It’s been well known for many years that niacin, a form of vitamin B3, may reduce total blood cholesterol and triglyceride levels and raise HDL (“good”) cholesterol levels. Now the New England Journal of Medicine reports that niacin, when combined with a cholesterol-lowering statin drug, has been found to reverse hardening of the arteries (atherosclerosis) in heart patients. In addition, the percentage of patients who suffered a major cardiovascular event (such as myocardial infarction or death from coronary heart disease) was significantly lower in the niacin group than in the ezetimibe group.

The new study involved 208 people who had, or were at high risk of developing, coronary artery disease and were being treated with a statin drug (primarily simvastatin [Zocor] or atorvastatin [Lipitor]). Participants were randomly assigned to receive niacin or a second cholesterol-lowering drug (ezetimibe; brand name Zetia) for an average of 14 months. Niacin was taken in the form of extended-release tablets at bedtime. The initial dose was 500 mg, which was increased as tolerated to a maximum of 2,000 mg each night.

The results:

• Atherosclerosis severity was assessed by measuring the thickness of the inner lining of the artery in the neck that leads to the brain (the carotid artery). There was a statistically significant decrease in carotid atherosclerosis in the group that received niacin, whereas no change was seen in the group that received ezetimibe.

• In addition, the percentage of patients who suffered a major cardiovascular event (such as myocardial infarction or death from coronary heart disease) was significantly lower in the niacin group than in the ezetimibe group (1% versus 5%). Those findings confirm the results of a study from the 1970s in which niacin supplementation reduced the death rate by 11% in people with high cholesterol.

• Niacin also produced a significant decrease in LDL (“bad”) cholesterol and triglyceride levels—above and beyond the improvements achieved with the statin drug—and significantly increased HDL cholesterol levels.

Form facts

In this study, niacin was well tolerated by most participants. However, niacin frequently causes a skin flush, which some people find intolerable, and 18% of the participants taking niacin discontinued it because of side effects.

On rare occasions, niacin in large doses (particularly extended-release forms of niacin) has caused liver damage. It is therefore important for anyone taking a large amount of niacin (such as more than 500 mg per day) to be monitored by a doctor. Despite these potential adverse effects, niacin has been shown to be an important weapon in the battle against cardiovascular disease.

Niacinamide, a form of vitamin B3 that is similar to niacin, does not cause a skin flush and does not lower serum cholesterol levels. Inositol hexanicotinate (sometimes called “no-flush niacin”) is another form that usually does not cause a skin flush. However, its effect on serum cholesterol levels appears to be minimal.

(N Engl J Med 2009;Nov 15. [E-pub ahead of print]

http://www.medfinds.com/healthnotes.php?org=medigrative%2Cmedigrative&page=newswire/newswire_2009_11_19_1.cfm