PURPOSE: To establish the most common stone composition, serum and urinary biochemical features of patients with gout and urolithiasis.
MATERIALS AND METHODS: We retrospectively searched for patients with gout diagnosis among those in our stone registry. A case-matched cohort of stone-formers was generated from our registry having the same age, gender and BMI. Primary end-points were baseline 24-hour urinary metabolic panels and stone composition. Medications were taken in consideration. Groups were compared using Student's t test and Chi-square/Fisher's exact test (significant if p< 0.05).
RESULTS: Stone panel evaluation: 181 patients met our inclusion criteria. There was no significant difference in 24-hour UA between non-gout and gout cohorts; hyperoxaluria was more common in gout patients (74 vs. 61%; p=0.009). Stone composition analysis: 393 patients were included. Gout cohort had lower amount of CaOMH (39.4 vs. 54.7%), CaODH (6.0 vs. 11.2%) and CaPh (9.6 vs. 14.1%; p< 0.001) and higher of UA (42.7 vs. 18.2%; p< 0.001). Pure UA stones were more common in gout patients (52.2 vs. 22.3%; p< 0.001); CaOMH (45.2 vs. 68.6%; p< 0.001), CaOHD (0.6 vs. 3.5%; p=0.017) and CaPh (1.6 vs. 4.9%; p=0.033) were more frequent in non-gout patients. Gout patients taking allopurinol had less pure UA (30.4 vs. 56.4%; p=0.001) and more CaOMH stones (69.6 vs. 40.7%; p< 0.001) than those without medications.
CONCLUSIONS: UA stones are the most common pure stone composition in patients with gout, but 48% will have non-UA stones. Allopurinol changes the distribution of stone composition in patients with gout, to a pattern similar to non-gout stone formers.
Written by:
Marchini GS, Sarkissian C, Tian D, Gebreselassie S, Monga M. Are you the author?
Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio.
Reference: J Urol. 2012 Sep 25. pii: S0022-5347(12)04999-3.
doi: 10.1016/j.juro.2012.09.102
PubMed Abstract
PMID: 23022002
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