Aerobic Exercise Alters Postprandial Lipemia in African American versus White Women

Abstract

Purpose:To determine whether ethnicity influences postprandial lipemia after a bout of aerobic exercise.Methods:Randomized crossover design. Healthy White (W; n = 6) and African American (AA; n = 6) women (age, W 27.0 ± 3.3 yr, AA 21.6 ± 1.4 yr; body-mass index, W 25.0 ± 0.93 kg/m2, AA 25.8 ± 0.79 kg/m2) participated in 2 treatments (control and exercise), each conducted over 2 d. On d 1, participants rested (control) or walked at 60% of maximal oxygen uptake for 90 min (exercise) and then consumed a meal. On d 2, after a 12-hr overnight fast, participants consumed an oral fat-tolerance test (OFTT) meal of 1.7 g fat, 1.65 g carbohydrate, and 0.25 g protein per kg fat-free mass. Blood was collected premeal and at 0.5, 1, 2, 3, 4, 5, and 6 hr post-OFTT and analyzed for triacylglycerol (TAG), glucose, and insulin. Areas under the curve (AUCs) were calculated for each blood variable.Results:A significantly lower TAG AUC was observed for AA (0.86 ± 0.24 mmol · L−1 · 6 hr−1) after exercise than for W (2.25 ± .50 mmol · L−1 · 6 hr−1). Insulin AUC was significantly higher for AA after exercise (366.2 ± 19.9 mmol · L−1 · 6 hr−1) than for the control (248.1 ± 29.2 mmol · L−1 · 6 hr−1).Conclusions:The data indicate that exercise performed ~13 hr before an OFTT significantly reduces postprandial lipemia in AA compared with W. It appears that AA women have an increased ability to dispose of TAG after exercise and a high-fat meal.