A new dementia risk score can predict an individual’s risk of developing the disease in the ensuing 14 years, it was announced today.
A long-term study, published today in BMJ Mental Health, found the UK Biobank Dementia Risk Score (UKBDRS) outperformed three other widely used risk scores originally developed in Australia (ANU-ADRI), Finland (CAIDE), and the UK (DRS).
With up to 50 million people worldwide believed to be living with dementia – and that figure projected to triple by 2050 – targeting key risk factors, several of which involve lifestyle, could potentially avert around 40% of cases, say the researchers, led by Oxford University.
Several risk scores have been devised to try and predict a person’s chances of developing dementia while preventive measures are still possible, but they are unreliable across different age groups and geographies. Some also rely on expensive and invasive tests.
For this study, the team drew on two large groups of 50- to73-year olds participating in two long-term studies: one group for developing the new risk score (UK Biobank study) and one for validating it (Whitehall II study).
In the final analysis, 220,762 people from the UK Biobank study, whose average age was 59) and 2934 from the Whitehall II study, whose average age was 57 were included.
A list of 28 established factors associated with a heightened or reduced risk of developing dementia was compiled, to which LASSO regression was applied to identify and discard the least relevant factors.
From the UKBDRS this produced 11 predictive factors for any type of dementia: age; education; history of diabetes; history of/ current depression; history of stroke; parental dementia; economic disadvantage (Townsend deprivation index); high blood pressure; high cholesterol; living alone; and male sex.
The APOE gene – a known risk factor for dementia – was identified for 157,090 participants in the UK Biobank study and 2315 in the Whitehall II study and this was added to the risk score (UKBDRS-APOE).
Within 14 years, 3813 (nearly 2%) and 93 (just over 3%) participants in the UK Biobank and Whitehall II groups, respectively, developed dementia.
The predictive values of UKBDRS with and without APOE were compared with that of age alone, and with three widely used risk scores: ANU-ADRI (Australian National University Alzheimer’s Disease Risk Index), CAIDE (Cardiovascular Risk Factors, Aging and Dementia), and DRS (Dementia Risk Score).
UKBDRS-APOE produced the highest predictive score.
Lead author Dr Raihaan Patel, of Oxford University, said the UKBDRS may best be used as an initial screening tool to stratify people into risk groups. Anyone identified as high risk could have more time-intensive follow-up assessments for more detailed characterisation.
Lead co-author associate Professor Sana Suri added: “It’s important to remember that this risk score only tells us about our chances of developing dementia; it doesn’t represent a definitive outcome.
“The importance of each risk factor varies and given that some of the factors included in the score can be modified or treated, there are things we can all do to help reduce our risk of dementia.”
Although there were limitations to the study, such as the differing classification of dementia between the two groups, as well as demographics, lifestyle, and health of the participants. Most participants were white and less likely to live in areas of deprivation than the general UK population. There were also significantly fewer women in the Whitehall II group.
Dr Patel said: “There are many steps we would need to take before we can use this risk score in clinical practice.
“It’s well known that dementia risk, onset, and prevalence vary by race, ethnicity and socioeconomic status. Therefore, while the consistent performance of UKBDRS across these two independent groups boosts our confidence in its viability, we need to evaluate it across more diverse groups of people both within and beyond the UK.”
Anatürk M, Patel R, Ebmeier KP et al. Development and validation of a dementia risk score in the UK Biobank and Whitehall II cohorts. BMJ Mental Health 25 August 2023; doi 10.1136/bmjment-2023-300719
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