Dementia: 11 key risk factors may predict disease 14 years sooner
- Researchers developed an 11-point risk factor score to predict dementia onset 14 years ahead of the typical diagnostic timeline.
- The score is up to 80% accurate in British populations.
- It could be used as an initial screening tool for dementia.
Millions of people around the world currently live with dementia, a progressive neurodegenerative condition that affects memory and cognitive skills.
As there is currently no cure for dementia, preventative strategies are crucial for reducing its impact on a person’s overall health and their quality of life.
Research suggests that up to 40% of dementia cases could be prevented by addressing 12 key risk factors, including low education levels, smoking, and hypertension.
While several prognostic models exist to predict dementia risk, they often carry significant limitations. For example, a 2019 systematic review of 61 dementia risk scores found that only eight had been validated by external samples. Meanwhile, those that had been validated often had poor and inconsistent performance in external validation.
Moreover, most developmental cohorts are from North America. Whether or not these risk scores apply to other populations remains unclear.
New risk scores that are externally validated and include diverse populations are crucial for identifying dementia risk and improving dementia prognosis.
Recently, researchers developed a dementia risk score consisting of 11 risk factors that can predict up to 80% of dementia cases 14 years before onset. They called it the UK Biobank Dementia Risk Score (UKBDRS).
The study was published in BMJ Mental Health.
What are the 11 key dementia risk factors?
For the study, the researchers examined healthcare data from the UK Biobank from 220,762 individuals with an average age of 60 years old. The researchers followed the participants for 14 years.
They also compiled a list of 28 risk and protective factors linked to dementia. After analyzing 80% of the UK Biobank-derived healthcare data in light of these factors, they identified 11 that strongly predicted dementia risk.
To test the reliability of these risk factors, the researchers first assessed them alongside the remaining 20% of the UK Biobank data.
In doing so, they found that the UKBDRS correctly predicted dementia incidence in 80% of individuals.
They next tested the risk score on external data from the Whitehall II study, which included 2,934 British civil servants with an average age of 57 years old at the beginning of the analysis. They were followed for 17 years. Ultimately, they found that the UKBDRS correctly predicted 77% of dementia cases in this cohort.
From sensitivity tests, the researchers showed that the UKBDRS most strongly predicted if a person was likely to develop dementia within the next 14 years.
They added that the UKBDRS achieved comparable results to APOE testing, which assesses the presence of a key genetic biomarker for dementia.
APOE testing predicted 83% of dementia cases in the UK Biobank sample, and 79% of cases in the UK Whitehall II study.
They further found that the UKBDRS outperformed three other widely used dementia risk scores that had also been externally validated.
Why might being male increase dementia risk?
Medical News Today spoke with Dr. Anita Szerszen, director of inpatient geriatrics at Staten Island University Hospital, not involved in the study, about why being male might be a risk factor for dementia.
This may come as a surprise, as data so far has suggested that women are at greater risk for Alzheimer’s disease, the most common form of dementia.
Dr. Szerszen noted that while there is a higher prevalence of dementia among women due to their longer life expectancy, some lifestyle factors more common to men may contribute to their higher dementia risk. These include smoking, drinking excessive amounts of alcohol, and certain occupational exposures to environmental toxins.
MNT also spoke with Dr. Joyce Gomes-Osman, vice-president of interventional therapy at Linus Health and physical therapist, who was not involved in the study, about the link between being male and dementia risk.
She noted that being male may increase dementia risk as men have higher cardiovascular risk than women, and are less likely to seek out medical assistance.
What about psychosocial variables?
MNT next spoke with Dr. Stella Panos, neuropsychologist and director of neuropsychology at the Pacific Neuroscience Institute in Santa Monica, CA, not involved in the study, about how psychosocial variables like material deprivation and living alone may increase dementia risk.
She told us:
“These variables can impact brain health indirectly via their impact on access to healthcare and other activities that promote cardiovascular and brain health over time such as having a safe space to walk or engage, quality education and cognitive stimulation including social stimulation.”
“These factors are also associated with chronic stress, which can have a direct effect on brain health over time. Material deprivation, for example, can lead to higher levels of stress, which can directly affect the brain via the neurotoxic effects of cortisol and other pathways,” Dr. Panos noted.
She added that these psychosocial factors may also produce changes in gene expression, such as increased activity of proinflammatory genes, which can negatively impact brain function over time.
What are the study limitations?
Dr. Gomes-Osman praised the study for including a “rich and unique” cohort alongside a careful methodology. She noted, however, that the findings are limited as the cohort was not diagnosed with dementia using gold-standard clinical processes or assessments.
Another limitation, she said, was that there were major differences between the two study samples in terms of available hospital records and self-reported outcome measures.
“The availability of more data in one setting resulted in a higher sensitivity for patients in that sample than in the other sample,” she noted.
MNT also spoke with Dr. Howard Pratt, board-certified medical director at Community Health of South Florida (CHI), not involved in the study, about its limitations.
“The study is limited to the metrics it is looking at. But since we don’t really know the cause of dementia, we don’t really know if we are asking all the right questions or whether we are looking at all of the metrics we need to look at when it comes to tracking dementia risk,” he said.
Diagnosing and preventing dementia
Dr. Katherine Ornstein, professor and director at the Center for Equity in Aging at Johns Hopkins University School of Nursing, not involved in the current study, told MNT that the UKBDRC may be useful for initial screening.
She said that high-risk individuals could get additional screening, such as cognitive testing or genetic screening.
A further benefit of the tool, she noted, is that it may help individuals and healthcare providers target and modify health behaviors before dementia onset.
“We do not have a cure for dementia so it is critical that we focus on prevention,” she said.
“It is important that if providers share dementia prediction tools with their patients, that they take the time to explain what they mean, and also to follow up to modify behaviors and help reduce their risk. Dementia is a very scary diagnosis and it is important that patients understand that being at a higher risk than others does not mean you will actually get the condition,” she advised.
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