Niacin May Be Good for Everyone's Heart

Sept. 12, 2000 -- Niacin is a popular drug for treating cholesterol problems -- but its use has been remote among diabetics due to the fear that it could raise blood sugar levels. Now, a new study may relieve some concerns by showing that niacin can be safely used to treat cholesterol levels in those with diabetes.

"Our study shows that niacin will not harm those patients with diabetes," researcher Marshall B. Elam, PhD, MD, tells WebMD. "While current guidelines should be followed, our results put the actual effects of niacin on diabetics in perspective. When niacin is initially given, the glucose level does slightly go up, but if you slightly increase the dosage and monitor it carefully, it can have a beneficial effect." Elam is associate professor of pharmacology and medicine at the University of Tennessee Health Science Center.

Diabetics often also have unhealthy cholesterol levels. Commonly, these people have too much LDL "bad" cholesterol, not enough HDL "good" cholesterol, and an overabundance of another blood fat called triglycerides.

Niacin, a vitamin, can be useful in patients with high LDL and triglycerides and low HDL when used at high doses, but doctors have traditionally avoided its use in diabetics because of its effects on blood sugar levels.

Six medical centers across the U.S. looked at almost 470 patients, including 125 with diabetes. The study's results show a significant increase in HDL "good" cholesterol and a decrease of triglycerides in the participants.

Blood sugar levels did go up slightly, but niacin did not appear to significantly change the blood sugar control overall during the treatment period, which lasted five months.

"While the participants were given a very high dose of niacin, which ultimately increased HDL levels, the overall results of the study are very encouraging for diabetics," Frank Hu, MD, PhD, tells WebMD. "There has been a lot of controversy about the use of niacin because it can raise [blood sugar] levels -- but this study does not show a significant increase of this." Hu, who was not involved in the study, is assistant professor in the department of nutrition at the Harvard School of Public Health in Boston.

Paul Coates, PhD, the director of the Office of Dietary Supplements at the NIH in Bethesda, Md., agrees with Hu's acceptance of niacin contributing to good cholesterol levels, but he remains skeptical of the vitamin's overall worthiness for diabetics.

"I am not entirely comforted that niacin has been shown to be safe for diabetics. There is still the issue of higher [blood sugar] levels because of its use, and this needs to be watched," says Coates, who also was not involved in the study.

Both Coates and Hu contend that the first line of defense for the diabetic's common cholesterol problem should be the use of the cholesterol-lowering "statin" drugs, such as Lipitor or Zocor.

"While statins have been shown to reduce the risk of [heart] disease, they are also the best method for controlling cholesterol in diabetics, and while the study is encouraging, niacin has not been shown to be as effective against high cholesterol as these drugs," says Hu. "The exact results of it effect against heart disease in diabetics has also yet to be shown."

Elam contends that the key to safely using niacin for its favorable results is proper monitoring by the diabetic's physician. "I have seen patients whose triglyceride levels are so high that statin drugs alone cannot make a difference. We are finding that the combination of statin drugs and niacin may be an effective way of controlling an otherwise uncontrollable cholesterol level in diabetics," says Elam, who is also staff cardiologist and director of the Lipid Clinic at the Memphis Veterans Affairs Medical Center in Tennessee.