Tea intake and risk of incident kidney stone: A meta-analysis

Tea intake and risk of incident kidney stone: A meta-analysis | 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 Article Tea intake and risk of incident kidney stone: A meta-analysis Jin Yin, Ning Li, qiu jun, Xiong Pan, Cai Liu, Kun Zhao, Yun Peng This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4006705/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: The formation of kidney stones is multifactorial and surveys have shown that not all fluids are equally beneficial in reducing the risk of kidney stones. Multiple studies have shown an association between tea intake and kidney stones. However, studies investigating the relationship between tea intake and the occurrence of kidney stones have been inconsistent. Objective: To clarify this association, we conducted this analysis to determine the link between tea intake and kidney stones. Study design: This study was a meta-analysis. PubMed, Web of Knowledge, Elsevier Science Direct, and Springer digital libraries were searched for studies reporting tea intake and kidney stones. A random-effects model was used to summarize the relationship between tea and kidney stones. The included articles were assessed for quality using the Newcastle–Ottawa scale. Results: A total of ten articles and 14 studies (men and women) were retrieved, including 9 cohort studies, 5 case-control studies, with a total of 1,318,071 participants and of 22,963 kidney stone patient. The results showed that tea intake was negatively correlated with kidney stone, (combined odds ratio [OR], 0.86; 95% confidence interval [CI], 0.81−0.91) with mild heterogeneity (I 2 =56.6.0%; P=0.005). Subgroup and sensitivity analyses confirmed the results. Conclusions: Tea intake was shown a potential protective effect on the development of kidney stones. Biological sciences/Physiology/Kidney Health sciences/Health care/Nutrition tea consumption kidney stones adult risk factors meta-analysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Kidney stones are one of the most common disorders affecting the urinary system and are characterized by a high incidence and recurrent attacks[ 1 , 2 ]. In recent decades, the incidence and prevalence of nephrolithiasis has continued to rise worldwide[ 3 ], and the incidence of nephrolithiasis has increased from 1.7–14.8%[ 4 ]. The prevalence of nephrolithiasis in the Chinese population is approximately 7.5%[ 5 ]. The kidney stone recurrence rate is also high, with a recurrence rate of approximately 30% within 5 years of initial onset[ 6 ]. Considering the medical cost and social burden of this disease, kidney stones should be considered an important health problem[ 7 ]. Previous studies have suggested that fluid and dietary intake, metabolic syndrome, and other factors may play an important role in the development of kidney stones[ 8 ]. A few prospective studies have investigated the association between tea drinking and kidney disease, however, the results are inconsistent. A large cohort study[ 9 ] involving 58,054 males in the Shanghai Men’s Health Study (SWHS) and 69,166 females in the Shanghai Women’s Health (SMHS) reported that individuals who currently consumed tea had a decreased risk of kidney stones compared with never and former tea consumption, with a standardized incidence ratio of 0.87 (95% CI, 0.77 − 0.98) and 0.78 (95% CI, 0.69 − 0.88). Other cohort studies from China and UK[ 10 – 12 ] reported that tea intake (both men and women) reduced the risk of kidney stones compared with non-drinking. Ferraro[ 13 ] study analyzed data from three cohorts ( The Health Professionals Follow-Up Study (HPFS) enrolled 51,529 men. The Nurses’ Health Study I (NHS I) enrolled 121,700 women nurses, and the Nurses’ Health Study II (NHS II) enrolled 116,430 women nurses ). The relative risk of kidney stones according to categories of tea intake of different cohort studies were HPFS (OR = 0.88; 95% CI, 0.74–1.04), NHS I (OR = 0.85; 95% CI, 0.74–0.98), NHS II (OR = 0.93; 95% CI, 0.82–1.04). A cohort study from Finland[ 14 ] was no direct connection with association between tea intake and kidney stones (OR = 1.05; 95% CI, 0.95–1.17). A case-control study from Yijishan Hospital of Wannan Medical College of China reported that tea intake with a preference for drinking strong tea were protective factors (OR = 0.793; 95% CI, 0.702–0.897)[ 15 ], however, a case-control study from China reported that tea intake has no direct relationship with kidney stones (men, OR = 1.13; 95%CI, 0.78 − 1.64 and women, OR = 0.91; 95%CI, 0.53 − 1.56) [ 16 ], and two case-control study from USA not demonstrated a positive association between tea intake and kidney stones[ 17 , 18 ]. Given the widespread tea consumption in word, it is important to determine whether there is a relationship between tea intake and kidney stone risk. The purpose of this meta-analysis was to determine the relationship between tea consumption and kidney stones. Materials and Methods Literature search strategy Based on keywords, PubMed, Web of Knowledge, Elsevier Science Direct, and Springer digital libraries were searched to identify relevant articles. The key words were as follows: “nephrolithiasis”, “kidney stones”, “urinary calculi”, and “behaviors”, “diet”, “tea consumption”, “tea intake”. To find all relevant research articles, we checked the references of the retrieved articles, and each gender was analyzed as a separate study if the studies were analyzed separately for gender. Literature Inclusion and Exclusion Criteria The following criteria were used for inclusion in this meta-analysis: (1) a cohort, case-control; (2) the study assessed the relationship between tea intake and kidney stones; (3) the outcome was defined as a medical diagnosis of kidney stones; and (4) the adjusted ORs and corresponding 95% CIs were provided. The exclusion criteria were as follows: (1) experimental studies involving animals; (2) lifestyle factors other than tea drinking were investigated; and (3) articles published in the form of letters, conference papers, reviews, or case reports. If a study reported a range of tea consumption and associated kidney stone risk, we included the effects of high tea consumption. Two trained investigators ( Haijin Zhang and Lixia Tian ) independently extracted data and resolved discrepancies through discussion. The following information was extracted: first author's last name, year of publication, follow-up, type of study, sex, sample size, area, tea consumption, OR value and the corresponding 95% CI, adjusted for covariates and study quality in the statistical analysis. If the article included both sexes, each sex was regarded as a separate study (e.g., [ 9 ] and [ 14 ]). The quality of the article was evaluated according to Newcastle–Ottawa scale (NOS)[ 19 ], This self-rating scale had a total of nine items and each item was worth 1 point. Each study was evaluated independently, and any inconsistent conclusions were resolved through group discussion. Based upon a previous study[ 20 ], the evaluation of article quality is divided into the following scoring categories: low, 0 − 5; moderate, 5 − 7; and high, 7 − 9. Statistical Analysis Association analysis between tea intake and kidney stones was based on the adjusted OR and the 95% CI, as reported by the eligible studies. Statistical