Bidirectional relationship between frailty and cognitive function among Chinese older adults

Frailty and cognitive function are two common aging-related conditions among older adults. This study examined the bidirectional relationship between frailty and cognitive function according to sex. All older adults aged ≥65 years who participated in the 2008 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey were included in this study. Binary logistic regression and generalized estimating equation models were used to determine the bidirectional relationship between frailty and cognitive function in cross-sectional and cohort studies, and sex differences were assessed. We included 12,708 participants who were interviewed in the baseline study. The participants' mean (standard deviation) age was 85.6 (11.1%) years. In the cross-sectional study, the multivariate-adjusted odds ratio (OR; 95% confidence interval [CI]) for pre-frailty and frailty among participants with cognitive impairment was 3.68 (3.29–4.13). Older adults with pre-frailty and frailty had higher risks of cognitive impairment (OR = 3.79, 95% CI: 3.38–4.25). The GEE models showed that pre-frailty and frailty predicted a higher likelihood of cognitive impairment (OR = 2.02, 95% CI, 1.67–2.46) during follow-up. Moreover, the temporal relationship between these relationships differed slightly by sex. Older women with cognitive impairment at baseline were more likely to develop pre-frailty or frailty than did older men. This study demonstrated a significant bidirectional relationship between frailty and cognitive function. Moreover, this bidirectional relationship varied by sex. These findings confirm the need to integrate sex-specific interventions for frailty and cognitive functioning problems to improve the quality of life of older adults.