老年人吸烟及戒烟与相关死亡的前瞻性研究

目的：前瞻性探讨男性老年人吸烟及戒烟与烟草有关疾病死亡的相互关系。方法：研究对象为1987年西安市22个军队干休所的全部男性离体干部,共计1268人,基线调查时,388人为不吸烟者,419人为吸烟者,461人为戒烟者。终点指标为全死因和与烟草有关疾病死亡。结果：截止1999年,共观察14163人年,平均随访11年。共死亡299人,943人存活,26人失访。在调整了年龄,血压、体重指数,总胆固醇,甘油三酯、饮酒,体育锻炼和既往病史等因素后,多元Cox生存分析模型显示：既往吸烟与该人群相关死亡的对危险度（95％CI）分别为总死亡1．34（1．02－1．76）、慢性阻塞性肺病（COPD）3．23（0．95－10．91）,肺癌、2．31（0．95－5．61）、冠心病1．60（0．81－3．19）。其死亡危险性随既吸烟量的增多和吸烟年限的延长而升高,存在明确的剂量反应关系。与继续吸烟者相比,戒烟总死亡和冠心病死亡和危险性分别下降56％和93％,但COPD的死亡危险却升高了174％。结论：（1）吸烟是中国男性老年人的主要死因之一,而戒烟降低总死亡和心血管病死亡;（2）戒烟者COPD死亡危险高于继续吸烟者的原因可能与“无病吸烟者作用”和“因病戒烟作用有关。

A prospective study on smoking, quitting and mortality in a cohort of elderly in Xi'an, China

Objective To prospective examine the relationship between smoking, quitting and mortality in older Chinese men by in Xi'an, China. Methods The design was a cohort analytic study. One thousand two hundred and sixty eight retired male military veterans aged 60 or older were examined in 1987. At baseline, there were 388 never smokers, 461 former smokers and 419 current smokers. Main outcome measure was all cause and tobacco associated mortality. Results Through 1999, 299 had died, 943 were alive and 26 lost. The mean follow up time was 11 years and total person year of follow up was 14 163 . After adjusting for age, blood pressure, body mass index, total cholesterol, triglycerides, alcohol intake, exercise and existing diseases, using Cox proportional hazard regression model, the relative risks (95% confidence intervals) for ever smoking, deaths resulting from all causes, chronic obstructive pulmonary disease (COPD), lung cancer and coronary heart disease (CHD) were 1.34(1.02 1.76), 3.23(0.95 10.91), 2.31( 0.95 5.61) and 1.60( 0.81 3.19) respectively. The risks increased significantly with increasing amount and duration of smoking. Compared with current smokers, former smokers had lower risks of total mortality (excess risk reduction of 56%) and from CHD death (93%), but had higher risks for COPD death (excess risk increased 174%). Conclusions Smoking is a major cause of death in older Chinese men and quitting can save lives. These results showing that higher risks of COPD death in former smokers with or without existing diagnosed COPD at baseline than those in current smokers could be explained by either the "healthy smoker effect" or the "ill quitter effect" or both. Early recognition of the significance of COPD symptoms followed by prompt quitting should be emphasized as strategies in the control of the growing tobacco epidemic.