Niacin


Niacin
Small studies had hinted that large doses of niacin might help prevent heart attack or stroke, and hopes were high that this might prove to be the case. Now those hopes appear dashed. The NIH has stopped a trial 18 months ahead of schedule after finding that combining extended-release, high-dose niacin with a statin doesn’t seem to reduce the risk of such cardiovascular events.

Niacin, or vitamin B3, is often taken to help reduce blood levels of triglycerides and LDL, the so-called bad cholesterol, and to boost levels of HDL, the so-called good cholesterol. And statins, of course, are drugs used to treat high cholesterol by limiting the body’s production of it.

It made sense to try to team them up, especially for people who already had low LDL (courtesy of a statin) but who were nonetheless at risk because of their history of cardiovascular disease and their low HDL levels and high triglyceride levels.

In the now-halted trial, 3,414 people took simvastatin (Zocor), and some also took a second cholesterol-lowering drug, ezetimibe (Zetia), to ensure that LDL levels remained low. About half of the participants also received a high daily dose of extended-release niacin.

Overall, those in the niacin group did have increased HDL levels and lowered triglyceride levels after 32 months, the researchers found, but they were no less likely to suffer heart attacks, strokes or be hospitalized for acute coronary syndrome.

In fact, a few more people in the niacin group experienced ischemic strokes, in which a clot blocks blood to the brain—one reason the trial was stopped early, according anannouncement Thursday from the National Heart, Lung, and Blood Institute.

From the institute’s statement:

"The lack of effect on cardiovascular events is unexpected and a striking contrast to the results of previous trials and observational studies," said Jeffrey Probstfield, co-principal investigator and professor of medicine and epidemiology at the University of Washington, Seattle.

Researchers will now begin examining their data in considerable detail. In the meantime, consumers might do well to read up on statins, lifestyle changes and niacin itself.