AUTHOR=Feng Wenjing , Ma Mingfeng , Gao Hanshu , Yuan Wei , Li Ruixue , Guo Hui , Gu Cuiying , Sun Zhaoqing , Zhang Yao , Zheng Liqiang 

TITLE=Association between handgrip strength asymmetry and cognitive function across ethnicity in rural China: a cross-sectional study

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 15 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2023.1191197

DOI=10.3389/fnagi.2023.1191197

ISSN=1663-4365

ABSTRACT=Background: The association between handgrip strength (HGS) asymmetry and cognitive function is unclear, especially across ethnic groups and cognitive domains.
Method: The population was from a longitudinal study in rural areas of Fuxin, Liaoning, China.  The Chinese version of Montreal Cognitive Assessment-basic (MOCA-BC) was used to evaluate the cognitive function. The HGS ratio was calculated as maximal non-dominant HGS divided by maximal dominant HGS. HGS ratio < 0.9 or > 1.1 was classified as asymmetric dominant/nondominant HGS, respectively. Generalized linear models were used to analyze the relationship between asymmetric HGS and cognitive function adjusted for HGS, handedness, wave, age, sex, education, ethnicity, smoking, drinking, physical labor level, BMI, hypertension, diabetes and dyslipidemia.
Result: A total of 2969 participants ≥ 50 years were included in this study. Adjusted for HGS and other confunding variables, there was an inverted U-shaped association between HGS ratio and MoCA-BC scores (P nonlinear = 0.004). The association between HGS ratio and MoCA-BC scores was inconsistent among ethnic groups (P interaction = 0.048). In Han, only asymmetric nondominant HGS was associated with lower cognitive scores (β = -0.67, 95% confidence interval [CI]: -1.26 ~ -0.08, P=0.027); in Mongolians, asymmetric dominant HGS(β = -0.60, 95% CI: -1.35 ~ 0.15, P=0.115) and asymmetric nondominant HGS (β = -0.56, 95% CI: -1.42 ~ 0.31, P=0.206) were all associated with lower cognitive scores, although no statistical significance was found. Asymmetric nondominant HGS and lower HGS, but not asymmetric dominant HGS were all independently associated with impairment of Delayed Recall (OR = 1.35, 95% CI: 1.05 ~ 1.74; OR per 5 kg decrease = 1.10, 95% CI: 1.01 ~ 1.21) and Fluency (OR = 1.43, 95% CI: 1.15 ~ 1.78; OR per 5 kg decrease = 1.10, 95% CI: 1.02 ~ 1.19). Both asymmetric dominant HGS (OR = 1.34, 95% CI: 1.07 ~ 1.67) and lower HGS (OR per 5 kg decrease = 1.21, 95% CI: 1.10 ~ 1.32) were associated with impairment of Visuoperception.
Conclusion: HGS and HGS asymmetry were all independently related to lower global cognitive performance.  The association between HGS asymmetry and cognitive function varies among ethnic groups.