Doctors often prescribe both a statin and niacin when either drug by itself fails to have sufficient effect, or when patients have low ("good") HDL cholesterol and/or high triglycerides as well as high ("bad") LDL cholesterol. The combination improves cholesterol levels more than either drug alone, but it has not been clear whether it is better at preventing heart attacks than a statin alone.
Preliminary results from a long-awaited federal study have now called into question the notion of adding niacin to statin therapy— at least in some people. The study, called AIM-HIGH, was halted early and has not been published yet; only sketchy data have been released.
The study involved 3,400 people with a history of cardiovascular disease who were already taking a statin to lower their LDL but still had low HDL and high triglycerides. Their statin doses were adjusted so they achieved the LDL target of less than 80. Some subjects were then also given high-dose extended-release prescription niacin (Niaspan), with the expectation that it would offer extra protection by raising HDL and lowering triglycerides.
The study was stopped after 32 months when, surprisingly, it became clear that the combination group, despite its higher HDL levels, did not have fewer heart attacks or other cardiovascular events than the statin-only group—and had slightly more strokes.
If you are taking niacin, don’t stop because of this study, at least not without consulting your doctor. This was a select group of older patients with existing coronary heart disease who had already achieved very low LDL levels. It’s possible that once LDL is so low, raising HDL may not matter much—that is, there may be little room for further reduction in cardiac risk. Niacin may still provide added benefits for people with a different risk profile or those who have not reduced their LDL level so dramatically. Moreover, none of the previous studies on niacin found an increased risk of stroke, and many experts believe this was a statistical fluke in the new study.
A much larger study of a niacin/statin combination is now underway and the results may clarify matters.