Postmenopausal factors may have an impact on the heart-protective qualities of high-density lipoproteins (HDL) – also known as ‘good cholesterol’ – according to a study led by researchers in the University of Pittsburgh Graduate School of Public Health.
The findings, published in Arteriosclerosis, Thrombosis, and Vascular Biology, a journal of the American Heart Association (AHA), indicate that this specific type of blood cholesterol may not translate into a lowered risk of cardiovascular disease in older women — bringing into question the current use of HDL cholesterol in a common equation designed to predict heart disease risk, particularly for women.
HDL is a family of particles found in the blood that vary in sizes and cholesterol contents. HDL has traditionally been measured as the total cholesterol carried by the HDL particles, known as HDL cholesterol. HDL cholesterol, however, does not necessarily reflect the overall concentration, the uneven distribution, or the content and function of HDL particles. Previous research has demonstrated the heart-protective features of HDL. This good cholesterol carries fats away from the heart, reducing the build-up of plaque and lowering the potential for cardiovascular disease.
“The results of our study are particularly interesting to both the public and clinicians because total HDL cholesterol is still used to predict cardiovascular disease risk,” said lead author Dr. Samar R. El Khoudary, associate professor in Pitt Public Health’s department of epidemiology. “This study confirms our previous work on a different group of women and suggests that clinicians need to take a closer look at the type of HDL in middle-aged and older women, because higher HDL cholesterol may not always be as protective in postmenopausal women as we once thought. High total HDL cholesterol in postmenopausal women could mask a significant heart disease risk that we still need to understand.”
Dr. El Khoudary’s team looked at 1,138 women aged 45 through 84 enrolled across the U.S. in the Multi-Ethnic Study of Atherosclerosis (MESA), a medical research study sponsored by the National Heart, Lung and Blood Institute of the National Institutes of Health (NIH). MESA began in 1999 and is still following participants today.
The study points out that the traditional measure of the good cholesterol, HDL cholesterol, fails to portray an accurate depiction of heart disease risk for postmenopausal women.
In contrast to HDL cholesterol, a higher concentration of total HDL particles was associated with lower risk of atherosclerosis. Additionally, having a high number of small HDL particles was found beneficial for postmenopausal women. These findings persist irrespective of age and how long it has been since women became postmenopausal.