Serum adipokines in patients with psoriatic arthritis and psoriasis alone and their correlation with disease activity.

OBJECTIVE: To compare the prevalence of metabolic syndrome (MetS) and the levels of related biomarkers in patients with psoriatic arthritis (PsA) and psoriasis without arthritis (PsC).

METHODS: This study compared patients with PsA and patients with PsC. The presence of MetS was determined. Serum levels of insulin, adiponectin and leptin were measured. The homeostasis model assessment for insulin resistance (HOMA-IR) was calculated. HOMA-IR, adiponectin and leptin were log-transformed. Continuous variables were compared using the t test and the χ(2) test was used for discrete variables. Multivariate regression models were used to investigate the association of MetS and adiponectin with PsA compared to PsC after adjusting for potential confounding variables.

RESULTS: 203 PsA and 155 PsC patients were analysed. The prevalence of MetS was higher in PsA patients compared to those with PsC. However, this did not reach statistical significance (36.5% vs 27.1%, p=0.056). The levels of adipokines were significantly higher in PsA compared to PsC: adiponectin (8.8±5.2 vs 7.4±4.5 log (µg/ml), p=0.009) and leptin in women (3.1±0.8 vs 2.8±0.8, log (ng/ml), p=0.04). HOMA-IR was also higher in PsA (0.97±0.63 vs 0.68±0.81, p<0.001). No difference was observed in leptin levels in men. In multivariate regression analysis, PsA (p=0.04) and the psoriasis area and severity index score (p=0.02) were associated with MetS. Adiponectin was significantly associated with PsA (p=0.005), the use of anti-tumour necrosis factor α therapy (p=0.03) and active joint count (p=0.001).

CONCLUSIONS: MetS and related adipokines correlated with an increased burden of skin and joint inflammation.