Association of regional and total body composition, plasma lipids, lipoproteins, apolipoproteins and the effects of long-term resistive training in the premenopausal female.

Abstract

The purpose of this study was to investigate the long term effects on plasma lipoproteins and body composition in a sample of 104 untrained premenopausal women, aged 28-40 years. Female participants were randomly assigned to an exercise (n = 56) and a control (n = 48) group. Plasma total cholesterol (tChol), triacylglycerol (TAG), high density lipoprotein cholesterol (HDL), along with the subfractions of HDL, HDL2 and HDL3, low density lipoprotein cholesterol (LDL) and the apolipoproteins A1 and B were evaluated at baseline and after 5, 12 and 18 months of resistive training. Body composition was assessed by dual energy x-ray absorptiometry (DXA). Analysis of baseline body composition data obtained by DXA has shown that some seldom used anthropometric indices such as the height to waist circumference ratio and the upper arm circumference may be a better index for body fat distribution than more commonly used indices of fat distribution. Further analysis of baseline data has demonstrated that the percentage of fat in the upper body (arms and trunk, particularly the upper trunk) is positively associated with the cardiovascular disease risk indices of tchol/HDL and the ratio of LDL/HDL. The results of long term resistance training in these women produced a significant change (P < 0.05) in the plasma total cholesterol and LDL cholesterol over the 18 month training period compared to the controls. Total HDL levels were unaffected by resistive training, but the HDL2 subfraction increased significantly in the exercise group (30%) relative to the controls (-16%) after 18 months of training (P < 0.04). The ratio of HDL2 to HDL3 also increased significantly (P < 0.04) in the exercise group relative to the controls. The plasma concentration of apolipoprotein A1 decreased in both the experimental and the controls after one year, however this trend was reversed in the exercise group after the 18 month training period. The HDL3 subfraction, plasma TAG and the apolipoprotein B levels did not change significantly with long term resistance training in these women. Total body fat, along with its distribution, was not altered in the exercise group during training; however, total body lean soft tissue in the exercising females increased by 1.3 kilograms (3.1%) (P < 0.01). In conclusion, the results from this study have shown that resistive training can alter plasma lipids towards a reduced risk for disease and might be a useful form of exercise in the premenopausal female population. (Abstract shortened by UMI.)