Understanding the surprising link between HDL cholesterol quality and Alzheimer’s risk

Higher levels of HDL-C, known as the ‘good cholesterol’, have been shown to correlate with an increased risk of Alzheimer’s disease. A new study published in the Journal of Clinical Endocrinology & Metabolism could explain why. Once women reach menopause, it is a matter of the quality, not quantity, of the total cholesterol carried by HDL particles circulating in a woman’s bloodstream, and that quality decreases over time. of time, according to a research team led by the University of Pittsburgh. Epidemiologist from the School of Public Health.

HDL particles vary in size, composition and level of functioning. The team measured these characteristics in the blood of 503 women from the Study of Women’s Health Across the Nation (SWAN) HDL supplemental study. The researchers found that over time, the number of larger HDL particles increased in women’s bodies; and these larger particles unfortunately did not function as well as their smaller counterparts.

The researchers conducted repeated assessments of the cognitive function of the study participants between 2000 and 2016 and compared this data with changes in the women’s HDL particles, composition and function as they aged.

“We were able to show that women who have more of the smaller particles already in middle age and women whose phospholipid particle concentrations have increased during the transition to menopause are likely to experience better episodic memory later in life,” says Samar. R. El Khoudary, Ph.D., MPH, professor of epidemiology at Pitt Public Health, adds that loss of working memory is the first sign of Alzheimer’s disease.

Previously, El Khoudary’s team has shown that health behaviors included in the American Heart Association’s (AHA) Life’s Essential 8 improve the quality of HDL particles, for example by adding more of the phospholipid-rich particles to the bloodstream.

That’s the good news in this evolving picture of brain health and “not so good” cholesterol. While higher levels of HDL-C may not be protective as you get older, there are things you can do that can help you even in your 40s. The same modifiable risk factors that the AHA advocates—including physical activity, ideal body weight, and smoking cessation—can also help you protect your brain.

Samar R. El Khoudary, Ph.D., MPH, professor of epidemiology, Pitt Public Health

Meiyuzhen Qi, Ph.D., postdoctoral researcher in the Department of Epidemiology at Pitt Public Health, is the first author of this study. Other co-authors 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.