The role of cardiorespiratory fitness and the effectiveness of exercise in altering visceral adipose tissue and cardio-metabolic risk factors in post-menopausal South Asian women

Background: South Asians have higher rates of type 2 Diabetes and cardiovascular disease (CVD) than Europeans with earlier disease onset. South Asians have been shown to have a unique obesity phenotype of greater visceral adipose tissue (VAT) at a given body size which may explain the higher cardio-metabolic risk factors compared to Europeans. Exercise has been shown to reduce VAT in Europeans but it is unknown if it is also effective in South Asians given their unique obesity phenotype.Objectives: The objectives of this thesis were threefold; 1) to explore the association between cardiorespiratory fitness (CRF) and VAT; 2) to assess the role of standard exercise and Bhangra dance in altering VAT and 3) to assess the association between exercise-induced change in VAT and change in cardio-metabolic risk in post-menopausal South Asian women.Methods: Multi-slice computed tomography was used to assess VAT, aerobic fitness via metabolic testing and cardio-metabolic risk factors through a 12-hour fasting sample. Seventy-five post-menopausal South Asian women were randomized into either three weekly sessions for 12-weeks of standard exercise, Bhangra dance or a non-exercise control group. One-way ANOVA was used to compare VAT across tertiles of CRF. General linear models were used to assess whether VAT was reduced in exercise compared to the referent control group. Bivariate correlations were used to assess the associations between change in VAT with change in cardio-metabolic risk factors. Results: Physically inactive post-menopausal South Asian women with higher levels of CRF were shown to have lower levels of VAT. There was a non-significant reduction in VAT after 12-weeks of aerobic exercise compared to the referent control group while the Bhangra dance group exhibited a significant improvement in CRF. The change in VAT was significantly associated with change in markers of glucose regulation.Discussion: Cardiorespiratory fitness is associated with VAT; however, a 12-week aerobic exercise program did not significantly reduce VAT in South Asian women. Nevertheless, those who reduced VAT saw improvements in cardio-metabolic risk factors. There may be a South Asian VAT “resistant” phenotype; however, Bhangra dance appears to be an effective physical activity option for increasing CRF.