In this study, we demonstrated that serum irisin levels were significantly higher in the T2DM patients with hypertriglyceridemia compared with the controls, and serum irisin was positively correlated with BMI, FBG, TC, and HDL, suggesting that irisin could play an important role in the delicate balance of energy metabolism and insulin resistance. This evidence concerns the gene FNDC5 and type 2 diabetes mellitus.