analysis was performed using Stata (version 12.0) software and a P value < 0.05 was considered statistically significant. I 2 was used to assess heterogeneity between studies ( I 2 values were 0%, 25%, 50%, and 75%, representing no, low, moderate, and high heterogeneity, respectively)[ 21 ]. If moderate or low heterogeneity was detected ( I 2 < 50%), a fixed-effects model was used to calculate the combined OR, otherwise a random-effects model was used[ 22 ]. The sensitivity analysis method was used to evaluate the stability between studies. Begg's test and Egger's test[ 23 ] was used for detection of publication bias. Results Study characteristics Based on keywords, a total of 151 potentially relevant articles were retrieved, of which 124 no relevant contents were deleted. After reading the titles and abstracts of 27 articles, 11 were excluded because the focus of the study was not tea drinking. Of the remaining 16 full-text articles, six were excluded; ten articles met the inclusion criteria, and the results of the study search are shown in Fig. 1 . This study included 14 studies published from 1996 − 2021, with sample sizes ranging from 632 to 502,621, including 6 cohort studies[ 9 – 14 ], four case-control studies[ 15 – 18 ]. The articles by Shu[ 9 ] and Ferraro[ 13 ]and Dai[ 16 ] reported studies involving both sexes, thus each study was split based on gender and regarded as independent studies. The quality of the articles was assessed according to the NOS ; three articles were of high quality and four articles were of moderate quality. The details of each study are presented in Table 1 . Table 1 Characteristics of the included studies Author, year (reference) Follow-up Type of study Sex Sample size Area Tea consumption OR 95% CI Adjusted for covariates Study quality Shu X(2019)[ 9 ] 1996–2000 2002–2006 Cohort women men 69166 58054 Shanghai China Never/former Current 0.87 0.78 0.770.98 0.690.88 Year, smoking, education, income, physical activity, BMI, WHR, history of coronary heart disease/ stroke/ type 2 diabetes/ hypertension/ cholelithiasis, energy/ dietary protein/ calcium /calcium/ vitamin C/ potassium/ magnesium and dietary oxalate intake. high Chen HY(2019)[ 10 ] 2001–2009 Cohort both 13842 Taiwan China None 0–20 cup-year ≥ 20 cup-year 0.79 0.660.94 Age, gender, BMI, hypertension, diabetes, plasma creatinine and uric acid level, smoking, alcohol consumption, and regular exercise. moderate Wang H(2021)[ 11 ] 2004–2008 Cohort both 502621 China Kadoorie Biobank China Never Less than daily Daily (1–6, ≥ 7cups/day) 0.73 0.650.83 Sex, education, occupation, income, smoking, physical activity, intake of red meat, dairy products, vegetables, vitamin, calcium, iron or zinc, BMI, waist-to-hip ratio,hypertension, and diabetes. high Littlejohns TJ[ 12 ] 2009–2010 Cohort both 439072 UK 0/1–2/3–4/5 + cups/day 0.85 0.78–0.92 Age, sex, Townsend deprivation score, education, ethnicity, smoking, BMI, and calcium supplementation high Author, year (reference) Follow-up Type of study Sex Sample size Area Tea consumption OR 95% CI Adjusted for covariates Study quality Ferraro PM [ 13 ] 1986- 1976- 1989- Cohort men women women 51529 121700 116430 HPFS Nurses’ Health Study I Nurses’ Health Study II USA 1/day 0.88 0.85 0.93 0.74–1.04 0.74–0.98 0.82–1.04 Age, race, region of residence, BMI, use of furosemide/thiazides, high blood pressure, diabetes, gout, intake of calcium, potassium, phytate, animal protein, vitamin C, total calories, profession and mutually adjusted for all the beverages. high Hirvonen T[ 14 ] 1985–1988 Cohort men 290406 Southwestern Finland No 170 ml/day 1.05 0.95–1.17 Age, supplementation group, other beverages, vocational training, marital status, and intakes of magnesium and fiber. high Zhuo D(2019)[ 15 ] 2017–2018 Case- control both 1519 Wannan China Light Medium Strong 0.793 0.702–0.897 Gender, age, occupation, residence, education level, dietary habits, fluid intake, and physical activity. moderate Dai M(2013)[ 16 ] 2010–2011 Case- control men women 1290 716 Guangzhou China < 1, 1–3,1–6 times/week ≥ 1 time/day 1.13 0.91 (0.781.64) (0.531.56) Age, BMI, smoke, occupation, education, hypertension. high Krieger JN[ 17 ] 1989–1992 Case- control men 392 + 240 Puget Sound region USA No or yes 0.74 0.52–1.06 NA moderate Goldfarb DS[ 18 ] 1965–1975 Case- control men 8870 Vietnam Era Twin USA 0/1–2/3–4/5 + cups/day 0.7 0.2–2.4 BMI, hypertension, and smoking moderate BMI, body mass index; HPFS, Health Professionals Follow-Up Study; NHS I, Nurses’ Health Study I; NHS II, Nurses’ Health Study II. Meta-analysis results Figure 2 shows the pooled ORs of kidney stones for the highest and lowest categories of tea intake. The combined OR was 0.86 (95% CI, 0.81 − 0.91), and mild heterogeneity existed among the included studies (I 2 = 56.6%, P = 0.005). Subgroup and sensitivity analyses Subgroup analysis based on the type of study, sex, and tea consumption did not change our findings. The combined ORs were as follows: cohort study (OR, 0.86; 95% CI, 0.83 − 0.90); case-control study (OR, 0.82; 95% CI, 0.73 − 0.91); male sex (OR, 0.92; 95% CI, 0.86 − 0.91); female sex (OR, 0.89; 95% CI, 0.83 − 0.95); China ( OR, 0.80; 95% CI, 0.76 − 0.85), USA/European ( OR, 0.91; 95% CI, 0.86 − 0.95); The samples from hospital ( OR, 0.86; 95% CI, 0.83 − 0.89), no-hospital ( OR, 0.87; 95% CI, 0.83 − 0.92); The sensitivity analysis (Fig. 3 ) verified stability after removing one study at a time, the pooled OR and ORs ranged from 0.82 (95% CI, 0.79 − 0.86) to 0.87 (95% CI, 0.81 − 0.93) for kidney stones. Estimation of publication bias A funnel plot was used to assess bias between studies. Due to the small number of studies, publication bias was not detected (Begg's test, p = 0.891; Egger’s test, p = 0.934), Fig. 4 . Discussion The current meta-analysis included data from 22,963 patients with kidney stones from four 6 cohort studies[9–14], 5 case-control studies[15–18]. Compared with controls, tea drinking had a significant preventive effect on the occurrence of kidney stones (OR = 0.86; 95% CI, 0.81 − 0.91). This is the first comprehensive analysis of the protective effect of tea consumption on kidney stones. Subgroup analysis showed that the risk of kidney stones decreased with increasing tea consumption, there were no significant differences between men and women, howere, Tea consumption has been shown to reduce kidney stones more in Chinese than in Europeans/Americans The sensitivity analysis in this meta-analysis confirmed the validity of our conclusions about the comparison between tea drinking and never tea drinking. The strength of our study lies in the complete adherence to a systematic review approach, including a two-stage screening process for published titles and abstracts by independent researchers, an assessment of the quality of each study, and an assessment of the risk of bias. All of the studies were well-designed and included people recruited from the general population, suggesting that the effects of the intervention were unlikely to depend on specific environmental factors. Changes in dietary habits are key to preventing stone formation and recurrence[ 24 ], and coffee and tea intake have previously been reported to be inversely associated with kidney stones[ 25 , 26 ]. Coffee and tea are sources of caffeine, which has been reported to moderately increase diuresis, while promoting excretion of magnesium, potassium, calcium, and sodium[ 27 ]. Recent evidence suggests that caffeine-induced natriuresis may be caused by Shirley DG[ 28 ]. Based on an experimental model, Ming and Lautt[ 29 ] proposed that caffeine, as an inhibitor of adenosine receptors, may have diuretic and natriuretic effects by interfering with hepatic A1 adenosine receptor-mediated liver-kidney reflex. Caffeine also reduces Na/KATPase and Na/H exchange activities and increases ANP and NO activities in the kidney[ 30 ]. Jeong et al.