Serum uric acid levels in psoriatic arthritis

It is widely accepted that hyperuricemia occurs frequently in patients with psoriasis and psoriatic arthritis. The evidence for this is conflicting, however. We have measured the serum urate level in 61 male patients with psoriatic arthritis (age: 43,97±SD 11.95 years; ponderal index: 40,50±SD 1.95 cm/kg(1/3)) and compared with two age, sex and ponderal index matched control groups: 64 patients with classical rheumatoid arthritis (age: 45.58±SD 13.57 years; ponderal index: 41.19±SD 1.88 cm/kg(1/3)) and 68 patients with ankylosing spondylitis (age: 36.29±SD 10.37 years; ponderal index: 41.19±SD 2.12 cm/kg(1/3)). Individuals were not included in the study if they had received medication(s) known to alter the serum urate level, if they had renal insufficiency (blood urea >50 mg/100ml) or if they were habitual drinkers (daily ingestion of wine exceeding 1 litre). The mean serum urate levels were as follows: psoriatic arthritis, 364.64±SD 93.99 μmol/l, rheumatoid arthritis, 337.28±SD 102.31 μmol/l, ankylosing spondylitis, 345.01±SD 93.39 μmol/l. Although the higher mean value was that of psoriatic arthritis, there was no significant difference between the groups. In the psoriatic patients there was no significant difference in serum urate level between those with axial and those with peripheral arthritis. We are not able, therefore, to support the view that, at least in male subjects, the mean serum urate level is significantly higher in patients with psoriatic arthritis than in those with rheumatoid arthritis or ankylosing spondylitis.