The role of irisin in the relationship between psoriasis and insulin resistance.

BACKGROUND: Irisin, a hormone like myokine, is identified to the relation with insulin resistance and metabolic syndrome recently. In the literature to date, there are no studies evaluating serum irisin levels in psoriasis patients. We aimed to elucidate the pathogenesis of insulin resistance in psoriasis patients by evaluating serum irisin levels and metabolic parameters associated with insulin resistance in patients with plaque-type psoriasis vulgaris.

METHODS: The study included 40 patients with moderate-to-severe chronic plaque-type psoriasis vulgaris and 37 healthy subjects. Body Mass Index (BMI) and waist circumference were measured, and serum irisin, fasting blood glucose (FBG), lipid profile, high-sensitivity CRP (hs-CRP) and insulin levels were assessed. To evaluate insulin resistance, the Homeostasis Model Assessment (HOMA-IR) and triglyceride/HDL (TG/HDL) ratio were used.

RESULTS: Serum irisin and HDL levels were significantly lower in patients than the control group (P<0.001, P=0.024). Within the patient group, there was a significant negative correlation between serum irisin and serum TG, LDL, and TG/HDL levels (P=0.041, P=0.022, P=0.025), and a positive correlation with HDL levels (P=0.036). The PASI scores and serum irisin levels were significantly positively correlated.

CONCLUSIONS: In conclusion, we observed that serum irisin levels were significantly lower in patients with psoriasis, and associated with serum lipid levels and disease activity in our study. These results can be interpreted that irisin is involved in the disease pathogenesis of patients with psoriasis in relation to metabolic dysregulation.