Frequency of frailty and its association with cognitive status and survival in older Chileans

Background: Age-associated brain physiologic decline and reduced mobility are key elements of increased age-associated vulnerability. Objective: To study the frequency of frailty phenotype and its association with mental health and survival in older Chileans. Methods: Follow-up of ALEXANDROS cohorts designed to study disability associated with obesity in community-dwelling people 60 years and older living in Santiago, Chile. At baseline, 2,098 (67% women) of 2,372 participants were identified as having the frailty phenotype: weak handgrip dynamometry, unintentional weight loss, fatigue/exhaustion, five chair-stands/ slow walking speed and difficulty walking (low physical activity). After 10-15 years, 1,298 people were evaluated and 373 had died. Information regarding deaths was available for the whole sample. Results: The prevalence of frailty at baseline (>= 3 criteria) in the whole sample was 13.9% (women 16.4%; men 8.7%) and the pre-frailty prevalence (1-2 criteria) was 63.8% (65.0% vs 61.4%), respectively. Frailty was associated with cognitive impairment (frail 48.1%; pre-frail 21.7%; nonfrail 20.5%, P<0.001) and depression (frail 55.1%; pre-frail 27.3%; nonfrail 18.8%, P<0.001). Logistic regression models for frailty adjusted for sex and age showed a strong association between frailty and mild cognitive impairment (MCI) (odds ratio [OR] = 3.93; 95% CI: 1.41-10.92). Furthermore, an important association was found for depression and frailty (OR = 2.36; 95% CI 1.82-3.06). Age-and sex-adjusted hazard ratios (HRs) for death showed an increased risk with increasing frailty: pre-frail HR = 1.56 (95% CI: 1.07-2.29), frail HR = 1.91 (95% CI: 1.15-3.19); after adjustment by age and sex, a higher risk of death was observed for people identified as frail (HR = 1.56, P=0.014) and pre-frail (HR = 1.30, P=0.065). MCI and dementia were also risk factors for death (MCI: HR = 1.69, P, 0.027; dementia: HR = 1.66, P=0.016). Conclusion: Frailty is highly prevalent and strongly associated with cognitive impairment and depression in older Chileans. The risk for death was higher for frail people, but underlying cognitive impairment is a key component of the lower survival rate.