“Good” cholesterol may not be good for everyone

According to a new study supported by the National Institutes of Health (NIH), “good cholesterol” may not be as effective as scientists once thought in uniformly predicting the risk of cardiovascular disease among adults of different racial and ethnic backgrounds.

The study challenges the role of “good” cholesterol in predicting overall heart disease risk.

Lower levels of HDL cholesterol were associated with an increased risk of heart attacks in white but not black adults, and higher levels were not protective for either group.

High-density lipoprotein (HDL) cholesterol, often called “good cholesterol,” may not be as effective as scientists previously thought at uniformly predicting cardiovascular disease risk among adults of different racial and ethnic backgrounds, a study suggests. The research was supported by the National Institutes of Health (NIH).

The study found that while low HDL cholesterol predicts an increased risk of heart attacks or related deaths for white adults — a long-recognized link — the same is not true for black adults. In addition, higher HDL cholesterol was not associated with a reduced risk of cardiovascular disease in either group. The study was published on November 21 in Journal of the American College of Cardiology,

LDL (low-density lipoprotein) cholesterol, sometimes called “bad” cholesterol, makes up most of the cholesterol in your body. High levels of LDL cholesterol increase the risk of heart disease and stroke. HDL (high-density lipoprotein) cholesterol, sometimes called “good” cholesterol, absorbs cholesterol in the blood and carries it back to the liver.

“The goal was to understand this long-established association that marks HDL as good cholesterol, and if that holds true across ethnic groups,” said Natalie Pamir, Ph.D., senior author of the study and associate professor of medicine at the Cardiovascular Institute. Knight at Oregon Health & Science University, Portland. “It has been recognized that low HDL cholesterol is harmful, regardless of race. Our study tested these assumptions.’

To do this, Pamir and her colleagues looked at data from 23,901 US adults who participated in Reasons for geographic and racial disparities in stroke research (Sincerely). Previous studies that shaped the concept of “good” cholesterol and heart health were conducted in the 1970s through studies with mostly white adult study participants. For the current study, researchers were able to look at how cholesterol levels in middle-aged black and white adults without heart disease who lived across the country correlated with future cardiovascular events.

Study participants who participated in REGARDS from 2003 to 2007 analyzed information collected over 10 to 11 years. Black and white study participants had similar characteristics, such as age, cholesterol levels and major risk factors for heart disease, including diabetes, high blood pressure or smoking. During that time, 664 black adults and 951 white adults experienced a heart attack or heart attack-related death. Adults with elevated levels of low-density lipoprotein (LDL) cholesterol and triglycerides had a modestly increased risk of cardiovascular disease, consistent with findings from previous studies.

However, the study was the first to find that lower HDL cholesterol only predicted an increased risk of cardiovascular disease for white adults. It also expands on findings from 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 in both black and white adults, suggesting that higher-than-optimal amounts of “good” cholesterol did not confer cardiovascular benefits in either group.

“What I hope this study establishes is the need to rethink the algorithm for predicting cardiovascular disease risk,” Pamir said. “This could mean that our doctors won’t be patting us on the back for higher HDL cholesterol in the future.”

Pamir explained that researchers are studying the role of HDL cholesterol in supporting heart health and exploring different theories. One is quality over quantity. That is, rather than raising HDL, the quality of HDL’s function—in collecting and transporting excess cholesterol from the body—may be more important to support cardiovascular health.

They also take a microscopic look at the properties of HDL cholesterol, including analyzing hundreds of proteins involved in cholesterol transport and how different associations based on a single protein or groups of proteins can improve cardiovascular health predictions.

“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). “These findings suggest that further investigation into the epidemiology of lipid metabolism is warranted, particularly in terms of how race may modify or mediate this relationship.”

The authors conclude that in addition to supporting current and future research with diverse populations to examine these associations, the findings suggest that Cardiovascular disease risk calculators the use of HDL cholesterol may 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.”

Reference: “Race-Dependent Association of High-Density Lipoprotein Cholesterol Levels with Coronary Artery Disease” By Neil A. Zakai, MD, Jessica Minier, MD, Monica M. Safford, MD, Yingsu Ko, PhD, Marguerite R. Irwin, MD Sergio Fazio, Ph.D., MD Mary Cushman, Ph.D. Virginia J. Howard and Natalie Pamir, Ph.D., November 21, 2022. Journal of the American College of Cardiology.
DOI: 10.1016/j.jacc.2022.09.027

The REGARDS study is jointly funded by the National Institute of Neurological Disorders and Stroke and the National Institute on Aging and has received additional support from the NHLBI. “Good” cholesterol may not be good for everyone

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