Handgrip performance as a predictor of incident cognitive decline in older adults: A systematic review and meta-analysis

BACKGROUND: Cognitive decline is a major concern in aging populations, making early identification crucial for timely intervention. Longitudinal studies suggest that handgrip performance (including strength, endurance, and bilateral asymmetry) may serve as an early predictor of cognitive decline. This study aimed to review longitudinal data on (a) changes in handgrip performance over time and (b) baseline handgrip performance as a predictor of cognitive decline in older adults. METHODS: A systematic search in PubMed, Web of Science, and PsycINFO identified prospective cohort studies examining handgrip performance and cognitive decline in individuals aged 45 + years. Study quality was assessed using the QUIPS checklist. Random-effects three-level meta-analyses calculated pooled estimates of relative risk (RR) and standardized regression coefficients (SRC). Moderator analyses were conducted for cognitive outcome, age, follow-up length, and percentage of women. RESULTS: Sixty studies (380,960 participants, 37 cohorts) were included, with 80.0% rated as moderate quality. Handgrip strength was positively associated with all cognitive subdomains. Three-level meta-analysis showed a reduced risk of cognitive decline with maintained or increased handgrip strength (RR=0.809, [95%CI: 0.738-0.886]) and stronger baseline strength (RR=0.812, [95%CI: 0.766-0.860]). The latter effect was stronger in larger studies and weaker in those with more women. Baseline handgrip strength was positively associated with global cognition (SRC= 0.237 [95%CI: 0.081-0.393]), but its link to cognitive change over time was nonsignificant. CONCLUSION: Maintaining handgrip strength over time or higher baseline handgrip strength reduced cognitive decline risk (both ∼19%), underscoring handgrip strength as a clinically meaningful biomarker. Future research should clarify underlying mechanisms.