Plasma Irisin Levels in Subjects with Type 1 Diabetes: Comparison with Healthy Controls.

Irisin is a myokine that increases energy expenditure. In this cross-sectional study, we examined for differences in plasma irisin concentrations between subjects with type 1 diabetes mellitus and healthy individuals and searched for associations between plasma irisin levels and clinical and biochemical characteristics as well as self-reported physical activity. A total of 79 subjects with type 1 diabetes [age 38.2±12.5 years, men/women (n): 27/52], were consecutively recruited. Moreover, 53 healthy controls, matched for age and body mass index with those with diabetes were recruited. Plasma irisin was measured with ELISA. Participants were asked about their physical activity during the last week. We also measured trunk and visceral fat. Circulating irisin levels were lower in subjects with diabetes than in controls [median value (interquartile range): 53.0 (35.2, 106.3) vs. 178.1 (42.6, 641.6) ng/ml, respectively, p<0.001]. In the group of diabetes, univariate analysis showed that irisin levels were associated with waist circumference (beta=-0.283, p=0.023), serum triglycerides (beta=-0.282, p=0.031), and trunk fat (beta=-0.324, p=0.012). In multivariate analysis after adjustment for potential confounders, irisin levels were associated independently only with waist circumference (beta=-0.403, p=0.005). Among controls, multivariate analysis demonstrated that irisin levels were associated with pack-years of smoking (beta=-0.563, p=0.012) and fasting triglycerides (beta=-0.338, p=0.041). Circulating irisin levels were lower in subjects with diabetes in comparison with healthy-matched controls. In conclusion, plasma irisin concentrations in subjects with diabetes were associated with waist circumference, while in controls with serum triglycerides and pack-years of smoking.