The Effects of Eight Weeks Consecutive Swimming Exercise and Estrogen Therapy on Cardiovascular Risk Factors in Ovariectomised Rat Model

Abstract

Menopause plays an important role in lipid distribution that leads to the apparent acceleration in cardiovascular diseases in women. The aim of this study is to investigate the effectiveness of combination of regular exercise and estrogen therapy in reducing cardiovascular risk factors in postmenopausal animal model. Forty-eight Sprague Dawley female rats aged 3 months were used in the study and randomly divided into two main groups which were ovariectomy and sham oper-ation groups. Later, four groups which were nontreatment, estrogen therapy, exercise and combination estrogen therapy and exercise derived from ovariectomy controlled group and nontreatment and exercise groups derived from sham-controlled group. Each group consists of seven to nine rats. Bilateral ovariectomy was done for all experimental and ovariectomised controlled groups while no ovary removal was performed to sham controlled groups. Estrogen ther-apy and swimming exercise were given for consecutive 8 weeks and body weight progress was measured weekly. Rats were sacrificed after a period of 8 weeks intervention and blood was taken for lipid analysis. The body weight progression of the rats was analyzed by using paired t-test and repeated measures ANOVA. The difference on plasma lipid profile was analyzed by using one-way ANOVA. The results showed that there was a significant (P < 0.05) increase in the body weight 4 weeks after ovariectomy. No significant difference (P > 0.05) detected in the body weight after 8 weeks intervention. Estrogen therapy and swimming exercise treatment lowered the total plasma cholesterol and low-density lipoprotein (LDL) cholesterol levels as compared with estrogen therapy only and a higher plasma high-density lipoprotein (HDL) cholesterol was observed in exercise treatment group. In conclusion, estrogen therapy and exercise treatment might be beneficial on lipid and lipoprotein metabolism which led to an increase in cardio-vascular health in ovariectomised rat model.