Associations of Handgrip Strength Weakness and Asymmetry with Lower Cognitive Function: Results from the National Health and Nutrition Examination Survey (2011-2014).

BACKGROUND: The joint associations of handgrip strength (HGS) weakness and asymmetry with cognitive decline remain understudied in older adults.

OBJECTIVE: To investigate the associations between HGS weakness, asymmetry, and lower cognitive function in a nationally representative sample of older Americans.

METHODS: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey 2011-2014. Weakness was defined as HGS <26 kg for men and <16 kg for women. Asymmetry was determined by calculating the ratio of dominant to non-dominant HGS. Participants with an HGS ratio <0.90 or >1.10 were classified as having any HGS asymmetry. Those with an HGS ratio >1.10 exhibited dominant HGS asymmetry, while those with an HGS ratio <0.90 displayed nondominant HGS asymmetry, respectively. Lower cognitive functioning was defined as global cognitive composite scores more than 1 standard deviation below the mean. Covariate-adjusted logistic regression models were used to analyze the associations between HGS asymmetry/weakness and lower cognitive functioning.

RESULTS: Compared to individuals with non-weak and symmetric HGS, those with any HGS asymmetry alone and weakness alone had 1.017 (95% confidence interval [CI]: 0.707-1.463) and 1.391 (95% CI: 0.542-3.571) greater odds for cognitive decline, while co-occurrence of both HGS asymmetry and weakness was associated with 3.724 (95% CI: 1.711-8.107) greater odds for lower cognitive function after controlling for confounders.

CNCLUSIONS: Individuals exhibiting both diminished and asymmetrical HGS demonstrated an elevated susceptibility to cognitive impairment, thereby implying that the inclusion of HGS asymmetry assessment in conjunction with weakness evaluation may enhance the accuracy of prognosticating cognitive decline.