Zammit et al., 2018. Associations between aging-related changes in grip strength and cognitive function in older adults: A systematic review.

Zammit, A.R., Robitaille., A., Piccinin, A.M., Muniz-Terrera, G. & Hofer, S.M. (2018). Associations between aging-related changes in grip strength and cognitive function in older adults: A systematic review. Journal of Gerontology: Medical Sciences: Series A. DOI: 10.1093/gerona/gly046

Year: 
2018
Status: 
complete
Abstract: 

Objectives. Grip strength and cognitive function reflect upper body muscle strength and mental capacities. Cross-sectional research has suggested that in old age these two processes are moderately to highly associated, and that an underlying common cause drives this association. Our aim was to synthesize and evaluate longitudinal research addressing whether changes in grip strength are associated with changes in cognitive function in healthy older adults.

Methods. We systematically reviewed English-language research investigating the longitudinal association between repeated measures of grip strength and of cognitive function in community-dwelling older adults to evaluate the extent to which the two indices decline concurrently. We used four search engines: Embase, PsychINFO, PubMed, and Web of Science.

Results. Of 459 unique citations, 6 met our full criteria: 4 studies reported a longitudinal association between rates of change in grip strength and cognitive function in older adults, 2 of which reported the magnitudes of these associations as ranging from low to moderate; 2 studies reported significant cross-sectional but not longitudinal associations among rates of change. All studies concluded that cognitive function and grip strength declined, on average, with increasing age, although with little to no evidence for longitudinal associations among rates of change.

Conclusions. Future research is urged to expand the study of physical and cognitive associations in old age using a within-person and multi-study integrative approach to evaluate the reliability of longitudinal results with greater emphasis on the magnitude of this association

Praetorius Björk et al., 2016. I forgot when I lost my grip—strong associations between cognition and grip strength in level of performance and change across time in relation to impending death

Björk, M. P., Johansson, B., & Hassing, L. B. (2016). I forgot when I lost my grip—strong associations between cognition and grip strength in level of performance and change across time in relation to impending death. Neurobiology of aging, 38, 68-72.

Year: 
2016
Status: 
complete
Abstract: 

An association between level of cognitive function and grip strength is well established, whereas evidence for longitudinal associations of change in the 2 functions is still unclear. We examined associations between cognition and grip strength in levels of performance and in longitudinal change in late life in a population-based sample, aged ≥80 years at baseline, followed until death. The sample consisted of 449 nondemented individuals drawn from the OCTO-Twin Study. A test battery assessing 6 cognitive domains and grip strength was administered at 5 occasions with measurements intervals of 2 years. We fitted time to death bivariate growth curve models, adjusted for age, education, and sex which resulted in associations between grip strength and cognition in both levels of performance (across all cognitive domains) and rates of change (in 4 of 6 domains). These results show that cognition and grip strength change conjointly in later life and that the association between cognition and grip strength is stronger before death than earlier in life.

    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.