北京市社区老年人群血压水平与认知功能变化的4年纵向研究

目的 探讨北京市社区老年人血压与通过简短精神状态(MMSE)量表检测的认知功能之间的关系。方法 以北京市一个有代表性的60岁及以上老年群体为研究对象,进行大样本的纵向流行病学研究。于1993年进行基线调查,检测血压,以MMSE为工具检查认知功能,并进行问卷调查,内容包括人口学情况、健康状况、生活状况等。1997年进行随访,以相同的工具复测认知功能并进行问卷调查,分析基线认知功能正常者4年后的变化。结果 2079名基线认知得分正常的老年人,平均收缩压为(141.77±24.94)mmHg(1mmHg=0.133kPa),平均舒张压为(81.76±12.08)mmHg。基线平均MMSE得分(25.65±3.59)分,4年后随访平均MMSE得分(23.24±5.63)分。随访得分与基线得分比较下降≥4分为认知功能明显下降。发现随着基线收缩压及舒张压水平增高,认知得分及认知功能明显下降的老年人比例增大。分层分析提示,在低龄(<75岁)、农村、无糖尿病及不用降压药物的老年人中,不同血压水平对认知功能改变有显著影响,血压水平高者认知得分明显下降的比例增大,这种关系在排除脑血管病和心脏病的影响后,在收缩压组依然存在。结论 纵向研究显示,老年人收缩压及舒张压升高可导致认知功能受损,随着血压水平的增高,认知功能下降的幅度增大。

Blood pressure and related cognition among elderly residents in the community in Beijing--a 4-year longitudinal study

OBJECTIVE: To investigate the association between blood pressure and related cognitive function with Mini-Mental State Examination (MMSE) in the elderly community residents in Beijing. METHODS: A selected sample of 60 years old and over from the communities was randomized ascertained to a longitudinal study in Beijing. The baseline data was produced in 1993, in which blood pressure, MMSE and a multidisciplinary questionnaire were involved. 4 years later in 1997, a similar procedure was repeated in 2079 elderly people whose MMSE scores were normal during the baseline study. RESULTS: The mean systolic blood pressure, diastolic blood pressure and MMSE score were 141.77 +/- 24.94 mm Hg, 81.76 +/- 12.08 mm Hg and 25.65 +/- 3.59 in baseline. The MMSE score was 23.24 +/- 5.63 in the follow-up study. Significant decline in cognition was defined as a decrease of 4 score and over during the 4-years study. The proportion of significant decline in cognition in the follow-up was larger when the systolic blood pressure or diastolic blood pressure having an increase in baseline data. Further stratified observation showed that factors as elderly with elevated blood pressure, under 75 years old from rural areas without diabetes mellitus or antihypertensive medication were more commonly seen in the ones with significant cognition decline. Increased incidence of cognitive decline was found in those with increased level of hypertension. This association was also seen in systolic blood pressure after adjustment of heart disease and cerebrovascular disease. CONCLUSIONS: In the 4-year longitudinal study, cognitive dysfunction might cause elevated baseline systolic and diastolic blood pressure in the elderly people whose baseline MMSE scores were normal.