BACKGROUND: The causal relationship between physical frailty and cognitive function is not yet completely confirmed.
OBJECTIVES: This study aimed at exploring the reciprocal relationship of frailty and cognitive function among Taiwanese older adults.
PARTICIPANTS AND SETTING: The study evaluated data from a five-wave survey conducted in Taiwanese older persons (n=3,155 respondents, 10,631 observations).
MEASUREMENTS: Frailty was defined as low physical activity, exhaustion, poor appetite, poor grip strength, and difficulty in carrying 10-pound objects; individuals were defined as frail if they met three or more of the above criteria. Cognitive function was assessed using five items from the Short Portable Mental Status Questionnaire (SPMSQ) scale. Time-lagged and time-concurrent models were performed to examine the reciprocal relationship between cognitive function and frailty. Growth-curve hierarchical linear modeling was applied.
RESULTS: Concurrent frailty was related to low cognitive function at the intercept and time slope and vice versa. Previous frailty also predicted later decline of cognitive function. Nevertheless, previous cognitive function was not found to have a significant relationship with subsequent frailty. Education, physical function and social support represented shared factors to both frailty and cognitive function.
CONCLUSIONS: Frailty and cognitive function are correlated, and frailty may occur prior to cognitive impairment.