Niacin Study: Doctors Caution Against Discontinuing Use
Despite the termination of the niacin study which revealed that the drug has no effect on lowering cardiovascular risk, doctors warn that patients should not discontinue use of the medication without consulting their physicians.
On Thursday, the National Institute of Health called an early end to their clinical trial investigating the affects of a commonly prescribed cholesterol medication, niacin, on lowering heart attacks and strokes. The study revealed that a high-dose of extended-release niacin not only has no protective effect against cardiovascular events, but may even increase one's risk for stroke.
Lack of Niacin Effect Surprised Researchers
"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, M.D., AIM-HIGH co-principal investigator and professor of medicine and epidemiology at the University of Washington, Seattle. "The AIM-HIGH findings do not support the trial's hypothesis that, in the population studied, adding extended-release niacin to simvastatin in participants with well-controlled LDL cholesterol can provide additional clinical benefit."
The clinical trial, conducted by the NIH and Niaspan (niacin) manufacturer Abbott Laboratories, began the enrollment of the 3,414 participants back in 2006. The goal of the trial was to evaluate how raising HDL, or “good” cholesterol, through niacin use while controlling LDL “bad” cholesterol with statin therapy, would affect one's risk for cardiovascular events such as heart attack and stroke. This design was based on previous smaller observational studies which had suggested that niacin, in conjunction with statin therapy, improves these health risks.
All study participants had a history of cardiovascular disease and were currently on statin drugs to control their LDL cholesterol levels. They also all had low HDL levels in conjunction with high triglycerides, placing them in a high-risk category for a recurrent cardiovascular event. Half of the participants were given a high-dose extended-release niacin (also known as vitamin B3) and the other half were given a placebo.
Study Reveals Niacin Group Had More Strokes
According to an independent data and safety monitoring board who reviewed the progress of the trial the niacin therapy had no impact on reducing heart attacks and other cardiovascular events. Furthermore, they noted, there was a surprise small increase in stroke risk associated with niacin group (1.6 percent vs. 0.7 percent) that warrants further investigation. Therefore, the board recommended an early termination of the trial.
"Seeking new and improved ways to manage cholesterol levels is vital in the battle against cardiovascular disease," said Susan B. Shurin, M.D., acting director of the NHLBI. "This study sought to confirm earlier and smaller studies. Although we did not see the expected clinical benefit, we have answered an important scientific question about treatment for cardiovascular disease."
Should Patients Currently Taking Niacin Stop Therapy?
Dr. Steven Schnur, cardiologist and CEO of a concierge medicine group, cautions patients not to stop taking niacin without consulting a physician first. “The patient population in this study had well-controlled LDL [bad] cholesterol, but in many patients this is not the case,” he says. “Further studies need to be done and several studies are currently [in progress].”
In addition, Dr. William E. Boden, M.D. co-investigator of the study says, "The results from AIM-HIGH should not be extrapolated to apply to potentially higher-risk patients such as those with acute heart attack or acute coronary syndromes, or in patients whose LDL cholesterol is not as well-controlled as those in [the niacin study]."
Currently, there are no proven adverse effects associated with niacin use and experts do not believe that those taking the niacin are at significant risk. Additionally, over-the-counter niacin supplements were not included in the study and the results cannot be applied.