Report offers interim guidelines to raise HDL levels

Physicians say that exercise, dietary control and smoking cessation are critical.

Cardiologists and other experts at Johns Hopkins University have issued interim guidelines for physicians on how best to treat low levels of HDL cholesterol and help keep arteries clear from LDL buildup.

In an article published online in the New England Journal of Medicine, the researchers reported that existing strategies to prevent heart disease have not addressed the best means to raise HDL cholesterol and instead have focused heavily on lowering LDL cholesterol.

“We have reached a turning point in the prevention of coronary heart disease, from an emphasis during the last 15 years on lowering LDL cholesterol levels to an emphasis in the next decade on raising levels of HDL cholesterol,” said Roger Blumenthal, MD, an associate professor and director of the Ciccarone Preventive Cardiology Center at Johns Hopkins University School of Medicine and Heart Institute. Blumenthal is an editorial board member of Cardiology Today’s Preventive Cardiology section.

Raising HDL levels

Roger Blumenthal

According to Blumenthal, existing guidelines from the National Institutes of Health and National Cholesterol Education Program primarily emphasize lowering LDL cholesterol to control blood lipid levels without considering the alternative of raising HDL cholesterol as the primary or even secondary goal.

Blumenthal noted, however, that every milligram-per-deciliter increase in HDL cholesterol lowers the risk of suffering a fatal myocardial infarction by about 3%.

Low levels of HDL cholesterol are known to increase overall risk of dying from heart disease and to increase risk of arteries narrowing again after angioplasty.

Low levels of HDL cholesterol, he said, are defined as less than 40 mg/dL of blood in men and 50 mg/dL in women.

In the report, Blumenthal and Dominique Ashen, PhD, an assistant professor at Johns Hopkins University School of Nursing, provide a comprehensive review and summary of the 50 most significant research studies on how best to manage HDL-cholesterol levels through modification of lifestyle risk factors and use of drug therapy.

The researchers included a table listing heart medications with guidelines about how and when the drugs — niacin, fibrates and statins or various combinations — can be used to raise HDL cholesterol. Also provided in the table are details on the drugs’ mechanisms of action and possible side effects.

Modifying lifestyle risk factors

To raise HDL cholesterol levels, the researchers recommend a regular exercise program of brisk aerobic exercise for 30 minutes, several times a week if not every day.

Quitting smoking, they said, provided an average increase in HDL levels of 4 mg/dL. Aids such as drug therapy, nicotine replacement products and counseling can help patients quit.

Weight control was also highlighted as critical to raising HDL levels. The researchers noted that every kilogram of weight lost raised HDL levels by an average 0.35 mg/dL. A reasonable weight loss goal for overweight or obese patients, they suggested, is one pound per week with a target BMI of less than 25.

Mild to moderate consumption of alcohol of no more than one to two drinks per day has been shown beneficial in raising HDL levels an average of 4 mg/dL, irrespective of the type of alcohol consumed.

The researchers cautioned that the potential risks may outweigh the benefits in people with liver or addiction problems.

They recommended a diet low in saturated fat and rich in the polyunsaturated fatty acids found in foods such as oils (olive, canola, soy and flaxseed); nuts (almonds, peanuts, walnuts and pecans); coldwater fish (salmon and mackerel) and shellfish.

Consumption of carbohydrates should be restricted because high-glycemic products such as processed cereals and breads are associated with lower HDL levels.

In the report, the researchers cited niacin as the most effective therapy for raising HDL cholesterol, leading to increases of 20% to 35%.

Fibrate therapy is also effective, they said, producing an average increase of 10% to 25%. Statins are the least effective of the three drug classes, used primarily to reduce LDL cholesterol, raising HDL levels by 2% to 15%.

When used in combination, low-dose statins and high-dose niacin have been shown to produce benefits of 21% to 26%.

Managing cholesterol

“Our report offers people interim guidelines on how best to manage HDL cholesterol levels while awaiting the results of national clinical trials, which could prove more definitive,” Ashen said in a press release.

They pointed out that research has not yet clearly distinguished which reductions in risk from heart disease are due to drug gains in HDL levels or other direct effects on the arteries.

“That has been responsible for delaying revisions to national guidelines on HDL cholesterol,” Blumethal said.

For more information:

• Ashen MD, Blumenthal RR. Low HDL cholesterol levels. New Engl J Med. 2005; 353:1252-1260.