Unexplained changes in cholesterol may help identify adults at risk of dementia

Results from a study of older adults in Australia and the US suggest year-to-year variations in cholesterol levels without changes in medication may help identify individuals at higher risk of developing dementia I'm doing it.¹

Data from 2017 to 2020 showed that 25.5% of U.S. adults had high levels of low-density lipoprotein cholesterol (LDL-C), defined as 130 mg/dL or higher. According to the American Heart Association (AHA) Heart Disease and Stroke Statistics 2024 Update, 3.72 million people worldwide died in 2021 due to excessive LDL-C levels.²

Cholesterol in the heart Image credit: © Rasi | stock.adobe.com

“Previous research has focused on the association between individual vascular risk factors and cognitive decline. However, increased fluctuations in certain functions in the body, such as blood pressure and blood sugar levels, There is evidence that both can be harmful,” said AHA Volunteer Specialist Fernando D. Testai, MD. FAHA, a professor of neurology and rehabilitation at the University of Illinois at Chicago, said in a news release.¹

Like high cholesterol levels, dementia is also a widespread concern. According to data from the CDC, there were an estimated 7 million adults age 65 and older with dementia in 2014, and that population is projected to grow to nearly 14 million by 2060.¹

High cholesterol is associated with an increased risk of dementia, and research suggests statin drugs may help reduce that risk, according to the Alzheimer's Association. The relationship between statins and dementia is complex, but researchers have found that statins reduce the risk of Alzheimer's disease by about 30% and the risk of vascular dementia by about 7%.³ However, this study primarily focused on high cholesterol levels rather than cholesterol fluctuations.

The results of this new study, presented at the AHA 2024 Scientific Sessions, utilized on-trial and post-trial data from participants enrolled in the ASPREE (ASPREE) randomized clinical trial and found that low-dose aspirin is effective. It was determined that It is not effective in reducing the risk of heart disease in adults in Australia and the United States. Although one-third of participants were taking cholesterol-lowering drugs, not one of the approximately 10,000 participants started, stopped, or changed lipid-lowering drugs during the follow-up period. did.¹

At the time of enrollment in the ASPREE trial, between 2010 and 2014, 87% of participants resided in Australia and 13% resided in the United States, according to a news release. This retrospective study using ASPREE data began in early 2024. Participants who started, discontinued, or changed cholesterol-lowering medications during the study period were excluded from the analysis.¹

All participants were relatively healthy adults without dementia and had their cholesterol levels monitored annually. The first three cholesterol measurements taken in the ASPREE study were used to determine how much each participant's lipid levels changed from year to year. During nearly 6 years of follow-up after annual assessment, 509 participants developed dementia and an additional 1760 developed cognitive decline without dementia.¹

Researchers found that large fluctuations in total cholesterol (in the top 25%) were associated with a 60% increase in dementia and a 23% increase in cognitive decline compared to people with the most stable cholesterol levels. discovered. In addition, changes in LDL-C and total cholesterol were associated with significantly lower overall cognitive health test scores and tests related to memory and reaction speed.¹

Finally, high fluctuations in triglycerides or high-density lipoprotein cholesterol (HDL-C), commonly referred to as “good” cholesterol, were not associated with dementia or cognitive decline. Triglycerides are the most common type of fat in the body and store excess energy from food.¹

“This study adds an important piece to the puzzle of maintaining brain health by providing evidence that increased variability in cholesterol levels is associated with decline in cognitive function,” said Testai. said. “This study did not include people who started or stopped taking lipid-lowering drugs during the study period. Therefore, the results cannot be explained by the effects of statins. If you don't stick to strategies to improve your lipid profile, such as diet and exercise, the negative effects of harmful fats on your brain can become even worse.”¹

The study authors noted that cholesterol measurements can fluctuate for a variety of reasons, including the fact that the relationship between cholesterol fluctuations and dementia risk may be influenced by these unanalyzed factors. , pointed out that there are some limitations. Additionally, most of the study participants were Caucasian adults (96%), so the findings may not apply to individuals from other population groups. As it is an observational study, it cannot prove cause and effect.¹

References

1. Unexplained changes in cholesterol may help identify older adults at risk for dementia. News release. American Heart Association. November 11, 2024. Accessed November 16, 2024. https://newsroom.heart.org/news/unexplained-changes-in-cholesterol-may-help-identify-older-Adults-at-risk-for-dementia?preview=070d&preview_mode=True

2. 2024 Heart Disease and Stroke Statistics Latest Fact Sheet. American Heart Association. 2024. Accessed November 16, 2024. https://www.heart.org/-/media/PHD-Files-2/Science-News/2/2024-Heart-and-Stroke-Stat-Update/2024-Statistics-At-A-Glance-final_2024. pdf?sc_lang=ja

3. Cholesterol and dementia risk. Alzheimer's Association. Updated August 2024. Accessed November 16, 2024. https://www.alzheimers.org.uk/about-dementia/managing-the-risk-of-dementia/possible-risks-of-dementia/cholesterol