MP13-17 ASSOCIATION OF OBESITY WITH INCREASED ENDOGENOUS OXALATE SYNTHESIS

Abstract

You have accessJournal of UrologyStone Disease: Epidemiology & Evaluation I1 Apr 2018MP13-17 ASSOCIATION OF OBESITY WITH INCREASED ENDOGENOUS OXALATE SYNTHESIS Kyle Wood, John Knight, Dean Assimos, Barbara Gower, Ashwani Singal, Carter Boyd, and Ross Holmes Kyle WoodKyle Wood More articles by this author , John KnightJohn Knight More articles by this author , Dean AssimosDean Assimos More articles by this author , Barbara GowerBarbara Gower More articles by this author , Ashwani SingalAshwani Singal More articles by this author , Carter BoydCarter Boyd More articles by this author , and Ross HolmesRoss Holmes More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.489AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Urinary oxalate levels are affected by both dietary and endogenous components. Prior studies have demonstrated the positive correlation between weight/body mass index (BMI) and urinary oxalate excretion. Our objective was to determine if this association is secondary to increased endogenous oxalate synthesis. METHODS Healthy subjects, between 18 and 65 years old, with variable BMI were recruited and separated into lower BMI (<28) and higher BMI (>33) cohorts. Every subject had a normal serum comprehensive metabolic panel. Subjects consumed a low oxalate controlled diet containing 16% protein, 30% fat, 54% carbohydrate, 1000 mg calcium, and 30 mg oxalate which was devoid of vitamin C and calcium supplements. The extremely low oxalate diet dramatically limits the contribution of dietary oxalate to the urinary oxalate pool and thus allows an accurate estimation of urinary oxalate derived from endogenous oxalate synthesis. Subjects remained on this diet for 3 days. 24-hour urine collections were performed on the last two days. Urinary oxalate was measured by ion chromatography coupled with mass spectroscopy. Statistical analysis included Chi-squared, correlation and linear regression analysis, and student t-test. RESULTS There were 5 subjects in the higher BMI group (3 female and 2 male; mean age 41±15 years; mean BMI 36.7±4.2) and three in the lower BMI group (2 female, 1 male; age 40±7 years; mean BMI 24.7±2.7). Subjects in the higher BMI cohort had a significantly greater excretion of urinary oxalate (36±7 vs 23±5 mg/day, p=0.021) compared to the lower BMI cohort. Urinary oxalate excretion (mg/day) was positively correlated with waist circumference (r=0.94, p=0.0006), waist to hip ratio (r=0.75, p=0.03), and BMI (r=0.9, p=0.002). CONCLUSIONS These results demonstrate a positive correlation between urinary oxalate derived from endogenous oxalate synthesis and BMI as well as other measures of obesity. This also provides an explanation for the association between stone risk and obesity. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e177-e178 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Kyle Wood More articles by this author John Knight More articles by this author Dean Assimos More articles by this author Barbara Gower More articles by this author Ashwani Singal More articles by this author Carter Boyd More articles by this author Ross Holmes More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...