- View Frailty as a Key Predictor of Dementia: An Accessible Biomarker Currently reading
In Brief | Neurology | Gerontology
Frailty as a Key Predictor of Dementia: An Accessible Biomarker
Time to read: 03:44Time to listen: 06:46
Originally Published: 11 November 2024
Sourced: JAMA Neurology
Type of article: In Brief
MedED Catalogue Reference: MNIB009
Category: Neurology
Cross Reference: Gerontology
Keywords: dementia, frailty, gerontology, burden of disease, Alzheimer's
Frailty levels significantly increased 4–9 years prior to dementia diagnosis. Even when frailty was measured earlier than this timeframe, it remained strongly linked to an elevated risk of developing dementia.
This article is a review of recent studies originally published in JAMA Neurology, 11 November 2024 . It does not represent the original research, nor is it intended to replace the original research. Access the full Disclaimer Information.
The World Alzheimer’s Report 2021 by ADI highlighted that over 55 million people globally live with dementia, with numbers rising rapidly. Projections estimate 78 million cases by 2030 and 139 million by 2050, with the greatest increases occurring in low- and middle-income countries.1,2
Early diagnosis is pivotal for implementing disease-modifying behaviours and interventions that could delay or even prevent dementia onset. Identifying an accessible marker of biological age and dementia risk is crucial for advancing prevention and treatment strategies.
Frailty has emerged as a potential candidate for such a marker, but the relationship between frailty and dementia remains poorly understood. Signs of frailty may precede cognitive symptoms by more than a decade in some instances, providing a clear opportunity to identify high-risk populations for targeted dementia prevention and clinical trials.1
In 2014, Kulmal et al. established a strong link between frailty, cognitive impairment, and clinically diagnosed dementia in individuals aged 76 and older, suggesting that cognitive impairment may be a clinical feature of frailty and should be incorporated into its definition.1
Despite this, the frailty-dementia connection has been insufficiently explored. Recent research published in JAMA Neurology now underscores frailty as a promising, accessible biomarker for biological age and dementia risk—key to advancing prevention and treatment strategies.
Study Purpose
The purpose of this study was to clarify the temporal relationship between frailty and incident dementia by investigating frailty trajectories in the years leading up to dementia onset.
The aim was to identify whether frailty can serve as an early indicator for dementia risk.
Study Methodology
Data were drawn from four prospective cohort studies: the English Longitudinal Study of Ageing (ELSA), the Health and Retirement Study (HRS), the Rush Memory and Aging Project (MAP) and the National Alzheimer’s Coordinating Center (NACC). Patient settings included retirement communities, national surveys, and a multi clinic cohort.
Data collection spanned twenty-seven years from 1997 to 2024
Participants were aged 60 or older and were free of cognitive impairment at baseline.
Frailty was quantified using retrospectively calculated frailty index scores, and incident all-cause dementia was determined through physician diagnoses, self-reports, informant reports, and cognitive testing.
Findings
The study analysed data from 29,849 participants with an average age of 71.6 years, 62% of whom were women.
Over 257,963 person-years of follow-up, 3,154 cases of dementia were recorded.
Of the participants who developed dementia, frailty scores were higher in women in most cohorts and consistently elevated in dementia groups.
Frailty levels began accelerating 4-9 years before dementia onset, with each 0.1 increase in frailty scores associated with a higher dementia risk.
Adjusted hazard ratios (aHRs) ranged from 1.18 in the HRS cohort to 1.73 in the NACC cohort, which showed the strongest association.
Even when baseline frailty measurements were taken before the predementia acceleration period, frailty remained positively associated with dementia risk, with aHRs ranging from 1.18 in the HRS cohort to 1.43 in the NACC cohort.
Discussion
The findings of this study suggest that frailty, as measured by frailty index scores, maybe a valuable early indicator for identifying individuals at high risk for dementia.
The accelerated decline in frailty scores observed in the years preceding dementia onset offers a critical window for early intervention. Importantly, frailty represents a modifiable target. Early identification provides an opportunity to implement targeted strategies, such as lifestyle and behavioural modifications, that could potentially delay or prevent the onset of dementia.
In the context of South Africa and other low- and middle-income countries (LMICs), the impact of frailty on dementia risk is particularly pertinent. Older age is recognized as the primary non-modifiable risk factor for dementia, but in LMICs, additional socio-economic factors such as poverty exacerbate the risk. This highlights the need for public policies that address socio-economic deprivation and improve the living conditions of older adults, potentially delaying the onset of dementia.
Frailty as a marker of risk could inform these policies, helping to identify individuals at risk earlier and implement preventive measures in at-risk populations. This shift in understanding underscores the potential for frailty assessments to serve as a tool for identifying high-risk individuals before the manifestation of cognitive decline.
Despite these insights, the frailty-dementia connection has not been fully explored, and further research is necessary to establish the mechanisms by which frailty influences dementia risk and how early interventions targeting frailty can impact cognitive outcomes.
Conclusion
In conclusion, frailty represents a promising avenue for early detection and prevention of dementia, particularly in settings like South Africa, where socio-economic factors significantly affect dementia risk. While the concept of frailty as a predictor for dementia is still evolving, the findings to date suggest that addressing frailty through interventions could play a pivotal role in delaying or preventing dementia. Public health strategies focused on frailty could be a key component in the fight against dementia, especially in LMICs, where the disease burden is expected to rise significantly.
Importance of this study for South Africa
Older age is widely acknowledged as the primary non-modifiable risk factor for dementia in South Africa and other low- and middle-income countries (LMICs). Estimates from studies in South Africa indicate that the prevalence of dementia among adults aged 65 and older ranges from 3.8% to 11.0%.
Additionally, the risk of dementia was found to be 2.31 times higher for adults experiencing multidimensional poverty. These findings highlight the potential for public policies that address poverty-related factors to delay the onset and reduce the prevalence of dementia in older adults. Early detection is key to shaping these policies and reducing the burden of disease.2
Access the original study
1. Kulmala, J., Nykänen, I., Mänty, M., & Hartikainen, S. (2014). Association between frailty and dementia: a population-based study. Gerontology, 60(1), 16–21. https://doi.org/10.1159/000353859
2. Trani JF, Moodley J, Maw MTT, Babulal GM. Association of Multidimensional Poverty With Dementia in Adults Aged 50 Years or Older in South Africa. JAMA Netw Open. 2022 Mar 1;5(3):e224160. doi: 10.1001/jamanetworkopen.2022.4160. PMID: 35333360; PMCID: PMC89569
Back to top
Disclaimer
This article is compiled from several resources researched and compiled by the contributor. It is in no way presented as an original work. Every effort has been made to attribute quotes and content correctly. Where possible all information has been independently verified. The Medical Education Network bears no responsibility for any inaccuracies which may occur from the use of third-party sources. If you have any queries regarding this article contact us
Fact-checking Policy
The Medical Education Network makes every effort to review and fact-check the articles used as source material in our summaries and original material. We have strict guidelines in relation to the publications we use as our source data, favouring peer-reviewed research wherever possible. Every effort is made to ensure that the information contained here is an accurate reflection of the original material. Should you find inaccuracies, out of date content or have any additional issues with our articles, please make use of the contact us form to notify us.
