Leptin and sex hormones in psoriasis and correlation with disease severity

Leptin, a 16-KDa peptide hormone secreted from the adipose tissue, plays an important role in the regulation of energyintake and expenditure and body weight regulation; furthermore, it has a regulatory function on the reproductive system. The aim of this study was to assess the relationship between serum leptin levels and sex hormones in psoriatic patients and control group and to determine the serum levels of leptin and sex hormones in patients and their association with disease severity. This cross-sectional study included 43 male patients with psoriasis and 42 age- and sex- matched healthy controls. We measured serum levels of leptin, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, and total testosterone in both groups. Psoriatic patients had significantly higher levels of leptin and lower levels of FSH than healthy controls. Psoriatic patients did not differ significantly in the serum concentrations of LH, total testosterone, SHBG, and PRL in comparison with healthy controls. The severity of the disease (PASI score) was positively correlated with leptin (p<.0001), Body Mass Index (p=0.001), and waist circumference (p=0.001), and was inversely correlated with serum LH levels (p=0.03). No significant associations were found between the severity of the disease and serum levels of FSH (p=0.38), total testosterone (p=0.14), SHBG (p=0.98), and PRL (p=0.76). Our results suggest that the serum leptin level is associated with psoriasis severity and duration; moreover, we found a relationship between LH and psoriasis severity. This association needs more extensive studies.