Am Fam Physician. 2017;96(2):129
Clinical Question
Is niacin effective to reduce cardiovascular events and mortality in patients with or at risk of coronary artery disease?
Bottom Line
We are now flush with data about the effects of niacin in patients with elevated cholesterol levels. Despite its ability to raise high-density lipoprotein (HDL) serum cholesterol levels, it does not add additional mortality or morbidity benefit to statin treatment. Patients with diabetes mellitus may also experience worse blood glucose control, as well as other niacin-related adverse effects. (Level of Evidence = 1a)
Synopsis
Niacin (nicotinic acid, vitamin B3) has been used to increase HDL levels since the 1970s, based on studies that showed a mortality benefit. However, these initial studies were conducted before the era of optimized statin therapy. The researchers conducting this meta-analysis searched for all randomized studies that compared niacin with placebo, either alone or in combination with statin treatment or other treatments that lower low-density lipoprotein cholesterol levels. The authors searched four databases, including Cochrane Central, and identified 13 studies that enrolled a total of 35,206 patients. The number of studies is misleading; a single study, published in 2013, provides 73% of the patients included in the analysis. The systematic review was conducted according to PRISMA standards.
Several studies published since 2000 have looked at the effect of niacin added to a statin. Although niacin can increase HDL levels by an average of 21.4%, it does not affect all-cause mortality rates. It also does not lower the risk of cardiovascular mortality, nonfatal myocardial infarction, stroke, or the need for revascularization. There was no significant heterogeneity among trials. Even studies that specifically enrolled patients with low HDL levels did not find benefit. In patients with pre-existing diabetes, treatment with niacin worsens blood glucose control (odds ratio = 1.44; 95% confidence interval, 1.31 to 1.59). Flushing and gastrointestinal and musculoskeletal adverse effects were also significantly more likely with niacin.
Study design: Systematic review
Funding source: Self-funded or unfunded
Setting: Various (meta-analysis)
Reference:GargASharmaAKrishnamoorthyPet alRole of niacin in current clinical practice: a systematic review. Am J Med2017;130(2):173–187.
