Niacin to boost your HDL 'good' cholesterol

Gerald Gau, M.D.

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Niacin has long been used to increase high-density lipoprotein (HDL), the "good" cholesterol. But compared with other cholesterol drugs, niacin hasn't gotten much respect. It's just a simple B vitamin, nothing fancy. Still, it's hard to deny niacin's often-significant impact on your HDL cholesterol levels.

A lot of the attention regarding cholesterol has been focused on lowering your low-density lipoprotein (LDL), or "bad" cholesterol. That's still an important goal. But as researchers learn more about how cholesterol is used by the body, they're realizing that boosting your HDL level is just as important as lowering your LDL cholesterol. Drug manufacturers have been busy trying to come up with new medications to increase HDL, but they haven't had much luck. One drug recently in development called torcetrapib looked promising, but it had too many dangerous side effects and was not approved by the Food and Drug Administration.

It may be time to refocus on the old standby niacin for raising HDL.

Gerald Gau, M.D., is a Mayo Clinic preventive cardiologist and is a specialist in internal medicine and cardiovascular diseases. He's been involved with the National Cholesterol Education Program Coordinating Committee, which develops national cholesterol guidelines. He answers some questions about niacin and HDL cholesterol.

What impact does niacin have on cholesterol?

Niacin can raise HDL — the "good" cholesterol — by 15 percent to 35 percent. This makes niacin the most effective drug available for raising HDL cholesterol. While niacin's effect on HDL is of most interest, it's worth noting that niacin also decreases your LDL and triglyceride levels. High levels of LDL and triglycerides are significant risk factors for heart disease.

Who might consider taking niacin?

It depends. Niacin has been shown to increase HDL in otherwise healthy people who have normal LDL levels, so your doctor might suggest you take niacin, even if your LDL is relatively normal and you're healthy.

However, don't start taking niacin to raise your HDL without talking to your doctor. Niacin must usually be given at higher doses to raise your HDL cholesterol, and the use of high-dose niacin needs to be monitored by your doctor to make sure it doesn't cause any harmful side effects.

Non-drug approaches are also helpful in boosting HDL. These include: Stop smoking if you are a smoker, eat a healthy diet and exercise. Exercise has been found to be especially effective in increasing your HDL levels. If you try steps like this and your HDL is still too low, your doctor may suggest you take niacin.

Niacin is usually given along with statins or other medications to people who have high LDL levels and low HDL. Check with your doctor before taking niacin with another medication to avoid any dangerous drug interactions. However, in general, niacin seems to work even better when used in combination with statins, drugs used to lower your LDL cholesterol. In fact, when used with some statins, niacin can increase your HDL level by 50 percent or more, as well as reduce LDL levels more than when just statins are used.

You may have heard of some prescription medications that combine statins and niacin, such as Simcor. Although these medications were approved by the Food and Drug Administration, no research studies have yet shown that the combination drugs lower cholesterol more than does taking niacin and a statin separately. If you're interested in taking a combination medication, talk to your doctor.

Are over-the-counter niacin supplements just as good as prescription niacin when it comes to increasing HDL cholesterol?

It's hard to say. Supplements sold over-the-counter (OTC) are not regulated like prescription medications. As a result, the ingredients, formulations and effect of over-the-counter niacin can vary widely. Again, it's necessary to work with your doctor if you are considering taking niacin to avoid harmful side effects.

Carotid angioplasty and stenting

Your carotid arteries are located on each side of your neck and are the main arteries supplying blood to your brain. They're particularly important because they carry blood to the cerebral cortex, which is responsible for most of your day-to-day functioning. When atherosclerosis affects these vessels, it's called carotid artery disease. It's the equivalent of coronary artery disease — atherosclerosis affecting the heart arteries — just the location of the disease is different.

Many people with carotid artery disease take medications such as aspirin, blood thinners and cholesterol-lowering drugs to keep atherosclerosis under control, and to prevent heart attack and stroke. But for some people, medications aren't enough. When an artery becomes significantly blocked — usually 70 percent blocked or more — surgery may be recommended. The most common surgery for carotid artery disease is called carotid endarterectomy, when atherosclerotic plaques are surgically removed from the carotid artery in the neck. However, a newer, less invasive procedure — carotid angioplasty and stenting — can be used in certain cases.

What is carotid angioplasty and stenting?
Angioplasty and stenting are commonly used to widen narrowed heart arteries for treatment of coronary artery disease. Carotid angioplasty and stenting work similarly, but their long-term effectiveness has not yet been determined.

During the procedure, a long, hollow tube called a catheter is inserted in an artery in your groin, and then threaded through the arteries. When it reaches the narrowed carotid artery, the doctor inflates a tiny balloon at the end of the catheter to flatten the fatty deposits against the artery wall. Then, a wire mesh stent is deployed to keep the artery propped open and prevent re-narrowing.

Carotid angioplasty uses only local anesthetic and a small incision in the groin, so recovery is generally faster than with traditional surgery. One of the more serious complications that can occur after angioplasty and stenting is a stroke from a blockage in the brain's arteries caused by a blood clot or other debris. To prevent this from happening, you'll be given blood thinners and monitored closely.

Who should get carotid angioplasty and stenting?
If you have a carotid artery with a 70 percent blockage or more, especially if you have stroke or warning stroke symptoms, and your doctor has ruled out carotid endarterectomy, carotid angioplasty and stenting may be an option for you.

The procedure may be appropriate for people who aren't in good enough health to undergo surgery — such as those with severe heart or lung disease, those who have had radiation for neck tumors, or those who have already had a carotid endarterectomy and experience new narrowing after surgery. Sometimes, carotid angioplasty and stenting is used when the location of the narrowing (stenosis) is difficult to access with endarterectomy.

Since the procedure is fairly new, doctors don't yet know how effective carotid angioplasty with stenting is as a stroke treatment or at preventing future strokes. However, it shows promise for people who need intervention but can't have a carotid endarterectomy.

Promising treatments but limited availability

Both of these procedures are relatively new and not available at many medical centers. In order for these stroke treatment and stroke prevention options to be successful, they need to be done by a physician with expertise in stenting brain arteries. Talk to your doctor about your treatment and prevention options if you have had a stroke or TIA.