青春晚期超重和吸烟影响成年后病死率的联合效应：全国队列研究

Combined effects of overweight and smoking in late adolescence on subsequent mortality： nationwide cohort study

研究目的研究青春晚期超重和吸烟影响成年后病死率的联合效应。研究设计用经过肌力、社会经济地位、年龄等因素校正的Cox比例风险模型进行连锁分析。研究地点瑞典军队征兵登记，死亡原因登记和普查数据。研究对象45920名瑞典人（平均年龄18．7岁，标准差为0．5），随访38年。主要观察指标体重指数（Body mass index，BMI）（低体重（BMI〈18．5），正常体重（18．5～24．9），超重（25～29．9），肥胖（≥30））；肌力，在1969-1970年间军队征兵的强制性测试中自报的吸烟状况（不吸烟者，轻度吸烟者（1～10支／天），重度吸烟者（〉10支／天）；全因死亡。结果在170万人年中，有2897人死亡。与正常体重的人群（病死率为17／10000，95％可信区间为16～18）相比，超重（风险比为1．33，1．15～1．53；病死率为23，20～26）和肥胖（风险比为2．14，1．61-2．85；病死率为38，27～48）的人群死亡的风险增高，同样，对吸烟者与非吸烟者的分析也得出类似的结论。尽管消瘦（BMI〈17）被认为与病死率增加有关（风险比为1．33，1．07～1．64；病死率为24，19～29），并没有发现低体重的人群中死亡风险增加（风险比为0．97，0．86～1．08；病死率为18，16～19）。源于体重指数和吸烟状况联合效应增加的相对危险度在任何一组人群中并不显著。同时，除了肥胖和重度吸烟（增加的相对危险度1．5，-1．7～3．7）以外，其他任何组合的联合效应与其单独存在时相比，差异均无统计学意义。与不吸烟者（病死率为14，13～15）相比，轻度（风险比为1．54，1．41—1．70；病死率为15，14～16）和重度（风险比为2．11，1．92—2．31；病死率为26，24—27）吸烟者的死亡风险均有所增加。结论无论吸烟状况如何，在青春晚期超重和肥胖均可致成年后的病死率增加。肥胖、超重的危害分别与重度吸烟、轻度吸烟相当，但是，体重指数和吸烟情况并没有交互影响。青少年中全球性的肥胖流行和吸烟仍然是促进公共卫生健康必须关注和解决的问题。

Objective To investigate the combined effects on adult mortality of overweight and smoking in late adolescence. Design Record linkage study with Cox proportional hazard ratios adjusted for muscle strength, socioeconomic position, and age. Setting Swedish military service conscription register, cause of death register, and census data. Participants 45 920 Swedish men （mean age 18.7, SD 0. 5） followed for 38 years. Main outcome measures Body mass index （underweight （ BMI 〈 18. 5 ）, normal weight （18.5-24. 9）, overweight （25-29. 9）, and obesity （ I〉 30））, muscle strength, and self reported smoking （ non-smoker, light smoker （ 1-10 cigarettes/day ）, heavy smoker （ 〉 10/day ） ） at mandatory military conscription tests in 1969-70. All cause mortality. Results Over 1.7 million person years, 2897 men died. Compared with normal weight men （incidence rate 17/10 000 person years, 95% confidence interval 16 to 18 ）, risk of mortality was increased in overweight （hazard ratio 1.33, 1.15 to 1.53 ; incidence rate 23, 20 to 26） and obese men （hazard ratio 2. 14, 1.61 to 2. 85; incidence rate 38, 27 to 48）, with similar relative estimates in separate analyses of smokers and non-smokers. No increased risk was detected in underweight men （hazard ratio 0. 97, 0. 86 to 1.08; incidence rate 18, 16 to 19）, though extreme underweight （BMI 〈 17 ） was associated with increased mortality （ hazard ratio 1.33, 1.07 to 1.64 ; incidence rate 24, 19 to 29）. The relative excess risk due to interaction between BMI and smoking status was not significant in any stratum. Furthermore, all estimates of interaction were of small magnitude,except for the combination of obesity and heavy smoking （relative excess risk 1.5, - 0. 7 to 3.7）. Compared with nonsmokers （incidence rate 14, 13 to 15）, risk was increased in both light （hazard ratio 1.54, 1. dl to 1.70 ; incidence rate 15, 14 to 16） and heavy smokers （hazard ratio 2. 11, 1.92 to 2. 31 ; incidence rate 26, 24 to 27）. Conclusions Regardless of smoking status, overweight and obesity in late adolescence increases the risk of adult mortality. Obesity and overweight were as hazardous as heavy and light smoking, respectively, but there was no interaction between BMI and smoking status. The global obesity epidemic and smoking among adolescents remain important targets for intensified public health initiatives.