Epidemiological Study On The Association Between Hand Grip Strength And Mild Cognitive Impairment In Rural Areas Of Liaoning Province

Objective:Mild cognitive impairment（MCI）represents an intermediate stage between normal cognitive aging and dementia,and research suggests that some individuals with MCI may exhibit reversibility to normal cognition,thus delaying or preventing the dementia.Previous studies have suggested a potential association between lower handgrip strength（HGS）and MCI,but the evidence remains limited,particularly in the absence of prospective cohort studies.Therefore,the aim of this study was to investigate the association between HGS and MCI in a Chinese population.Methods:This study was based on the project of"Comprehensive Demonstration Study on Prevention and Control of Major Chronic Diseases in Northeast China"of the National Key R&D Program of the 13th Five-Year Plan.A combination of cross-sectional and prospective cohort study designs was used.The baseline survey recruited 4,689 individuals（≥35 years old）who met the inclusion criteria from June to August,2019.We excluded individuals who did not participate in cognitive assessments（n=309）,had a history of stroke,other mental disorders,or brain diseases（n=393）,had missing covariates（n=104）,did not have handgrip strength measurements（n=887）,and potential dementia patients,resulting in a final sample of 2,633 participants included in the cross-sectional analysis.Among them,757 cognitively normal participants completed follow-up assessments from June to August 2021.After excluding those with missing variables,743 participants included in the prospective cohort study.Handgrip strength（kg）was measured using a Jamar Plus+dynamometer（Patterson Medical,United States）,and the HGS index was calculated as the average of maximum grip strength from both hands.The Montreal Cognitive Assessment-Basic Chinese version（MOCA-BC）was used to assess MCI and potential dementia,and the diagnostic criteria for MCI were based on recommendations from the National Institute on Aging and the Alzheimer’s Association（NIA-AA）.Logistic regression analyses were conducted to examine the association between HGS（as a continuous variable and by quintiles）and the presence and incidence of MCI,with additional analyses exploring the interaction between gender and HGS on incident MCI.Models were stratified by gender and adjusted for age,ethnicity,education level,marital status,income,physical labor level,body mass index,smoking,alcohol consumption,hypertension,diabetes,dyslipidemia,and coronary heart disease.Additional adjustments were added for baseline MOCA-BC scores in the cohort study analysis.Results:In the cross-sectional study,the mean age of participants was 56.6±9.8 years old,and 1713（65.1%）were females.The baseline prevalence of MCI was 36.7%.After adjusting for confounding factors,the logistic regression model showed that,in males,the third quintile（OR:1.90;95%CI:1.18,3.09;P<0.001）and the first quintile（OR:2.66;95%CI:1.54,4.64;P<0.001）of HGS were associated with increased risk of MCI compared to the fifth quintile of HGS.In females,the lowest quintile of HGS was associated with increased risk of MCI compared to the highest quintile of HGS（OR:1.70;95%CI:1.17,2.49;P=0.006）.In the cohort study,the baseline age of participants was54.8±9.8 years old,and 1125（67.5%）were females.The interaction model showed a significant interaction effect between sex and HGS on the incident MCI（P=0.015）.After adjusting for confounding factors,the logistic regression model showed that,in females,the second quintile（OR:4.28;95%CI:1.55,13.98;P=0.008）and the first quintile（OR:3.93;95%CI:1.39,13.01;P=0.015）of HGS were associated with higher risk of MCI compared to the fifth quintile of HGS,and there was a dose-response relationship between lower grip strength and higher risk of MCI(P _{for trend}=0.014).No significant association was found in males.Conclusion:This study provides evidence that lower handgrip strength is a risk factor for MCI.Lower baseline handgrip strength is associated with an increased risk of MCI,particularly in females.However,no significant association was observed in males.The gender difference in this association should be further investigated in future research.