Hyperuricemia in psoriatic arthritis: prevalence and associated features.

We aimed to assess the prevalence of hyperuricemia in a cohort of patients with psoriatic arthritis (PsA) and to determine the influence of skin involvement on serum uric acid (SUA) levels. Patients followed at the University of Toronto Psoriatic Arthritis clinic from 1991-1997 were studied. Those who developed hyperuricemia (SUA >/= 450 mumol/L for males or >/=360 mumol/L for females) and the next 3 normouricemic PsA patients were studied. Skin involvement was assessed using the Psoriasis Area and Severity Index score. Of 265 patients, 55 (20.7%) had </=1 episode of hyperuricemia. There was no association between Psoriasis Area and Severity Index score and SUA. In multivariate analysis, the best predictors of hyperuricemia were elevated serum creatinine and elevated total cholesterol. One or both values were elevated in 70.9% of patients with hyperuricemia and 35.2% of controls (p </= 0.001. SUA in PsA is not associated with the extent of skin involvement but reflects metabolic changes, especially hypercholesterolemia and renal impairment.