Fructose-induced hyperuricemia in psoriasis and psoriatic arthritis

Acute intravenous infusion of fructose was given to 30 normal subjects and 27 normo-uricemic patients affected by psoriasis, 12 with cutaneous involvement only and 15 with psoriatic arthritis. Serum uric acid was measured before and after infusion. A significantly lower increase in serum uric acid levels was found in psoriatic patients in comparison to controls, and the increase rate appeared to be significant only in controls. Moreover, the overall fructose-induced hyperuricemia was significantly lower in the group of patients with psoriatic arthritis than in normal subjects. Since the fructose-induced increase of serum uric acid is most probably achieved by an augmented turnover of preformed purine nucleotides, it is suggested that in normouricemic patients with psoriasis the "pool" of purine nucleotides is lower than normal. Such a condition seems to be more evident in psoriatic arthritis.