This study examined the effect of exercise training without weight loss on high-density lipoprotein (HDL) metabolism in overweight men. We evaluated HDL metabolism using 125I-radiolabeled autologous HDL in 17 overweight men aged 40 ± 7 years (mean ± SD) before and after 1 year of exercise training. Subjects consumed defined diets in a metabolic kitchen during the metabolic studies. They performed endurance exercise under supervision for 1 hour four times weekly and maintained their pretraining body weight. Maximal oxygen uptake (V̇O2max) increased 27% (P < .001) with exercise training. HDL- cholesterol (HDL-C) and apolipoprotein (apo) A-I increased 10% and 9%, respectively (P < .001 for both), whereas triglycerides and apo B decreased 7% and 10%, respectively (P < .05). Postheparin lipoprotein lipase increased 11% (P = NS). Hepatic triglyceride lipase activity (HTGLA) decreased 12% (P < .05). The fractional catabolic rate (FCR) of HDL protein and of apo A-I decreased 5% and 7%, respectively (P < .05 for both). The synthetic rate of apo A-I increased 13% (P < .01). Increased HDL after exercise training is associated with both decreased HDL protein catabolism and increased HDL apo A-I synthesis. Weight loss is not required to increase HDL-C with exercise training in overweight men, but without weight loss, even prolonged exercise training produces only modest changes in HDL-C concentrations.
Bibliographical noteFunding Information:
From the Lipid Research Laboratory, Division of Cardiolog3; The Miriam Hospital and Brown University, Providence, RI; and the Division of Cardiology, University of Pittsburgh, Pittsburgh, PA. Submitted May 21, 1996; accepted August 6, 1996. Supported by National Institutes of Health Grant No. HL-28467 and by the Miriam Foundation, the Haire Family, William Jakober, and the McNul~ Family. Address reprint requests to Paul D. Thompson, MD, 1212 Kaufmann Building, University of Pittsburgh Heart Institute, 200 Lothrop St, Pittsburgh, PA 15213. Copyright © 1997 by W.B. Saunders Company 0026-0495/97/4602-0019503.00/0