Monash University’s research indicates a concerning correlation between elevated levels of ‘good cholesterol’ (HDL-C) and a higher risk of dementia among the elderly, underscoring the necessity for extensive investigation in this area.
According to the university-led study, unusually high levels of HDL-C, commonly referred to as ‘good cholesterol’, are linked to a heightened risk of dementia in senior citizens.
Researchers note that the very heightened HDL-C levels associated with dementia were rare and not due to dietary factors, but rather more likely to be indicative of a metabolic disorder.
These recent discoveries could help healthcare professionals identify older individuals at risk for dementia, particularly in those aged 75 and above.
Identifying Risks in Elderly Populations
Published inThe Lancet Regional Health – Western Pacific, this study is one of the largest of its kind, focusing on the link between elevated HDL-C levels and dementia among previously healthy older individuals, mostly aged over 70, who participated in the ASPREE* study.
Over a roughly 6.3-year period, participants with exceptionally high HDL-C levels (over 80 mg/dL or over 2.07 mmol/L) at the start of the study were found to have a 27% higher likelihood of developing dementia compared to those with optimal HDL-C levels. Further, those aged 75 and older also exhibited a 42% increased risk compared to individuals with optimal levels.
Very high HDL-C levels were defined as 80 mg/dL (above 2.07 mmol/L) or more. For men, the optimal HDL-C level was 40 to 60 mg/dL (1.03–1.55 mmol/L), while for women, it was 50 to 60 mg/dL (1.55–2.07 mmol/L), which was generally beneficial for heart health.
Participant Data and Additional Research
The analysis involved 18,668 participants, among which 2709 had very high HDL-C at the beginning of the study. In patients under 75 with very high levels, there were 38 dementia incidents, rising to 101 in patients aged 75 and older with very high levels.
Dr. Monira Hussain, the first author and senior research fellow at Monash University School of Public Health and Preventive Medicine, noted that more research is necessary to explain the apparent link between very high HDL cholesterol levels and the risk of developing dementia.
Need for Additional Research
Dr. Hussain emphasized that while the significance of HDL cholesterol for cardiovascular health is well-known, this study suggests that further exploration is crucial to understand the role of extremely high HDL cholesterol in relation to brain health. Taking high HDL cholesterol levels into account in forecasting dementia risk could potentially be beneficial.
Reference: “Association of plasma high-density lipoprotein cholesterol level with risk of incident dementia: a cohort study of healthy older adults” by Sultana Monira Hussain, Catherine Robb, Andrew M. Tonkin, Paul Lacaze, Trevor T.-J. Chong, Lawrence J. Beilin, Chenglong Yu, Gerald F. Watts, Joanne Ryan, Michael E. Ernst, Zhen Zhou, Johannes T. Neumann and John J. McNeil, 29 November 2023, The Lancet Regional Health – Western Pacific.
*The Aspirin in Reducing Events in the Elderly (ASPREE) trial is a double-blind, randomised, placebo-controlled trial of daily aspirin in healthy older people. ASPREE recruited 16,703 participants aged ≥70 years (from Australia) and 2,411 participants aged ≥65 years (from the US) between 2010 and 2014. Participants had no diagnosed cardiovascular disease, dementia, physical disability, or life-threatening illness at enrolment. The study continues in the observational follow-up phase, ASPREE-XT (Extension).