MP58-06 PREDICTORS OF PROGRESSIVE STONE DISEASE IN CALCIUM PHOSPHATE STONE FORMERS

Abstract

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology I1 Apr 2016MP58-06 PREDICTORS OF PROGRESSIVE STONE DISEASE IN CALCIUM PHOSPHATE STONE FORMERS Steeve Doizi, Margaret Pearle, John Poindexter, Beverley Huet, Khashayar Sakhaee, and Naim Maalouf Steeve DoiziSteeve Doizi More articles by this author , Margaret PearleMargaret Pearle More articles by this author , John PoindexterJohn Poindexter More articles by this author , Beverley HuetBeverley Huet More articles by this author , Khashayar SakhaeeKhashayar Sakhaee More articles by this author , and Naim MaaloufNaim Maalouf More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.804AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To assess the predictive factors of progressive stone disease in calcium phosphate (CaP) stone formers (SF). METHODS This retrospective single center study included patients with history of CaP stone containing at least 50% of hydroxyapatite or brushite who completed at least two 24 hour urine collections and had annual radiographic follow-up evaluation. Exclusion criteria were: presence of any struvite in stone composition, pregnant women, hyperparathyroidism, distal renal tubular acidosis, neurogenic bladder, eGFR<70mL/min, use of: diuretics, topiramate and calcium. CaP SF included were classified as non-progressors (NP) or progressors (P), defined by new stone formation (new stone of any size detected on imaging, or stone passage if patient was previously stone free) or enlargement of pre-existing stone(s) by at least 2mm in any axis between two identical imaging modalities (kidney-ureter-bladder + ultrasound or CT-scan). We compared 24-hr urinary biochemical parameters at different times: T1 was the first analysis before any medical intervention or dietary instructions, T2 was the first analysis after start of any therapy (diet alone, diet+potassium citrate, diet+potassium citrate+thiazide (hydrochlorothiazide or indapamide)), T3: last analysis available for patients without progression or urine chemistry at time of progression. Saturation (RSR, calculated by EQUIL2) and Supersaturation Index (SI, calculated by JESS) were calculated with respect to brushite (Br). RESULTS 40 patients were included, 19 P and 21 NP. The two groups were comparable for age, gender, BMI, number of previous stone events. Among the different parameters evaluated, total volume, urinary calcium in mg/day, RSR Br and SI Br adjusted by fixed urine volume (2 liters) were significantly higher in P than NP at T1 (Table). Following initial evaluation at T1, more P patients were started on thiazide diuretics. At T2, no biochemical difference between the groups was observed. At T3, pH, RSR Br and SI Br were significantly higher in P compared with NP. In multivariate analysis assessing baseline clinical and biochemical parameters, SI Br/2 liters was the single best predictor of progression with an area under the curve on ROC analysis of 0.78. CONCLUSIONS Brushite supersaturation appears to be the best predictor of progression in calcium phosphate stone formers. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e777-e778 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Steeve Doizi More articles by this author Margaret Pearle More articles by this author John Poindexter More articles by this author Beverley Huet More articles by this author Khashayar Sakhaee More articles by this author Naim Maalouf More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...