Role, importance and assessment of dietary habits in urolithiasis patient.

Urolithiasis, which prevalence is increasing, poses a risk for chronic kidney disease in patients. Dietary habits play a significant role in stone formation, growth and recurrence. Also, comorbidities and lifestyle changes are among the factors affecting stone formation. The next step should be to detect metabolic disorders, if any, with analyzes to be made after a detailed anamnesis, and to arrange the necessary treatment. Insufficient fluid intake is considered to be the main dietary risk factor for urolithiasis. A daily fluid intake of 2.5-3.0 L/day or diuresis of 2.0-2.5 L/day is recommended to prevent recurrence of kidney stones. Not all beverages are beneficial, and some may even increase the risk of stone formation. Dietary management, vitamins and supplements, physical activity are important components in reducing the risk of recurrent urolithiasis. A detailed dietary assessment is recommended as dietary habits affect the faith of the disease. In this review we evaluated the dietary approach of urolithiasis patients with and without comorbidities, the recommended daily fluid intake, vitamin supplementation, and relation of the urolithiasis with physical activity.

Do men with bladder stones benefit from treatment of benign prostatic obstruction?

OBJECTIVE: To identify whether men aged ≥40 years with bladder stones (BS) benefit from treatment of benign prostatic obstruction (BPO). PATIENTS AND METHODS: A regional, retrospective study of patients undergoing BS surgery between January 2011 and December 2018 was performed using a prospectively collected database. The primary outcome was BS recurrence after successful removal. Kruskal-Wallis and chi-squared statistical tests were used. RESULTS: A total of 174 patients underwent BS removal and 71 (40.8%) were excluded due to BS formation secondary to causes other than BPO. Hence, 103 men aged ≥40 years had BS successfully removed, of which 40% had a history of upper tract urolithiasis. These men were divided into three groups: those undergoing contemporaneous medical, surgical, or no BPO treatment. Age, diabetes, previous urolithiasis and previous BPO surgery were well matched between the BPO treatment groups. In all, 18 of these men (17%) had BS recurrence after 46 months follow-up. Recurrences were significantly lower following BPO surgery; one of 34 (3%) men versus five of 28 (18%) with no BPO treatment (P = 0.048) and 12 of 41 (29%) with medical BPO treatment (P = 0.003). Recurrences after medical and no BPO treatment were similar (P = 0.280). In all, 34 men (33%) had BPO complications that were similar between groups (P = 0.378). CONCLUSION: This is the largest reported cohort of men, with the longest follow-up after BS removal. Most men aged ≥40 years with BS benefit from BPO surgery. However, the study findings also support a multifactorial aetiology for BS, which questions the dogma that BS are an 'absolute indication' for BPO surgery, as is stated in the Non-neurogenic Male Lower Urinary Tract Symptoms European Association of Urology Guideline. Assessment and management of all causative factors is likely to enable selection of which men will benefit from BPO surgery and to reduce BS recurrence rates.

Oncologic safety of Carrel patch hepaticojejunostomy for treating cystic-type choledochal cyst in children based on 20-plus years follow-up.

AIM: During choledochal cyst (CC) excision, the hepaticojejunostomy anastomosis (HJA) can be performed conventionally (CHJA) or with a Carrel patch (CPA). CPA can increase CHD diameter to 10-13 mm, preventing anastomotic stenosis and intrahepatic bile duct (IHBD) stones but may be at risk for malignant transformation. METHODS: The medical records of 83 cystic-type CC with CHD ≤ 9 mm followed up for at least 20 years were reviewed retrospectively. Available excised CC specimens (70/83) were re-examined blindly for pre-malignant changes. A questionnaire about suturing narrow lumens was conducted. RESULTS: All 83 had pancreaticobiliary maljunction. Group data were similar. Anastomoses were CPA (n = 43) and CHJA (n = 40). Mean diameter for CPA was 11.4 mm (range: 10-13 mm); for CHJA was 7.4 mm (range: 5-9 mm). Mean follow-up was 27.7 years (range: 20-42). Postoperative anastomotic stenoses were less after CPA: 1/43 (2.3%) versus 5/40 (12.5%) (p = 0.10), but CHJA had significantly more postoperative IHBD stones: 0% versus 4/40 (10.0%) (p < 0.05). All IHBD stone patients had anastomotic stenosis. Excised specimens showed no pre-malignant cytology. Lumen diameter ≤ 9 mm was considered challenging by 10/10 surgical trainees and ≤ 7 mm by 16/22 pediatric surgeons. CONCLUSIONS: CPA appears to be oncologically safe because of the absence of malignant transformation for at least 20 years.

