Methods: This study included 800 older adults (aged ≥65), who attended the baseline survey in 2012 and 511 of them completed the follow-up survey in 2014. The outcome variable was cognitive ability assessed by the Alzheimer disease-8 items (AD8) in 2012 and 2014. Percentage body fatness was examined by a bioelectrical impedance device (TBF 300-GS). The sway rate (mm/sec) was collected by the Posture Scale Analyzer (Midot Medical Technolog) in a standing position with eyes open, representing balance function. Hand grip strength was measured twice with the dominant hand by a digital straingauge hand dynamometer (Takei TKK 5401). Participants were asked to estimate the amount of time they spent sitting or lying down to watch television, using computer/tablet, reading, or chatting. Univariate and multivariate linear regressions were conducted to examine the associations of fitness and sedentary with cognitive ability. Covariates included age, sex, years of schooling, marital status, living arrangements, smoking and drinking habits, Charlson index of comorbidity, mood (Brief Symptom Rating Scale-5), sleep (Chinese Athens Insomnia Scale), and AD8 at baseline.
Results: Participants had a mean age of 73.7(±5.7) at baseline. Among them, 54% of the cohort was male, 9.2% was current smoker, 25.1% consumed alcohol, and 14.1% lived alone. At baseline, the mean AD8 score was 0.3(±0.7) and the overall sedentary time was 4.2 hours/day (watching television 2.5 hours/day, using computer/tablet 0.5 hours/day, reading 0.6 hours/day, and chatting 0.6 hours/day). The average body fatness was 26.6(±9.3) %, the sway rate was 15.2(±6.8) mm/sec, and the strength of hand grip was 23.0(±8.4) kg. In the univariate analysis, sway rate (p=0.004), hand grip strength (p=0.001), reading (p=0.040), and chatting (p<0.001) were significantly associated with cognitive impairment. The fully adjusted model explained 13.8% of the variance, showing sway rate (p=0.011), hand grip strength (p=0.030), and chatting (p=0.002) were significantly associated with cognitive impairment after two years.
Conclusion: Good balance, strong hand grip, and time spending on chatting were significantly associated with better cognitive ability after two years among older adults.