Is frailty a prodromal stage of vascular dementia? Results from the Three-City Study.

OBJECTIVES: To investigate the relationship between frailty and incident vascular dementia (VaD).

DESIGN: Seven-year longitudinal study.

SETTING: Three-City Study, a French prospective study designed to evaluate the risk of dementia and cognitive decline attributable to vascular risk factors.

PARTICIPANTS: Five thousand four hundred eighty community-dwelling persons aged 65 to 95.

MEASUREMENTS: An expert committee established a clinical diagnosis of VaD. Frailty was defined as having at least three of the following criteria: weight loss, weakness, exhaustion, slowness, and low physical activity. Participants with prior stroke or prevalent dementia at baseline were excluded from analyses. Multivariate models were used to evaluate the relationship between frailty and incident VaD.

RESULTS: At baseline, 6.5% of participants were classified as frail. After 7 years of follow-up, 54 persons were diagnosed with VaD, seven of whom where frail. In the proportional hazards models, frailty was marginally associated with greater risk of all types of dementia and was not associated with incident Alzheimer's disease, but frailty status was independently associated with incident VaD.

CONCLUSION: Frailty is a major risk factor for incident VaD, so its identification could contribute to better estimates of the risk of VaD in elderly adults.