Lauren Dempsey, MS in Biomedicine and Law, RN, FISM News
It has been widely accepted in the medical community that high-density lipoprotein (HDL) cholesterol — aka the “good” cholesterol — is associated with many positive health benefits.
However, according to a new study funded by the National Institutes of Health (NIH) and published in the Journal of the American College of Cardiology, there are no heart benefits to high levels of HDL, and the benefits of normal levels may differ based on race or ethnicity.
Researchers from the Oregon Health & Science University’s Knight Cardiovascular Institute evaluated almost 24,000 medical records from a previous study — Reasons for Geographic and Racial Differences in Stroke Study (REGARDS) — and compared various clinical and behavioral risk factors to predict coronary heart disease (CHD) based on race.
When the data was evaluated for “sex-specific clinical HDL-C categories,” low HDL cholesterol levels were associated with increased CHD risk in white adults, but not in black adults. High HDL cholesterol levels were not associated with decreased CHD events in either race. Black and white men had similar incident rates of CHD. Black women had higher incidence rates of disease when compared to white women and more cardiac events were fatal in black adults than in white adults.
All participants, regardless of race, had baseline characteristics that were similar, including age, cholesterol levels, diabetes, high blood pressure, and smoking.
Nathalie Pamir, the senior author of the study wrote in a statement, “It’s been well accepted that low HDL cholesterol levels are detrimental, regardless of race. Our research tested those assumptions.”
The researchers evaluated if the effects of LDL cholesterol and triglyceride levels were also race-specific. The team found they were not race-specific, as levels of LDL had similar associated risks of CHD in both black and white participants.
The authors of the study wrote that these “race-dependent observations indicate that the underlying biologic mechanism by which HDL-C associates with incident CHD in white and black participants is different from that of other lipid risk factors.”
Cholesterol is essential to certain bodily functions like creating hormones and digestion, which the body produces on its own. However, additional cholesterol is found in food and can impact cholesterol levels. The CDC estimates that almost 2 in 5 American adults have high cholesterol and unfavorable levels were found in 6.1% of male adolescents and 3.0% of females.
LDL cholesterol is associated with heart disease because it can cause plaque to build up in the arteries, whereas HDL cholesterol is important for absorbing cholesterol and transporting it to the liver where it is then flushed out of the body.
Pamir remains hopeful that what “this type of research establishes is the need to revisit the risk-predicting algorithm for cardiovascular disease. It could mean that in the future we don’t get a pat on the back by our doctors for having higher HDL cholesterol levels.”
“When it comes to risk factors for heart disease, they cannot be limited to one race or ethnicity,” said Pamir. “They need to apply to everyone.”