Urinary Stone Risk Research Articles

Age, Body Mass Index, and Gender Predict 24-Hour Urine Parameters in Recurrent Idiopathic Calcium Oxalate Stone Formers.

Despite guidelines, routine 24-hour urine testing is completed in <10% of high-risk, recurrent stone formers. Using surrogates for metabolic testing, such as key patient characteristics, could obviate the cost and burden of this test while providing information needed for proper stone prevention counseling. We performed a retrospective study of 392 consecutive patients from 2007 to 2014 with ≥2 lifetime stone episodes, >70% calcium oxalate by mineral analysis, and ≥1 24-hour urine collection. We compared mean 24-hour urine values by age in decades. We used logistic regression and receiver operating characteristic (ROC) curve analysis to assess the predictive ability of age, gender, body mass index (BMI), and comorbidities to detect abnormal 24-hour urine parameters. The mean age of the cohort was 51 ± 16 years. Older age was associated with greater urinary oxalate (p-trend <0.001), lower urinary uric acid (UA) (p-trend = 0.007), and lower urinary pH (p-trend <0.001). A nonlinear association was noted between age and urinary calcium or citrate (calcium peaked at 40-49 years, p = 0.03; citrate nadired at 18-29 years, p = 0.001). ROC analysis of age, gender, and BMI to predict 24-hour urine abnormalities performed the best for hyperuricosuria (area under the curve [AUC] 0.816), hyperoxaluria (AUC 0.737), and hypocitraturia (AUC 0.740). Including diabetes mellitus or hypertension did not improve AUC significantly. In our recurrent calcium oxalate cohort, age significantly impacted urinary calcium, oxalate, citrate, and pH. Along with gender and BMI, age can be used to predict key 24-hour urine stone risk results. These data lay the foundation for a risk prediction tool, which could be a surrogate for 24-hour urine results in recurrent stone formers, who are unwilling or unable to complete metabolic testing. Further validation of these findings is needed in other stone populations.

Reference intervals for stone risk factors in 24-h urine among healthy adults of the Han population in China.

The aim of the study was to establish reference intervals for 24-h urinary stone risk factors in the healthy Chinese Han population. From May 2013 to July 2014, we collected and analyzed 24-h urine samples from healthy adult Han population during a cross-sectional study across China. The protocol for analysis of 24-h urine included volume, pH, oxalate, citrate, sodium, potassium, chloride, calcium, phosphorous, creatinine, urate, magnesium, the ion activity products of calcium oxalate (AP(CaOx) indexs) and calcium phosphate (AP(CaP) indexs). We calculated the reference intervals according to the Clinical and Laboratory Standards Institute (CLSI) 2008 guidelines and compared them with those recorded in other studies. A total of 132 male and 123 female healthy subjects with a mean (SD, range) age of 52.4 (15.2, 19-89) years were eligible in the final analysis. Men had higher 24-h excretion of creatinine, calcium, urate and phosphorus and lower levels of citrate, magnesium, chloride, sodium and potassium than women. AP(CaOx) indexs and AP(CaP) indexs were significantly higher among men than women. When urinary findings were compared with the reference intervals, most of our data showed a high abnormality rate, especially for creatinine, calcium, citrate, magnesium, chloride, sodium and potassium. The present study revealed the normal metabolic status for stone risk factors of the Chinese Han population. It is therefore necessary for each country or region to define their own reference intervals for comparison of stone risk factors between patients and healthy subjects.

Association of urinary citrate excretion, pH, and net gastrointestinal alkali absorption with diet, diuretic use, and blood glucose concentration.

