RESUMO
INTRODUCTION: Patients with psoriasis and psoriatic arthritis (PsA) have metabolic disturbances, which may be due to chronic inflammation. AIM: Because interleukin-6 (IL-6) regulates both metabolic and inflammatory processes, we evaluated IL-6 as a potential marker of inflammation and metabolic disturbances in psoriasis. MATERIAL AND METHODS: This study involved 93 patients with psoriasis, including 31 patients with concurrent PsA. We investigated whether serum markers of lipid metabolism and inflammation, including IL-6, were related to each other and to disease activity. RESULTS: We found that concurrent PsA was associated with higher serum concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and IL-6. In patients with psoriasis alone, the IL-6 serum concentration correlated positively with the concentrations of TC and LDL-c and with erythrocyte sedimentation rates (ESRs). Moreover, IL-6 concentrations tended to correlate positively with the percentage of the body area affected by psoriatic lesions. Among all patients, those with normal blood lipids had lower ESRs and IL-6 concentrations than patients with abnormal blood lipids. A logistic regression model showed that PsA, Psoriasis Area Severity Index (PASI), and ESR were significant predictors of the serum IL-6 concentration. CONCLUSIONS: Interleukin-6 may be an indicator of inflammatory activity in psoriasis. Moreover, IL-6 may be related to lipid abnormalities in patients with this disease.