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

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

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区平原和远郊山区 ,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 5 5岁以上人群 2 0 86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≥ 2 5 .0和 2 0 .0～ 2 4.9组老人死亡的危险分别比BMI<2 0 .0组老人低 6 2 %(HR =0 .38,95 %CI:0 .2 9～ 0 .49)和 39%(HR =0 .6 1,95 %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。

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 edlerly hypertensives.