Urinary citrate (Ucit) protects against urinary stone formation. Acid base status and diet influence Ucit. However, the effect of demographics, diet, and glucose metabolism on Ucit excretion, urinary pH (U‐pH) and net gastrointestinal alkali absorption (NAA) are not known. Twenty‐four hour urine samples, blood glucose, creatinine, and cystatin C were obtained from non‐Hispanic white sibships in Rochester, MN (n = 446; 64.5 ± 9 years; 58% female). Diet was assessed by a food frequency questionnaire. The impact of blood glucose, demographics and dietary elements on Ucit excretion, U‐pH, and NAA were evaluated in bivariate and multivariable models and interaction models that included age, sex, and weight. NAA significantly associated with Ucit and U‐pH. In multivariate models Ucit increased with age, weight, eGFRC ys, and blood glucose, but decreased with loop diuretic and thiazide use. U‐pH decreased with serum creatinine, blood glucose, and dietary protein but increased with dietary potassium. NAA was higher in males and increased with age, weight, eGFRC ys and dietary potassium. Significant interactions were observed for Ucit excretion with age and blood glucose, weight and eGFRC ys, and sex and thiazide use. Blood glucose had a significant and independent effect on U‐pH and also Ucit. This study provides the first evidence that blood glucose could influence urinary stone risk independent of urinary pH, potentially providing new insight into the association of obesity and urinary stone disease.

The variation in urinary calcium levels in adult patients with fracture and surgical intervention

BackgroundGenerally, a higher calcium diet is fed to fracture patients after surgery. However, recent studies have indicated that higher dietary calcium intakes increase the risk of urinary stones for fracture patients. Therefore, this study aimed to observe the variation in urinary calcium levels among fracture patients who underwent surgery, based on fracture type, fracture location, age and gender.MethodsA total of 768 subjects were enrolled in this study from 2012 to 2015 and were divided into 2 groups: group A (fracture patients who underwent surgery) and group B (normal patients without fracture). Urine samples were collected for a 24-h period (24-h urine), at multiple specific time points before and after surgery for group A, or after hospitalisation for group B. Subsequently, urine calcium was detected and the changes were evaluated according to fracture location, fracture type, age and gender, as well as the distribution of hypercalciuria.ResultsCompared with group B, the level of urine calcium in group A significantly increased at different time points during the study period (P < 0.05). There were significant differences in the changes in urine calcium levels according to fracture location, fracture type and age, but not gender. Further, there were more patients with hypercalciuria in group A at the different time points, compared with group B.ConclusionVariation in urinary calcium among fracture patients that underwent surgery was of a regular pattern and hypercalciuria was also found in these patients. Therefore, a high-calcium diet and calcium supplements should be used with caution in this patient population.

Different effects of γ-linolenic acid (GLA) supplementation on plasma and red blood cell phospholipid fatty acid composition and calcium oxalate kidney stone risk factors in healthy subjects from two race groups with different risk profiles pose questions about the GLA-arachidonic acid-oxaluria metabolic pathway: pilot study.

Fatty acid (FA) composition of phospholipids in plasma and red blood cells (RBC) can influence calciuria, oxaluria and renal stone formation. In this regard, the ratio of arachidonic acid (AA) and its precursor linoleic acid (LA) appears to be important. Administration of γ-linolenic acid (GLA) has been shown to increase the concentration of dihomo-gamma linoleic acid (DGLA) relative to AA indicating that it may attenuate biosynthesis of the latter. Such effects have not been investigated in race groups having difference stone occurrence rates. Black (B) and white (W) healthy males ingested capsules containing linoleic acid (LA) and GLA, for 30days. Plasma and RBC total phospholipid (TPL) FA profiles, serum and 24h urine biomarkers of hypercalciuria and urinary stone risk factors were determined on days 0 and 30. Data were tested for statistical significance using GraphPadInstat version 3.02. Concentration and percentage content of DGLA in plasma TPL increased in W but not in B. Arachidonic acid (AA) did not change in either group. There was no change in calcium excretion in either group but oxalate and citrate excretion increased in W. We suggest that elongation of GLA to DGLA may occur more rapidly than desaturation of DGLA to AA in W and that depressed activity of the enzyme elongase may occur in B. Calciuric and citraturic effects may be dependent on the quantity of LA or on the mass ratio of LA/GLA in the FA supplement. Questions about the mooted DGLA-AA-oxaluria pathway arise. We speculate that there exists a potential for using GLA as a conservative treatment for hypocitraturia. The observation of different responses in B and W indicates that such differences may play a role in stone formation and prevention.