[Current state of metaphylaxis of urinary stones in Russian Federation].

INTRODUCTION: Urolithiasis is one of the most common urological diseases in adults. Increased life expectancy of the population in developed countries, make urolithiasis topical issue and requires close attention. Due to the high risk of recurrent stone formation causing repeated surgical interventions, the issue of effective urinary stone metaphylaxis is very important today. MATERIALS AND METHODS: To study the current state of the problem of urolithiasis metaphylaxis among Russian urologists, an anonymous questionnaire was applied. A 25-question questionnaire was sent to e-mail to more than 4,000 Russian urologists. A total of 1,238 specialists completed the questionnaire. The database compiled from the received responses was processed and presented with descriptive statistics in the form of tables and charts. RESULTS: According to the survey, more than half of the 831 (67.1%) specialists specialized in the treatment of urolithiasis. It was noted that 626 (86%) inpatient urologists and 205 (40%) outpatient urologists specialized in the treatment of urolithiasis. Only 521 (69.6%) urologists specializing in surgical treatment of urolithiasis give a patient a stone fragment to analyze its chemical composition. At the same time, half of the respondents reported that less than 10% of patients come to them for further metaphylaxis. One of the main reasons for not analyzing the chemical composition of the stone was the fact that 877 (70,84%) specialists indicated the inaccessibility of analysis under the state guarantee program, 503 (40,63%) specialists indicated the patients satisfaction with the results of minimally invasive surgical treatment and lack of sufficient motivation for further examinations. At the same time, less than 3% of specialists can perform stone analysis within the framework of the state guaranty program. 1180 (96,8%) respondents practiced the prophylaxis of recurrent calculi formation, but only 336 (28,47%) performed comprehensive metabolic examination of all patients followed by prescription of drug therapy and appropriate diet. CONCLUSIONS: Our survey revealed low involvement of urologists at the outpatient level in the process of conservative treatment and metaphylaxis of urolithiasis, low activity of urologists in performing complex metabolic study and comprehensive prevention of recurrent stone formation, low percentage of performing chemical composition analysis of stone and low activity of urologists in performing primary litholytic therapy of urate stones. Based on this analysis of the responses of most Russian urologists, it is possible to formulate recommendations to remove the obstacles to providing patients with urolithiasis with quality medical care in terms of conservative therapy and metaphylaxis of urolithiasis.

Assessing the Relationship Between Serum Urate and Urolithiasis Using Mendelian Randomization: An Analysis of the UK Biobank.

RATIONALE & OBJECTIVE: The association between hyperuricemia and urolithiasis has been previously reported. However, this association is based on observational data, which are prone to residual confounding. The aim of this work was to use Mendelian randomization (MR) to evaluate if this relationship represents a causal effect of hyperuricemia. STUDY DESIGN: MR analysis using 2 approaches: 2-stage MR and 2-sample MR. SETTING & PARTICIPANTS: Participants aged 40-69 years from the UK Biobank Resource. EXPOSURE: Serum urate. OUTCOME: Urolithiasis. ANALYTICAL APPROACH: An observational analysis testing for an association between serum urate level and urolithiasis was performed using logistic regression. For MR analyses, serum urate-associated single-nucleotide polymorphisms, identified from genome-wide association data, were used as instrumental variables for serum urate. In the 2-stage MR analysis, a weighted genetic urate score was calculated from the instrumental variables, and a control function estimation model was fit. In the 2-sample MR analysis, multiple-instrument MR via the inverse-variance weighted method was performed. RESULTS: Individual-level data were available for 359,827 participants, of whom 6,398 (1.8%) reported urolithiasis. In the observational analysis, serum urate was positively associated with urolithiasis in an unadjusted analysis (odds ratio [OR], 1.47 [95% CI, 1.42-1.51]); however, after adjustment for relevant confounders, no association was observed (OR, 1.03 [95% CI, 0.99-1.08]). In the 2-stage MR analysis, no significant causal effect of serum urate level on urolithiasis was observed in the unadjusted (OR, 0.93 [95% CI, 0.81-1.08]) or adjusted (OR, 0.94 [95% CI, 0.80-1.09]) models. In the 2-sample MR analysis, multiple-instrument MR did not indicate a causal effect of serum urate on urolithiasis. LIMITATIONS: Stone composition and urinalysis data, including urine pH, were not available for this study. CONCLUSIONS: Our analyses do not support a causal effect of serum urate level on urolithiasis. The association between serum urate level and urolithiasis reported in observational studies is likely due to residual confounding.

