Does Baseline High Density Lipoprotein Cholesterol Influence Post-exercise Change Associated With Acute Exercise?

Abstract

PURPOSE: The purpose of this study was to determine if baseline levels of high density lipoprotein cholesterol (HDL) affects the change in HDL levels associated with an acute bout of exercise of varying energy expenditure. METHODS: Two groups of healthy untrained male volunteers participated in this study. Subjects were assigned to one of two groups according to their baseline HDL levels. The LOW HDL group consisted of 13 subjects with clinically low HDL (< 40mg/dl) and the NORMAL HDL group consisted of 14 subjects with normal HDL (≥ 45mg/dl). Age, diet, VO2max and anthropometric data were collected prior to initiation of the experimental protocol and were similar for both groups. Age, height, weight, BMI, VO2max and resting HDL for LOW were 21.9 ± 2.0 yrs, 1.8 ± 0.1 m, 80.9 ± 7.9 kg, 25.2 ± 2.2 kg/m2, 45.8 ± 5.1 ml/kg/min and 35.7 ± 2.7 mg/dl, respectively while characteristics of the NORMAL group were 23.4 ± 7.1yrs, 1.8 ± 0.1 m, 78.6 ± 7.6 kg, 24.3 ± 2.5 kg/m2, 47.5 ± 4.8 ml/kg/min and 53.9 ± 5.8 mg/dl. Subjects completed two nonconsecutive exercise sessions (on separate days) expending 500 and 700 kcals while running on a treadmill at 65% of VO2max. Venous blood was collected pre-exercise, immediately post-exercise (IPE), and 24 hours post-exercise (+24) and analyzed for HDL and subfractions of HDL (HDL2and HDL3) and corrected for any shift in plasma volume. RESULTS: No differences in HDL or HDL subfractions were observed between NORMAL and LOW HDL groups at any post-exercise times. With both groups pooled HDL was significantly increased (p<0.05) by 2.5mg/dl (5.6%) at IPE, but not at +24 when compared to pre-exercise values. The increase in HDL post exercise was due for the most part to increased HDL3 (3.5mg/dl, 13.6%) whereas the HDL2 subfraction remained statistically unchanged. CONCLUSIONS: Baseline HDL status does not appear to affect the magnitude of post-exercise HDL-C alterations in untrained men. Furthermore, post-exercise increases in HDL associated with acute exercise appear due to increased HDL3 and not HDL2 in the subjects of this study.