Urinary metals in a spontaneous canine model of calcium oxalate urolithiasis.

Calcium oxalate urolithiasis is a common and painful condition in people. The pathogenesis of this disease is complex and poorly understood. Laboratory animal and in vitro studies have demonstrated an effect of multiple trace metals in the crystallization process, and studies in humans have reported relationships between urinary metal concentrations and stone risk. Dogs are a spontaneous model of calcium oxalate urolithiasis, and the metal content of canine calcium oxalate stones mirrors that of human stones. The aim of this study was to test for a relationship between urinary metals and calcium oxalate urolithiasis in dogs. We hypothesized that urinary metals would differ between dogs with and without calcium oxalate urolithiasis. Urine from 122 dogs (71 cases and 51 stone-free controls) was analyzed for calcium and 12 other metals. The cases had higher urinary calcium, copper, iron, and vanadium and lower urinary cobalt. Higher urinary vanadium in the cases was associated with being fed a therapeutic stone-prevention diet. Urinary calcium had a strong positive correlation with strontium and moderate positive correlations with chromium, nickel, and zinc. The results of this study complement the findings of similar human studies and suggest a potential role of trace metals in calcium oxalate urolithiasis. Further investigation into how trace metals may affect stone formation is warranted.

Probiotics for prevention of urinary stones.

Urinary supersaturation is one key determinant of calcium oxalate (CaOx) urinary stone formation, and urinary excretions of oxalate and citrate are two key determinants. Each is influenced by gastrointestinal processes. Open label and randomized placebo studies have examined the effect of oral probiotic preparations on urinary supersaturation and oxalate excretion. Cross sectional studies in humans have studied the association of Oxalobacter formigenes colonization status and urinary oxalate excretion and prevalence of urinary stones. The intestinal microbiome of representative animals adapted to a high oxalate diet has been defined. The fecal content of O. formigenes, the best studied oxalate-degrader, varies depending on stone status. However, trials with probiotics designed to degrade oxalate including those containing O. formigenes, Lactobacillus, and/or Bifidobacterium spp., have been disappointing. Multiple intestinal segments of animals on a high oxalate diet contains diverse communities of microorganisms that can function together to degrade and detoxify a large oxalate load. Although the intestinal microbiome seems likely to play a role to modify gastrointestinal absorption of lithogenic substances and hence urinary stone risk, whether we can develop tools to manipulate it and decrease this kidney stone risk remains to be determined.

Urinary tract stone development in patients with myelodysplasia subjected to augmentation cystoplasty.

Patients with myelodysplasia who have undergone augmentation cystoplasty are at risk for urinary tract stones. We sought to determine the incidence and risk factors for stone development in this population. The charts of 40 patients with myelodysplasia who have undergone augmentation cystoplasty were reviewed. None had a prior history of urinary tract stones. All patients were seen on an annual basis with plain abdominal imaging, renal ultrasonography, and laboratory testing. Statistical analysis included a multivariable bootstrap resampling method and Student's t-test. Fifteen (37.5%) patients developed stones, 14 with bladder stones and 1 with a solitary renal stone, at a mean of 26.9 months after augmentation. Five (33.3%) developed recurrent bladder stones. The patient with a renal stone never developed a bladder stone. The mean follow-up for the stone formers was 117.2 months and for non-stone formers was 89.9 months. The stone incidence per year was 6.8%. Risk factors included a decline in serum chloride after augmentation (P = .02), female sex, younger age at time of augmentation, longer time period since augmentation, and bowel continence. A significant proportion of patients with myelodysplasia subjected to augmentation cystoplasty develop urinary tract stones, predominantly in the bladder. Dehydration may play a role in development of lower urinary tract stones as the decline in serum chloride suggests contraction alkalosis, which could lead to constipation and improved bowel continence. Therefore, improved hydration should be a goal in this cohort.

