The effects of exercise and diet on selected physiological and biochemical parameters in a sedentary Indian male cohort.

Abstract

In common with other expatriate Indian Populations, the Indian community of South Africa has a high incidence of coronary heart disease (CHD). Little information is available on the effects of exercise and diet on risk factors in this group. The present study is directed at the functional changes occurring as a result of a moderate aerobic physical activity programme, comprising 30 minutes of supervised exercise, three times per week for 15 weeks. Healthy male volunteers were recruited from the staff of the University of Durban-Westville, who were not on any lipid lowering medication and were not involved in any programme of physical activity for at least 12 weeks before the start of the project. The 41 subjects were assigned into one of three groups: exercise only (E) (15 subjects); exercise and diet (ED) (14 subjects) and a control (C) (12 subjects) group on no intervention. Besides laboratory investigations all participants were subjected to standardized fitness and anthropomorphological evaluation, a brief family history for coronary artery disease and a detailed dietary history was compiled. Baseline lipid results indicate that only 7 of the 41 subjects had normal lipid profiles using as cut-off points 5.2 mmol/l for cholesterol, 1.5 mml!l for triglyceride and 0.9 mmol/l for HDL-C. Obesity was moderately prevalent before intervention, with a mean decrease of 25% in body fat in both E and BD groups(p~0.05). The experimental subjects became leaner. After the intervention programme an average 20 percent increase was evident in physical working capacity as measured by peak V~ in both experimental groups (p~0.01). The controls showed little variation over the 15 weeks. The indices of muscular endurance and

flexibility showed statistically significant changes (P~ 0.05) in both experimental groups after intervention. This certainly indicates elevated levels of fitness after the intervention. The lipid profiles show little alteration in total cholesterol, with a 7.3% decrease in triglyceride levels in the E group (which was not statistically significant) compared with a 14.7% increase in the controls. HDL-C showed an increase in both experimental groups (p~0.01). The total cholesterol to HDL-C ratio had an average fall of 11.9% in the experimental groups (P~0.05) compared with a 5.6% decrease in the control group. These data support the claim that regular, moderate exercise reduces the risk of heart disease through its effects on coronary risk factors in a high risk South African population.