Longitudinal associations of depression, mild cognitive impairment, and quality of life with handgrip strength

Background: . Mental health and quality of life (QoL) are key components of healthy aging, and their deterioration may lead to a loss of health, dependence, and mortality among older adults. Handgrip strength (HGS) has been widely used given its practicality and reliability as an indicator of general health status and physical functioning and even as a biomarker of aging. This study aimed to estimate the longitudinal associations of handgrip strength (HGS) with depression, mild cognitive impairment (MCI), and quality of life (QoL). Methods: . Data come from the first three wave of the Study on Global Aging and Adult Health in Mexico (2009, 2014, 2017). 2,943 older adults aged 50 years or older were included. HGS was measured using a handheld dynamometer. We used the Composite International Diagnostic Interview for the diagnosis of depression based on DSM‐IV criteria. MCI was determined according to the recommendations of the National Institute on Aging and the Alzheimer's Association of the United States. Quality of life was assessed using the WHOQOL (WHO Quality of Life) instrument. HGS was considered as a time-varying exposure and the between- and within-person effects were disaggregated using the hybrid models with random intercept. Results: . Higher HGS values were significantly associated with the three outcomes, decreasing the probability of depression (OR=0.98, p=0.02) and MCI (OR=0.97, p<0.01), and increasing quality of life levels (β=0.10, p<0.01). Likewise, those with weak grip strength had a higher probability of depression (OR=1.36, 95% CI 1.01;1.82), MCI (OR=1.32, 95% CI 1.03;1.68) and lower quality of life (β= -1.21 95% CI -1.95;-0.47). a higher proportion of this association will be better explained by between-person differences than within-person differences. A predominance of between-person effects over within-person effects was observed. Conclusion: Given the explanatory power of HGS, routine use of its measurement should be implemented, both in the community and in clinical settings, to identify older adults at risk for adverse health outcomes.