[Foreign body in the urinary bladder intrauterine device].

The article provides a rare observation of a 34-year-old woman who, 12 years before admission to a urological clinic, a gynecologist installed an intrauterine contraceptive device (IUD). The subject migrated into the abdominal cavity, and after 10 years the patient developed dysuria and hematuria. In October 2017, ultrasound and cystoscopy revealed the migration of IUD into the bladder. A foreign body was removed from the bladder - an IUD of a T-shape with the formation of a stone on it with a maximum size of 4.5 cm. During a follow-up examination after 2 years, pathology was not established.

[Interdisciplinary approach for prevention of recurrent urinary stone disease].

Urolithiasis is a multifactorial metabolic disease caused by the interaction of genetic, environmental factors and is directly related to lifestyle. Multiple factors influencing the initiation of stone formation and the growth of urinary crystals are presented in the article. Based on the available data, an involvement of various specialists, including urologists, geneticists, physician office laboratory, radiation diagnostics specialists, nutritionists, endocrinologists, immunologists, physiotherapy and balneotherapy specialists, general practitioner, is necessary for effective treatment of patients with kidney stones.

Antibiotic Use and Risk of Incident Kidney Stones in Female Nurses.

RATIONALE & OBJECTIVE: The intestinal microbiome may affect urinary stone disease by modulating the amount of oxalate absorbed from the intestine and subsequently excreted in urine. This study sought to explore the association between antibiotics, which alter the intestinal microbiota, and risk for urinary stone disease. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 5,010 women in the Nurses' Health Study (NHS) I and II who had collected 24-hour urine samples. EXPOSURES: Use of antibiotics during the age range of 40 to 49 (NHS II), 40 to 59 (NHS I), and 20 to 39 years (both cohorts). OUTCOMES: Incident symptomatic urinary stone disease; urine composition. ANALYTICAL APPROACH: Cause-specific hazards regression adjusted for age, body mass index, comorbid conditions, thiazide use, and dietary factors. Follow-up was censored at the time of asymptomatic kidney stones, cancer, or death. RESULTS: Cumulative use of antibiotics for a total of 2 or more months during the age range of 40 to 49 years (NHS II) and 40 to 59 years (NHS II) was associated with significantly higher risk for developing incident stones compared with no use (pooled HR, 1.48; 95% CI, 1.12-1.96). Similar results were found for the period of 20 to 39 years (pooled HR, 1.36; 95% CI, 1.00-1.84). Results were unchanged after excluding participants who reported urinary tract infection with their stone event or as the most common reason for antibiotic use. Urine composition was generally similar across antibiotic groups except for marginally lower urine pH and citrate values among those taking antibiotics for 2 or more months. LIMITATIONS: Observational design; lack of information for type of antibiotic used; relatively large span of time between antibiotic use and urine collection. CONCLUSIONS: Use of antibiotics for more than 2 months in early adulthood and middle age is associated with higher risk for urinary stone disease in later life.

[Methanaphylaxis of urolithiasis. Part 3. The factors associated with increase in incidence of urinary stone disease. Current views on the mechanisms of stone formation].

All theories of stone formation are based on the common condition, which is the supersaturation of stone-forming elements. The microelements involved in the stone formation, the most common metabolic disorders and their role in stone formation are discussed.

Risk of ESRD and Mortality in Kidney and Bladder Stone Formers.

