PD04-06 SIGNIFICANT POST-PRANDIAL URINARY HYPEROXALURIA OBSERVED BY SPOT TESTING INDIVIDUAL URINARY VOIDS

Abstract

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology I (PD04)1 Apr 2020PD04-06 SIGNIFICANT POST-PRANDIAL URINARY HYPEROXALURIA OBSERVED BY SPOT TESTING INDIVIDUAL URINARY VOIDS William Donelan*, Pedro Espino-Grosso, Tina Esfandiary, Alexandria Voigt, Paul Dominguez-Gutierrez, Cuong Nguyen, and Benjamin Canales William Donelan*William Donelan* More articles by this author , Pedro Espino-GrossoPedro Espino-Grosso More articles by this author , Tina EsfandiaryTina Esfandiary More articles by this author , Alexandria VoigtAlexandria Voigt More articles by this author , Paul Dominguez-GutierrezPaul Dominguez-Gutierrez More articles by this author , Cuong NguyenCuong Nguyen More articles by this author , and Benjamin CanalesBenjamin Canales More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000824.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Urinary oxalate is a vital component of supersaturation profiles and a major driving force for crystallization. Although routinely assessed by metabolic testing, the 24-hour urine collection lacks the ability to measure spikes in urine oxalate concentration, particularly those that follow the consumption of a high oxalate-containing meal. To determine whether oxalate spikes are important for predicting stone risk, we measured oxalate concentration in each void over a 24-hour period in individuals who ingested a high oxalate-containing meal. METHODS: After IRB approval, healthy non-stone formers (6 F, 5 M) were prospectively enrolled to collect consecutively voided urine specimens over a 24-hour period. Participants were given a dietary log and instructed to consume food low in oxalate throughout the entire collection period. At noon on their collection day, participants were asked to consume a high-oxalate load (HOL) in the form of 100g spinach. Participants collected urinary voids in separate containers approximately every 3 hours during the day. Oxalate levels were evaluated on each specimen as well as the final combined 24-hour collection using the Trinity Biotech Oxalate Assay. RESULTS: The 24-hour average urinary oxalate concentrations measured approximately 0.45mM, which is at the normal high end for healthy individuals. We found that within the time period 2-8 hours post-HOL, 43.7% of the daily oxalate excretion occurred, and participants had hyperoxaluric voids that were significantly higher compared to baseline levels or the mean of the entire 24-hour period. CONCLUSIONS: The study demonstrates that significant post-prandial urinary hyperoxaluric spikes occur that are missed using the classical 24-hour urine test. This, together with hyperoxaluria as a potential etiopathological entity in a variety of disease processes, underscores the need for regular temporal-based monitoring of urinary oxalate levels. Source of Funding: This work was supported in part by the Urology Care Foundation Research Scholar Award Program and The Endourological Society; and by The National Institutes of Health Grant 5T32DK094789-05. © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e80-e80 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information William Donelan* More articles by this author Pedro Espino-Grosso More articles by this author Tina Esfandiary More articles by this author Alexandria Voigt More articles by this author Paul Dominguez-Gutierrez More articles by this author Cuong Nguyen More articles by this author Benjamin Canales More articles by this author Expand All Advertisement PDF downloadLoading ...