Objective: To investigate the association between BMI and gastric cancer risk in Chinese males. Methods: Data on body weight, body height and incidence of gastric cancer were collected on a biennial basis in males in Kailuan Cohort during 2006-2015. In addition, electronic databases of hospitals affiliated to Kailuan Group, insurance system of Kailuan Group and medical insurance system of Tangshan were used for supplementary information. Males with normal body weight (18.5 kg/m(2)≤BMI<24.0 kg/m(2)) were used as controls. Cox proportional hazards regression model was used to evaluate the association between baseline BMI and the risk of gastric cancer in males through the calculations of hazard ratio and 95% confidence interval. Results: A total of 109 600 males were included and 272 new gastric cancer cases were identified in Kailuan male cohort study, with a follow-up of 860 399.79 person-years during 2006-2015. The median follow-up period was 8.8 years. When compared with normal weight, the hazard ratios (HR) of underweight (BMI≤18.5 kg/m(2)) for gastric cancer risk were 2.11 (95%CI: 1.23-3.62) after adjusting for potential confounding factors (age, education level, smoking status, alcohol drinking status, dust exposure, salty food intake, tea drinking status). However, overweight or obesity showed no significant association with gastric cancer risk. The stratified analyses based on age, education level, status on smoking, alcohol drinking, tea drinking and dust exposure indicated that underweight showed significant association with gastric cancer risk in those with older age, those with high education level, non-smokers, non-alcohol drinkers, non-tea drinkers and those with dust exposure. Conclusion: Underweight might increase the risk of gastric cancer in males in China, and this positive association might be associated with age, education level, status on smoking, alcohol-drinking, tea-drink, and dust exposure.
目的： 研究基线BMI与男性胃癌发病风险之间的关联。 方法： 基于开滦队列（2006-2015年）男性人群，收集身高、体重等流行病学信息。每两年随访1次，收集胃癌发病结局资料；检索开滦附属医院医疗信息系统、开滦集团保险系统、唐山市医疗保险系统，补充收集随访过程中可能遗漏的胃癌新发病例。以体重正常（18.5 kg/m(2)≤BMI<24.0 kg/m(2)）人群为参照组，利用Cox风险比例模型分析基线BMI与男性胃癌发病风险的关联，计算发病风险比（HR）及其95%CI。 结果： 共纳入109 600名男性，共随访860 399.79人年，中位随访时间8.8年，收集胃癌新发病例272例。和正常体重人群相比，调整年龄、文化程度、吸烟状态、饮酒频率、粉尘暴露、食盐习惯、饮茶习惯等潜在的混杂因素后，体重过轻人群（BMI<18.5 kg/m(2)）胃癌发病风险升高（HR=2.11，95%CI：1.23~3.62），超重/肥胖与胃癌发病风险无统计学关联。按照年龄、文化程度、吸烟、饮酒、饮茶、粉尘暴露等进行分层分析，结果显示，高年龄组、高文化程度、不吸烟、不饮酒、不饮茶、有粉尘暴露人群中，低体重与胃癌发病关联依然有统计学意义。 结论： 体重过轻可能增加男性胃癌发病风险，且该关联受年龄、文化程度、吸烟、饮酒、饮茶、粉尘暴露等因素影响。.
Keywords: Body mass index; Cohort study; Gastric neoplasm; Male.