Does weight loss cause the exercise-induced increase in plasma high density lipoproteins?

Abstract

Studies showing an increase in plasma concentration of high density lipoprotein cholesterol (HDL-C) with moderate exercise have usually rejected the role of body weight change in the HDL-C raising process, ostensibly because the amount of weight lost has been negligible. To investigate HDL-C changes more thoroughly, we followed initially sedentary middle-aged men randomly assigned to either a moderate running (n = 36) or a sedentary control (n = 28) group for one year. Among runners, one-year changes in plasma HDL-C concentrations correlated strongly with their body weight changes (r = - 0.53, P less than 0.001). Curve-fitting procedures and regression analysis suggested that processes associated with weight change produce much of the plasma HDL-C changes induced by moderate exercise and that changes in HDL-C concentration predominantly reflect changes in the reputedly anti-atherogenic HDL2 sub-component. Further, the interaction between weight change and plasma HDL-C concentration was significantly different (P less than 0.001) in exercisers and controls suggesting that the metabolic consequences of exercise-induced weight change are different from the consequences of weight change in the sedentary state.

Figure 1

Smoothed scatterplot curves for 1-year changes in lean, fat, and total body mass versus 1-year average reported miles run in exercisers (N = 36).

Figure 2

Smoothed scatterplots and Spearman's correlation coefficient (ρ) for 1-year changes in daily total dietary calorie intake versus Δtotal body mass and reported miles run in exercisers. Horizontal and vertical lines display corresponding mean changes for the control group (n = 28).

Figure 3

Smoothed scatterplots and Spearman's correlation coefficient (ρ) for the assocations among 1-year changes in plasma HDL-C concentrations, total body mass, and reported miles run in exercisers. Horizontal and vertical lines display corresponding mean changes for the controls.

Figure 4

Smoothed scatterplots and Spearman's correlation coefficient (ρ) for baseline to 6-month changes in plasma HDL-C concentrations versus Δtotal body mass. Multiple regression analyses suggest the inverse association between ΔHDL-C and Δtotal body mass in exercisers is significantly different (P < 0.0001) from the slightly positive association between these variables in controls.