Cohort Study On The Relationship Between ApoE Gene Polymorphism And Cognitive Function Decline In Communities

Objective : Studies have suggested that association between apolipoprotein E gene polymorphisms and cognitive decline are inconsistent in different populations.In this study,the community population in Ningxia was used as the research subjects and cohort study design was employed to explore the correlation between Apo E ?4 allele carrying and cognitive decline,and to provide a reference for exploring early cognitive impairment disorders.Methods: Baseline levels of cognitive function were determined using the Chinese version of the Mini-mental State Examination(MMSE).A total of 1029 eligible subjects were enrolled during year 2011 to 2015 upon the public health examination.Follow up interview were conducted by the unified training investigators from July 2016 to March 2018.The survey included general conditions and MMSE assessments.Peripheral blood granulocyte DNA was extracted,and the polymorphism of the 112 th amino acid sequence(rs429358)and the 158 th amino acid sequence(rs7412)of the Apo E gene locus was detected by high resolution melting curve method.Unconditional logistic regression models were used to analyze possible associations.The influencing factors of cognitive decline degree and decline rate were analyzed using multiple linear regression models.Results: 1.A total of 527 subjects completed the follow-up questionnaire evaluation,followed up for a total of 1896.77 person-years and the average follow-up time was(3.60±1.97)years;84 of them were ?4 allele carriers,followed up for a total of 248.26 person-years;a total of 309 subjects had a decrease in MMSE scores,and the incidence density was 16.3/100 person-years,The incidence of cognitive decline in ?4 allele carriers was significantly higher(0.25/100 person-years)than in non-carriers(0.15/100 person-years),RR=1.67;multiple factors Analysis of possible factors that influence the risk of cognitive decline include: ?4 allele carrying(OR=1.53,95% CI:1.18-2.00,P=0.008),age(OR=0.76,95% CI: 0.66-0.89,P < 0.001),gender(OR = 0.77,95% CI: 0.64-0.94,P = 0.002),education level(OR = 0.85,95% CI: 0.78-0.94,P < 0.001),ethnicity(OR = 0.54,95% CI: 0.44-0.67,P=0.002),urban /rural(OR=0.69,95% CI: 0.57-0.86,P<0.001).2.The decrease of MMSE score was higher in ?4 allele carriers(1.64±2.85)than non-carrier(0.96±2.74),the difference was statistically significant(t=2.07,P=0.039);With age increase,the decline in MMSE scores increased(trend F = 57.78,P < 0.001).After controlling the demographic variables,multiple linear regression model showed that the ?4 allele carrying(?=0.091,P=0.026)was significantly associated with the degree of cognitive decline.3.The MMSE score reduction rate of the study subjects was higher in the ?4 allele carriers than that of non-carriers,the difference was statistically significant(t=2.10,P=0.036);the MMSE score reduction rate gradually increased with age(Trend F=61.28,P<0.001);multiple linear regression model analysis showed: ?4 allele carrying(?=0.091,P=0.037),education level(?=-0.091,P=0.033)were significantly associated with the speed of cognitive decline.Conclusion: 1.The decline of cognitive function in the population aged 55 and over is commonly exist.The Apo E gene polymorphism is significantly associated with the decline of cognitive function in the elderly,and?4 carriers is significantly higher risk than that of non-carriers,indicate practical implication value of early screening of cognitive impairment disorder.2.The rate of and degree of cognitive function decline in the communities aged 55 and over is significantly different among different populations,and the cognitive function of ?4 carriers declines more rapidly,and suggest that early cognitive function maintenance training for high-risk groups may have a certain practical value in slowing down the decline of cognitive function.