In patients who form renal and ureteral stones, obesity is associated with a higher risk of stones composed of uric acid (UA) compared with other substances, according to report in the Korean Journal of Urology (2011;52:622-625).

In a study of renal and ureteral stones removed surgically from 490 patients, obese patients were nearly 3.5 times more likely to form UA stones than stones made of both calcium oxalate and calcium phosphate (COP) and 2,8 times more likely to form UA stones than calcium phosphate (CP) stones. Obese patients also were 2.7 times more likely to form calcium oxalate (CO) than COP stones and two times more likely to form CO than CP stones.