[ 31 ] evaluated the cytotoxicity of epigallocatechin gallate (EGCG), one of the main components of green tea catechins, against oxalate in an animal model and found that EGCG inhibited oxalic acid-induced free radical production. In addition, tea can reduce the excretion of oxalic acid in the urine, and green tea has an inhibitory effect on the formation of urinary stones, which is largely due to the antioxidant effect of EGCG. Taken together, these changes increase diuresis and have a potentially protective effect against stone formation. Tea is one of the most common drinks in China, next only to water. Even though the oxalic acid content in tea poses a risk for stone formation, based on a large number of clinical studies, we found that the vast majority of people favor the idea of a protective effect against urolithiasis[ 32 ]. There are several factors for this. First, tea consumption is essentially a supplement to daily fluid intake, and this is only the beneficial part of explaining the effects of tea on stone formation. In addition, tea contains caffeine, which has diuretic and natriuretic effects on the kidneys; however, the specific mechanism by which tea exerts a protective effect against kidney stones is still unclear. Several potential limitations need to be considered, as follows: (1) lacking accurate information regarding exposure to tea intake. Despite a feasibility of crude classifications, typo was inevitable; (2) tea is divided into different species and different substances, which may affect the results; (3) due to the different measurement methods used in the study on the amount of tea consumed, it is difficult to unify the information on the dose-response relationship in this study; and (4) we selected study subjects adjusted for potential confounders, however, it is difficult to demonstrate the presence of other risk factors that may contribute to kidney stones. For example, there are people in the Chinese population who drink both tea and coffee, and studies have shown that drinking coffee can reduce the incidence of kidney stones[ 33 ]. In conclusion, this meta-analysis showed that tea consumption was more effective in reducing the risk of kidney stones in the population and may play a key role in preventing stone formation and recurrence. Declarations Statement of Ethics Not required, as this is a review of existing literature. Consent to participate statement This paper did not contain human participants enrolled by any of the authors. Conflict of Interest Statement The authors have no conflicts of interest to declare. Funding Sources This work was not supported by any Funding Sources. Author Contributions Ning Li and Jun Qiu conceived the study. Xiongfeng Pan and Jinzhu Yin participated in the statistical analysis. Ning Li and Jun Qiu drafted the article. All authors read and approved the final version of the manuscript. Data Availability Statement This paper is meta that all data are fully available without restriction. References Khan SR, Pearle MS, Robertson WG, Gambaro G, Canales BK, Doizi S, et al. Kidney stones. Nature reviews Disease primers. 2016;2(1):1–23 Rule AD, Lieske JC, Li X, Melton III LJ, Krambeck AE, Bergstralh EJ. The ROKS nomogram for predicting a second symptomatic stone episode. 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China","correspondingAuthor":false,"prefix":"","firstName":"Kun","middleName":"","lastName":"Zhao","suffix":""},{"id":276939035,"identity":"e7e34f33-0c9a-4b1b-8c55-a2a7b946c2c5","order_by":6,"name":"Yun Peng","email":"","orcid":"","institution":"Medical College of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Yun","middleName":"","lastName":"Peng","suffix":""}],"badges":[],"createdAt":"2024-03-02 14:20:51","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4006705/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4006705/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":52454567,"identity":"6c136c2d-0c32-45f3-9ffd-26997261f8d0","added_by":"auto","created_at":"2024-03-11 19:40:35","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":22904,"visible":true,"origin":"","legend":"\u003cp\u003eSelection of studies for inclusion in meta-analysis.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4006705/v1/e327af3d9367d622aba5e4d5.png"},{"id":52454569,"identity":"103079ae-1064-477f-86ac-dd67aa01acbc","added_by":"auto","created_at":"2024-03-11 19:40:35","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":589819,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot of meta-analysis.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4006705/v1/676cae8dc0977c638ef203db.jpeg"},{"id":52454568,"identity":"d1effbf3-ffbf-46ef-8390-6d08128320c5","added_by":"auto","created_at":"2024-03-11 19:40:35","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":46831,"visible":true,"origin":"","legend":"\u003cp\u003eThe result of sensitivity analysis.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-4006705/v1/2072aaf163db81577914da54.png"},{"id":52454570,"identity":"a462483c-7a6b-41a1-b0a7-40b8b95eb16e","added_by":"auto","created_at":"2024-03-11 19:40:35","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":30791,"visible":true,"origin":"","legend":"\u003cp\u003eThe funnel plot of meta-analysis.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4006705/v1/dc9aa96aa57b5ea367184913.png"},{"id":56794976,"identity":"201d4a9b-1567-4ae6-8b05-f1621f3275c8","added_by":"auto","created_at":"2024-05-20 14:34:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1188783,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4006705/v1/12de1959-c351-4d8d-b0d1-867ee1a3f876.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e conflict of interest to disclose.","formattedTitle":"Tea intake and risk of incident kidney stone: A meta-analysis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eKidney stones are one of the most common disorders affecting the urinary system and are characterized by a high incidence and recurrent attacks[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In recent decades, the incidence and prevalence of nephrolithiasis has continued to rise worldwide[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], and the incidence of nephrolithiasis has increased from 1.7\u0026ndash;14.8%[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The prevalence of nephrolithiasis in the Chinese population is approximately 7.5%[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The kidney stone recurrence rate is also high, with a recurrence rate of approximately 30% within 5 years of initial onset[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Considering the medical cost and social burden of this disease, kidney stones should be considered an important health problem[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Previous