RATIONALE & OBJECTIVES: Kidney stones have been associated with increased risk for end-stage renal disease (ESRD). However, it is unclear whether there is also an increased risk for mortality and if these risks are uniform across clinically distinct categories of stone formers. STUDY DESIGN: Historical matched-cohort study. SETTING & PARTICIPANTS: Stone formers in Olmsted County, MN, between 1984 and 2012 identified using International Classification of Diseases, Ninth Revision codes. Age- and sex-matched individuals who had no codes for stones were the comparison group. PREDICTOR: Stone formers were placed into 5 mutually exclusive categories after review of medical charts: incident symptomatic kidney, recurrent symptomatic kidney, asymptomatic kidney, bladder only, and miscoded (no stone). OUTCOMES: ESRD, mortality, cardiovascular mortality, and cancer mortality. ANALYTICAL APPROACH: Cox proportional hazards models with adjustment for baseline comorbid conditions. RESULTS: Overall, 65 of 6,984 (0.93%) stone formers and 102 of 28,044 (0.36%) non-stone formers developed ESRD over a mean follow-up of 12.0 years. After adjusting for baseline hypertension, diabetes mellitus, dyslipidemia, gout, obesity, and chronic kidney disease, risk for ESRD was higher in recurrent symptomatic kidney (HR, 2.34; 95% CI, 1.08-5.07), asymptomatic kidney (HR, 3.94; 95% CI, 1.65-9.43), and miscoded (HR, 6.18; 95% CI, 2.25-16.93) stone formers, but not in incident symptomatic kidney or bladder stone formers. The adjusted risk for all-cause mortality was higher in asymptomatic kidney (HR, 1.40; 95% CI, 1.18-1.67) and bladder (HR, 1.37; 95% CI, 1.12-1.69) stone formers. Chart review of asymptomatic and miscoded stone formers suggested increased risk for adverse outcomes related to diagnoses including urinary tract infection, cancer, and musculoskeletal or gastrointestinal pain. CONCLUSIONS: The higher risk for ESRD in recurrent symptomatic compared with incident symptomatic kidney stone formers suggests that stone events are associated with kidney injury. The clinical indication for imaging in asymptomatic stone formers, the correct diagnosis in miscoded stone formers, and the cause of a bladder outlet obstruction in bladder stone formers may explain the higher risk for ESRD or death in these groups.

Do dental calculi predict the presence of renal stones?

OBJECTIVE: Pathological calcifications that occur in various parts of the body may cause stone formation over time. The structure of these stones is similar in many regions of the body. We have studied the relationship between dental calculi and kidney stones. MATERIAL AND METHODS: A total of 183 patients with dental stone complaints or dental calculi were included between April and August 2016 in the Cagri Dental Hospital, Elazig, Turkey. Patients were evaluated with regard to a urinary tract ultrasonography, urinalysis, oral hygiene, and stone and surgical disease history. All information was statistically investigated. RESULTS: The age of the patients in the kidney stones group was significantly higher than the non-kidney stone patients (p < 0.05). In the group with kidney stones, the percentage of dental calculus formation was significantly higher than the group without stones (p < 0.05). In the groups with and without kidney stones, dental stone recurrence rates did not differ significantly (p < 0.05). Urinary pH was significantly lower in the group with stones than the group without stones (p < 0.05). CONCLUSIONS: During a physical examination, the formation of a visible stone, such as a dental calculus, may be an indicator of other types of stones, such as kidney stones, and this should be further investigated.

[Time to recurrence after complete removal of calculi from different parts of the urinary system. five-year follow-up study].

INTRODUCTION: The usage of minimally invasive technologies (MIT), such as: extracorporeal shock wave lithotripsy (ESWL), transurethral ureterolithotripsy (URS), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotripsy (PNL), allows to remove the stones from the calyx and pelvis system with 71- 96% of patients, and those from the ureter in 96.2% cases. However, a high incidence of stone recurrences (35-75%) demands the necessity of repeated lithotripsies and the search of the most appropriate methods of lithotripsy for reduction this indicator. The main goal. To determine the number of patients with recurrence of stone formation during five years after different types of lithotripsy in different parts of the urinary system. MATERIALS AND METHODS: The results of the process were analyzed with 491 patients, who had been devided into two groups: group I - 358 patients suffering from the concrements of the ureter; group II - 133 patients having stones in kidney. RESULTS: According to the age criterion, the sample data did not differ from each other (50 years for both groups (p=0.576). The initial number of lithotripsies with complete removal of stones was 80.7% in group I and 70.7% in gr. II, the repeated lithotripsy with usage of the same method was 5.9% and 12.8%, respectively. The usage of an additional method in repeated lithotripsy was necessary in 13.4% and 16.5% of cases respectively. There were differences between the sizes of stones in groups (p<0.0001), besides both groups showed the difference in recurrence time of stone formation (p=0,014). In gr. I weak negative correlation (-0.28) between age and time of recurrence was revealed. The age difference between men and women in both groups (p=0.00001 and p=0.0492, respectively) was found. There occurred differences in the size of stones in men and women groups (p=0.0000001 and p=0.0000001, respectively) and in the time of recurrence between men and women in I gr. (p=0.043). Most of stones were compose of CaOx, the second most important element was Uric Acid. All this testifies to peculiarities of the diet in the region of residence of the patients under control - the Republic of Bashkortostan, where people generally use meat and milk products. DISCUSSION: The usage of MIT opened the possibility of complete stone removal from the urinary system with the most sparing technique. The lithotripsy of stones with any composition having been conducted, additional stone crushing is carried out with 21-59% of patients within 5 years. The investigation of patients detected a great number of recurrences of stones in the kidney stones group. CONCLUSION: 1. After lithotripsy the recurrences during two years did not exceed 4,2% with patients in gr. I and 8,2% in gr. II patients. 2. Significant dependence of recurrent stone formation of gender composition was identified in gr. I and the time of recurrence was less in women. 3. The quantity of CaOx urolithiasis corresponds to global indicators. However, a large number of stones with Uric Acid in the composition indicates possible peculiarities of the patients diet. 4. The highest number of recurrences were in patients with CaOx (42.3%) and CaOx with CaF in the composition (23.1%), and in third place were patients with uric acid stones (19.2%).

