The interactive effect of aerobic-resistance exercise and estrogen replacement therapy on visceral adipose tissue, serum omentin-1 concentration, insulin resistance and lipid profiles in ovariectomized rats

The aim was to investigate the interactive effect of aerobic- resistance training and estrogen replacement therapy on visceral adipose tissue, serume omentin-1 level, insulin resistance and lipid profiles in ovariectomized (OVX) rats. Methods: Fifty female Wistar rats were ovariectomized and divided into 5 OVX groups (n=10 rats per group):Ovx+sedentary (Sedentary), aerobic-resistance training (Ovx+Exe), aerobic-resistance training+estrogen replacement therapy (Ovx+Exe+Est), estrogen replacement therapy (Ovx+Est) and vehicle group or sesame oil (Ovx+Oil). The aerobic-resistance training (20 m/min, 3 days/week, 60 min/day, 10% slope, Load; 3% body weight); 17b-estradiol valerate (30µg/kg bw; in 0.2ml sesame oil) were injected subcutaneously, three days a week during 8 week; and the aerobic-resistance exercise+estrogen therapy received both exercise and estradiol protocol same as previous groups. The Ovx+Oil group, also, was given equal volumes of sesame oil for this period. Data were analyzed with independent t-test, ANOVA in P 0.05. After eight-week of interventions, visceral fat and BMI significantly reduced in Ovx+Exe and Ovx+Exe+Est groups compared to Sedentary rats (p 0.05), without no significant changes in body weight. Also, BMI significantly reduced in Ovx+Est compared to Ovx+Oil rats (p 0.05). Serum omentin-1 level was significantly increased in Ovx+Exe group compared to Sedentary group. It was significantly increased in Ovx+Est group compared to Ovx+Oil group. Also, it was significantly increased in Ovx+Est+Est group compared to Sedentary and Ovx+Oil groups. Omentin-1 was in Ovx+Exe group greater compared to Ovx+Exe+Est and Ovx+Est groups, respectively (P 0/05). Insulin resistance significantly decreased in Ovx+Exe, Ovx+Exe+Est and Ovx+Est groups (P 0/05). Although these intervention changed lipid profiles, they were not statistically significant in neither of groups. Conclusion: 8-week aerobic-resistance training, 17-b estradiol replacement and aerobic-resistance exercise training+estrogen supplementation induces a decrease in visceral fat and BMI, and these reduction without weight loss increased serum omentin-1 and improved insulin resistance in ovariectomized rats. Interestingly, exercise lonley furture increased omentin-1. It seems that exercise lonely is effective than HRT and CET+HRT.