体质指数与非吸烟男性肺癌发病关系的前瞻性队列研究

Association between body mass index and risk of lung cancer in non-smoking males： a prospective cohort study

目的 利用前瞻性队列研究，探讨BMI与非吸烟男性肺癌发病的关系。方法 利用始建于2006年5月的开滦集团动态人群队列，收集基线调查时社会人口学资料，吸烟、饮酒等生活方式和身高、体重等测量指标及肺癌发病结局信息。采用多因素Cox比例风险回归模型分析非吸烟男性基线BMI与其肺癌发病的风险比（HR）及其95% CI。结果 截止2011年12月31日在纳入的48 799名非吸烟男性中，共计随访214 620.18人年，平均随访4.40年，共收集肺癌新发病例198例。以BMI（kg/m2）正常组（18.5≤BMI 〈 24.0）为参比组，调整年龄、教育程度、饮酒情况、体育锻炼、工作环境和糖尿病史后，低体重组（BMI〈18.5）、超重组（24.0≤BMI〈28.0）和肥胖组（BMI≥28）的HR值及其95% CI分别为1.14（0.53～2.45）、0.57（0.41～0.78）和0.61（0.38～0.97），趋势检验差异有统计学意义（P〈0.001）。将BMI作为连续性变量，调整年龄、教育程度、饮酒、体育锻炼、工作环境和糖尿病史后，BMI每增加5 kg/m2，肺癌的发病风险降低22%（HR=0.78，95% CI：0.64～0.95）。在年龄≥50岁组、锻炼频率〈4次/周组、不饮酒组以及井上作业组中，BMI每增加5 kg/m2，其肺癌的发病风险分别降低26%（HR=0.74，95% CI：0.60～0.92），24%（HR=0.76，95% CI：0.62～0.95），20%（HR=0.80，95% CI：0.65～1.00）和23%（HR=0.77，95% CI：0.61～0.97），剔除随访1年内新发肿瘤患者及其贡献的人年数后，结果无明显变化。结论 该队列人群中非吸烟男性的BMI与肺癌发病相关，且发病风险随BMI增加呈下降趋势。

Objective To assess the association between baseline body mass index （BMI） and risk of lung cancer in non-smoking males. Methods A dynamic non-smoking male cohort was established on May, 2006. Baseline information on demography, lifestyle, such as smoking status and alcohol consumption, anthropometry, such as body height and weight, were collected during the baseline interview, and the information of newly-diagnosed lung cancer cases were also collected during the follow-up period. Multivariable Cox proportional-hazards regression model was used to analyze the association between baseline BMI and lung cancer in non-smoking males. Results By December 31, 2011, a total of 48 799 male non-smokers had been assessed in the study and there were 214 620.18 person-years of follow-up and 4.40 years of average follow-up period. During follow-up, 198 lung cancer cases were identified among the 48 799 non-smoking males. Compared with those with normal BMI （kg/m2） （18.5≤BMI 〈 24.0）, the hazard ratio （95%CI） of lung cancer were 1.14（0.53-2.45）, 0.57（0.41-0.78） and 0.61（0.38-0.97） for underweight （BMI〈18.5）, overweight （24.0≤BMI 〈 28.0） and obese males （≥28.0）, respectively, after adjustment for potential confounding factors, including age, education level, alcohol consumption, physical activity, history of diabetes and work environment. Baseline BMI was negatively associated with the risk of lung cancer in non-smoking males and the risk would be reduced by 22% （HR=0.78, 95%CI：0.64-0.95） for per 5 kg/m2 BMI increase. The negative association between BMI and risk of lung cancer was significant among non-smoking males who aged ≥50 years, and in those who had physical exercise〈4 times/week, never drunk and worked above the coal mine, and for per 5 kg/m2 BMI increase, the risk of lung cancer would be reduced by 26%（HR=0.74, 95%CI：0.60-0.92）, 24%（HR=0.76, 95%CI：0.62-0.95）, 20%（HR=0.80, 95%CI：0.65-1.00） and 23% （HR=0.77, 95%CI：0.61-0.97）, respectively. The result was similar after excluding the cancer patients newly diagnose within 1-year and their contribution person years. Conclusion Baseline BMI might be negatively associated with risk of lung cancer in non-smoking males.