Plasma triglyceride lowering by exercise despite increased food intake in patients with type IV hyperlipoproteinemia

Abstract

Exercise can lower fasting triglyceride levels (TG). This study was undertaken to determine whether the exercise-induced decrease in TG is the result of a negative caloric balance. Five subjects with primary type IV hyperlipoproteinemia were given diets comparable in composition to their usual diets. During one experimental period the subjects exercised while maintaining their usual caloric intakes. During another experimental period their caloric intake was increased to compensate for the exercise-induced increase in energy expenditure. The exercise, which consisted of 30 min of treadmill walking per day for 4 days, resulted in a progressive decrease in TG. The reduction in TG, which averaged 120 mg/100 ml, occurred regardless of whether or not the increase in caloric expenditure was compensated for by an increase in food intake. The decrease in TG was limited to the very low density lipoprotein fraction. No significant changes occurred in total plasma cholesterol concentration or in the distribution of cholesterol between the lipoprotein fractions. Fasting plasma glucagon concentration was constant for each individual and was unaffected by the exercise. The finding that exercise induces a decrease in TG despite increased food intake indicates that the TG lowering effect of exercise is not mediated by a negative caloric balance.

Calorie restriction or exercise: effects on coronary heart disease risk factors. A randomized, controlled trial

“…Exercise generally lowers plasma TG concentrations when TG are moderately to markedly elevated, and high-intensity exercise is more effective than low-intensity exercise (4,11). Most of our subjects who were assigned to the EX intervention participated in regular, long periods of low-intensity exercise, mostly walking and jogging.…”

“…It is not known whether long-term negative energy balance induced by exercise alone or by caloric restriction alone is more beneficial in reducing CHD risk factors. However, data from epidemiological and physiological studies suggest that exercise has weight loss-independent benefits on CHD risk (1,4,5,19,21).We conducted a 1-yr randomized, controlled trial in middleaged lean and overweight men and women to evaluate the effect of body fat reduction induced by a 20% increase in energy expenditure alone or by a 20% decrease in energy intake alone on metabolic risk factors for CHD. We hypothesized that fat reduction induced by exercise would have greater beneficial effects on CHD risk factors than similar fat reduction induced by CR.…”

“…It is not known whether long-term negative energy balance induced by exercise alone or by caloric restriction alone is more beneficial in reducing CHD risk factors. However, data from epidemiological and physiological studies suggest that exercise has weight loss-independent benefits on CHD risk (1,4,5,19,21).…”

Demographic, behavioral, biochemical, and dietary correlates of plasma triglycerides. Lipid Research Clinics Program Prevalence Study.

“…In these data, the association was independent of differences between active and sedentary men in body mass, alcohol consumption, cigarette smoking, age, and FPG. While it has been suggested that negative caloric balance may explain the inverse association between exercise and TG levels, Gyntelberg et al 51 showed a reduction in TG levels in men participating in an exercise program, whether or not their increased caloric expenditure was compensated for by an increased caloric intake. A more likely explanation may be a direct, more chronic influence of activity on VLDL synthesis or catabolism.…”

“…Lower TG values in active individuals have been reported from other cross-sectional data, 47 and decreases in TG have been observed in association with physical conditioning. 48 " 51 The mechanism by which physical activity may influence TG levels is unclear. In these data, the association was independent of differences between active and sedentary men in body mass, alcohol consumption, cigarette smoking, age, and FPG.…”