Evaluation of nutritional characteristics of commercial canned cat diets

To evaluate commercial complete canned cat foods according to their composition, labeling and nutritional characteristics. A total of 21 commercial complete canned compound feeds for adult cats were analyzed for crude nutrients, minerals, vitamins, selected amino acids and taurine. The analyzed parameters were compared to the internal set of standards of the European Pet Food Industry Federation (FEDIAF). The energy content was calculated and compared with the labeled recommendations regarding the amounts of diet that should be fed. Analyzed nutrients were compared with the labeled nutrients according to the regulations of the EU food and feed law (directive EU regulation 767/2009). In many cases, the labeled feeding protocols did not match the calculated daily energy requirements. In eight complete foods, the recommended daily feed amounts were underestimated and four recommendations exceeded energy requirements of adult cats. In 12 complete foods, the calcium and phosphorus contents were threefold higher than the respective requirement. In 16 of 21 complete foods, substantial discrepancies were observed between the recommendations and the analyzed trace elements. In particular, selenium contents exceeded the selenium requirement more than threefold. The vitamin, arginine and taurine contents showed no significant discrepancies to the recommendations. With respect to the labeled nutrients, there were only minor deviations from the regulations of the European law. In general, healthy adult cats are adequately supplied with energy and nutrients when feeding commercial canned complete diets for cats. In cases of body weight loss or gain, the labelled feed amounts should be questioned. The high phosphorus contents are an issue of concern, because a high phosphorus intake can potentially increase the risk for urinary stones and particularly for older cats the risk for renal insufficiency. Furthermore, it is recommended to decrease the high selenium levels by the reduction of selenium-rich feed materials such as offal.

Water and other fluids in nephrolithiasis: State of the art and future challenges

ABSTRACT Adequate hydration, as to maintain urinary volume over 2 L/day, has long been considered as the cornerstone medical prescription for preventing nephrolithiasis. However, scientific evidence about what kind of water stone formers should drink and about the effects of other beverages on urinary stone risk factors is sometimes unclear. Moreover, the recommendation that water therapy prevents kidney stone recurrence relies on only one randomized controlled trial, even if more epidemiologic and basic science studies seem to support this assumption. Therefore, in this review we analyze current evidence that support water therapy in nephrolithiasis and we highlight the possible effects of different types of water and other beverages on lithogenic risk, giving some practical recommendations for what stone formers should be advised to prevent recurrence.

Systemic endothelial function measured by flow-mediated dilation is impaired in patients with urolithiasis.

Some in vitro and animal studies have shown endothelial dysfunction in hyperoxaluria models indicating its role in pathogenesis of urolithiasis and relation to CVD. The aim of this study was to investigate endothelial function in patients with urolithiasis in relation to urinary stone risk factors and metabolic parameters. A total of 120 subjects without any known CVD (60 with urolithiasis and 60 healthy subjects) were included into study. Fasting blood and 24-h urine samples were collected to study metabolic parameters (glucose and lipids) and urine stone risk factors (oxalate, citrate, uric acid, and calcium, pH). Endothelial function was assessed as flow-mediated dilation (FMD) at the brachial artery. Age, sex, and body mass index were similar in patients and controls. Of urine stone risk factors, oxalate and citrate were higher in patients than controls. Fasting blood glucose, total LDL cholesterol, and triglyceride were higher, and HDL cholesterol was lower in patients than controls. Although within normal limits systolic blood pressure was higher in patient group, patients with urolithiasis had a lower %FMD than controls. Percent FMD was negatively correlated with urinary oxalate/creatinine ratio (p=0.019, r=-0.315), calcium/creatinine ratio (p=0.0001, r=-0.505) age (p<0.001, r=-0.694), BMI (p<0.001, r=-0.838), total cholesterol (p<0.001, r=-0.559), and triglyceride (p<0.001, r=-0.529). Urine oxalate/creatinine ratio was positively correlated with age (p=0.01, r=0.327) and calcium/creatinine ratio with BMI (p=0.001, r=0.410). This is the first study demonstrating endothelial dysfunction in human subjects with urolithiasis. This indicates a possible predictive role of urolithiasis in future development of cardiovascular diseases.