studies have suggested that fluid and dietary intake, metabolic syndrome, and other factors may play an important role in the development of kidney stones[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. A few prospective studies have investigated the association between tea drinking and kidney disease, however, the results are inconsistent. A large cohort study[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] involving 58,054 males in the Shanghai Men\u0026rsquo;s Health Study (SWHS) and 69,166 females in the Shanghai Women\u0026rsquo;s Health (SMHS) reported that individuals who currently consumed tea had a decreased risk of kidney stones compared with never and former tea consumption, with a standardized incidence ratio of 0.87 (95% CI, 0.77\u0026thinsp;\u0026minus;\u0026thinsp;0.98) and 0.78 (95% CI, 0.69\u0026thinsp;\u0026minus;\u0026thinsp;0.88). Other cohort studies from China and UK[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] reported that tea intake (both men and women) reduced the risk of kidney stones compared with non-drinking. Ferraro[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] study analyzed data from three cohorts ( The Health Professionals Follow-Up Study (HPFS) enrolled 51,529 men. The Nurses\u0026rsquo; Health Study I (NHS I) enrolled 121,700 women nurses, and the Nurses\u0026rsquo; Health Study II (NHS II) enrolled 116,430 women nurses ). The relative risk of kidney stones according to categories of tea intake of different cohort studies were HPFS (OR\u0026thinsp;=\u0026thinsp;0.88; 95% CI, 0.74\u0026ndash;1.04), NHS I (OR\u0026thinsp;=\u0026thinsp;0.85; 95% CI, 0.74\u0026ndash;0.98), NHS II (OR\u0026thinsp;=\u0026thinsp;0.93; 95% CI, 0.82\u0026ndash;1.04). A cohort study from Finland[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] was no direct connection with association between tea intake and kidney stones (OR\u0026thinsp;=\u0026thinsp;1.05; 95% CI, 0.95\u0026ndash;1.17). A case-control study from Yijishan Hospital of Wannan Medical College of China reported that tea intake with a preference for drinking strong tea were protective factors (OR\u0026thinsp;=\u0026thinsp;0.793; 95% CI, 0.702\u0026ndash;0.897)[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], however, a case-control study from China reported that tea intake has no direct relationship with kidney stones (men, OR\u0026thinsp;=\u0026thinsp;1.13; 95%CI, 0.78\u0026thinsp;\u0026minus;\u0026thinsp;1.64 and women, OR\u0026thinsp;=\u0026thinsp;0.91; 95%CI, 0.53\u0026thinsp;\u0026minus;\u0026thinsp;1.56) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], and two case-control study from USA not demonstrated a positive association between tea intake and kidney stones[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGiven the widespread tea consumption in word, it is important to determine whether there is a relationship between tea intake and kidney stone risk. The purpose of this meta-analysis was to determine the relationship between tea consumption and kidney stones.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e \u003cb\u003eLiterature search strategy\u003c/b\u003e \u003c/p\u003e \u003cp\u003eBased on keywords, PubMed, Web of Knowledge, Elsevier Science Direct, and Springer digital libraries were searched to identify relevant articles. The key words were as follows: \u0026ldquo;nephrolithiasis\u0026rdquo;, \u0026ldquo;kidney stones\u0026rdquo;, \u0026ldquo;urinary calculi\u0026rdquo;, and \u0026ldquo;behaviors\u0026rdquo;, \u0026ldquo;diet\u0026rdquo;, \u0026ldquo;tea consumption\u0026rdquo;, \u0026ldquo;tea intake\u0026rdquo;. To find all relevant research articles, we checked the references of the retrieved articles, and each gender was analyzed as a separate study if the studies were analyzed separately for gender.\u003c/p\u003e\n\u003ch3\u003eLiterature Inclusion and Exclusion Criteria\u003c/h3\u003e\n\u003cp\u003eThe following criteria were used for inclusion in this meta-analysis: (1) a cohort, case-control; (2) the study assessed the relationship between tea intake and kidney stones; (3) the outcome was defined as a medical diagnosis of kidney stones; and (4) the adjusted ORs and corresponding 95% CIs were provided. The exclusion criteria were as follows: (1) experimental studies involving animals; (2) lifestyle factors other than tea drinking were investigated; and (3) articles published in the form of letters, conference papers, reviews, or case reports. If a study reported a range of tea consumption and associated kidney stone risk, we included the effects of high tea consumption.\u003c/p\u003e \u003cp\u003eTwo trained investigators ( Haijin Zhang and Lixia Tian ) independently extracted data and resolved discrepancies through discussion. The following information was extracted: first author's last name, year of publication, follow-up, type of study, sex, sample size, area, tea consumption, OR value and the corresponding 95% CI, adjusted for covariates and study quality in the statistical analysis. If the article included both sexes, each sex was regarded as a separate study (e.g., [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]). The quality of the article was evaluated according to Newcastle\u0026ndash;Ottawa scale (NOS)[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], This self-rating scale had a total of nine items and each item was worth 1 point. Each study was evaluated independently, and any inconsistent conclusions were resolved through group discussion. Based upon a previous study[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], the evaluation of article quality is divided into the following scoring categories: low, 0\u0026thinsp;\u0026minus;\u0026thinsp;5; moderate, 5\u0026thinsp;\u0026minus;\u0026thinsp;7; and high, 7\u0026thinsp;\u0026minus;\u0026thinsp;9.\u003c/p\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eAssociation analysis between tea intake and kidney stones was based on the adjusted OR and the 95% CI, as reported by the eligible studies. Statistical analysis was performed using Stata (version 12.0) software and a \u003cem\u003eP\u003c/em\u003e value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. \u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e was used to assess heterogeneity between studies (\u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e values were 0%, 25%, 50%, and 75%, representing no, low, moderate, and high heterogeneity, respectively)[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. If moderate or low heterogeneity was detected (\u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;50%), a fixed-effects model was used to calculate the combined OR, otherwise a random-effects model was used[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The sensitivity analysis method was used to evaluate the stability between studies. Begg's test and Egger's test[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] was used for detection of publication bias.