McGrath · Journal of Alzheimer's disease : JAD 2025 · longitudinal cohort study · n=12368

Examining the directional associations of handgrip strength asymmetry and cognitive function in American males and females.

Level 3 - non-randomized controlled study

Longitudinal prospective cohort study

PubMed 40462625 · doi:10.1177/13872877251346722 · record verified 2026-08-26

What was done

Researchers analyzed data from 5,298 male and 7,070 female participants aged 50 years and older from the 2006–2018 waves of the Health and Retirement Study. Handgrip strength (HGS) was measured using a dynamometer on both hands to determine categorical and continuous HGS asymmetry. Cognitive function was assessed via the Telephone Interview of Cognitive Status. Generalized estimating equations evaluated bidirectional associations between HGS asymmetry and cognitive impairment stratified by sex.

What was found

In males, categorical asymmetric HGS was associated with greater odds of future cognitive impairment (OR: 1.25, 95% CI: 1.01–1.54), and each unit increase in continuous HGS asymmetry ratio increased odds of impairment (OR: 1.37, 95% CI: 1.04–1.80). Cognitive impairment in males did not significantly predict future asymmetric HGS (OR: 1.18, 95% CI: 0.97–1.44). In females, no significant directional associations were found in either direction.

Why it matters

Assessing asymmetry between dominant and non-dominant grip strength may provide an accessible, non-invasive physical biomarker for future cognitive decline in older men beyond standard total grip strength measures.

Limits

The study is observational and cannot establish causality. Cognitive function was measured via telephone screening rather than comprehensive clinical evaluation. The abstract does not specify the exact threshold used to define categorical asymmetry, and the underlying mechanism for the observed sex-specific discrepancy remains unmeasured.