� Background & objectives: Obesity and visceral fat accumulation after menopause are associated with lipid profile changes, metabolic syndrome and c ardiovascular diseases. The aim of this study was to investigate the effect of 8-week aerobic - resistance training and estrogen replacement therapy on visceral fat and cardiovascular risk factors in ov ariectomized rats.

� Methods: Fifty female Wistar rats were ov ariectomized 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 exercise consisted of aerobic-resistance training (20 m/min, 3 days/week, 60 min/day, 10% slope, Load 3% body weight) 17b-estradiol valerate (30 �g/kg bw in 0.2 ml sesame oil) were injected subcutaneously three days a week during 8 week. The co-treatment group received both exercise and estradiol protocol as same as previous groups.

� Results: After 8-week of interventions, visceral fat significantly reduced by Ovx+Exe and Ovx+Exe+Est compared to Sedentary rats (p<0.05), however no significant difference in body weight was observed. BMI significantly reduced in Ovx+Exe and Ovx+Exe+Est groups compared to Sedentary group. Also, BMI significantly reduced in Ovx+Est compared to Ovx+Oilgroup (p<0.05). Although this intervention changed lipid profiles, they were not statistically significant in neither of groups. Statistical comparisons between groups were performed usingone-way ANOVA test followed by Tukey&rsquos post-hoc test. The differences were considered significant at p<0.05.

� Conclusion: Eight weeks aerobic-resistance training successfully decreases visceral fat and BMI.

Background & objectives: Estrogen reduction after the menopause is associated with visceral adipose tissue accumulation and insulin resistance. Serum omentin-1 level is also decreased by abdominal obesity and insulin resistance. This study investigated the effect of estrogen on visceral fat, omentin-1 and insulin resistance in ovariectomized (OVX) rats.

Methods: Thirty 13-week-old female Wistar rats weighing180±5 gr were randomly matched on their body weight and divided into OVX (n=20) and sham-operated (SHAM; n=10) groups. OVX rats were subdivided into estrogen replacement therapy (Ovx+Est; n=10), and control (Ovx+sesame Oil; n=10) groups. The estrogen replacement therapy received 17b-estradiol (30µg/kg bw; in 0.2 ml sesame oil) three days a week, for eight weeks. Ovx+Oil received the same sesame oil subcutaneously as vehicle. All intra-abdominal fat depots were dissected out and weighed immediately. Omentin-1 concentration was measured by rat omentin ELISA kit and HOMA-IR was used to estimate the insulin resistance. Obtained data were analyzed by ANOVA and post hoc Tukey test.

Results: Visceral fat was decreased by 12.84% in Ovx+Est compared to Ovx+Oil group; but it wasn ́t significant. Whereas, body weight was significantly decreased by 7.87 % in Ovx+Est compared to Ovx+Oil; and it was significantly increased by 12.5% in Ovx+Oil compared to SHAM group. Omentin-1 level was significantly increased by 41% in Ovx+Est compared to Ovx+Oil group; whereas it was significantly decreased by 13.9% in Ovx+Oil compared to SHAM group. The levels of glucose, insulin and HOMA-IR were significantly decreased to 51.16%, 24.23% and 61.52%, respectively, in Ovx+Est group compared to the rats in Ovx+Oil group (p=0.0001).

Conclusion: 8-week estrogen reduces body weight and improves insulin resistance probably via increase in omentin-1.