Latent overproductive hyperuricemia increases in patients during the intermittent phase of gouty arthritis under long-term antihyperuricemic treatment

Abstract

This work was undertaken to determine baseline urate metabolism in patients during the intermittent phase of gouty arthritis in order to decide on the best treatment for hyperuricemia. Parameters affecting serum urate levels, including uric acid clearance and urinary urate excretion, were re-evaluated in 30 patients who had shown normouricemia and no gouty attacks for at least 1 year and who were receiving urate-lowering drugs. The parameters determined at 2 weeks after discontinuation of the treatment (re-evaluation) were compared with those determined at initial diagnosis (initial evaluation). The discontinuation of urate-lowering drugs at re-evaluation led to a hyperuricemic state in all patients. The serum urate levels at re-evaluation were significantly higher than those at initial evaluation. The mean quantity of urinary urate excretion in patients showing increases in serum urate levels and the number of patients classified with overproductive hyperuricemia increased at re-evaluation. There was a significant increase in γ-glutamyl transpeptidase level, but no changes in body weight or creatinine and uric acid clearance. Asymptomatic patients at intermittent phases of gout may be in a latent, but progressing, hyperuricemic state as a result of urate overproduction. Physicians should assess latent hyperuricemia periodically, and choose a treatment with xanthine oxidase inhibitor when necessary.