Patients Attending Shared Medical Appointments for Metabolic Stone Prevention Have Decreased Stone Risk Factors.

Shared medical appointments (SMAs) have decreased patients' wait time to initial stone clinic appointment, standardized education, and increased exposure to nutrition therapy. We assessed the effectiveness of SMAs in reducing patients' urinary stone risk factors. Patients who established care in our stone clinic in an SMA between March 2012 and August 2015 were sequentially identified. After eliminating those without follow-up urine collections or whose urinary creatinine excretion between the two collections varied by >40%, 113 patients were included (M:F 63:50; 54 ± 15 years; body mass index [BMI] 30.6 ± 6.7). Results from before and after the SMA were compared with those from a similar cohort of patients who attended individual patient appointments (IPAs) for their first stone clinic visit (n = 63; M:F 37:26; 54 ± 14 years; BMI 30.1 ± 8.2). All patients received individualized medical therapy for stone prevention. After medical and nutritional therapy, SMA patients with elevated risk(s) at baseline achieved significant reductions in uric acid, calcium, and sodium; p ≤ 0.001 for all. Those with low urine magnesium, low urine volume, low urine pH, and/or low urine citrate at baseline achieved increases; p ≤ 0.0008 for all. IPA patients with elevated baseline risk factors achieved reductions in oxalate and uric acid (p ≤ 0.004 for both) but neither calcium nor sodium and an increase in citrate (p = 0.003) but not magnesium. Patients from SMAs reduced their stone recurrence risk and compared favorably with patients from IPAs. Contributing factors may include shorter time from stone event to appointment and more standardized education for patients attending SMAs.

Kinetics of calcium oxalate crystal formation in urine.

It is routinely observed that persons with increased urinary stone risk factors do not necessarily form uroliths. Furthermore, stone formers can present with urinalyses that do not reflect the clinical picture. We explain this discrepancy by differences in crystallization kinetics. In 1162 urines, crystallization of Ca-oxalate was induced according to the BONN-Risk-Index (BRI) method. The urine's relative light transmissivity (RLT) was recorded from 100% at start of titration to 95% due to nuclei formation and crystal growth. From the RLT changes, a measure of the thermodynamic inhibition threshold of crystal formation (BRI) and of crystal growth kinetics is derived ("turbidity slope" after crystallization onset). On average, subjects presenting with a low inhibition threshold, i.e., high BRI, also present significantly higher crystal growth rates compared with subjects in lower BRI classes. Only subjects in the highest BRI class show a lower growth rate than expected, probably due to a depletion of supersaturation by massive initial nucleation. With increasing thermodynamic risk of crystal formation (i.e., increasing BRI) due to an imbalance between inhibitors and promoters of crystal formation, an increase in the imbalance between inhibitors and promoters of crystal growth (i.e., increasing growth rate) is observed. Both lead to an increased urolith formation risk. Healthy subjects with increased BRI are an exception to this trend: their urine is thermodynamically prone to form stones, but they show a kinetic inhibition preventing nuclei from significant growth.

The kidney stone and increased water intake trial in steel workers: results from a pilot study

