HDL cholesterol function may be important factor in heart disease risk
A 2015 study from the University of Pennsylvania found that how well a patient’s HDL cholesterol functions may be an important consideration when it comes to heart disease risk. The authors of this study found that people with high HDL function had fewer heart attacks or other heart disease problems as the years went by.
These researchers noted that further study might target future ways to improve HDL function.
In the meantime, Randall S. Hall, DO, a board-certified cardiologist on the medical staff at Baylor Regional Medical Center at Grapevine, offered some ways patients can improve their cholesterol levels.
“If you’re overweight, if you lose even a few pounds, you can not only help your blood pressure and sugar control but for every 6 pounds you lose, you can increase your good HDL cholesterol by 1 milligram per deciliter,” Dr. Hall was not involved in the current study.
Dr. Hall added, “For lowering blood pressure and cholesterol, an average of 40 minutes of moderate-to-vigorous intensity aerobic activity 3 or 4 times per week is recommended. In just two months of aerobic activity, you can see you HDL cholesterol increase by 5 percent.”
Among Dr. Hall’s other suggestions were not smoking, light alcohol consumption with a doctor’s approval, limiting saturated and trans fats and talking to your doctor about what medications can up your HDL cholesterol.
HDL stands for high-density lipoprotein. Scientists and medical professionals have known for some time that a higher level of HDL in the blood may help protect patients from heart disease.
HDL helps clear out the cells in plaque — a fatty substance that builds up on artery walls and can restrict blood flow. The HDL molecules act like tiny freight trains, carrying the cholesterol to the liver where it can be excreted in the bile.
When those freight trains operate at maximum efficiency, they can decrease the risk of heart attack and heart disease because plaque doesn’t build up as fast. In essence, HDL cholesterol operating at maximum efficiency may reverse the processes that can lead to heart disease.
The authors of this study, led by Daniel J. Rader, MD, who directs the Preventive Cardiovascular Medicine and Lipid Clinic at Penn Medicine, analyzed frozen blood samples to determine the efficiency of the HDL molecules.
“This is a definitive finding that HDL function, even in people who are still relatively young and healthy, does predict later heart disease events, which implies that therapies that boost HDL function might reduce risk,” Dr. Rader said in a press release.
Dr. Rader and colleagues studied more than 25,000 men and women in eastern England. The study began in 1993 and was continued until 2009.
As part of this study, patients gave blood samples, which were frozen and stored.
Of the study patients, 1,745 developed heart disease. Dr. Rader and colleagues matched these patients with a control group, none of whom had heart disease.
Dr. Rader and team analyzed the frozen blood samples for both groups. They found that patients who had scores indicating their HDL had very good function had 36 percent fewer heart attacks than those whose HDL cholesterol showed poor function.
Although past research had indicated a link between HDL function and heart disease risks, this was the largest and longest study on this subject so far.
“We don’t fully understand why people differ in their HDL cholesterol [efficiency], but we have known for some time that the size, lipid content, and protein cargo of HDL particles can vary, and there is also some evidence for functional impairment of HDLs in heart disease and diabetes,” Dr. Rader said. “I think we now have a convincing story that HDL’s ability to promote cholesterol [efficiency] is predictive of future heart disease events even when measured early in a healthy person’s life.”
This study was published in the May 2015 issue of The Lancet Diabetes & Endocrinology.
The National Heart, Lung and Blood Institute funded this research. Dr. Rader is a founder of VascularStrategies, which performs HDL function testing. Study author Dr. John J. P. Kastelein received fees from several companies that make drugs for treating cholesterol, such as Eli Lilly, AstraZeneca, Merck and Sanofi.