遗传和环境对于男性开始吸烟影响的双生子研究

Study of twin-birth on genetic or environmental determinants of male Chinese smoking initiation

目的:分析遗传和环境因素分别对于男性吸烟行为和开始吸烟年龄的影响。方法:回顾性调查1006对18岁及以上成年双生子的吸烟状况及开始吸烟年龄,在分析同卵和异卵双生子同吸烟率的基础上分别计算吸烟行为和开始吸烟年龄的遗传度。结果:与西方文化不同,该双生子人群中男性吸烟比例达66.8%,相比之下女性仅有0.2%。同卵双生子中,88.7%(566/638对)的双生子对中两个成员都是吸烟者或者具有吸烟经历或均不吸烟,而异卵双生子此比例仅为63.6%(234/368对)。该双生子样本吸烟行为的遗传度为69.0%±4.1%。双生子平均开始吸烟年龄(20.4±5.3)岁,同卵双生子开始吸烟年龄相关系数0.393,而异卵双生子达0.860。结论:中等程度的遗传度显示遗传因素对于男性双生子选择是否吸烟具有一定的影响,但是什么时候开始吸烟,更多取决于个人环境的影响。

Objective：To determine the role of genetic and environmental factors in the onset of smo-king in Chinese male twins.Methods：Retrospective data on initiation and age at onset of smoking,reported by 1 006 adult twin pairs [aged 18 year-old or more,638 pairs of monozygotic（MZ）twins and 368 pairs of dizygotic（DZ）twins] were analyzed to calculate the heritability of smoking behavior and smoking initiation.Results：Different from western culture,66.8% of males in this Chinese sample are smokers or have the experience of smoking,but only 0.2% of females do so.In the MZ twins,88.7%（566/638 pairs）of them are both smokers or have smoking experience or both non-smokers,while the number is 63.6%（234/368 pairs）in the DZ twins.The heritability of smoking in this Chinese twin sample is 69.0%±4.1%.The smokers usually started their smoking at the age of 20.4±5.3 years old.The correlation coefficient for age at onset of smoking in male MZ twin smokers is 0.393,compared to correlation coefficient 0.860 in male DZ twin smokers.Conclusion：The moderate level of heritability shows that genetic factors have influence on smoking choice;when the smokers start their smoking,however,this depends more on individual environmental variation in our Chinese twin sample.