Niacin (Nicotinic Acid) -- The Old Drug Is Making a Comeback With A New Act

Linda Brookes, MSc

Disclosures

June 12, 2007

In This Article

Niacin as Treatment for the Metabolic Syndrome

Niacin has been proposed as a viable alternative to statin treatment in patients with the metabolic syndrome, but this has not been studied extensively.[3,4] Martin Thoenes, MD (Technical University, Dresden, Germany) and coinvestigators at Emory University School of Medicine (Atlanta, Georgia) presented the results of a study that demonstrated the beneficial effects of ER niacin on CIMT and endothelial function in patients with metabolic syndrome.[5] The metabolic syndrome is characterized by raised triglycerides and low serum HDL cholesterol and impaired endothelial function in a proinflammatory vascular environment, which is a hallmark of progression of the syndrome. The results of this study also suggested that niacin has anti-inflammatory effects and confirmed previous studies as to the effects of niacin on HDL cholesterol, triglycerides, and adiponectin. Finally, there was no significant increase in fasting glucose levels with niacin, a potential concern raised by previous investigators.

Dr. Thoenes and his colleagues recruited 50 subjects aged ≥ 18 years who had the metabolic syndrome according to the National Cholesterol Education Program (NCEP)/Adult Treatment Panel III (ATP III) criteria[6,7] and were unable or unwilling to take a statin. The subjects were randomized in a double-blind manner and in a 1:2 ratio to either placebo or 1 g daily of ER niacin (Slow-niacin, Upsher-Smith Laboratories, Minneapolis, Minnesota) for 52 weeks. The ER niacin dose was selected on the basis of previous studies. Five subjects withdrew from the study, 3 in the niacin group due to flushing and 2 in the placebo group due to nausea. Measurements were obtained at baseline and 52 weeks. Pill counts were obtained to determine compliance with the protocol.

At 52 weeks, compared with placebo, treatment with ER niacin was associated with a significant 17% decrease in LDL cholesterol and a significant 24% increase in HDL cholesterol ( Table 4 ). Triglycerides were also significantly decreased with ER niacin vs placebo. There was no significant effect of ER niacin on adiponectin, an adipokine negatively associated with risk of atherosclerosis. Dr. Thoenes noted that, contrary to reports that have suggested niacin may increase insulin resistance, fasting glucose did not change significantly over 52 weeks with either placebo or niacin treatment in this study.

In the ER niacin group, there was a reduction in high-sensitivity C-reactive protein (hsCRP), compared with no change in the placebo group ( Table 5 ). Flow-mediated dilation (FMD) increased significantly from 4.58 ± 0.57% to 5.47 ± 0.79% with niacin. CIMT, the primary end point of the study, was increased in the placebo group, whereas it decreased in the ER niacin group (from 0.700 mm ± 0.018 to 0.695 ± 0.16 mm).

Copresenter Bobby V. Khan, MD, PhD (Emory University School of Medicine) concluded that treatment with ER niacin appears to have a sustained effect in reducing the progression of atherosclerosis, as measured by CIMT, and there is also a concomitant improvement in endothelial function with improvements in FMD. In a word, "Niacin really hits on metabolic syndrome."

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