北京市55岁以上人群体重指数与高血压及全死因死亡率的关系

目的：探索老年人体重指数（BMI）与高血压和死亡的关系。方法：1992年在北京市区和近郊山区，各随机抽取1个区／县，在所抽取的区／县采取分层、分段及整群抽样的方法抽取55岁以上人群2086名进行队列研究。结果：BMI随年龄的上升而下降，高血压患病率则随BMI和年龄的增高而上升。BMI与全死因死亡率呈负相关关系，BMI≥25．0和20．0－24．9组老人的死亡危险分别比BMI＜20．0组老人低62％（HR＝0．38，95，CI：0．29－0．49）和39％（HR＝0．61，95％；CI：0．49－0．75）；Cox多因素分析表明，在控制年龄、性别、地区（城乡）、高血压患病史、认知功能、健康自评等因素后，上述关系依然存在。结论；在老年人群不应过分强调减肥，但结果有待于进一步深入研究和证实。

The relationship between body mass index, hypertension and all-cause mortality in the populaton over 55 year old in Beijing

OBJECTIVE: To study the relationship between body mass index (BMI), hypertension and all-cause mortality in the elderly population in Beijing. METHODS: In 1992, a cohort of 3 257 people above 55 years old was selected from 3 different areas of Beijing, i.e. urban and suburbs (both plain and mountain areas). Information on physical condition, history of chronic diseases, self-perceived health, as well as smoking and drinking status was collected. Blood pressure, body height and weight were measured among 2 086 of 3 257 subjects. RESULTS: BMI was decreasing with age, while the prevalence of hypertension increased with age. Meanwhile the prevalence of hypertension increased with age as well as with BMI. There was a reverse relationship between BMI and all-cause mortality, i.e. the risk of death was 39.0% lower for those with BMI = 20.0 - 24.9 kg/m(2) (Hazard ratio: 0.61, 95% Confidence interval: 0.49 - 0.75) and 62% lower for those with BMI >/= 25.0 kg/m(2) (Hazard ratio: 0.38%, 95% Confidence interval: 0.29 - 0.49) than those with BMI < 20.0 kg/m(2). After controlling for age, gender, residential place, hypertension as well as self-perceive health status and cognition function, low BMI remained a significant and independent predictor to death. CONCLUSION: The distribution of BMI was different in elderly from the youth. The findings suggested that it was important to control the body weight among the elderly hypertensives.