Preventing dehydration in subjects at risk may provide a means of primary prevention of kidney stones. The purpose of this pilot study was to assess the hydration status of an at-risk group of steel plant workers based on end-of-shift ('post-shift') spot urine osmolality and 24-h urinary stone risk parameters. 100 volunteers were recruited from Gerdau Midlothian steel mill in Texas on 11/14/14 and 12/5/14. Clinical data were recorded and post-shift spot urine sample was used to measure urine osmolality. Participants were invited to submit a 24-h urine sample within 4weeks of enrollment. The mean age was 41years and 95% were men. The majority of subjects were white (75%), followed by 10% Hispanic and 9% black. The mean body mass index was 30.1kg/m2 and overall 16% had a past history of stone disease. Mean post-shift urine spot osmolality was 704.5mOsm (169-1165mOsm) and was >800 and >700mOsm in 39 and 57%, respectively. Among 59 24-h urines samples, the mean volume was 1.89±0.92l/day, with 56%<2L and 17%<1L. Elevated levels of urinary analytes were found in 29% of subjects for calcium (>250mg/TV), 39% for uric acid (>700mg/TV), 25% for oxalate (>45mg/TV) and 50% for sodium (>200meq/TV). The prevalence of stone disease in this population of steel workers was higher than the published prevalence of stone disease in the general population. A significant number of workers had concentrated post-shift and 24-h urines and elevated levels of urinary analytes.

URINARY STONE RISK PROFILE IN STONE FORMER PATIENT

Objective: We were comparing the urinary stone risk profiles in stone former subjects group with normal population (non stone-former) group. Material &amp; method: In this study, each group consist of 10 subjects. Urine samples used was a 24-hour-urine. All subjects in this study were previously informed and voluntarily participating. Inclusion criteria in this study were adult, stone free, residing in Jakarta. Measurement was performed in Department of Molecular Biology and Biochemistry Faculty of Medicine Indonesia University. Statistical analysis was performed using SPSS 20 (Chicago, USA) with Student’s t-test or Mann-Whitney (p &lt; 0.05 was considered significant). Results: There was a significant difference in the mean age of two groups with no significant difference in weight and height. Significant difference (p &lt; 0.05) in urinary profile was found in urea, uric acid, chloride, potassium, phosphate, and ammonia. Conversely, we found no significant differences (p &gt; 0.05) in sodium, creatinine, calcium, magnesium, oxalate, and citrate levels. Conclusion: There were no significant differences in urinary stone promoting and inhibiting factors between two groups. Bigger number of sample size with better sampling method must be conducted for future studies.

Dietary treatment of urinary risk factors for renal stone formation. A review of CLU Working Group.

Dietary treatment of urinary risk factors for renal stone formation. A review of CLU Working Group.

Clinical and demographic factors associated with compliance and subsequent urinary metabolic changes in first-time ureteral stone formers

Dietary and lifestyle modifications are widely prescribed to prevent recurrence of urolithiasis, although little is known about the clinical and demographic factors associated with patient compliance and urinary metabolic changes. The present study assessed the clinical and demographic factors influencing compliance with a modified diet and lifestyle in first-time ureteric stone formers as well as determined the effects of compliance on urinary stone risk factors. We retrospectively reviewed the medical records of 53 patients presenting with ureteric calcium stones. Using a self-completed questionnaire, patients were classified according to compliance with seven recommendations for modifying diet and lifestyle into good compliance group (complied with ≥ three recommendations) and poor compliance group. Before (on a random diet) and after prescribing the modifications, 24 hour urine samples were collected from those in the good and poor compliance group. The stone size at presentation and initial treatment modality were closely associated with patient compliance (P=0.019, P=0.027, respectively). Citrate excretion significantly increased in the good compliance group after adopting modifications (P=0.012), whereas the poor compliance group did not show a statistically significant difference. Moreover, patients in the poor compliance group showed significantly increased urinary calcium excretion by the end of the study (P=0.040). After adjustments for age, sex, body mass index, and metabolic abnormality status, poor compliance was found to be an independent risk factor for persistence or development of hypocitraturia (OR: 3.885; 95% CI: 1.102~13.694; P=0.035). In conclusion, our results imply that patient education programs regarding diet and lifestyle should be tailored to the individual’s clinical and demographic characteristics.

