You might be interested in…Dementia Prevention

Globally, dementia is one of the fastest- growing causes of death and disability, and it poses a significant social, health, and economic problems. Dementia prevalence is rising, with one-in-14 people aged >65 years in the UK living with dementia. Dementia research has predominantly focused on cure or care, much less so on the prevention of dementia.

GPs play an increasingly important role in proactively preventing dementia. The Lancet Commission in 2020 estimated that dementia in 40 per cent of patients could be prevented or delayed by targeting 12 modifiable risk factors throughout life.1 These are: less education, hypertension, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes, and low social contact, excessive alcohol consumption, traumatic brain injury, and air pollution.

This report has been recently updated by The Lancet Commissions 2024 report.2 This report summarises the new research prioritising systematic reviews and meta-analyses and triangulating findings from different studies showing how cognitive and physical reserve develop across the life course and how reducing vascular damage (e.g., by reducing smoking and treating high blood pressure) is likely to have contributed to a reduction in age-related dementia incidence.

The authors claim that evidence is increasing and is now stronger than before that tackling the many risk factors for dementia that were modelled previously reduces the risk of developing dementia. In this report, they add the new compelling evidence that untreated vision loss and high LDL cholesterol are risk factors for dementia.

However, little is known about how GPs perceive their role in dementia prevention and the associated barriers. The aim of this qualitative study3 was to explore the role of GPs in dementia prevention. The findings were that GPs reported that they rarely explicitly discuss dementia risk with patients, even when patients are presenting with risk factors, but acknowledge that dementia prevention should be part of their role.

They advocate for adopting a whole team approach to primary care preventive practice, using long-term condition/medication reviews or National Health Service (NHS) health checks as a platform to enable dementia risk communication targeting already at-risk individuals.

Barriers included a lack of time and an absence of knowledge and education about the modifiable dementia risk factors, as well as a reluctance to use ‘dementia’ as a term within the appointment for fear of causing health anxiety. ‘Brain health’ was perceived as offering a more encouraging discursive tool.

This next paper discusses how the expected increase of dementia prevalence in the coming decades will mainly be in low-income and middle-income countries and in people with low socioeconomic status in high-income countries.4 The study aimed to reduce dementia risk factors in underserved populations at high-risk using a coach-supported mobile health (mHealth) intervention.

It was an open-label, blinded endpoint, hybrid effectiveness–implementation randomised controlled trial (RCT) which investigated whether a coach-supported mHealth intervention can reduce dementia risk in people aged 55–75 years of low socioeconomic status in the UK or from the general population in China with at least two dementia risk factors.

The primary effectiveness outcome was change in cardiovascular risk factors, ageing, and incidence of dementia (CAIDE) risk score from baseline to after 12–18 months of intervention. 1,488 people (601 male and 887 female) were randomly assigned (734 to intervention and 754 to control), with 1,229 (83 per cent) of 1,488 available for analysis of the primary effectiveness outcome. After a mean follow-up of 16 months, the mean CAIDE score improved 0·16 points in the intervention group versus 0·01 in the control group. The conclusions were that the intervention is modestly effective in reducing dementia risk factors in those with low socioeconomic status in the UK and any socioeconomic status in China.

Implementation is challenging in these populations, but those reached actively participated. Whether this intervention will result in less cognitive decline and dementia requires a larger RCT with long follow-up.

With all of this hope, it is disappointing to learn in another narrative review5 that, to date, no randomized clinical trial data conclusively confirm that interventions of any kind can prevent dementia. Nevertheless, addressing risk factors may have other health benefits and should be considered.

Another paper from The Lancet Commission carried out a systematic review and meta-analysis to estimate the population attributable fraction (PAF) for dementia associated with modifiable risk factors.6 Overall, PAFs were reported for 61 modifiable risk factors, with sufficient data available for meta-analysis of 12 factors (n=48 studies). In meta-analysis, the highest pooled unweighted PAF values were estimated for low education (17·2 per cent), hypertension (15·8 per cent), hearing loss (15·6 per cent), physical inactivity (15·2 per cent), and obesity (9·4 per cent).

The authors recommend that governments need to invest in a life-course approach to dementia prevention, including policies that enable quality education, health-promoting environments, and improved health. This investment is particularly important in low and middle income countries (LMICs), where the potential for prevention is high, but resources, infrastructure, budgets, and research focused on ageing and dementia are limited.

References:

1. Livingston G et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet 2020; 396(10248): 413–446. doi: 10.1016/S0140-6736(20)30367-6
2. Livingstone G et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet Commissions Volume 404, Issue 10452p572-628August 10, 2024. doi: 10.1016/S0140-6736(24)01296-0
3. Jones D et al. Dementia prevention and the GP’s role: a qualitative interview study. Br J Gen Pract 2024 Mar 27;74(741):e242-e249. doi: 10.3399/BJGP.2023.0103 Print 2024 Apr.
4. Moll van Charante E et al. Prevention of dementia using mobile phone applications (PRODEMOS): a multinational, randomised, controlled effectiveness–implementation trial. Lancet Healthy Longev 2024; 5: e431–42 Published Online May 16, 2024 https://doi.org/10.1016/S2666-7568(24)00068-0
5. Reuben D et al. Dementia Prevention and Treatment A Narrative Review. JAMA Intern Med. 2024;184(5):563-572. doi:10.1001/jamainternmed.2023.8522
6. Stephan B et al. Population attributable fractions of modifiable risk factors for dementia: a systematic review and meta-analysis. Lancet Healthy Longev 2024; 5: e406–21. doi: 10.1016/S2666-7568(24)00061-8