Uric acid handling in autosomal dominant polycystic kidney disease with normal filtration rates

purpose: Patients with autosomal dominant polycystic kidney disease (ADPKD) are alleged to have more frequent or more pronounced alterations of uric acid homeostasis than are seen in most other types of chronic renal diseases. We performed this study to examine the hypothesis that individuals with ADPKD have abnormal uric acid homeostasis that is manifest before the development of renal insufficiency. patients and methods: We studied 301 subjects, 163 with ADPKD and 138 relatives without ADPKD (NADPKD), by ultrasonography. The subjects were interviewed and examined. Venous blood and two 24-hour urine collections were obtained for uric acid and creatinine determinations. results: Presence of hyperuricemia, serum uric acid levels, uric acid clearance, and fractional excretion of uric acid did not differ between ADPKD and NADPKD subjects with normal renal function (creatinine clearance greater than 80 mL/minute/1.73 m²). Clearance of uric acid decreased and fractional excretion increased in subjects with decreased renal function in both groups. Female gender enhanced renal excretion of uric acid in both groups and hypertension depressed it except in men with ADPKD, who had higher fractional excretions for uric acid than did hypertensive NADPKD men. conclusions: Uric acid homeostasis is preserved in individuals with ADPKD with normal renal function when compared to unaffected family members. Hyperuricemia and decreased renal excretion of uric acid develop as renal function worsens in ADPKD, similar to that in control subjects. The expected depressing effect of hypertension on renal handling of uric acid was not seen in men with ADPKD, speculatively due to an effect of atrial natriuretic factor.