Association between cognitive reserve proxies and frailty phenotype: data from UK Biobank

A potential protective role of cognitive reserve proxies against frailty has been suggested in older adults. We explored the cross-sectional association between cognitive reserve indicators and frailty phenotype. Data were obtained from the UK Biobank. We included 31,975 dementia-free participants aged ≥ 60 years (50.7% females, 2.2% frail) who completed a web-based cognitive assessment (fluid intelligence, working memory, visuospatial attention and processing speed, and executive functioning). Frailty was defined according to the Fried's phenotype (unintentional weight loss, exhaustion, low physical activity, slowness, and weakness). Participants meeting three or more criteria were classified as frail. Cognitive performance was compared between nonfrail and frail groups, and regression models were employed to analyze the associations between cognitive reserve proxies (education, skill level of occupation, social support, and multiple deprivation index (MDI)) and the likelihood of frailty. Frail and nonfrail groups significantly differed on cognitive function, with frail individuals demonstrating poorer performance on all cognitive functions (all p < .05) except fluid intelligence. Regression analysis showed that, after adjusting for age and sex, a lower educational level (odds ratio (OR) .797, 95% confidence interval (CI) .673-.944, p = .009), having maintained occupations with low cognitive requirements (OR .790, 95% CI .668-.936, p = .006), having less social support (OR .755, 95% CI .631-.903, p = .002), and living in a region with a high rate of multiple deprivation (OR 1.025, 95% CI 1.019-1.031, p < .001), significantly increased the probability of experiencing frailty. Our findings support the relationship between declined cognitive functions and frailty emphasizing the importance of implementing public health measures to enhance cognitive reserve.