Uric acid homeostasis in lean and obese girls during pubertal development

Serum uric acid concentration and fractional excretion were evaluated in lean (n = 67) and obese (n = 56) girls before and during pubertal development. In both lean and obese girls, uricemia gradually increased as puberty advanced. Obese girls were hyperuricemic compared with lean controls (prepubertal: 184 +/- 83 v 130 +/- 29 mumol/L, P = .007; Tanner stage II-III: 190 +/- 53 v 178 +/- 47 mumol/L, NS; Tanner stage IV-V: 232 +/- 53 v 191 +/- 53 mumol/L, P = .02). Fractional excretion of urate decreased with puberty in lean girls (6.46% +/- 2.29%, 4.61% +/- 2.48%, and 3.54% +/- 1.84%), but not in obese subjects (3.74% +/- 2.27%, 4.01% +/- 1.90%, and 4.26% +/- 2.26%). Urate homeostasis was similar in prepubertal obese girls and in adolescent lean controls. We conclude that an increased serum urate concentration occurring at puberty may be due to decreased renal clearance of urate in lean girls, and at least in part to urate overproduction in obese subjects. Obesity may prematurely evoke changes in urate metabolism usually observed at puberty.