[Methanaphylaxis of urolithiasis. Part 1. Factors for increasing incidence of urolithiasis. Current theories of renal stone formation].

Urolithiasis is one of the most actively progressing diseases, a metabolic disorder that is strongly associated with a combination of genetic, lifestyle, and environmental factors. The first part presents current views on the factors triggering the formation of stones and the theory of stone formation. More specifically, the article discusses factors that contribute to the activation and inhibition of nucleation and aggregation of stone-forming substances.

[Recurrence prevention for urinary stone disease. Part II.The factors associated with increase in incidence of urinary stone disease. Current views on the mechanisms of stone formation (continuation)].

Urinary stone disease is one of the most actively progressing diseases, which are associated with metabolic disturbances and are influenced by the genetic, environmental factors and lifestyle \. In the article the current views on initiation factors of stone formation and theories of stone formation are reviewed. The factors that play an important role in the activation and inhibition of nucleation and aggregation of stone-forming substances are discussed. All theories of stone formation are based on the common condition, which is the supersaturation of stone-forming elements. The microelements involved in the stone formation, the most common metabolic disorders and their role in stone formation are discussed.

[Clinical and biochemical aspects of pathogenesis of urolithiasis].

AIM: To investigate the role of infection in the pathogenesis of urolithiasis using chromatography mass spectrometry analysis. MATERIALS AND METHODS: The study analyzed clinical and laboratory data of 316 urolithiasis patients hospitalized between February 2005 and January 2015. All patients underwent a comprehensive clinical examination, including laboratory tests (hematological and biochemical blood tests, clinical and bacteriological tests of urine) and chromatography mass spectrometry analysis urine and blood. The laboratory testing was carried out both during the patients hospital stay and outpatient follow-up. RESULTS: We analyzed the biological material for the presence of characteristic ions. Urine samples of 316 urolithiasis patients were found to contain activators of "cooperative sensitivity." Moreover, there was a significant increase in the concentration of signaling compounds of the "cooperative sensitivity" of microorganisms in patients with complicated urolithiasis in comparison with the control indices (lactones-0.006 plus/minus 0.0004 mmol/L, normal values less than 0.002, quinolones 0.004 plus/minus 0.0003 mmol/l, normal values - less than 0.002 and furan esters - 0.005 plus/minus 0.0004, normal values less than 0.002). Threshold values of the activators of "cooperative sensitivity" demonstrated the readiness of the microbial community to initiate an inflammatory process. The presence of activators such as lactones, quinolones and furan esters in the samples of urolithiasis patients predisposes to the activation of pathogenic genes in a large group of microorganisms, including gram positive and gram negative species. DISCUSSION: In our opinion, to improve the quality of diagnostic, treatment and preventive measures in patients with different types of stone formation, it is advisable to use chromatography mass spectrometry analysis, which allows determination of priority clinical and laboratory indicators. CONCLUSION: The data on the role of infection in the pathogenesis of urolithiasis obtained by chromatographic methods suggest the possibility of using the indicators of the activators of the "cooperative sensitivity" of microbes in patients with various forms of urolithiasis to assess the disease severity.

Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones.

