Summary: Higher levels of HDL, the so-called “good cholesterol,” may not protect against Alzheimer’s in postmenopausal women, with the risk potentially tied to the quality, not quantity, of HDL particles. A new study shows that larger HDL particles, which increase during menopause, lose efficiency in supporting cognitive health.
Researchers found that women with more smaller HDL particles and phospholipid-rich particles in midlife maintained better memory over time. The study suggests that health behaviors can improve HDL quality, aiding brain health. This adds to evidence that lifestyle changes, even in one’s 40s, may reduce Alzheimer’s risk in later years.
Key Facts:
- HDL quality, not just levels, is linked to cognitive health in postmenopausal women.
- Larger, less functional HDL particles increase as women transition through menopause.
- Lifestyle factors can improve HDL quality, potentially supporting brain health.
Source: University of Pittsburgh
Higher levels of HDL-C—known as the “good cholesterol”—have been shown to correlate with heightened risk for Alzheimer’s disease.
A new study published in the Journal of Clinical Endocrinology & Metabolism might explain why.
Once women reach the menopause transition, it’s a matter of the quality, rather than quantity, of the total cholesterol carried by HDL particles circulating in a woman’s bloodstream, and that quality declines over time, according to a research team led by a University of Pittsburgh School of Public Health epidemiologist.
HDL particles vary in their size, composition and level of functioning. The team measured these features in the blood of 503 women from the Study of Women’s Health Across the Nation (SWAN) HDL ancillary study.
The researchers found that, over time, the number of larger HDL particles in the women’s bodies increased—and these larger particles, unfortunately, did not function as well as their smaller counterparts.
The researchers conducted repeated assessments of study participants’ cognitive function from 2000 to 2016 and compared these data to changes in the women’s HDL particles, composition and function as they aged.
“We were able to show that as early as midlife, women who have more of the smaller-sized particles and those whose particles’ concentrations of phospholipids increased over the menopause transition are more likely to experience better episodic memory later in life,” said Samar R. El Khoudary, Ph.D., M.P.H., professor of epidemiology at Pitt Public Health, adding that loss of working memory is the first sign of Alzheimer’s disease.
Previously, El Khoudary’s team has shown that health behaviors—such as those included in the American Heart Association’s (AHA) Life’s Essential 8—work to improve the quality of HDL particles, for example by adding more of the phospholipid-rich particles in the bloodstream.
“That’s the good news in this developing picture of brain health and the ‘not-so-good-after-all’ cholesterol,” said El Khoudary.
“Even though higher levels of HDL-C may not be protective as you get older, there are things you can do that might help, even as early as your 40s. The same, modifiable risk factors that the AHA is advocating for—including physical activity, ideal body weight and quitting smoking—can help you protect your brain, too.”
Meiyuzhen Qi, Ph.D., post-doctoral researcher in the Department of Epidemiology at Pitt Public Health, is first author of this study.
Additional coauthors include scientists from the University of Pennsylvania Perelman School of Medicine, Rush University Rush Medical Center, University of California Los Angeles David Geffen School of Medicine, Albert Einstein College of Medicine, University of Michigan School of Public Health and University of Massachusetts Medical School.
About this Alzheimer’s disease research news
Author: Allison Hydzik
Source: University of Pittsburgh
Contact: Allison Hydzik – University of Pittsburgh
Image: The image is credited to Neuroscience News
Original Research: Open access.
“High-density lipoprotein over midlife and future cognition in women: The SWAN HDL ancillary study” by Samar R. El Khoudary et al. The Journal of Clinical Endocrinology & Metabolism
Abstract
High-density lipoprotein over midlife and future cognition in women: The SWAN HDL ancillary study
Context
Limited data provides evidence-based insights on the association between comprehensive metrics of high-density lipoproteins (HDL) and cognitive performance, especially in midlife women for whom benefit might be the greatest.
Objective
To assess the associations of serum HDL metrics including HDL lipid content [HDL cholesterol, phospholipid (HDL-PL), triglyceride], proteins/subclasses [apolipoprotein A-1 (apoA-1); small, medium, large, total HDL particle (HDL-P); and HDL size], and cholesterol efflux capacity with cognitive performance in midlife women.
Methods
This prospective cohort study was conducted among 503 midlife women (1234 observations) from the Study of Women’s Health Across the Nation HDL ancillary study. Joint models were applied to examine associations of HDL metrics assessed at midlife (50.2 ± 2.9 years, baseline of the current study) and their changes over midlife (6.1 ± 3.9 years of duration) with subsequent cognitive performance [working memory (Digit Span Backward Test), processing speed (Symbol Digit Modalities Test), and episodic memory immediate and delayed recall (East Boston memory test)] assessed repeatedly (maximum 5 times) 1.5 ± 1 years later over 7.72 ± 4.10 years of follow up.
Results
Higher total HDL-P and smaller HDL size at midlife were associated with a better subsequent immediate recall, delayed recall and/or processing speed. Greater increase in HDL-PL, apoA-1, medium HDL-P, and total HDL-P and less increase in HDL size over midlife were associated with a better subsequent immediate and/or delayed recall.
Conclusions
Enhancing specific serum HDL metrics during midlife could be promising in cognitive restoration, particularly memory, the initial and predominant symptom of Alzheimer’s disease.
