PURPOSE: To clarify whether the clinical profiles of patients with a history of urolithiasis ("stone formers") truly reflect those of patients who currently have renal stones ("stone carriers").
MATERIALS AND METHODS: 463 gout patients were investigated by helical computed tomography (CT), urolithiasis history, and relevant clinical parameters.
RESULTS: 1) Nephrolithiasis was observed in 157(34%) of the 463 on CT. However, only 75(16%) of the 463 had a urolithiasis history. 107(68%) of the 157 stone carriers did not have the urolithiasis history. 2) Serum urate(Sua) and serum creatinine (Scr) levels of the 157 was higher (p=0.017) and the estimated glomerular filtration rate (eGFR) and urinary pH of the 157 were lower than those of the 306 non-stone carriers (p=0.0096, p=0.0249, respectively). However, there were no significant differences in laboratory findings between 75 stone formers and 388 non-stone formers. 3) Sua and Scr were higher and eGFR and urine pH of bilateral stone carriers were lower than those of unilateral stone carriers.4)According to Houndfield units of densities in CT, a one-third of the calculi complicated in 31 recent gout patients was estimated as uric acid stone.
CONCLUSIONS: The concept of "stone formers" may lead to underestimating the prevalence of urolithiasis. Our analysis of "stone carriers" found that a higher stone burden is associated with greater renal derangement as determined by Sua, Scr, eGFR and urine pH. To accurately clarify the correlation of gout and urolithiasis, it is advantageous to select stone carriers as subjects of study.
Written by:
Shimizu T, Kitada H, Umeyama M, Hori H, Takasaki N. Are you the author?
Chief, Gout Clinic in Dept. of Rheumatology, Midorigaoka Hospital, 3-13-1 Makami-cho, Takatsuki-shi, Osaka 569-1121, JAPAN.
Reference: J Urol. 2012 Nov 15. pii: S0022-5347(12)05570-X.
doi: 10.1016/j.juro.2012.11.076
PubMed Abstract
PMID: 23159585
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