Abstract
BACKGROUND Aerobic exercise and niacin are frequently used strategies for reducing serum triglycerides, and, yet, there is no information regarding the combined effects of these strategies on postprandial triglycerides. OBJECTIVE We compared the effects of aerobic exercise and 6 wk of extended-release niacin on postprandial triglycerides in men with the metabolic syndrome. DESIGN Fifteen participants underwent each of 4 conditions: control--high-fat meal only (100 g fat); exercise--aerobic exercise performed 1 h before a high-fat meal; niacin--high-fat meal consumed after 6 wk of niacin; and niacin + exercise--high-fat meal consumed after 6 wk of niacin and 1 h after aerobic exercise. Temporal responses for triglyceride and insulin concentrations were measured and total (AUC(T)) and incremental (AUC(I)) areas under the curve were calculated. Differences were determined by using a 2-factor repeated-measures analysis of variance (P < 0.05 for all). RESULTS Exercise lowered the triglyceride AUC(I) by 32% compared with control (724 +/- 118 and 1058 +/- 137, respectively). Niacin had no influence on the triglyceride AUC(I) and attenuated the triglyceride-lowering effect of exercise when combined. Niacin + exercise had no effect on the triglyceride AUC(I) but decreased the insulin AUC(I) after niacin administration. CONCLUSIONS Aerobic exercise lowers the postprandial triglyceride response to a high-fat meal. Niacin lowers fasting but not postprandial triglycerides and appears to influence the triglyceride-lowering effect of aerobic exercise when combined. However, exercise decreases postprandial insulin concentrations after niacin administration, which illustrates the potential metabolic benefits of exercise in persons taking niacin.
