Background Several studies have shown increased prevalence of obesity in patients with psoriasis.
Objectives To characterize both inflammatory- and oxidative stress-related differences between obese patients with psoriasis (OPP) and normal-weight patients with psoriasis (NWPP).
Methods The plasma concentrations of adiponectin and interleukin (IL)-6 were analysed by quantitative sandwich enzyme immunoassay technique in 10 patients with a body mass index (BMI) < 25 and 12 patients with a BMI > 30. Total glutathione and oxidized glutathione levels were measured spectrophotometrically.
Results Plasma concentration of adiponectin in NWPP was more than twice the level in healthy normal-weight controls (P < 0·001), while such an elevation did not occur in OPP. OPP were characterized by a significantly increased IL-6 level, which correlated negatively with the adiponectin level (r = −0·85, P < 0·001). The glutathione redox status, which was also inversely correlated with the adiponectin level (r = −0·63, P < 0·05), was associated with significantly increased oxidative stress in the OPP compared with the NWPP or controls.
Conclusions Obesity in patients with psoriasis is associated with both decreased plasma levels of protective adiponectin compared with NWPP, and enhanced systemic inflammation and oxidative stress. These findings are in concordance with high prevalence of diseases related to lower adiponectin levels among psoriasis patients.