsp; Funding statement-The study was funded by an Intramural Research Grant from Jawaharlal Institute of Postgraduate Medical Education \u0026amp; Research (JIPMER), Puducherry-605006. India\u003c/p\u003e\n\u003cp\u003e6. \u0026nbsp; Data availability declaration-Data of this study is available with the corresponding author and can be provided when needed, for review.\u003c/p\u003e\n\u003cp\u003e7. \u0026nbsp; Competing interests-All authors declare that they have no competing interests to declare.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e-The authors gratefully acknowledge the financial support provided for the study by Jawaharlal Institute of Postgraduate Medical Education \u0026amp; Research (JIPMER), Puducherry.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions statement\u003c/strong\u003e-\u003c/p\u003e\n\u003cp\u003e1. \u0026nbsp; Rahul Kumar Tomar-Formal analysis, investigation, writing-original draft preparation\u003c/p\u003e\n\u003cp\u003e2. \u0026nbsp; Vadivelan Mehalingam-Conceptualization, writing-original draft preparation \u0026amp; editing\u003c/p\u003e\n\u003cp\u003e3. \u0026nbsp; Prashant S Adole-Methodology, writing-review\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGross JL, de Azevedo MJ, Silveiro SP, Canani LH, Caramori ML, Zelmanovitz T. Diabetic nephropathy: diagnosis, prevention, and treatment. Diabetes Care. 2005;28:164-76.\u003c/li\u003e\n\u003cli\u003eGheith O, Farouk N, Nampoory N, Halim MA, Al-Otaibi T. Diabetic kidney disease: world wide difference of prevalence and risk factors. J Nephropharmacol. 2015 9;5:49-56. \u003c/li\u003e\n\u003cli\u003eRico-Fontalvo J, Aroca-Mart\u0026iacute;nez G, Daza-Arnedo R, Cabrales J, Rodr\u0026iacute;guez-Yanez T, Cardona-Blanco M, Montejo-Hern\u0026aacute;ndez J, Rodelo Barrios D, Pati\u0026ntilde;o-Pati\u0026ntilde;o J, Osorio Rodr\u0026iacute;guez E. Novel Biomarkers of Diabetic Kidney Disease. Biomolecules. 2023;13:633. \u003c/li\u003e\n\u003cli\u003eChang J, Yan J, Li X, Liu N, Zheng R, Zhong Y. Update on the Mechanisms of Tubular Cell Injury in Diabetic Kidney Disease. Front Med (Lausanne). 2021;8:661076.\u003c/li\u003e\n\u003cli\u003eBoyer NP, Gupton SL. Revisiting Netrin-1: One Who Guides (Axons). Front Cell Neurosci. 2018;12:221.\u003c/li\u003e\n\u003cli\u003eWang W, Reeves WB, Ramesh G. Netrin-1 and kidney injury. I. Netrin-1 protects against ischemia-reperfusion injury of the kidney. Am J Physiol Renal Physiol. 2008;294:F739-47.\u003c/li\u003e\n\u003cli\u003eMohammed EM, El-Messallamy FA, Mazroue AM, Elsayed IA, Zidan AA. Urinary netrin-1 as an early marker for diabetic nephropathy. Egypt J Hosp Med. 2020;81:1924-30.\u003c/li\u003e\n\u003cli\u003eJayakumar C, Nauta FL, Bakker SJ, Bilo H, Gansevoort RT, Johnson MH, Ramesh G. Netrin-1, a urinary proximal tubular injury marker, is elevated early in the time course of human diabetes. J Nephrol. 2014;27:151-7. \u003c/li\u003e\n\u003cli\u003eWhite JJ, Mohamed R, Jayakumar C, Ramesh G. Tubular injury marker netrin-1 is elevated early in experimental diabetes. J Nephrol. 2013;26:1055-64. \u003c/li\u003e\n\u003cli\u003eElkholy RA, Younis RL, Allam AA, Hagag RY, Abdel Ghafar MT. Diagnostic efficacy of serum and urinary netrin-1 in the early detection of diabetic nephropathy. J Investig Med. 2021;69:1189-95.\u003c/li\u003e\n\u003cli\u003eZheng Z, Zheng F. Immune Cells and Inflammation in Diabetic Nephropathy. J Diabetes Res. 2016;2016:1841690. \u003c/li\u003e\n\u003cli\u003eBehnoush AH, Khalaji A, Shokri Varniab Z, Rahbarghazi A, Amini E, Klisic A. Urinary and circulatory netrin-1 as biomarker in diabetes and its related complications: a systematic review and meta-analysis. Endocrine. 2024;84:328-44. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-endocrine-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bend","sideBox":"Learn more about [BMC Endocrine Disorders](http://bmcendocrdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bend/default.aspx","title":"BMC Endocrine Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Urinary netrin-1, diabetic nephropathy, albuminuria","lastPublishedDoi":"10.21203/rs.3.rs-6801534/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6801534/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e-Netrin-1 is a urinary protein that may help in the diagnosis of diabetic nephropathy. The objectives of this study were to assess urinary netrin-1 levels in patients with type 2 diabetic nephropathy and to determine its correlation with renal function among them.