Irisin levels in the progression of diabetes in sedentary women.

Context: The recently discovered peptide irisin has been hypothesized to be a regulator of body metabolism. However, studies ended up with controversial results. In the present study, we aimed to investigate irisin levels in sedentary women at different stages of prediabetes.

Design, Setting, And Subjects: We performed a cross-sectional analysis of circulating levels of irisin in 263 females similar for age and body mass index (BMI) and the groups included 52 normal glucose tolerance (NGT), 60 isolated impaired fasting glucose (IFG), 36 isolated impaired glucose tolerance (IGT), 65 both IFG and IGT and 50 type 2 diabetic patients. All patients were exercising less than 150 min/week.

Results: Plasma irisin levels were significantly lower in IFG+IGT (2.86 ± 0.6 μg/mL, p: 0.019) and T2DM (2.83 ± 0,5 μg/mL, p: 0.005) patients compared to NGT (3.16 ± 0.3 μg/mL) patients. After age adjustment there was a negative correlation between irisin and BMI (r: -0.141; p: 0.031), postprandial glucose (PPG) (r: -0.142; p: 0.030), low density lipoprotein-cholesterol (LDL-C) (r: -0.138; p: 0.035) and triglyceride (TG) (r: -0.214; p: 0.001) and a positive correlation between irisin and high density lipoprotein-cholesterol (HDL-C) (r:.142; p: 0.030). After adjustment for age and BMI; PPG (r: -0. 137; p: 0.037), LDL-C (r: -0. 143; p: 0.029) and TG (r: -0.203; p: 0.002) were considered to correlate with irisin levels. Subgroup analysis revealed that TG levels were correlated with irisin levels in IFG (r: -0.347; p: 0.014) and IGT (r: -0.397; p: 0.030) patients.

Conclusion: In our cohort of sedentary women, irisin levels were lower in patients with IFG+IGT and with diabetes than in patients with NGT. There is no correlation between irisin levels and BMI. Irisin is a myokine decreasing gradually with the progression of glucose intolerance and T2DM and is not correlated with BMI in sedentary women.