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cb\u003eStudy characteristics\u003c/b\u003e \u003c/p\u003e \u003cp\u003eBased on keywords, a total of 151 potentially relevant articles were retrieved, of which 124 no relevant contents were deleted. After reading the titles and abstracts of 27 articles, 11 were excluded because the focus of the study was not tea drinking. Of the remaining 16 full-text articles, six were excluded; ten articles met the inclusion criteria, and the results of the study search are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e. This study included 14 studies published from 1996 − 2021, with sample sizes ranging from 632 to 502,621, including 6 cohort studies[\u003cspan additionalcitationids=\"CR10 CR11 CR12 CR13\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e–\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], four case-control studies[\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e–\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. The articles by Shu[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and Ferraro[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]and Dai[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] reported studies involving both sexes, thus each study was split based on gender and regarded as independent studies. The quality of the articles was assessed according to the NOS ; three articles were of high quality and four articles were of moderate quality. The details of each study are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\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\u003eCharacteristics of the included studies\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"11\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAuthor, year\u003c/p\u003e \u003cp\u003e(reference)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFollow-up\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eType of study\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSample size\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eArea\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eTea consumption\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eOR\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e95% CI\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAdjusted for covariates\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eStudy\u003c/p\u003e \u003cp\u003equality\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShu X(2019)[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1996–2000\u003c/p\u003e \u003cp\u003e2002–2006\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCohort\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ewomen\u003c/p\u003e \u003cp\u003emen\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e69166\u003c/p\u003e \u003cp\u003e58054\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eShanghai\u003c/p\u003e \u003cp\u003eChina\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNever/former\u003c/p\u003e \u003cp\u003eCurrent\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.87\u003c/p\u003e \u003cp\u003e0.78\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.770.98\u003c/p\u003e \u003cp\u003e0.690.88\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eYear, smoking, education, income, physical activity, BMI, WHR, history of coronary heart disease/ stroke/ type 2 diabetes/ hypertension/ cholelithiasis, energy/ dietary protein/ calcium /calcium/ vitamin C/ potassium/ magnesium and dietary oxalate intake.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ehigh\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChen HY(2019)[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2001–2009\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCohort\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eboth\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13842\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTaiwan\u003c/p\u003e \u003cp\u003eChina\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003cp\u003e0–20 cup-year\u003c/p\u003e \u003cp\u003e≥ 20 cup-year\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.79\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.660.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAge, gender, BMI, hypertension, diabetes, plasma creatinine and uric acid level, smoking, alcohol consumption, and regular exercise.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003emoderate\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWang H(2021)[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2004–2008\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCohort\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eboth\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e502621\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eChina Kadoorie Biobank\u003c/p\u003e \u003cp\u003eChina\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNever\u003c/p\u003e \u003cp\u003eLess than daily\u003c/p\u003e \u003cp\u003eDaily (1–6, ≥ 7cups/day)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.73\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.650.83\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eSex, education, occupation, income, smoking, physical activity, intake of red meat, dairy products, vegetables, vitamin, calcium, iron or zinc, BMI, waist-to-hip ratio,hypertension, and diabetes.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ehigh\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLittlejohns TJ[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2009–2010\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCohort\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eboth\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e439072\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eUK\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0/1–2/3–4/5 + cups/day\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.78–0.92\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAge, sex, Townsend deprivation score, education, ethnicity, smoking, BMI, and calcium supplementation\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ehigh\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAuthor, year\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(reference)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eFollow-up\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eType of study\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eSex\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eSample size\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eArea\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003eTea consumption\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003eOR\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e95% CI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003eAdjusted for covariates\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cb\u003eStudy\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003equality\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFerraro PM [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1986-\u003c/p\u003e \u003cp\u003e1976-\u003c/p\u003e \u003cp\u003e1989-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCohort\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003emen\u003c/p\u003e \u003cp\u003ewomen\u003c/p\u003e \u003cp\u003ewomen\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e51529\u003c/p\u003e \u003cp\u003e121700\u003c/p\u003e \u003cp\u003e116430\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHPFS\u003c/p\u003e \u003cp\u003eNurses’ Health Study I\u003c/p\u003e \u003cp\u003eNurses’ Health Study II\u003c/p\u003e \u003cp\u003eUSA\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt; 1,1,2–4,5–6/week,\u0026gt;1/day\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.88\u003c/p\u003e \u003cp\u003e0.85\u003c/p\u003e \u003cp\u003e0.93\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.74–1.04\u003c/p\u003e \u003cp\u003e0.74–0.98\u003c/p\u003e \u003cp\u003e0.82–1.04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAge, race, region of residence, BMI, use of furosemide/thiazides, high blood pressure, diabetes, gout, intake of calcium, potassium, phytate, animal protein, vitamin C, total calories, profession and mutually adjusted for all the beverages.