Does Disease Activity Influence the Levels of Uric Acid in Psoriatic Arthritis?

Abstract

Background: Hyperuricemia is not only associated with the development of gout but also with renal and vascular dysfunction. The prevalence of this condition has already been studied in psoriasis, but there are a few studies that have been carried out in psoriatic arthritis (PsA). Some studies have shown an association with metabolic syndrome, while others with the extent of cutaneous involvement, but there are no studies that have evaluated the disease activity with compound indexes. Objective: The aim of the study was to determine if disease activity, measured by different composite scores, influences the levels of uric acid. Method: This was a cross-sectional, observational study, which included 52 PsA patients. Clinical assessments included dactylitis, tender and swollen joint counts, Psoriasis Area and Severity Index, Leeds Enthesis Index, Minimal Disease Activity and Disease Activity for Psoriatic Arthritis. Hyperuricemia was defined as serum uric acid levels ≥ 6mg/dL in females and ≥ 7mg/dL in males. Results: Among the 52 included patients, 55.76% were female. The mean age was 54.9 ± 11.6 years. Hyperuricemia occurred in 26.92%. Demographic data, diet, comorbidities and medication were similar between patients with and without hyperuricemia. Patients with hyperuricemia had higher waist circumference (p <0.0046). There was no difference in disease activity between groups, either in the isolated items or in the composite indexes. There was a significant difference in uric acid levels according to the classification of chronic kidney disease by estimated glomerular filtration rate (p=0.0016). Individuals using leflunomide had significantly lower levels of uric acid than those who were not using (p=0.0071). Conclusion: This study supports the notion that, in PsA, hyperuricemia is more related to metabolic factors than to disease activity.