| Objective1.To understand the prevalence and distribution characteristics of Alzheimer’s disease(AD)among the elderly aged 65 years and over in the study areas;2.To explore the influencing factors of AD and establish the causal hypothesis of related factors and AD;3.To explore the serum levels of Aβ42 protein and p-tau protein in the elderly aged 65 years and over in the survey areas,and to provide data for the development of normal reference ranges of AD-related serum biomarkers.Methods1.In the first part of the study,a survey based on the current situation of the community population was carried out.A questionnaire survey was conducted on the elderly≥ 65 years old in 13 communities of Zhongluotan Town,Baiyun District,Guangzhou,and the Mini-mental State Examination was obtained.MMSE)score,self-care ability assessment grade of the elderly,AD disease,demographic information,healthrelated behaviors,disease history,physical examination results and other data.The measurement data were described by mean ± standard deviation(x±s),and the adoption rate and component ratio of count data were described.Chi-square test(2)and unqualified Logistic regression model([Method=LR(backward)α into=0.05,α out=0.10,multiple classification variables into the model as dummy variables)were used to analyze OR values and 95%CI of risk factors associated with AD disease.2.In the second part,based on the cross-sectional study,the patients with newly diagnosed AD were selected as cases,and people with normal cognitive function were selected as controls in the first part.Age(±2 years)and gender were used as matching factors to carry out a 1:1 individual matched case-control study.Conditional Logistic regression analysis of individual matched data(stratified Cox regression model was used for fitting)was used to screen the risk factors of AD from the influencing factors that may be related to AD in the results of the first part of univariate analysis(P<0.05),and the OR value and 95%CI were calculated.3.In the third part,based on the blood samples collected,80,70 and 250 subjects who met the test conditions were randomly selected from the AD case group,the MMSE preliminarily screened AD group and the normal control group in the first part,respectively.Enzyme linked immunosorbent assay(ELISA)was used to measure the levels of serum A342 protein and serum p-tau protein in the subjects.The results were described by(x±s)standard deviation,and the two independent sample t test was used for comparison between groups.Results1.In the first part of the cross-sectional study,1324 people should be investigated,and 1274 people were actually investigated(50 invalid questionnaires were excluded),with a response rate of 96.22%;The results of MMSE showed that 514 patients were initially screened for AD,and the prevalence of AD was 40.34%(514/1274).The average score of MMSE was 16.54±5.22 in the AD group and 24.98±2.71 in the MMSE negative group,and the difference between the two groups was statistically significant(t=33.80,P<0.001).The abnormal rate of activities of daily living(mild dependence,moderate dependence and inability to take care of themselves)was 8.71%(111/1274).Among 1274 adults aged 65 years and over,the prevalence of AD was 7.61%(97/1274),and the age-standardized prevalence of AD was 8.90%(130038/1460333).2.In part II,the results of 1:1 individual matched case-control study showed that physical exercise(OR=0.28,95%CI:0.12-0.66)and denture(OR=0.10,95%CI:0.03-0.33)were protective factors for AD in univariate analysis,and sleep duration(OR=2.15,95%CI:1.14-4.06),taking nutrient supplements(OR=2.83,95%CI:1.12-7.19),diabetes mellitus(OR=3.50,95%CI:1.15-10.63)were the risk factors for AD.The results of multivariate analysis showed that physical exercise(OR=0.57,95%CI:0.38-0.86)and denture use(OR=0.39,95%CI:0.18-0.85)were protective factors for AD.3.The results of the third part of serum biomarkers showed that the level of serum Aβ42 protein in 77 AD patients was 266152.88pg/ml,and the level of p-tau protein was 22.638.62ng/ml.The serum levels of Aβ42 protein and p-tau protein in 69 AD patients screened by MMSE were 221.12131.53pg/ml and 21.353.70ng/ml,respectively.The serum levels of Aβ42 protein in 229 normal controls were 253.21147.18pg/ml.The p-tau protein level was 19.067.90ng/ml.The serum levels of P-tau protein in the case group and the MMSE initial screening AD group were higher than those in the normal control group,and the differences were statistically significant(P<0.05).The serum levels of Aβ42 protein in the case group and the MMSE initial screening AD group were not significantly different from those in the normal control group(P>0.05).Conclusions1.The prevalence of AD in the residents aged≥65years in the study area was higher than the average prevalence of AD in the population aged≥65years in China,and higher than the prevalence of AD in the residents aged≥65years in Guangzhou in previous surveys.2.The results of this case-control study showed that physical exercise and denture were protective factors for AD,while long sleep duration,taking nutrient supplements and diabetes were risk factors for AD.3.This study found that the average level of serum p-tau protein in AD cases and AD high-risk population was higher than that in normal population,but the difference of serum Aβ42 protein level between AD cases and AD high-risk population and normal population was not found. |
PDF Full Text Request