Summary: A large study of nearly 10,000 adults in their 70s reveals that unexplained year-to-year changes in cholesterol levels might serve as an early warning sign for dementia risk. The research, conducted over six years, found that people with the most variable cholesterol levels showed a 60% higher risk of developing dementia compared to those with stable levels.
Journal: American Heart Association Scientific Sessions 2024, Abstract 4142561 | Reading time: 5 minutes
Hidden Signals in Routine Blood Tests
Your yearly cholesterol test might reveal more than just heart health. New research suggests that unexpected swings in cholesterol levels could offer early clues about cognitive decline, potentially years before memory problems become apparent.
“Older people with fluctuating cholesterol levels unrelated to whether they were taking lipid-lowering medications – particularly those experiencing big year-to-year variations — may warrant closer monitoring and proactive preventive interventions,” explains lead author Zhen Zhou, Ph.D., a postdoctoral research fellow at Monash University’s School of Public Health and Preventive Medicine in Melbourne, Australia.
A Six-Year Window into Brain Health
The research team analyzed data from nearly 10,000 adults with an average age of 74, tracking their cholesterol levels and cognitive health over six years. Importantly, none of the participants changed their cholesterol medications during the study, allowing researchers to focus on natural variations in cholesterol levels.
The findings were striking. During the follow-up period, 509 participants developed dementia, while 1,760 showed signs of cognitive decline without full dementia. Those with the highest cholesterol fluctuations faced significantly higher risks.
The Numbers Tell a Complex Story
The study revealed specific patterns in how cholesterol variations related to brain health. Compared to participants with stable levels, those with high fluctuations in total cholesterol showed a 60% increased risk of dementia and a 23% higher chance of cognitive decline.
Particularly concerning were the variations in LDL (often called “bad”) cholesterol. These fluctuations correlated with faster declines in memory and reaction speed. Interestingly, changes in HDL (“good”) cholesterol and triglycerides didn’t show the same connection to cognitive decline.
Understanding the Connection
“We need future studies to help us understand the relationship between cholesterol variability and dementia risk,” Zhou notes. “Are cholesterol variability levels a real risk factor, a precursor or a biomarker of dementia risk? One possible explanation is that significant fluctuations in total and LDL cholesterol levels may destabilize atherosclerotic plaques, which are mostly composed of LDL cholesterol.”
Glossary
- LDL cholesterol: Low-density lipoprotein cholesterol, often called “bad” cholesterol
- HDL cholesterol: High-density lipoprotein or “good” cholesterol
- Atherosclerotic plaques: Buildups of cholesterol and other substances in artery walls
- Cognitive decline: Decrease in mental abilities such as memory and thinking speed
Quiz
- What percentage increase in dementia risk was associated with high cholesterol fluctuations?
Answer: 60% - How many participants developed dementia during the study?
Answer: 509 participants - What was the average age of study participants?
Answer: 74 years - Which type of cholesterol fluctuations were NOT associated with cognitive decline?
Answer: HDL (“good”) cholesterol and triglycerides
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