我国拥有世界上最多的烟民、快速增多的超重及肥胖人群和逐年攀升的心血管病的发病及死亡。而目前吸烟和超重/肥胖对国人心血管病发病及死亡是否存在联合/交互作用及其相关机制尚不十分清楚。本研究拟利用既往建立的三个人群队列（1976年西安队列、2001年北京队列和2003年广州队列）中吸烟、体重和相关指标的重复测量数据，采用规范的队列研究和巢式病例对照研究设计，前瞻性探讨国人吸烟和超重/肥胖的联合/交互作用与心血管病结局(冠心病和脑卒中)的关系；同时依托队列人群的生物样本库，研究烟草成瘾者、体重易胖者及两者并存的人群是否具有相关或共同的代谢变化、易感基因和表观遗传调控途径及其与心血管病事件的关联，从人群现象、代谢变化、遗传背景和基因表达等多个层面探讨吸烟和超重/肥胖致心血管病的可能联合作用机制，为相关病因假说的建立和探讨两大可预防危险因素的综合干预措施提供人群流行病学的基础数据。

China has the largest number of smokers in the world, rapidly increasing overweight and obesity people and rising death caused by cardiovascular diseases year by year. However, the combined effect/interaction of smoking behaviors and obesity on cardiovascular diseases (CVD) and the relative mechanisms still lack prospective evidence in China. Through the design of prospective cohort study and nested case-control study in three long term follow-up Chinese cohort (1976 in Xi’an, 2001 in Beijing and 2003 in Guangzhou), in this study we try to prospectively examine the relationship between the combined effect/interaction between smoking behaviors and obesity and the risk of incidence and mortality of CVDs (coronary heart disease and stroke). Supported by the biological resource database of the cohorts, we also investigate the possible metabolic changes，genetic background and epigenetic mechanisms of the combined effect/interaction of smoking behaviors and obesity on CVDs. To provide epidemiological data evidence for establishing etiological hypothesis and making decision on the comprehensive interventions of the two important preventable risk factors.