Association between handgrip strength asymmetry and cognitive impairment: a systematic review and meta-analysis

Handgrip strength (HGS) asymmetry has been proposed as a marker of neuromuscular dysfunction and early neurological decline, but its association with cognitive impairment remains unclear. This meta-analysis aimed to clarify this relationship in adults. This study was registered with PROSPERO (CRD420251246822). The PubMed, Embase, Web of Science, and Cochrane Library databases were searched from inception to December 31, 2025. Observational studies reporting adjusted effect estimates for the association between HGS asymmetry and cognitive impairment were included. The risk of bias was assessed using the Newcastle–Ottawa scale and the Agency for Healthcare Research and Quality checklist. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random effects models. Heterogeneity was assessed using I 2 . Sensitivity analyses were performed using leave-one-study-out analysis and replacement of direction-specific estimates. Publication bias was assessed using funnel plots, trim-and-fill analysis, and Egger’s test. Six studies were included in the quantitative synthesis after accounting for overlapping populations and multiple estimates from the same study. HGS asymmetry was associated with increased odds of cognitive impairment (OR = 1.06, 95% CI 1.01–1.11; I 2 = 0.0%). Subgroup analyses revealed generally consistent directions of association across study-level characteristics, but no clear between-subgroup differences were observed. Sensitivity analyses revealed a consistent direction but attenuated significance in some analyses. Publication bias assessment was limited by the small number of study-level estimates. HGS asymmetry was modestly associated with cognitive impairment, but the very small effect size suggests limited standalone clinical relevance. It may be considered a complementary physical performance indicator rather than a strong risk factor or screening marker. Further large prospective studies using standardized definitions are needed. Protocol registration This systematic review protocol was registered with PROSPERO (CRD420251246822).