Active endurance athletes have higher HDL-cholesterol concentrations than sedentary individuals. It is not known whether such elevations are produced by enhanced HDL synthesis, decreased catabolism, or both. Furthermore, the metabolic mechanisms by which changes in exercise or diet alter HDL concentrations are not well defined. The present proposal will compare HDL metabolism in active and sedentary men under controlled dietary conditions. We will also examine HDL metabolism in initially sedentary men undergoing exercise training and in sedentary subjects provided diets with varying contents of polyunsaturated and saturated fats. The interaction of diet and exercise will be examined in acute exercise studies and in studies providing distance runners diets high in carbohydrate or fat during periods of training and inactivity. Parameters of HDL metabolism including apoprotein synthetic and catabolic rates will be measured using radiolabeled HDL. HDL-cholesterol and apoprotein concentrations and the ultracentrifugal distribution of HDL lipids and lipoproteins will be quantitated as will the activity of lipoprotein lipase (LPLA) and hepatic triglyceride hydrolase in post-heparin plasma. These studies are designed to test the hypotheses that exercise and diet alter HDL concentrations via LPLA-mediated changes in HDL catabolism. Individual protocols address additional questions including: Do initial HDL cholesterol levels determine the change in HDL with exercise training?; Do the metabolic responses to exercise differ in men who do or do not reduce body weight?; What is the acute effect of exercise on LPLA?; Does exercise training limit the reduction in HDL produced by carbohydrate-rich diets?; By what mechanism does an increase in polyunsaturated fat reduce HDL concentrations? This research should provide insight into the regulation of HDL concentrations and the metabolic alterations produced by exercise and diet. Because of the inverse association between HDL and coronary artery disease (CAD) risk, the results should also yield information relevant to strategies for CAD prevention.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL028467-06
Application #
3339853
Study Section
Nutrition Study Section (NTN)
Project Start
1981-07-01
Project End
1988-03-31
Budget Start
1986-09-01
Budget End
1988-03-31
Support Year
6
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Miriam Hospital
Department
Type
DUNS #
039318308
City
Providence
State
RI
Country
United States
Zip Code
02906
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Thompson, P D; Yurgalevitch, S M; Flynn, M M et al. (1997) Effect of prolonged exercise training without weight loss on high-density lipoprotein metabolism in overweight men. Metabolism 46:217-23
Zmuda, J M; Bausserman, L L; Maceroni, D et al. (1997) The effect of supraphysiologic doses of testosterone on fasting total homocysteine levels in normal men. Atherosclerosis 130:199-202
Zmunda, J M; Thompson, P D; Dickenson, R et al. (1996) Testosterone decreases lipoprotein(a) in men. Am J Cardiol 77:1244-7
Sadaniantz, A; Yurgalevitch, S; Zmuda, J M et al. (1996) One year of exercise training does not alter resting left ventricular systolic or diastolic function. Med Sci Sports Exerc 28:1345-50
Marcus, B H; Albrecht, A E; Niaura, R S et al. (1995) Exercise enhances the maintenance of smoking cessation in women. Addict Behav 20:87-92
Cullinane, E M; Yurgalevitch, S M; Saritelli, A L et al. (1995) Variations in plasma volume affect total and low-density lipoprotein cholesterol concentrations during the menstrual cycle. Metabolism 44:965-71
Podl, T R; Zmuda, J M; Yurgalevitch, S M et al. (1994) Lipoprotein lipase activity and plasma triglyceride clearance are elevated in endurance-trained women. Metabolism 43:808-13
Bausserman, L L; Saritelli, A L; Milosavljevic, D (1994) High-density lipoprotein subfractions measured in stored serum. Clin Chem 40:1713-6
Zmuda, J M; Fahrenbach, M C; Younkin, B T et al. (1993) The effect of testosterone aromatization on high-density lipoprotein cholesterol level and postheparin lipolytic activity. Metabolism 42:446-50

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