MP34-04 INHIBITION OF GLYCOLATE OXIDASE REDUCES URINARY OXALATE EXCRETION IN A MOUSE MODEL OF PRIMARY HYPEROXALURIA TYPE 1

INTRODUCTION AND OBJECTIVES: Cumulative evidences indicate a tight association between urinary stone and dyslipidemia. Statins are widely used in clinical treatment of dyslipidemia. It is interesting and also important to know whether statin use can reduce the risk of upper urinary tract stone in patients with dyslipidemia. METHODS: We used data sourced from Longitudinal Health Insurance Database, which consists of one million randomly selected subjects from the National Health Insurance Research Database of Taiwan. Health Insurance System of Taiwan covers approximately 23 million people (98% of population). From 1997 to 2001, a total of 11785 subjects, 5926 males and 5859 females, with age 18-year-old or older were identified as dyslipidemia. All subjects did not have previous diagnosis of urinary stone. A cohort of 23570 (2 for each subject with dyslipidemia) age and gender matched subjects without the diagnosis of dyslipidemia and urinary stone were enrolled as the control group. All subjects were followed up to the end of 2009 with a minimal follow-up of 8 years. Multi-variables, including statin use, hypertension, and diabetes mellitus (DM), were taken into account. A Cox proportional hazard regression model was used to calculate the risk of upper urinary tract stone in study and control groups. RESULTS: At the end of follow-up, 1817 (15.4%) of the 11785 dyslipidemia subjects and 2445 (10.4%) of the 23570 control subjects developed upper urinary tract stones. After adjusting for age, gender, hypertension and DM, dyslipidemia was associated with a significantly increased risk of urinary stone (hazard ratio 2.086, 95% confidence interval, 1.929 2.256, p< 0.0001). The dyslipidemia subjects were further stratified into statin user group and non-statin user group. Nine hundred and sixty eight (15.1%) of the 6401 statin users and 849 (15.8%) of the 5384non-statin users developedupper urinary tract stones.Dyslipidemia patients who received statin treatment were not less likely to develop upper urinary tract stone than the patients who never used statin (hazard ratio 1.074, 95% confidence interval, 0.976 1.181, p 1⁄4 0.1430). CONCLUSIONS: Dyslipidemia is an independent risk factor for upper urinary tract stone. The findings of this study suggest that the use of statin cannot reduce the risk of upper urinary tract stone in patients with dyslipidemia.

MP34-03 CAN STATIN USE REDUCE THE RISK OF UPPER URINARY TRACT STONE IN PATIENTS WITH DYSLIPIDEMIA? A NATION-WIDE POPULATION-BASED AND WITH AN 8-YEAR FOLLOW-UP STUDY

INTRODUCTION AND OBJECTIVES: Cumulative evidences indicate a tight association between urinary stone and dyslipidemia. Statins are widely used in clinical treatment of dyslipidemia. It is interesting and also important to know whether statin use can reduce the risk of upper urinary tract stone in patients with dyslipidemia. METHODS: We used data sourced from Longitudinal Health Insurance Database, which consists of one million randomly selected subjects from the National Health Insurance Research Database of Taiwan. Health Insurance System of Taiwan covers approximately 23 million people (98% of population). From 1997 to 2001, a total of 11785 subjects, 5926 males and 5859 females, with age 18-year-old or older were identified as dyslipidemia. All subjects did not have previous diagnosis of urinary stone. A cohort of 23570 (2 for each subject with dyslipidemia) age and gender matched subjects without the diagnosis of dyslipidemia and urinary stone were enrolled as the control group. All subjects were followed up to the end of 2009 with a minimal follow-up of 8 years. Multi-variables, including statin use, hypertension, and diabetes mellitus (DM), were taken into account. A Cox proportional hazard regression model was used to calculate the risk of upper urinary tract stone in study and control groups. RESULTS: At the end of follow-up, 1817 (15.4%) of the 11785 dyslipidemia subjects and 2445 (10.4%) of the 23570 control subjects developed upper urinary tract stones. After adjusting for age, gender, hypertension and DM, dyslipidemia was associated with a significantly increased risk of urinary stone (hazard ratio 2.086, 95% confidence interval, 1.929 2.256, p< 0.0001). The dyslipidemia subjects were further stratified into statin user group and non-statin user group. Nine hundred and sixty eight (15.1%) of the 6401 statin users and 849 (15.8%) of the 5384non-statin users developedupper urinary tract stones.Dyslipidemia patients who received statin treatment were not less likely to develop upper urinary tract stone than the patients who never used statin (hazard ratio 1.074, 95% confidence interval, 0.976 1.181, p 1⁄4 0.1430). CONCLUSIONS: Dyslipidemia is an independent risk factor for upper urinary tract stone. The findings of this study suggest that the use of statin cannot reduce the risk of upper urinary tract stone in patients with dyslipidemia.

