Do age and baseline LDL cholesterol levels determine the effect of regular exercise on plasma lipoprotein cholesterol and apolipoprotein B levels?

Apolipoprotein B (apoB) concentration and age are independently associated with an increased risk for cardiovascular disease. Age is also associated with increased apoB concentration. The purpose of this study was to determine the effects of exercise on apoB and examine the association between age and lipoproteins. Forty-one sedentary individuals exercised for 6 months, four times/week for 40 min between 60 and 85% of their maximal heart rate. Lipids were determined three times: before training, 24 and 72 h after the last training session. Exercise did not alter apoB (1.2+/-0.05 g/l vs. 1.2+/-0.05 g/l; P>0.05), or other lipids or lipoproteins. When participants were sequestered by baseline low density lipoprotein cholesterol (LDLc), total cholesterol (TC) was decreased at 24 h post (6.3+/-0.2 mmol/l vs. 6.0+/-0.2 mmol/l, P<0.05) and LDLc after 24 and 48 h post (4.3+/-0.1 mg/dl vs. 3.9+/-0.1 and 4.1+/-0.2 mg/dl, P<0.05) in the high LDLc group. In the low LDLc group both TC (4.4+/-0.2 mmol/l vs. 4.6+/-0.2 and 4.6+/-0.2 mmol/l, P>0.05) and LDLc (2.6+/-0.1 mmol/l vs. 2.8+/-0.1 and 2.8+/-0.2 mmol/l, P<0.05) were elevated at 24 h and remained elevated at 72 h post compared to baseline. Age does not affect apoB or lipoproteins in response to exercise. Individuals with high baseline LDLc experienced acute reduction in TC and LDLc produced by each exercise session.

Moderate exercise-induced energy expenditure does not alter leptin levels in sedentary obese men.

OBJECTIVE: The purpose of the study was to determine whether exercise-induced increases in energy expenditure (EE) alter circulating leptin levels in obese individuals. DESIGN: Participants were randomized to an exercise intervention group (n = 8) or nonexercising control (n = 7). SETTING: All data were collected on an outpatient basis at the exercise physiology laboratory at the University of Central Florida. PATIENTS: Fifteen healthy obese males (24.9 +/- 1.4 years old, body mass index 33.4 +/- 0.7 kg . m). INTERVENTIONS: Members of the intervention group underwent a single exercise session of moderate intensity (58.4 +/- 1.3% of VO2max) for 60 minutes. MAIN OUTCOME MEASUREMENTS: Postexercise, 24 hour postexercise, and 48 hour postexercise levels of leptin, insulin, and ghrelin. RESULTS: The exercise session elicited an EE of 567 +/- 25 Kcal. No significant main effect or time-by-group interactions for leptin or ghrelin were observed immediately after the exercise bout or in the days following the intervention. CONCLUSIONS: These preliminary data suggest that a bout of acute exercise of moderate intensity and duration does not affect leptin concentration. It is possible that a higher level of EE is required to elicit substantial changes.