Dementia risk factors related to cardiovascular health may be increasing over time, compared with factors such as smoking and lower education levels, a new study by UCL researchers has found.
The study, published in the Lancet Public Health journal, investigated how the prevalence of dementia risk factors has changed over time and how this may affect dementia rates in the future.
It is estimated that there are currently 944,000 people living with dementia in the UK, meaning that 52% of UK people – 34.5 million people – know someone diagnosed with dementia. Dementia is one of the leading causes of death in the UK and has been the leading cause of death for UK women since 2011.
There is growing interest in potentially modifiable risk factors because, in theory, eliminating these risk factors could prevent around 40% of dementia cases, according to a study led by researchers at University College London.*
In the new study, researchers analyzed 27 papers with data on dementia patients worldwide collected between 1947 and 2015, with the most recent published in 2020. The researchers extracted data on dementia risk factors from each paper and calculated what proportion of dementia cases was attributable to each risk factor over time.
Dementia usually develops due to a combination of genetic and environmental factors, such as high blood pressure, obesity, diabetes, education, and smoking.
The team found that lower education and smoking have declined over time and are associated with lower dementia incidence, while the incidence of obesity and diabetes has increased over time, increasing their contribution to dementia risk.
It is worth noting that hypertension remained the greatest risk factor for dementia in most studies reviewed, although active management of hypertension has also increased over time.
Lead author Dr Naheed Mukadam (UCL Psychiatry) said: “Cardiovascular risk factors may contribute significantly to dementia risk over time, so future dementia prevention efforts need to target these.”
“Our findings show that education levels have increased over time in many high-income countries, indicating that this is no longer an important risk factor for dementia. Meanwhile, smoking has become less socially acceptable and more expensive, so smoking rates are also falling in Europe and the United States.”
These patterns suggest that population-level interventions could have a major impact on the development of dementia risk factors, and governments should consider implementing initiatives such as global education policies and smoking restrictions.”
Dr Naheed Mukadam, Psychiatry, University College London
The research was funded by the National Institute for Health and Care Research (NIHR) Three School Dementia Research Programme.
Study limitations
In particular, although reported levels of cardiovascular risk factors may have increased over time, active management of these diseases has also increased over time in many countries, so that the effect on dementia may be neutral or may decrease the risk of dementia over time.
Additionally, all of the studies analyzed in the new study are from before 2015, so they may not reflect changes in trends since then.
sauce:
University of London
Journal References:
Mukadam, N., et al. (2024). Changes in the prevalence and incidence of dementia and risk factors for dementia: Analysis from a cohort study. Lancet. Public Health. doi.org/10.1016/s2468-2667(24)00120-8.
