2054 EFFECT OF GLOMERULAR FILTRATION RATE ON 24-HOUR URINE ANALYSIS

Abstract

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20112054 EFFECT OF GLOMERULAR FILTRATION RATE ON 24-HOUR URINE ANALYSIS Adam Kadlec, Kristin Greco, Zach Fridirici, Daniel Gerber, and Thomas Turk Adam KadlecAdam Kadlec Maywood, IL More articles by this author , Kristin GrecoKristin Greco Maywood, IL More articles by this author , Zach FridiriciZach Fridirici Maywood, IL More articles by this author , Daniel GerberDaniel Gerber Hamilton, NY More articles by this author , and Thomas TurkThomas Turk Maywood, IL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2285AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We tested the hypothesis that 24-hour urine analyses collected from patients with low glomerular filtration rates (GFR <60) would differ from normal counterparts. METHODS We used the Modification of Diet in Renal Disease (MDRD) equation to calculate GFR in 146 patients who gave a 24-hour urine analysis after undergoing urologic surgery for kidney stones. Patients were grouped by GFR with a cutpoint of 60 ml/hr. A two-sample t-test was used to calculate p-values. RESULTS Patients with GFR <60 had less urinary calcium excretion and a lower urinary pH. They also excreted more oxalate and sodium. Other commonly measured parameters did not significantly differ between groups. Supersaturation indices (SSI) did not differ between groups. CONCLUSIONS The levels of clinically relevant urinary minerals vary depending on GFR. Patients with impaired GFR have lower urine pH than normal counterparts. Table 1. Urinary excretion of certain lithogenic minerals is dependent on GFR status GFR <60 GFR ≥60 p-value Calcium (mg/day) 149±108 213±167 0.033 Oxalate (mg/day) 40±20 33±15 0.022 Uric Acid (mg/day) 485±237 558±216 0.089 Citrate (mg/day) 433±352 511±343 0.242 Urine pH 5.79±0.63 6.13±0.59 0.005 Volume (L/day) 1.94±0.69 1.86±0.74 0.559 Sodium (meq/day) 194±86 157±75 0.013 Sulfate (mmol/day) 17±10 16±8 0.675 Phosphorus (mg/day) 960±405 889±331 0.298 Magnesium (mg/day) 84±42 100±115 0.430 Table 2. Supersaturation Indices (SSI) Did Not Differ Between Groups SSI GFR <60 GFR >60 p-value Calcium Oxalate 1.40±1.13 1.79±1.12 0.073 Brushite 1.86±5.44 1.73±1.36 0.825 Monosodium Urate 2.05±1.95 2.60±2.26 0.194 Struvite 0.30±0.56 2.93±5.95 0.142 Uric Acid 1.68±1.26 2.21±7.70 0.684 © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e822 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Adam Kadlec Maywood, IL More articles by this author Kristin Greco Maywood, IL More articles by this author Zach Fridirici Maywood, IL More articles by this author Daniel Gerber Hamilton, NY More articles by this author Thomas Turk Maywood, IL More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...