Niacin supplementation improves endothelial dysfunction, meta-analysis shows
- Meta-analysis of 7 randomized, placebo-controlled clinical trials with 441 subjects
- Changes in endothelial function measured by brachial artery flow-mediated dilation (FMD)
- Niacin treatment significantly improves endothelial function
This systematic review and meta-analysis was designed to investigate the effect of niacin on endothelial function, as measured by brachial artery flow-mediated dilation (FMD).
Eligible for inclusion were randomized controlled trials investigating the impact of niacin therapy on brachial artery FMD. Meta-analysis of eligible studies was conducted using a random-effects model. Pooled effects were measured by weighted mean difference (WMD) and 95% confidence intervals. Quality assessment, and subgroup, meta-regression and sensitivity analyses were conducted using standard methods. Seven studies with a combined total of 441 subjects met the inclusion criteria and were included in the analysis.
In an overall pooled estimate, niacin therapy significantly improved FMD (WMD: 1.98%; 95% CI: 0.91-3.05%; P=.0003) and this effect was robust in the sensitivity analysis. The effect size was greater in the subgroup of studies administering higher doses of niacin (≥ 2,000 mg/day) as well as those studies administering niacin for primary prevention of atherosclerotic cardiovascular disease.
Meta-regression indicated no association between niacin-induced changes in FMD and changes in plasma HDL-cholesterol, LDL cholesterol or triglycerides. None of the included studies reported any significant effect of niacin on nitroglycerin-mediated dilation.
These findings indicate treatment with niacin supplementation improves endothelial function.