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ehigh\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHirvonen T[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1985–1988\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCohort\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003emen\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e290406\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSouthwestern Finland\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003cp\u003e170 ml/day\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.95–1.17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAge, supplementation group, other beverages, vocational training, marital status, and intakes of magnesium and fiber.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ehigh\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZhuo D(2019)[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2017–2018\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCase-\u003c/p\u003e \u003cp\u003econtrol\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eboth\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1519\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eWannan\u003c/p\u003e \u003cp\u003eChina\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLight\u003c/p\u003e \u003cp\u003eMedium\u003c/p\u003e \u003cp\u003eStrong\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.793\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.702–0.897\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eGender, age, occupation, residence, education level, dietary habits, fluid intake, and physical activity.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003emoderate\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDai M(2013)[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2010–2011\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCase-\u003c/p\u003e \u003cp\u003econtrol\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003emen\u003c/p\u003e \u003cp\u003ewomen\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1290\u003c/p\u003e \u003cp\u003e716\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eGuangzhou\u003c/p\u003e \u003cp\u003eChina\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt; 1, 1–3,1–6 times/week\u003c/p\u003e \u003cp\u003e≥ 1 time/day\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.13\u003c/p\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e(0.781.64)\u003c/p\u003e \u003cp\u003e(0.531.56)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAge, BMI, smoke, occupation, education, hypertension.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003ehigh\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKrieger JN[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1989–1992\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCase-\u003c/p\u003e \u003cp\u003econtrol\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003emen\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e392 + 240\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePuget Sound region\u003c/p\u003e \u003cp\u003eUSA\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNo or yes\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.74\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.52–1.06\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003emoderate\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGoldfarb DS[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1965–1975\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCase-\u003c/p\u003e \u003cp\u003econtrol\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003emen\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8870\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eVietnam Era Twin\u003c/p\u003e \u003cp\u003eUSA\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0/1–2/3–4/5 + cups/day\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.2–2.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eBMI, hypertension, and smoking\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003emoderate\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"11\" nameend=\"c11\" namest=\"c1\"\u003e \u003cp\u003eBMI, body mass index; HPFS, Health Professionals Follow-Up Study; NHS I, Nurses’ Health Study I; NHS II, Nurses’ Health Study II.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e\n\u003ch3\u003eMeta-analysis results\u003c/h3\u003e\n\u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the pooled ORs of kidney stones for the highest and lowest categories of tea intake. The combined OR was 0.86 (95% CI, 0.81 − 0.91), and mild heterogeneity existed among the included studies (I\u003csup\u003e2\u003c/sup\u003e = 56.6%, P = 0.005).\u003c/p\u003e\n\u003ch3\u003eSubgroup and sensitivity analyses\u003c/h3\u003e\n\u003cp\u003eSubgroup analysis based on the type of study, sex, and tea consumption did not change our findings. The combined ORs were as follows: cohort study (OR, 0.86; 95% CI, 0.83 − 0.90); case-control study (OR, 0.82; 95% CI, 0.73 − 0.91); male sex (OR, 0.92; 95% CI, 0.86 − 0.91); female sex (OR, 0.89; 95% CI, 0.83 − 0.95); China ( OR, 0.80; 95% CI, 0.76 − 0.85), USA/European ( OR, 0.91; 95% CI, 0.86 − 0.95); The samples from hospital ( OR, 0.86; 95% CI, 0.83 − 0.89), no-hospital ( OR, 0.87; 95% CI, 0.83 − 0.92);\u003c/p\u003e \u003cp\u003eThe sensitivity analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e3\u003c/span\u003e) verified stability after removing one study at a time, the pooled OR and ORs ranged from 0.82 (95% CI, 0.79 − 0.86) to 0.87 (95% CI, 0.81 − 0.93) for kidney stones.\u003c/p\u003e\n\u003ch3\u003eEstimation of publication bias\u003c/h3\u003e\n\u003cp\u003eA funnel plot was used to assess bias between studies. Due to the small number of studies, publication bias was not detected (Begg's test, \u003cem\u003ep\u003c/em\u003e = 0.891; Egger’s test, \u003cem\u003ep\u003c/em\u003e = 0.934), Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e "},{"header":"Discussion","content":"\u003cp\u003eThe current meta-analysis included data from 22,963 patients with kidney stones from four 6 cohort studies[9–14], 5 case-control studies[15–18]. Compared with controls, tea drinking had a significant preventive effect on the occurrence of kidney stones (OR = 0.86; 95% CI, 0.81 − 0.91). This is the first comprehensive analysis of the protective effect of tea consumption on kidney stones. Subgroup analysis showed that the risk of kidney stones decreased with increasing tea consumption, there were no significant differences between men and women, howere, Tea consumption has been shown to reduce kidney stones more in Chinese than in Europeans/Americans\u003c/p\u003e\u003cp\u003eThe sensitivity analysis in this meta-analysis confirmed the validity of our conclusions about the comparison between tea drinking and never tea drinking. The strength of our study lies in the complete adherence to a systematic review approach, including a two-stage screening process for published titles and abstracts by independent researchers, an assessment of the quality of each study, and an assessment of the risk of bias. All of the studies were well-designed and included people recruited from the general population, suggesting that the effects of the intervention were unlikely to depend on specific environmental factors.