BACKGROUND: Previous studies of vitamin C and kidney stones were conducted mostly in men and either reported disparate results for supplemental and dietary vitamin C or did not examine dietary vitamin C. STUDY DESIGN: Prospective cohort analysis. SETTING & PARTICIPANTS: 156,735 women in the Nurses' Health Study (NHS) I and II and 40,536 men in the Health Professionals Follow-up Study (HPFS). PREDICTOR: Total, dietary, and supplemental vitamin C intake, adjusted for age, body mass index, thiazide use, and dietary factors. OUTCOMES: Incident kidney stones. RESULTS: During a median follow-up of 11.3 to 11.7 years, 6,245 incident kidney stones were identified. After multivariable adjustment, total vitamin C intake (<90 [reference], 90-249, 250-499, 500-999, and ≥1,000mg/d) was not significantly associated with risk for kidney stones among women, but was among men (HRs of 1.00 [reference], 1.19 [95% CI, 0.99-1.46], 1.15 [95% CI, 0.93-1.42], 1.29 [95% CI, 1.04-1.60], and 1.43 [95% CI, 1.15-1.79], respectively; P for trend = 0.005). Median total vitamin C intake for the 500- to 999-mg/d category was ∼700mg/d. Supplemental vitamin C intake (no use [reference], <500, 500-999, and ≥1,000mg/d) was not significantly associated with risk for kidney stones among women, but was among men (HR, 1.19 [95% CI, 1.01-1.40] for ≥1,000mg/d; P for trend = 0.001). Dietary vitamin C intake was not associated with stones among men or women, although few participants had dietary intakes > 700mg/d. LIMITATIONS: Nutrient intakes derived from food-frequency questionnaires, lack of data on stone composition for all cases. CONCLUSIONS: Total and supplemental vitamin C intake was significantly associated with higher risk for incident kidney stones in men, but not in women.

Refining the intraoperative measurement of the distal intrapancreatic part of a choledochal cyst during laparoscopic repair allows near total excision.

During surgery for choledochal cyst (CC), any intrapancreatic CC (IPCC) must also be excised to prevent postoperative pancreatitis and stone formation. We report our technique for laparoscopic total IPCC excision (n = 16; mean age 6.0 years). We insert a fine ureteroscope with a light source into the opened CC through an extra 3.9-mm trocar placed in the epigastrium through a minute incision to identify the pancreatic duct orifice. By pulling the end of the ureteroscope emerging from the trocar gently to withdraw the tip from the pancreatic duct to where distal dissection was ceased under laparoscopic view, the IPCC can be measured. If longer than 5 mm, the distal CC is dissected further caudally until it is less than 5 mm. For accuracy, the distal CC is elevated with a suture that is exteriorized and clamped to provide constant traction. The IPCC was able to be measured in 11/16 (68 %). Initial lengths measured were 3-10 mm (5.2 ± 2.7 mm). Final IPCC were all 5 mm or less. Surgery was uncomplicated without any pancreatic duct injury and postoperative recovery was unremarkable. Follow-up MRI at 32 months showed no IPCC in any case. Measuring the IPCC enables total CC excision, thus reducing the potential for postoperative complications.

Overweight and high-sensitivity C-reactive protein are weakly associated with kidney stone formation in Japanese men.

OBJECTIVES: To investigate longitudinal relationships between obesity/inflammation and kidney stone formation in a population where obesity is not prevalent. METHODS: Using Cox regression models, associations between kidney stone formation and body mass index, waist circumference, high-sensitivity C-reactive protein and other possible risk factors were retrospectively examined in a health screening Japanese population including 1726 men and 992 women. RESULTS: During 4 years of follow up (mean 3.2 years), kidney stones were formed in 238 men (34.5 per 1000 person-years) and 82 women (20.7 per 1000 person-years). In men, when the possible risk factors were separately examined as continuous parameters, body mass index (P = 0.030) and waist circumference (P = 0.025) were significantly, and log C-reactive protein (P = 0.092) were marginally, associated with kidney stone formation. However, none of these parameters was independently associated with kidney stone formation after fully adjusted. In women, none of the aforementioned three parameters was associated with kidney stone formation. As a categorical parameter, the higher two quintiles of C-reactive protein were significantly associated with kidney stone formation compared with the lower two quintiles in men (P = 0.026). CONCLUSIONS: Overweight and C-reactive protein are weakly associated with kidney stone formation in Japanese men. Inflammation might be an underlying mechanism of the association between obesity and kidney stone formation.