[Case-control study on the influencing factors related to cognitive impairment in the elderly population of China].

Objective: To explore the influencing factors affecting the cognitive impairment of the elderly population in China. Methods: A stratified multi-stage cluster sampling was used in 6 provinces (autonomous administrative regions and municipalities) to select the sample. A total 24 000 urban and rural residents aged 60 years and above received a set of standardized questionnaire interview, physical examinations, laboratory test of lipid and glucose levels of blood and apolipoprotein E (APOE) genotype. The primary screening of cognitive function was assessed by using the Chinese Version of Ascertain Dementia 8, and then suspicious cognitive impairment cases with more than two abnormal results would receive the further cognitive function assessment by using the Mini-Mental State Examination (MMSE). 1 300 cases with cognitive impairment and 2 600 controls without cognitive impairment were recruited and matched according to their age, gender and resident area in a 1∶2 case-control study. The conditional logistic regression model was used to analyze the association between relevant factors and cognitive impairment. Results: Factors negatively associated with cognitive impairment and their OR (95%CI) values were primary or middle school as 0.63 (0.51-0.77), high school and above as 0.59 (0.39-0.88), daily neighborhood communication as 0.61 (0.50-0.75), weekly participating in social activities 0.59 (0.44-0.79), daily tea drinking as 0.71 (0.58-0.88) and doing regular exercise as 0.71 (0.57-0.88), reading newspaper (occasional: 0.50 (0.37-0.67); frequent: 0.40 (0.28-0.57)), playing majiang or cards (occasional: 0.51 (0.34-0.74); frequent: 0.50 (0.36-0.68)) respectively. Factors positively associated with cognitive impairment and their OR (95%CI) values were APOE-ε4 heterozygote as 1.31 (1.08-1.58), homozygote as 2.74 (1.52-5.00), diabetes onset before 50 years of age and after as 9.03 (3.07-33.60) and 4.40 (3.18-6.17), stroke as 1.90 (1.35-2.69), asthma as 1.95 (1.11-3.42) respectively. Conclusion: APOE-ε4 alleles, lower educational level, stroke, asthma, diabetes are risk factors of cognitive impairment in the elderly. Keeping a healthy lifestyle and preventing chronic diseases in the whole life course could significantly reduce the incidence of cognitive impairment in the elderly.目的：探讨中国老年人认知异常发生的相关因素。 方法：调查对象来自老年期重点疾病预防和干预项目试点调查。该调查采用多阶段分层整群随机抽样方法，在中国6个省（自治区、直辖市）抽取24 000名60岁及以上城乡居民，进行了问卷调查、身体测量、血糖和血脂检测以及载脂蛋白E（ApoE）基因型检测。采用中文版痴呆筛查量表进行初筛，有2项及以上存在异常的作为初筛可疑认知异常病例，再使用简易精神状况检查（MMSE）量表([3])进行认知功能评定。以筛查出的1 300名认知功能异常者作为病例组，以年龄、性别和常住地区为配对因素选取2 600名非认知异常者为对照组，采用1∶2匹配资料的多因素条件logistic回归模型分析认知异常的相关因素。 结果：与认知异常负相关的因素为：教育程度高（小学或初中：OR=0.63，95%CI=0.51~0.77，高中及以上：OR=0.59，95%CI=0.39~0.88），每天与邻居交往（OR=0.61，95%CI=0.50~0.75）、每周参加社会活动（OR=0.59，95%CI=0.44~0.79）、每天喝茶（OR=0.71，95%CI=0.58~0.88）、每天锻炼身体（OR=0.71，95%CI=0.57~0.88）、看报读书（偶尔：OR=0.50，95%CI=0.37~0.67；经常：OR=0.40，95%CI=0.28~0.57）、打牌或玩麻将（偶尔：OR=0.51，95%CI=0.34~0.74；经常：OR=0.50，95%CI=0.36~0.68）。与认知异常正相关的因素有：ApoE含ε4等位基因型（ε4杂合子：OR=1.31，95%CI=1.08~1.58；ε4纯合子：OR=2.74，95%CI=1.52~5.00）、糖尿病（早发病：OR=9.03，95%CI=3.07~33.60；晚发病：OR=4.40，95%CI=3.18~6.17）、脑卒中（OR=1.90，95%CI=1.35~2.69）、哮喘（OR=1.95，95%CI=1.11~3.42）。 结论： APOE-ε4等位基因、低受教育程度、脑卒中、哮喘和糖尿病是老年认知异常发生的危险因素，保持良好的生活方式和全生命历程预防慢性病能够显著降低老年认知异常的发生。.