\u003c/p\u003e\u003cp\u003eChanges in dietary habits are key to preventing stone formation and recurrence[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], and coffee and tea intake have previously been reported to be inversely associated with kidney stones[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Coffee and tea are sources of caffeine, which has been reported to moderately increase diuresis, while promoting excretion of magnesium, potassium, calcium, and sodium[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Recent evidence suggests that caffeine-induced natriuresis may be caused by Shirley DG[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Based on an experimental model, Ming and Lautt[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] proposed that caffeine, as an inhibitor of adenosine receptors, may have diuretic and natriuretic effects by interfering with hepatic A1 adenosine receptor-mediated liver-kidney reflex. Caffeine also reduces Na/KATPase and Na/H exchange activities and increases ANP and NO activities in the kidney[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Jeong et al.[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] evaluated the cytotoxicity of epigallocatechin gallate (EGCG), one of the main components of green tea catechins, against oxalate in an animal model and found that EGCG inhibited oxalic acid-induced free radical production. In addition, tea can reduce the excretion of oxalic acid in the urine, and green tea has an inhibitory effect on the formation of urinary stones, which is largely due to the antioxidant effect of EGCG. Taken together, these changes increase diuresis and have a potentially protective effect against stone formation. Tea is one of the most common drinks in China, next only to water. Even though the oxalic acid content in tea poses a risk for stone formation, based on a large number of clinical studies, we found that the vast majority of people favor the idea of a protective effect against urolithiasis[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. There are several factors for this. First, tea consumption is essentially a supplement to daily fluid intake, and this is only the beneficial part of explaining the effects of tea on stone formation. In addition, tea contains caffeine, which has diuretic and natriuretic effects on the kidneys; however, the specific mechanism by which tea exerts a protective effect against kidney stones is still unclear.\u003c/p\u003e\u003cp\u003eSeveral potential limitations need to be considered, as follows: (1) lacking accurate information regarding exposure to tea intake. Despite a feasibility of crude classifications, typo was inevitable; (2) tea is divided into different species and different substances, which may affect the results; (3) due to the different measurement methods used in the study on the amount of tea consumed, it is difficult to unify the information on the dose-response relationship in this study; and (4) we selected study subjects adjusted for potential confounders, however, it is difficult to demonstrate the presence of other risk factors that may contribute to kidney stones. For example, there are people in the Chinese population who drink both tea and coffee, and studies have shown that drinking coffee can reduce the incidence of kidney stones[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. In conclusion, this meta-analysis showed that tea consumption was more effective in reducing the risk of kidney stones in the population and may play a key role in preventing stone formation and recurrence.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eStatement of Ethics\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot required, as this is a review of existing literature.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis paper did not contain human participants enrolled by any of the authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no conflicts of interest to declare.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Sources\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was not supported by any Funding Sources.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNing Li and Jun Qiu conceived the study. Xiongfeng Pan and Jinzhu Yin participated in the statistical analysis. Ning Li and Jun Qiu drafted the article. All authors read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis paper is meta that all data are fully available without restriction.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKhan SR, Pearle MS, Robertson WG, Gambaro G, Canales BK, Doizi S, et al. Kidney stones. Nature reviews Disease primers. 2016;2(1):1\u0026ndash;23\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRule AD, Lieske JC, Li X, Melton III LJ, Krambeck AE, Bergstralh EJ. The ROKS nomogram for predicting a second symptomatic stone episode. Journal of the American Society of Nephrology: JASN. 2014;25(12):2878\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSorokin I, Mamoulakis C, Miyazawa K, Rodgers A, Talati J, Lotan Y. Epidemiology of stone disease across the world. World journal of urology. 2017;35:1301\u0026ndash;20\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRomero V, Akpinar H, Assimos DG. Kidney stones: a global picture of prevalence, incidence, and associated risk factors. Reviews in urology. 2010;12(2\u0026ndash;3):e86\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang W, Fan J, Huang G, Li J, Zhu X, Tian Y, et al. Prevalence of kidney stones in mainland China: A systematic review. Scientific reports. 2017;7(1):41630\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRule AD, Lieske JC, Pais VM. Management of kidney stones in 2020. Jama. 2020;323(19):1961\u0026ndash;2\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTrinchieri A. 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World Journal of Urology. 2019;37:379\u0026ndash;84\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang H, Fan J, Yu C, Guo Y, Pei P, Yang L, et al. Consumption of tea, alcohol, and fruits and risk of kidney stones: a prospective cohort study in 0.5 million Chinese adults. Nutrients. 2021;13(4):1119\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLittlejohns TJ, Neal NL, Bradbury KE, Heers H, Allen NE, Turney BW. Fluid intake and dietary factors and the risk of incident kidney stones in UK Biobank: a population-based prospective cohort study. European urology focus. 2020;6(4):752\u0026ndash;61\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFerraro PM, Taylor EN, Gambaro G, Curhan GC. Soda and other beverages and the risk of kidney stones. Clinical journal of the American Society of Nephrology: CJASN. 