Physical frailty, genetic predisposition, and incident dementia: a large prospective cohort study.
Level 3 - non-randomized controlled study
Prospective cohort study
PubMed 38802408 · doi:10.1038/s41398-024-02927-7
What was done
Prospective cohort analysis of 274,194 UK Biobank participants (mean age 57.24 years; 53.45% female) evaluating the relationship between physical frailty, dementia polygenic risk scores (PRS), and incident dementia using Cox proportional hazards regression models.
What was found
Over follow-up, 3,353 participants (1.22%) developed dementia. Compared to non-frailty, dementia risk was elevated in prefrailty (HR 1.396, 95% CI 1.294–1.506, P < 0.001) and frailty (HR 2.304, 95% CI 2.030–2.616, P < 0.001). Participants with both frailty and high PRS had an HR of 3.908 (95% CI 3.051–5.006, P < 0.001) compared to those with non-frailty and low PRS. Individual frailty components independently associated with dementia risk included slow walking speed (HR 1.817), low physical activity (HR 1.719), exhaustion (HR 1.670), low grip strength (HR 1.606), and weight loss (HR 1.464; all P < 0.001).
Why it matters
Physical frailty substantially magnifies dementia risk across genetic risk tiers, suggesting that maintaining physical function and managing frailty components could be key modifiable targets for dementia prevention.
Limits
Observational design prevents causal inference and leaves room for reverse causation, where prodromal dementia contributes to emerging physical frailty. The UK Biobank cohort exhibits healthy volunteer bias and predominantly European ancestry. The abstract does not specify follow-up duration, detailed covariate adjustment, or dementia subtype analyses.
Cited by
- supports A study found that frailty increased the risk of developing Alzheimer's disease by threefold among individuals at high genetic risk.