MP80-17 DO 24-HOUR URINE SUPERSATURATIONS PREDICT STONE COMPOSITION?

You have accessJournal of UrologyStone Disease: Evaluation II1 Apr 2015MP80-17 DO 24-HOUR URINE SUPERSATURATIONS PREDICT STONE COMPOSITION? Mohamed Omar, Alaa El Mahdy, Ahmed Gamal, and Manoj Monga Mohamed OmarMohamed Omar More articles by this author , Alaa El MahdyAlaa El Mahdy More articles by this author , Ahmed GamalAhmed Gamal More articles by this author , and Manoj MongaManoj Monga More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2853AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To evaluate the correlation between 24 hour urine supersaturation levels and the crystalline stone composition. METHODS We retrospectively reviewed the results of stone analysis of 386 patients who had completed 24 hour urine stone risk profiles within 6 months of stone analysis. Patients were characterized as calcium oxalate, calcium phosphate or Uric acid stone formers based on the predominant component (>60%) of their stone. Patients with <50% of one stone composition were characterized as a mixed stone former. Sensitivity, specificity and accuracy of the 24-hour urine supersaturation for predicting the corresponding stone component were calculated. RESULTS The distribution of stone compositions was 235(61%) CAOX, 98(25%) CAPH, 35(9%) Uric acid and 18(5%) mixed stone group. The accuracy of supersaturation for predicting the predominant stone composition was 52.5% for CAOX, 70% for CAPH and 67% for Uric acid group. Even when the predominant stone composition exceeded 90%, the accuracy of supersaturation didn't change remarkably, coax (49 %, p=0.6641), cap (77%, p= 0.361) and uric acid (67%, p=0.9593) CONCLUSIONS 24-hour urine supersaturation has a poor accuracy to predict the predominant stone composition. Accuracy is highest for patients with calcium phosphate stone compositions. Bivariate comparison of 24-hour urine elements across stone type groups Demographics CaOx CaP Uric A Mixed P Value No. of patients (%) 235 (61%) 98 (25%) 35 (9%) 18 (5%) 386 Gender: Male 151 (64%) 31 (32%) 24 (69%) 10 (56%) <.0001 Gender: Female 84 (36%) 67 (68%) 11 (31%) 8 (44%) <.0001 Mean age 56±15 54±17 60±10 50±14 0.390 BMI 29±7.5 29.3±9.3 31.2±6.4 30.5±7.4 0.3781 pH 5.9±0.4 6.4±0.6 5.8±0.6 6.4±0.6 <.0001 Urine volume 2±0.9 2.1±1 1.9±0.8 1.9±1 0.6195 CaOx SS 6.74±3.6 6.6±3.7 5.9±3.7 5.6±3.2 0.3202 CaP SS 1±0.96 1.6±1.2 0.7±1.1 1.5±1.2 <.0001 Uric Acid SS 1±0.87 0.46±0.5 1.4±1 0.5±0.87 <.0001 Accuracy of supersaturation at different cut-off values of predominant stone composition Mineral Calcium oxalate Calcium phosphate Uric Acid >60% 52.5% 70% 67% >70% 54% 72% 67% >80% 54% 76% 67% >90% 49% 77% 67% © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e1025-e1026 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mohamed Omar More articles by this author Alaa El Mahdy More articles by this author Ahmed Gamal More articles by this author Manoj Monga More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...