2013;8(8):1389\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHirvonen T, Pietinen P, Virtanen M, Albanes D, Virtamo J. Nutrient intake and use of beverages and the risk of kidney stones among male smokers. American journal of epidemiology. 1999;150(2):187\u0026ndash;94\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhuo D, Li M, Cheng L, Zhang J, Huang H, Yao Y. A study of diet and lifestyle and the risk of urolithiasis in 1,519 patients in Southern China. Medical science monitor: international medical journal of experimental and clinical research. 2019;25:4217\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDai M, Zhao A, Liu A, You L, Wang P. Dietary factors and risk of kidney stone: a case\u0026ndash;control study in southern China. Journal of Renal Nutrition. 2013;23(2):e21-e8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrieger JN, Kronmal RA, Coxon V, Wortley P, Thompson L, Sherrard DJ. Dietary and behavioral risk factors for urolithiasis: potential implications for prevention. American journal of kidney diseases. 1996;28(2):195\u0026ndash;201\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoldfarb DS, Fischer ME, Keich Y, Goldberg J. A twin study of genetic and dietary influences on nephrolithiasis: a report from the Vietnam Era Twin (VET) Registry. Kidney international. 2005;67(3):1053\u0026ndash;61\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStang A. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. European journal of epidemiology. 2010;25:603\u0026ndash;5\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTimmermans L, de Goede B, van Dijk SM, Kleinrensink G-J, Jeekel J, Lange JF. Meta-analysis of sublay versus onlay mesh repair in incisional hernia surgery. The American Journal of Surgery. 2014;207(6):980\u0026ndash;8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHiggins JP, Thompson SG. Quantifying heterogeneity in a meta-analysis. Statistics in medicine. 2002;21(11):1539\u0026ndash;58\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHiggins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. Bmj. 2003;327(7414):557\u0026ndash;60\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEgger M, Smith GD, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. Bmj. 1997;315(7109):629\u0026ndash;34\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLetendre J, Cloutier J, Villa L, Valiquette L. Metabolic evaluation of urinary lithiasis: what urologists should know and do. World journal of urology. 2015;33:171\u0026ndash;8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCurhan GC, Willett WC, Rimm EB, Spiegelman D, Stampfer MJ. Prospective study of beverage use and the risk of kidney stones. American journal of epidemiology. 1996;143(3):240\u0026ndash;7\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCurhan GC, Willett WC, Speizer FE, Stampfer MJ. Beverage use and risk for kidney stones in women. Annals of internal medicine. 1998;128(7):534\u0026ndash;40\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMassey LK, Wise KJ. Impact of gender and age on urinary water and mineral excretion responses to acute caffeine doses. Nutrition research. 1992;12(4\u0026ndash;5):605\u0026ndash;12\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShirley D, Walter S, Noormohamed F. Natriuretic effect of caffeine: assessment of segmental sodium reabsorption in humans. Clinical Science. 2002;103(5):461\u0026ndash;6\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMing Z, Lautt WW. Caffeine-induced natriuresis and diuresis via blockade of hepatic adenosine-mediated sensory nerves and a hepatorenal reflex. Canadian journal of physiology and pharmacology. 2010;88(11):1115\u0026ndash;21\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee J, Ha JH, Kim S, Oh Y, Kim SW. Caffeine decreases the expression of Na+/K+-ATPase and the type 3 Na+/H\u0026thinsp;+\u0026thinsp;exchanger in rat kidney. Clinical and Experimental Pharmacology \u0026amp; Physiology. 2002;29(7):559\u0026ndash;63\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJeong BC, Kim BS, Kim JI, Kim HH. Effects of green tea on urinary stone formation: an in vivo and in vitro study. Journal of endourology. 2006;20(5):356\u0026ndash;61\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFerraro PM, Taylor EN, Gambaro G, Curhan GC. Caffeine intake and the risk of kidney stones. The American journal of clinical nutrition. 2014;100(6):1596\u0026ndash;603\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaughan RJ, Griffin J. Caffeine ingestion and fluid balance: a review. Journal of Human Nutrition and Dietetics. 2003;16(6):411\u0026ndash;20\u003c/span\u003e\u003c/li\u003e \u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"tea consumption, kidney stones, adult, risk factors, meta-analysis","lastPublishedDoi":"10.21203/rs.3.rs-4006705/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4006705/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eThe formation of kidney stones is multifactorial and surveys have shown that not all fluids are equally beneficial in reducing the risk of kidney stones. Multiple studies have shown an association between tea intake and kidney stones. However, studies investigating the relationship between tea intake and the occurrence of kidney stones have been inconsistent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjective: \u003c/strong\u003eTo clarify this association, we conducted this analysis to determine the link between tea intake and kidney stones.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy design:\u003c/strong\u003e This study was a meta-analysis. PubMed, Web of Knowledge, Elsevier Science Direct, and Springer digital libraries were searched for studies reporting \u003cstrong\u003etea intake\u003c/strong\u003e and kidney stones. A random-effects model was used to summarize the relationship between tea and kidney stones. The included articles were assessed for quality using the Newcastle–Ottawa scale.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eA total of ten articles and 14 studies (men and women) were retrieved, including 9 cohort studies, 5 case-control studies, with a total of 1,318,071 participants and of 22,963 kidney stone patient. The results showed that tea intake was negatively correlated with kidney stone, (combined odds ratio [OR], 0.86; 95% confidence interval [CI], 0.81−0.91) with mild heterogeneity (I\u003csup\u003e2\u003c/sup\u003e=56.6.0%; P=0.005). Subgroup and sensitivity analyses confirmed the results.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Tea intake was shown a potential protective effect on the development of kidney stones.\u003c/p\u003e","manuscriptTitle":"Tea intake and risk of incident kidney stone: A meta-analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-11 19:40:30","doi":"10.21203/rs.3.rs-4006705/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3a98b4eb-c6be-4c9f-a77f-9e7dfe92e92e","owner":[],"postedDate":"March 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":29187808,"name":"Biological sciences/Physiology/Kidney"},{"id":29187809,"name":"Health sciences/Health care/Nutrition"}],"tags":[],"updatedAt":"2024-05-20T14:26:25+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-11 19:40:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4006705","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4006705","identity":"rs-4006705","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}