A study supported by the National Institutes of Health found that high-density lipoprotein (HDL) cholesterol, often called “good cholesterol,” may not be as effective as scientists believed in uniformly predicting cardiovascular disease risk among adults of different racial and ethnic backgrounds. .
The research, published in the Journal of the American College of Cardiology, found that while low levels of HDL cholesterol predicted an increased risk of heart attacks or related deaths for white adults, a long-accepted association, the same was not true for blacks. adults. In addition, higher levels of HDL cholesterol were not associated with a reduced risk of cardiovascular disease for either group.
“The goal was to understand this long-established link labeling HDL as the beneficial cholesterol, and whether this holds true for all ethnicities,” said Nathalie Pamir, Ph.D., lead author of the study and associate professor of medicine within. the Knight Cardiovascular Institute at Oregon Health & Science University, Portland. “It has been well accepted that low levels of HDL cholesterol are harmful, regardless of race. Our research tested these assumptions.”
To do this, Pamir and colleagues reviewed data from 23,901 adults in the United States who participated in the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS). Previous studies that shaped perceptions of “good” cholesterol levels and heart health were conducted in the 1970s using research with mostly white adult study participants. For the current study, researchers were able to see how the cholesterol levels of middle-aged black and white adults without heart disease living across the country overlapped with future cardiovascular events.
Study participants were enrolled in REGARDS between 2003 and 2007, and researchers analyzed the information collected over a 10- to 11-year period. Black and white study participants shared similar characteristics, including age, cholesterol levels, and underlying risk factors for heart disease, such as having diabetes, high blood pressure, or smoking. During that time, 664 black adults and 951 white adults had a heart attack or heart attack-related death. Adults with higher levels of LDL cholesterol and triglycerides had modestly increased risks of cardiovascular disease, which was in line with previous research findings.
However, the study was the first to find that lower levels of HDL cholesterol only predicted an increased risk of cardiovascular disease for white adults. It also extends the results of other studies showing that high HDL cholesterol levels are not always associated with reduced cardiovascular events. The REGARDS analysis was the largest US study to show that this was true for both white and black adults, suggesting that higher-than-optimal amounts of “good” cholesterol may not provide cardiovascular benefits for no group
“What I hope this kind of research establishes is the need to revise the risk prediction algorithm for cardiovascular disease,” Pamir said. “It could mean that in the future we don’t get a pat on the back from our doctors for having higher levels of HDL cholesterol.”
Pamir explained that as researchers study the role of HDL cholesterol in supporting heart health, they are exploring different theories. One is quality over quantity. That is, rather than having more HDL, the quality of HDL’s function, to collect and transport excess cholesterol from the body, may be more important in supporting cardiovascular health.
They are also taking a microscopic look at the properties of HDL cholesterol, including analyzing hundreds of proteins associated with cholesterol transport and how different associations, based on a protein or groups of proteins, can improve predictions of cardiovascular health.
“HDL cholesterol has long been an enigmatic risk factor for cardiovascular disease,” explained Sean Coady, deputy chief of epidemiology in the Division of Cardiovascular Sciences at the National Heart, Lung and Blood Institute (NHLBI). “The results suggest that a deeper dive into the epidemiology of lipid metabolism is warranted, particularly regarding how race may modify or mediate these relationships.”
The authors conclude that, in addition to supporting ongoing and future research with diverse populations to explore these connections, the results suggest that cardiovascular disease risk calculators using HDL cholesterol could lead to inaccurate predictions for black adults.
“When it comes to heart disease risk factors, they can’t be limited to one race or ethnicity,” Pamir said. “They should apply to everyone.”
The REGARDS study is co-funded by the National Institute of Neurological Disorders and Stroke and the National Institute on Aging and received additional support from NHLBI.
For more information on cholesterol and heart health, visit https://www.nhlbi.nih.gov/health/blood-cholesterol.
For information on heart healthy living, visit https://www.nhlbi.nih.gov/health/heart-healthy-living.
About the National Heart, Lung, and Blood Institute (NHLBI):
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