Frailty linked to 74% higher risk of dementia in older Australians

New research from UNSW Sydney’s Centre for Healthy Brain Ageing (CHeBA) has found older adults living with frailty had a 74% higher risk of developing dementia than their robust peers, highlighting physical frailty as an important marker of brain health in later life.

The study, published in The Journal of Frailty & Aging, followed 967 dementia-free older Australians for up to 12 years as part of CHeBA’s long-running Sydney Memory and Ageing Study.

Researchers examined the relationship between physical frailty, living arrangements and the subsequent development of dementia, finding that people classified as frail at the beginning of the study had 1.74 times the risk of developing dementia compared with those classified as robust.

Lead author Kate McEwen from CHeBA said the findings add to growing evidence that physical health and brain health are closely connected as we age.

“Frailty is often thought of primarily in terms of physical health, but our findings show it may also be an important indicator of a person’s future dementia risk,” Ms McEwen said.

“Importantly, frailty is not necessarily an inevitable or irreversible part of ageing. Identifying people experiencing frailty gives us an opportunity to consider interventions that support both their physical health and their brain health.”

Living alone may compound vulnerability

The researchers also investigated whether living alone influenced the relationship between frailty and dementia.

The researchers found that living alone itself did not increase dementia risk. But frailty appeared to matter more among people who lived alone: frail older adults living alone had almost double the risk of dementia compared with robust adults living alone.

The same difference was not seen among people who lived with others. Because the difference between the two groups was not statistically significant, the study does not definitely prove that living alone makes frailty more harmful. Nevertheless, it highlights frail older adults who live alone as a potentially vulnerable group deserving further investigation.

Senior author Dr Katya Numbers from CHeBA said the findings nevertheless raise important questions about how physical and social vulnerabilities can intersect in later life.

“Living alone does not necessarily mean someone is socially isolated, and our study importantly found that living alone on its own did not increase dementia risk,” Dr Numbers said.

“What our exploratory findings suggest, however, is that older people who are both physically frail and living alone may represent a particularly vulnerable group.

“This warrants further investigation and raises the possibility that approaches which address physical frailty while also strengthening social connection and support could have important benefits for healthy ageing.”

Twelve years tracking ageing and dementia

The research used data from 967 community-dwelling older adults who were free of dementia when they entered CHeBA’s Sydney Memory and Ageing Study. As participation required each person to have an informant - such as a family member or friend who knew them well - the study sample may not fully represent the broader older population, particularly people living alone.

Participants were classified as robust, pre-frail or frail based on a widely used measure of physical frailty incorporating factors such as weakness, exhaustion, physical activity, walking speed and weight loss.

Participants underwent comprehensive neuropsychological assessments every two years, with dementia diagnoses determined through clinical consensus.

Over the 12-year follow-up period, researchers were able to examine whether a person’s initial frailty status and living arrangements predicted their subsequent risk of developing dementia.

Scientia Professor Henry Brodaty, Co-Director of CHeBA and a co-author of the study, said the findings reinforce the importance of looking beyond the brain alone when considering dementia prevention.

“Dementia develops through a complex combination of factors across the course of our lives, and increasingly we understand that maintaining brain health means maintaining our overall health,” Professor Brodaty said.

“Frailty can involve declining strength, mobility and resilience, but importantly these are areas where there may be opportunities to intervene."

“Research like this helps us identify who may be at greater risk and where prevention efforts could potentially have the greatest impact.”

The researchers say future studies should investigate whether interventions combining physical activity, nutrition, frailty prevention and social support could help reduce dementia risk among vulnerable older adults.

CHeBA Research Authors: Kate McEwen, Dr Suraj Samtani, Rory Chen, Dr John Crawford, Scientia Professor Perminder Sachdev, Scientia Professor Henry Brodaty, Dr Katya Numbers