Abstract

INTRODUCTION

Frailty and dementia are prevalent, interrelated conditions in aging populations; yet the temporal relationship between frailty progression and dementia risk remains underexplored. This study aimed to investigate how both baseline frailty and its subsequent changes over time are associated with the risk of incident dementia in three large prospective cohorts.  

METHODS

This study analyzed data from 25,357 participants in three prospective cohorts: China Health and Retirement Longitudinal Study (CHARLS) 2011-2020, U.S. Health and Retirement Study (HRS) 2006-2020, and English Longitudinal Study of Ageing (ELSA) 2004-2023. Cox proportional hazard models were used to calculate the hazard ratio (HR) and 95% confidence interval (95% CI) between frailty and risks of dementia after adjusting for potential confounders. Analyses were conducted in 2025.

RESULTS

Across all three cohorts, participants who were pre-frail (HRs ranging from 1.13 to 1.17) or frail (HRs ranging from 1.37 to 1.54) at baseline had a significantly increased risk of dementia compared to their robust peers. This risk was most pronounced for those whose frailty status worsened over time; robust participants who transitioned to a frail state had increased risks of dementia (HRs ranging from 2.09 to 2.77). Participants who transitioned from pre-frail to frail showed significantly elevated risks of dementia (HR = 1.32). Participants with the upper and middle tertiles of total frailty index, and those in the upper tertile of change in frailty index, exhibited significantly increased risks of dementia. 

CONCLUSIONS

The findings from three large, multi-national cohorts consistently demonstrate a strong link between frailty progression and an increased risk of dementia particularly for those shifting from robust to frail state. This highlights that frailty is a globally relevant, modifiable target for dementia prevention, accentuating the necessity for proactive healthcare approaches to manage its onset and progression.

Citation

Xin Ye,Xinfeng Wang,Mingzheng Hu & Yingying Ouyang.(2025).Frailty and Risks of Dementia among Middle-aged and Older Adults: Evidence from Three Prospective Cohort Studies..American journal of preventive medicine,69(6),108088.https://doi.org/10.1016/J.AMEPRE.2025.108088.Online