Omentin-1 is a newly discovered protein expressed and secreted from visceral adipose tissue that increases insulin sensitivity.We examined the effects of 12 weeks of aerobic training on serum omentin-1 concentrations together with cardiovascular risk factors in overweight and obese men. Eighteen overweight and obese participants (age 43.1 ± 4.7 years, BMI ≥ 25 kg . m ⁻² ) were assigned to exercise training (n = 9) and control (n = 9) groups. A matched control group of normal weight participants (n = 8; age 42.2 ± 3.8 years, BMI < 25 kg . m ⁻² ) were also recruited for baseline comparison. The obese exercise group participated in 12 weeks of progressive aerobic training 5 days a week. Measures of serum omentin-1, insulin resistance, lipid profiles, blood pressure, and body composition were obtained before and after the 12 weeks. At baseline, normal weight participants had significantly higher serum omentin-1 concentrations than overweight and obese participants, and there were inverse correlations between omentin-1 and each of waist circumference, fasting glucose, insulin resistance, total cholesterol,triglyceride, and systolic blood pressure (P < 0 .05). After the aerobic training, waist circumference, percent body fat, fasting glucose, insulin resistance, triglyceride, total cholesterol, low-density lipoprotein cholesterol, and systolic blood pressure were all significantly decreased (P < 0.05). In contrast, serum omentin-1 concentration was significantly increased after the aerobic programme (P < 0.05), and correlated with changes in insulin resistance (r = − 0.67, P= 0.04), glucose (r = − 0.65, P = 0.05), waist circumference (r = −70, P = 0.03), and aerobic fitness r = −.68, P = 0.04). Aerobic training resulted in an improvement in cardiometabolic risk factors in obese participants, and this improvement was accompanied by increased omentin-1 concentrations.