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethodology\u003c/strong\u003e- This cross-sectional analytical study was conducted at a tertiary care teaching hospital in south India for 18 months. Study subjects were divided into four groups: non-diabetics, diabetics with normal to mildly increased albuminuria, moderately increased albuminuria, and severely increased albuminuria. Urinary albumin was quantified by nephelometry for all study subjects. The ELISA technique estimated urinary netrin-1 levels in all groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults- \u003c/strong\u003eUrinary netrin-1 levels were higher in diabetic subjects with normal to mildly increased and severely increased albuminuria than in the control group. Correlation analysis showed that there was a positive correlation of urinary netrin-1 with urinary albumin-creatinine ratio (UACR) and no correlation with estimated glomerular filtration rate (eGFR). Urinary netrin-1 showed a sensitivity of 88.3% and specificity of 75% at a cut-off value of 889.74 pg/mg creatinine for diagnosing diabetic nephropathy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e-Urinary netrin-1 levels were elevated in diabetic subjects with moderately and severely increased albuminuria as compared to non-diabetic subjects. It showed a positive correlation with the urinary albumin-creatinine ratio and no correlation with eGFR in diabetic subjects.\u003c/p\u003e","manuscriptTitle":"Utility of Urinary Netrin-1 in Patients With Type 2 Diabetic Nephropathy and Its Correlation With Renal Function","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-08 05:58:37","doi":"10.21203/rs.3.rs-6801534/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-05T11:55:12+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"145135141826677750988687599962971531747","date":"2025-08-05T11:45:01+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-03T18:39:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"106808407959064468147773512739125784374","date":"2025-08-03T18:39:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-03T09:44:22+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-03T00:49:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"298758261172789976630766315748515306751","date":"2025-08-02T16:43:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"138152274288674920173666178828938892933","date":"2025-07-31T23:42:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"193973424389829815365347475493574343674","date":"2025-07-31T19:24:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-31T12:01:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"253685226944940274616618913987870288288","date":"2025-07-31T11:18:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"206143324870452293332931747355733412638","date":"2025-07-31T09:13:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"302972683833398093036971096482004917864","date":"2025-07-29T19:14:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"6099009359028904288275924517992697424","date":"2025-07-29T19:02:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-23T08:08:23+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-20T13:21:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"217619102635599859297683111124083957617","date":"2025-07-18T09:57:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243266890217806502664962677135798362428","date":"2025-07-13T09:36:37+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-03T10:01:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-06-10T05:50:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-09T04:30:41+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-09T04:29:11+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Endocrine Disorders","date":"2025-06-02T10:56:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-endocrine-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bend","sideBox":"Learn more about [BMC Endocrine Disorders](http://bmcendocrdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bend/default.aspx","title":"BMC Endocrine Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e84255fe-ed22-43cf-88f5-51491d7a9dc1","owner":[],"postedDate":"July 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-10T16:06:45+00:00","versionOfRecord":{"articleIdentity":"rs-6801534","link":"https://doi.org/10.1186/s12902-025-02049-1","journal":{"identity":"bmc-endocrine-disorders","isVorOnly":false,"title":"BMC Endocrine Disorders"},"publishedOn":"2025-11-05 15:57:38","publishedOnDateReadable":"November 5th, 2025"},"versionCreatedAt":"2025-07-08 05:58:37","video":"","vorDoi":"10.1186/s12902-025-02049-1","vorDoiUrl":"https://doi.org/10.1186/s12902-025-02049-1","workflowStages":[]},"version":"v1","identity":"rs-6801534","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6801534","identity":"rs-6801534","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}