Recent studies suggest that serum irisin might be a predictor of insulin resistance in obese subjects. The aim of the study was to analyze the effect of life style intervention on insulin sensitivity, irisin, and visfatin concentrations.
Methods: A group of 43 obese patients (13M/30F; 43.0 ±12.4 years; BMI 31.2 ± 6.3 kg/m2) participated in a weight loss interventional program (NCT02325804) following an 8-week program consisting of hypocaloric diet (-30% energy intake) and physical activity 150 minutes/week. Insulin sensitivity was evaluated according to the homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity indices according Matsuda and Cederholm were calculated (ISIMat and ISICed). Plasma ALT, AST, irisin, visfatin, and physical fitness were measured.
Results: The average reduction of body weight was 6.8±4.9 kg (0-15 kg; p=0.0006), accompanied with significant reduction of body fat mass (p=0.03), and waist circumference (p=0.02). Insulin sensitivity improved (IR HOMA 2.71±3.90 vs. 1.24 ±0.83; p=0.01; ISIMat 6.64±4.38 vs. 8.93±5.36 p ≤ 0.001; ISICed 59.1±21.4 vs. 64.7±22.2 p=0.03). Total and LDL cholesterol, as well as triglycerides decreased (p=0.02, p=0.02, p=0.resp.), Physical fitness significantly improved after intervention (as measured by VO2 max: 25.1±5.9 vs. 28.0±6.0 ml.kg-1.min-1, p ≤ 0.001). Plasma irisin significantly decreased after intervention (233 ± 66 vs. 167 ± 88 ng/mL; P ≤ 0.001), while visfatin levels did not changed.
Conclusion: Eight weeks of diet and physical activity intervention program in obese otherwise healthy subjects leaded to improvement of insulin sensitivity, as well as physical fitness and lowering of plasma irirsin levels. Irisin strongly reflects body fat mass, suggesting that the irisin circulating levels are conditioned by adiposity level.
A. Penesova: None. Z. Radikova: None. B. Bajer: None. M. Vlcek: None.