Aerobic exercise alters postprandial lipemia in African American versus White women

To determine whether ethnicity influences postprandial lipemia after a bout of aerobic exercise.

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 pre-meal 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.

A significantly lower TAG AUC was observed for AA (0.86+/-0.24 mmol x L(-1) x 6 hr(-1)) after exercise than for W (2.25+/- .50 mmol x L(-1) x 6 hr(-1)). Insulin AUC was significantly higher for AA after exercise (366.2+/-19.9 mmol x L(-1) x 6 hr(-1)) than for the control (248.1+/-29.2 mmol x L(-1) x 6 hr(-1)).

The data indicate that exercise performed approximately 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.