Associations of a biopsychosocial frailty phenotype with all-cause dementia, Alzheimer’s disease, vascular dementia, and other dementias: the Italian PRoject on the Epidemiology of Alzheimer’s disease (IPREA)

Frailty is a critical intermediate status of the aging process including physical, cognitive, and psychosocial domains/phenotypes. We operationalized a new biopsychosocial frailty construct, estimating its impact on the odds of all-cause dementia, Alzheimer's disease (AD), vascular dementia (VaD), and other dementias in 2838 older individuals from the population-based Italian PRoject on the Epidemiology of Alzheimer's disease (IPREA). Biopsychosocial frailty operationalization was based on the results of a previous comprehensive geriatric assessment and the presence of physical frailty. In this cross-sectional study, participants with biopsychosocial frailty showed an increased odds ratio of all-cause dementia [odds ratio (OR): 5.55, 95% confidence interval (CI): 3.72-8.28, p < 0.001], in particular for probable AD (OR: 3.62, 95% CI: 1.55-8.45, p < 0.001), probable VaD (OR: 10.05, 95% CI: 5.05-19.97, p < 0.001), and possible VaD (OR: 17.61, 95% CI: 6.42-48.32, p < 0.001). No statistically significant association was found between this biopsychosocial frailty phenotype and possible AD (OR: 2.84, 95% CI: 0.81-9.97, p = 0.09) or other dementias (OR: 1.77, 95% CI: 0.75-0.21, p = 0.19). In conclusion, in a large cohort of Italian older individuals, a biopsychosocial frailty model was associated to all-cause dementia, probable AD, and probable and possible VaD. In the next future, other large and prospective population-based studies evaluating the association between the biopsychosocial frailty phenotype and incident all-cause dementia, AD, and VaD are needed, addressing also potential bias and confounding sources.