中国22万男性人群体重指数与缺血性心脏病关系的15年前瞻陛研究

目的 探讨中国人群尤其是低体重人群中体重指数(BMI)与缺血性心脏病(IHD)死亡之间的关系.方法 数据来源于1990-1991年已随访15年共涉及中国220 000名40～79岁男性对象的前瞻性队列研究.利用Cox比例风险模型,在调整年龄、吸烟史及其他潜在混杂因素后,计算BMI与IHD死亡间的相对危险度(解).结果 基线BMI平均值为21.7 kg/m~2.15年随访期间,共有2763例对象死于IHD(占总死亡的6.8%).在排除了基线调查时已报告息有心脑血管疾病史的对象后,BMI与IHD死亡率之间呈"J"形关系.当BMI＞20 kg/m~2时,BMI与IHD死亡风险呈正相关.BMI值每升高5 kg/m~2,IHD死亡率相应增高21%(95%CI:9%～35%,P=0.0004).而当BMI＜20kg/m~2时,IHD死亡风险反而随着BMI的下降呈上升的趋势.在BMI值为20～21.9、18～19.9、＜18 kg/m~2范围时,其对应的RR值分别为1.00、1.11和1.14.在排除了前3年随访中死亡的病例或将分析局限于从不吸烟者中,BMI与IHD死亡风险的关系仍呈现相同趋势.结论 对于处在所谓正常BMI范围值内(20～25 kg/m~2)的人群,BMI与IHD死亡风险呈正相关,但当BMI低于这一范围,两者的关联极有可能为负相关.

Body mass index and mortality from isehaemic heart disease in China:a 15-year prospective study on 220000 adult men

Objective To assess the relationship between body mass index (BMI) and ischaemic heart disease (IHD) mortality,especially in populations with low mean BMI levels.Methods We examined the data from a population-based,prospective cohort study of 220 000 Chinese men aged 40-79,who were enrolled in 1990-1991,and followed up ever since to 1/1/2006.Relative risks of the deaths from IHD by the baseline BMI were calculated,after controlling age,smoking,and the other potential confounding factors.Results The mean baseline BMI was 21.7 kg/m~2,and 2763 IHD deaths were recorded during the 15-year follow-up (6.8% of all deaths) program.Among men without prior vascular diseases at baseline,there was a J-shaped association between BMI and IHD mortality.When baseline BMI was above 20 kg/m~2,there was a strongly positive association of BMI with IHD risk,with each 5 kg/m~2 higher in BMI associated with 21%(95%CI:9%-35%,P=0.0004) higher IHD mortality.Below this BMI range,the association appeared to be reverse,with the risk ratios as 1.00,1.11,and 1.14,respectively,for men with BMI 20-21.9,18-19.9,and ＜ 18 kg/m~2.The excess IHD risk observed at low BMI levels persisted after restricting analysis to never smokers or excluding the first 3 years of follow-up.Conclusion Lower BMI was associated with lower IHD risk among people in the so-called 'normal range' of BMI values (20-25 kg/m~2).However,below that range,the association might well be reversed.