Extended-release Niacin Acutely Suppresses Postprandial Triglyceridemia

OBJECTIVE: Postprandial triglyceridemia predicts cardiovascular events. Niacin might lower postprandial triglycerides by restricting free fatty acids. Immediate-release niacin reduced postprandial triglycerides, but extended-release niacin failed to do so when dosed the night before a fat challenge. The study aims were to determine whether extended-release niacin dosed before a fat challenge suppresses postprandial triglycerides and whether postprandial triglycerides are related to free fatty acid restriction. METHODS: A double-blinded, placebo-controlled, random-order crossover experiment was performed, in which healthy volunteers took 2 g extended-release niacin or placebo 1 hour before heavy cream. We sampled blood over 12 hours and report triglycerides and free fatty acid as means +/- standard deviation for incremental area under the curve (AUC) and nadir. RESULTS: By combining 43 fat challenges from 22 subjects, postprandial triglycerides incremental AUC was +312 +/- 200 mg/dL*h on placebo versus +199 +/- 200 mg/dL*h on extended-release niacin (33% decrease, P = .02). The incremental nadir for free fatty acid was -0.07 +/- 0.15 mmol/L on placebo versus -0.27 +/- 0.13 mmol/L on extended-release niacin (P < .0001), and free fatty acid incremental AUC decreased from +2.9 +/- 1.5 mmol/L*h to +1.5 +/- 1.5 mmol/L*h on extended-release niacin (20% decrease, P = .0015). The incremental AUC for triglycerides was strongly related to the post-dose decrease in free fatty acid (r = +0.58, P = .0007). CONCLUSIONS: Given right before a fat meal, even a single dose of extended-release niacin suppresses postprandial triglyceridemia. This establishes that postprandial triglycerides suppression is an acute pharmacodynamic effect of extended-release niacin, probably the result of marked free fatty acid restriction. Further study is warranted to determine whether mealtime dosing would augment the clinical efficacy of extended-release niacin therapy. (C) 2012 Elsevier Inc. All rights reserved. The American Journal of Medicine (2012) 125, 1026-1035