Exenatide treatment increases serum irisin levels in patients with obesity and newly diagnosed type 2 diabetes

Objective: Irisin is a myokine secreted by skeletal muscle during exercise. Abnormal serum irisin levels are associated with obesity and type 2 diabetes (T2D). This study investigated the changes in serum irisin in the obese patients with newly diagnosed T2D following glucagon-like peptide-1 (GLP-1) receptor agonist (exenatide) treatment. Methods: Fifty-four obese patients with T2D were treated with exenatide for 12 weeks. The control group included 54 age-, sex-, and body mass index (BMI)-matched subjects with normal glucose tolerance. Results: Patients with T2D had lower irisin than the control group (38.06 [29.29-53.79] vs. 58.01 [43.07-87.79] ng/mL, P < 0.01]. Serum irisin was negatively associated with BMI (r = 0.178, P < 0.05), fasting blood glucose (FBG; r = 0.170, P < 0.05), and glycosylated hemoglobin (HbA1c; r = 0.189, P < 0.01) in patients with T2D. Exenatide treatment markedly increased serum irisin by 19.28 ng/mL (12.59-25.98) compared to baseline (P < 0.01). Increased irisin was significantly correlated with decreased FBG and HbA1c after exenatide treatment (FBG: r = 0.35; HbA1c: r = 0.37; both P < 0.05). Conclusions: Exenatide treatment significantly increased irisin in patients with T2D. Post-treatment changes in irisin were correlated with decreases in FBG and HbA1c. The upregulation of irisin might be a novel mechanism for the beneficial effects of exenatide in type 2 diabetic patients. (C) 2016 Elsevier Inc. All rights reserved.