Roberts, Rosebud O.

Objectives To characterize frailty in cognitively normal older adults at baseline and to investigate the relationship between frailty and mortality. Design Population‐based prospective cohort study: Mayo Clinic Study of Aging. Setting Olmsted County, Minnesota. Participants Cognitively normal older persons aged 70 and older (mean age 78.8 ± 5.2, 50.2% male; N = 2,356). Measurements Frailty was assessed at baseline using a 36‐item Frailty Index. Four frailty subgroups were identified based on the Frailty Index (≤0.10 (fit), 0.11–0.20 (at risk), 0.21–0.30 (frail), >0.30 (frailest)). All participants underwent comprehensive clinical and cognitive assessments. The association between frailty and mortality was assessed using Cox proportional hazards models. Results The median Frailty Index was 0.17 (interquartile range 0.11–0.22). Frailty increased with age and was more common in older men than in older women. Over a median follow‐up of 6.5 years (range 7 days to 8.9 years), 500 of the 2,356 participants died, including 292 men. The frailest participants had the greatest risk of death (hazard ratio ( HR ) = 3.91, 95% confidence interval ( CI ) = 2.69–5.68). The association was stronger in women ( HR = 5.26, 95% CI = 2.88–9.61) than men ( HR = 3.15, 95% CI = 1.98–5.02). Conclusion Baseline frailty was common, especially in older men, and increased with age. Frailty was associated with significantly greater risk of death, particularly in women. These sex differences should be considered when designing a geriatric care plan.

AbstractIntroductionFew studies have examined the effects of amyloid and apolipoprotein E (APOE) genotype on cognition among middle‐aged individuals.MethodsWe included 464 cognitively normal, test‐naïve, participants with Pittsburgh compound B positron emission tomography amyloid imaging, mean age of 62.7 (range, 51–71 years), enrolled in the Mayo Clinic Study of Aging. Participants completed multiple cognitive assessments, including a standard neuropsychological battery and the CogState computerized battery, over 30 months of follow‐up. Linear mixed models were used to examine the effects of amyloid and APOE genotype on baseline cognition and cognitive decline.ResultsElevated amyloid was not associated with tests of episodic memory but did predict declines on tests of executive function. APOE genotype was not associated with cognition. Among APOE ɛ4 noncarriers, higher amyloid was predictive of decline on tests of executive function and on one episodic memory test.DiscussionElevated amyloidosis and APOE genotype do not appear to exert a dramatic influence on cognition in middle age.