Clouston et al., 2014. The Dynamic Relationship Between Physical Function and Cognition in Longitudinal Aging Cohorts

Clouston, S., Brewster, P., Kuh, D., Richards, M., Cooper, R., Hardy, R., Rubin, M., & Hofer, S. M. (2013). The dynamic relationship between physical function and cognition in longitudinal aging cohorts: A systematic review. Epidemiologic Reviews. Published online 2013 January 24.  doi: 10.1093/epirev/mxs004.

Year: 
2013
Status: 
complete
Abstract: 

On average, older people remember less and walk more slowly than do younger persons. Some researchers argue that this is due in part to a common biologic process underlying age-related declines in both physical and cognitive functioning. Only recently have longitudinal data become available for analyzing this claim. We conducted a systematic review of English-language research published between 2000 and 2011 to evaluate the relations between rates of change in physical and cognitive functioning in older cohorts. Physical functioning was assessed using objective measures: walking speed, grip strength, chair rise time, flamingo stand time, and summary measures of physical functioning. Cognition was measured using mental state examinations, fluid cognition, and diagnosis of impairment. Results depended on measurement type: Change in grip strength was more strongly correlated with mental state, while change in walking speed was more strongly correlated with change in fluid cognition. Examining physical and cognitive functioning can help clinicians and researchers to better identify individuals and groups that are aging differently and at different rates. In future research, investigators should consider the importance of identifying different patterns and rates of decline, examine relations between more diverse types of measures, and analyze the order in which age-related declines occur.

Bendayan et al., 2017. Hierarchy and Speed of Loss in Physical Functioning: A Comparison Across Older U.S. and English Men and Women.

Bendayan, R., Cooper, R., Wloch, E. G., Hofer, S. M., Piccinin, A. M., & Muniz-Terrera, G. (2016). Hierarchy and speed of loss in physical functioning: A comparison across older US and English men and women. Journals of Gerontology Series A: Biomedical Sciences and Medical Sciences, 72(8), 1117-1122.

Year: 
2017
Status: 
complete
Abstract: 

Background: We aimed to identify the hierarchy of rates of decline in 16 physical functioning measures in U.S. and English samples, using a systematic and integrative coordinated data analysis approach.

Methods: The U.S. sample consisted of 13,612 Health and Retirement Study participants, and the English sample consisted of 5,301 English Longitudinal Study of Ageing participants. Functional loss was ascertained using self-reported difficulties performing 6 activities of daily living and 10 mobility tasks. The variables were standardized, rates of decline were computed, and mean rates of decline were ranked. Mann–Whitney U tests were performed to compare rates of decline between studies.

Results: In both studies, the rates of decline followed a similar pattern; difficulty with eating was the activity that showed the slowest decline and climbing several flights of stairs and stooping, kneeling, or crouching the fastest declines. There were statistical differences in the speed of decline in all 16 measures between countries. American women had steeper declines in 10 of the measures than English women. Similar differences were found between American and English men.

Conclusions: Reporting difficulties climbing several flights of stairs without resting, and stooping, kneeling, or crouching are the first indicators of functional loss reported in both populations.