Psoriasis in obesity: comparison of serum levels of leptin and adiponectin in obese subjects - cases and controls

BACKGROUND: Psoriasis and obesity are somewhat related to a low-grade systemic inflammatory response. OBJECTIVES: To determine leptin and adiponectin levels in psoriasis patients compared to control patients matched for weight. METHODS: A case-control study was performed, evaluating 113 psoriasis patients and 41 controls with other dermatologic diseases. RESULTS: The prevalence of obesity was 33% in cases and 21.9% in controls. All evaluated comorbidities were more prevalent among cases. When stratified by weight, the comorbidities were more frequent in overweight patients. We found no correlation between being overweight (p=0.25), leptin (p=0.18) or adiponectin (p=0.762) levels and psoriasis severity. When overweight cases and controls were compared, we found differences in the adiponectin values (p= 0.04). The overweight cases had lower adiponectin levels than the overweight controls. We found no differences in the leptin dosage between cases and controls. The overweight cases had higher leptin values than the normal weight cases (p<0.001). STUDY LIMITATIONS: Several patients used systemic anti-inflammatory medication. CONCLUSIONS: The prevalence of obesity among psoriasis cases (33%) was higher than in the general population (17.4%). We did not find any correlation between severity of psoriasis and inflammatory cytokines and the condition of being overweight. The overweight cases had lower values of adiponectin than the overweight controls. It seems, therefore, that there is a relationship between adiponectin and psoriasis, but this relationship depends on the presence of obesity.