Introduction: Overweight and obesity has been introduced as a problem of health system. Irisin derive of FNDC 5 myokine gene, can produce energy and heat during exercise and physical activity like Brown fat tissue. Irisin can reduce resistance to Insulin and improve Glucose Tolerance. The aim of this investigation is evaluation of effect of aerobic exercise on plasma levels of Irisin in overweight postmenopausal and premenopausal women.
Methods: 12 postmenopausal women (mean age 53/42 ± 6/02 and weight 73/83 ± 9/46 kg) and12 premenopausal women (mean age32/08 ± 7/91 years and mean weight 74/33± 11/2 kg) participated in this study. Training schedual, include 24 session of aerobic exercises, during 8 weeks, 3times in weeks with 40-80% Maximal heart rate estimated. Duration of exercise in first week was 25 minutes and it reaches to 45 minutes and it reaches to 45 minutes in 8th week. Irisin plasma level, Glucose, Insulin, Insulin resistance and BMI index was measured before and after exercise period.
Results: No significant changes was observed in weight, BMI and WHR after 8 weeks of aerobic training (p>0.05). However, body fat percentage was significantly reduced in both groups (p≤0.01). Maximal oxygen consumption significantly increased in postmenopausal women (p<0.01) and not significant changes was observed in premenopausal women (p>0.05). Plasma levels of irisin in postmenopausal women showed a significant increase (p<0.05) while no significant changes was observed in premenopausal women (p>0.05). It also found no significant changes in fasting blood glucose levels in both groups (p>0.05). Insulin and insulin resistance index were significantly decreased in the group of postmenopausal women (respectively p≤0.01 and p<0.05), but no significant changes in premenopausal women (p>0.05). Significant negative correlation was found between irisin changes with insulin resistance index, weight, body mass index and insulin changes (p<0.05) While there was no significant correlation between irisin with glucose, body fat percentage, waist to hip ratio and maximal oxygen consumption (p>0.05).
Conclusions: Aerobic training can changes plasma levels of irisin and improve the insulin resistance index and physiological index in the overweight postmenopausal women.