Brain Research · Mar 31, 2026

Neural correlates of handgrip strength asymmetry in normal aging and older adults with mild cognitive impairment

By Younis M, Vints WAJ, Kušleikienė S et al.

BACKGROUND: Handgrip strength asymmetry (HGS-A) has emerged as a potential non-invasive biomarker reflecting cognitive and neural vulnerability in older adults, yet the neural mechanisms linking asymmetry with cognitive decline remain incompletely characterized. This study aimed to determine the relationships between HGS-A, cognitive function, and regional cortical thickness in healthy older adults and individuals with mild cognitive impairment (MCI). METHODS: Sixty-eight community-dwelling adults aged 60-85 (42 cognitively healthy, 26 MCI) underwent bilateral handgrip strength assessment using Jamar dynamometry. Cognitive evaluations included global cognition (MoCA) and domain-specific functions (ANAM4 battery). Structural MRI was performed, and cortical thickness was quantified from T1-weighted images within regions affected in MCI and Alzheimer's disease. Associations between HGS-A, cognitive performance, and cortical thickness were examined using partial correlation analyses adjusted for age and sex. RESULTS: In cognitively healthy participants, greater handgrip strength asymmetry within normal limits (<15%) significantly correlated with higher global cognitive scores (MoCA; r = 0.32, p = 0.043) and increased cortical thickness in the left postcentral gyrus (r = 0.52, p < 0.001; FDR-corrected). Conversely, these relationships were absent in participants with MCI and in those exhibiting high asymmetry levels (≥15%). Domain-specific cognitive tasks showed no significant associations with HGS-A in either group. Exploratory analyses suggested an inverted U-shaped relationship, where both minimal and excessive asymmetry reflect worse cognitive function. CONCLUSIONS: Handgrip strength asymmetry within normal limits (<15%) is linked to better cognition and cortical integrity, whereas both minimal and excessive asymmetry may reflect reduced cognitive function in older adults.

doi.org/10.1016/j.brainres.2026.150299 Open access PubMed 41933684 Biomarkers