[The joint effects of major lifestyle factors on stomach cancer risk among Chinese men: a prospective cohort study].

Objective: To investigate the combined impact of lifestyle factors on stomach cancer risk. Methods: We analyzed the data from the Shanghai Men's Health Study (SMHS) (2002-2013). The SMHS was conducted in eight neighborhood communities of urban Shanghai. From 2002 through June 2006, 61 480 residents aged 40 to 74 years old with no history of cancer were recruited. Failure time was the date of stomach cancer incidence, death or date of the last follow-up (December 31, 2013). The first two in-person follow-up surveys were conducted in 2004-2008, and 2008-2011, respectively. Using data on lifestyle, the healthy lifestyle index (HLI) was developed. The following lifestyle factors were included: smoking, alcohol consumption, diet habit, overweighted and physical activity. Cox proportional hazard models were used to evaluate the association of stomach cancer risk with lifestyle factors and HLI. Results: Over 9.28 years' follow-up, 477 incident cases of stomach cancer were identified from 59 503 study participants. Participants with zero, one, two, three, four, and five favorable lifestyle behaviors accounted for 3.44% (n=2 045), 18.14% (n=10 793), 33.68% (n=20 041), 29.43% (n=17 511), 12.82% (n=7 627), and 2.50% (n=1 486), respectively. Among all the five lifestyle factors, smoking and alcohol use were significantly related to stomach cancer risk. The relative risk of stomach cancer was 0.71 (95%CI: 0.57-0.87) for those who never smoked or quitted smoking for no less than 10 years and 0.70 (95%CI: 0.55-0.90) for those who consumed alcohol no more than 14 drinks per week. For each increment of healthy lifestyle index, the relative risk of stomach cancer was 0.86 (95%CI: 0.79-0.95). Compared to men with none or one healthy lifestyle factor, the relative risk for those with four or five was 0.62 (95%CI: 0.46-0.83). When we rebuilt HLI using more categories of each lifestyle factors, the HLI ranged from 0 to 11. For each point increase, the relative risk of stomach cancer was 0.93 (95%CI: 0.89-0.97). Compared those with 0 to 3 points, the relative risk of those with 8 to 11 points was 0.64 (95%CI: 0.47-0.87). Conclusion: In the SMHS, only a small proportion of men adhered to all the five healthy lifestyle factors. Compared to those with none or one healthy lifestyle behaviors, those with five may prevent about 1/3 stomach cancer incidence and the HLI was inversely associated with stomach cancer risk.目的： 探讨多种生活方式共同作用对胃癌发病的影响。 方法： 以2002—2013年上海男性健康队列的调查资料进行分析。上海男性健康队列以上海市某区8个街道40~74岁未患恶性肿瘤的常住男性居民为研究对象，2002—2006年期间有61 480名对象完成了基线调查。以胃癌发生或研究对象死亡或最后一次随访（2013年12月31日）作为观察截止点。分别于2004—2008和2008—2011年完成了两次随访。选择调查中的生活方式的数据，构建健康生活指数（HLI）。HLI主要纳入了吸烟、饮酒、饮食、肥胖和体育锻炼5种常见的生活方式因素。采用Cox比例风险模型评估不同生活方式、HLI指数与胃癌的关系。 结果： 经过9.28年的随访，59 503名纳入此次分析的对象中发生胃癌病例477例。有0、1、2、3、4、5种健康生活方式的人群所占比例分别为3.44%（2 045名）、18.14%（10 793名）、33.68%（20 041名）、29.43%（17 511名）、12.82%（7 627名）和2.50%（1 486名）。在这五种生活方式中，吸烟和饮酒因素与胃癌的关系有统计学意义，不吸烟或戒烟时间不小于10年者患胃癌RR（95%CI）值为0.71（95%CI：0.57~0.87），每周饮酒量不超过14份者患胃癌RR（95%CI）值为0.70（0.55~0.90）。平均每增加1种健康生活方式因素，患胃癌RR（95%CI）值为0.86（0.79~0.95）。相对于仅有0或1种健康生活方式的人群，有4~5种健康生活方式的人群患胃癌RR（95%CI）值为0.62（0.49~0.83）。按照生活方式因素多分类进行分组，构建的HLI分值在0~11分之间，平均每增加1分，患胃癌RR（95%CI）值为0.93（0.89~0.97）；与得分0~3之间的人群相比，得分8~11的对象患胃癌RR（95%CI）值为0.64（0.47~0.87）。 结论： 上海男性健康队列中满足全部5种健康生活方式的人群比例较低；相对于没有或者仅有一种健康生活方式的人群，生活方式完全健康的人群胃癌风险约能降低1/3；HLI与胃癌发生风险呈负相关。.