The Current State of Niacin in Cardiovascular Disease Prevention A Systematic Review and Meta-Regression
ABSTRACT OBJECTIVES: This study sought to assess the efficacy of niacin for reducing cardiovascular disease (CVD) events, as indicated by the aggregate body of clinical trial evidence including data from the recently published AIM-HIGH (Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides: Impact on Global Health Outcomes) trial. BACKGROUND: Previously available randomized clinical trial data assessing the clinical efficacy of niacin has been challenged by results from AIM-HIGH, which failed to demonstrate a reduction in CVD event incidence in patients with established CVD treated with niacin as an adjunct to intensive simvastatin therapy. METHODS: Clinical trials of niacin, alone or combined with other lipid-altering therapy, were identified via MEDLINE. Odds ratios (ORs) for CVD endpoints were calculated with a random-effects meta-analyses. Meta-regression modeled the relationship of differences in on-treatment high-density lipoprotein cholesterol with the magnitude of effect of niacin on CVD events. RESULTS: Eleven eligible trials including 9,959 subjects were identified. Niacin use was associated with a significant reduction in the composite endpoints of any CVD event (OR: 0.66; 95% confidence interval: 0.49 to 0.89; p = 0.007) and major coronary heart disease event (OR: 0.75; 95% confidence interval: 0.59 to 0.96; p = 0.02). No significant association was observed between niacin therapy and stroke incidence (OR: 0.88; 95% confidence interval: 0.5 to 1.54; p = 0.65). The magnitude of on-treatment high-density lipoprotein cholesterol difference between treatment arms was not significantly associated with the magnitude of the effect of niacin on outcomes. CONCLUSIONS: The consensus perspective derived from available clinical data supports that niacin reduces CVD events and, further, that this may occur through a mechanism not reflected by changes in high-density lipoprotein cholesterol concentration.
- Stroke 09/2013; 44(10):2688-2693. DOI:10.1161/STROKEAHA.113.001529 · 6.02 Impact Factor
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ABSTRACT: Niacin has been used for many years in the treatment of dyslipidemia due to its ability to decrease serum levels of triglycerides and low-density lipoprotein cholesterol and to increase levels of high density lipoprotein cholesterol. However, niacin causes severe flushing resulting in poor patient compliance. The discovery of hydroxy-carboxylic acid receptor 2 (HCA2) as a high affinity receptor for niacin has opened avenues to investigate the mechanism of action of niacin, and to potentially discover agonists which maintain the antilipolytic effects of niacin accessed by a decrease in circulating non-esterified fatty acids (NEFA) and thereby perhaps the lipid/lipoprotein effects, but avoid the flushing side effects. Here we describe the strategy we implemented to identify such compounds. This approach resulted in the discovery of GSK256073, a highly potent HCA2 agonist, which produced similar NEFA lowering effects to niacin in preclinical models (rat and guinea pig). A guinea pig model was used to predict flushing, via an increase in ear temperature, and GSK256073 was found to have a minimal effect in this model. These preclinical models appeared to be predictive of human response, since in a first-time-in-human study, GSK256073 displayed long lasting NEFA and triglyceride lowering effects in healthy male subjects, which were not associated with flushing. GSK256073 can be used as a pharmacological tool to better understand the role of HCA2 in lipid metabolism. Copyright © 2015. Published by Elsevier B.V.European Journal of Pharmacology 03/2015; 756. DOI:10.1016/j.ejphar.2015.01.051 · 2.68 Impact Factor
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ABSTRACT: Lipoprotein(a) [Lp(a)] is a cardiovascular risk factor; in addition to being a low-density lipoprotein (LDL)-like particle, it contains highly heterogeneous apolipoprotein(a) [apo(a)]. No prior studies have evaluated extended-release (ER) niacin effect on Lp(a) level depending on apo(a) phenotype. For this 24-week, prospective, open-label clinical trial we recruited 30 men (mean age 46.2 ± 7.5 years) with Lp(a) levels >20 mg/dL. No participant had previously received lipid lowering therapy, and started ER niacin 500 mg with stepwise dose increasing up to 1.5-2.0 g. Subjects were evaluated for Lp(a), lipids, high-sensitivity C-reactive protein, lipoprotein-associated phospholipase A2 (Lp-PLA2), and fibrinolytic markers (plasminogen activator inhibitor-1, tissue plasminogen activator/plasminogen activator inhibitor-1 complex, plasmin-antiplasmin complex). Patients were divided into two groups with major low- (LMW) or high-molecular weight (HMW) apo(a) isoforms determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of plasma under reducing conditions followed by immunoblotting. At baseline, groups were comparable in age, lipid, inflammatory and fibrinolytic biomarkers levels. There was a significant difference in baseline Lp(a) concentrations: 92 ± 29 mg/dL versus 54 ± 46 mg/dL in LMW and HMW apo(a) groups, respectively, p < 0.01. During the course of niacin treatment Lp(a) decreased by 28% (p < 0.003), Lp-PLA2 by 22% (p < 0.001), C-reactive protein by 24% (p = 0.07) in LMW apo(a) group, whereas no changes in Lp(a) and biomarkers levels were obtained in HMW apo(a) group. High-dose ER niacin declines elevated Lp(a) level in male subjects with low- but not high-molecular weight apo(a) phenotype. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.Atherosclerosis. Supplements 05/2015; 18. DOI:10.1016/j.atherosclerosissup.2015.02.008 · 9.67 Impact Factor