Department of Public Health, University of Helsinki, Helsinki, Finland.
Obesity (Silver Spring). 2012 Mar;20(3):583-9. doi: 10.1038/oby.2011.304. Epub 2011 Oct 13.
To investigate how parental education modifies genetic and environmental influences on variation in BMI during adolescence, self-reported BMI at 11-12, 14, and 17 years of age was collected from a population sample of 2,432 complete Finnish twin pairs born in 1983-1987. Based on parental report, twins were divided to those with high (both parents high school graduates), mixed level (one parent a graduate, the other not), and limited (neither parent a graduate) parental education. Genetic and environmental influences on variation in BMI in different education classes were modeled using twin analysis. Heritability of BMI among 11-12-year-olds with high parental education was 85-87% whereas it was 61-68% if parental education was limited or mixed level. Common environmental effect, i.e., effect of environmental factors shared by family members, was found (17-22%) if parental education was limited or mixed level but not if it was high. With increasing parental education, common environmental variance in BMI decreased at age 14 among boys (from 22 to 3%) and girls (from 17 to 10%); heritability increased among boys from 63 to 78%, but did not change among girls. The common environmental component disappeared and heritability of BMI was larger at the age of 17 in all parental education classes. To conclude, common environment did not affect variation of adolescent BMI in high-educated families but did so in families with limited parental education. This suggests that intervention and prevention campaigns could effectively target families identified by limited parental education.
为了探究父母教育如何改变遗传和环境因素对青少年 BMI 变化的影响，本研究从一个 1983-1987 年出生的完整芬兰双胞胎样本中收集了自我报告的 11-12 岁、14 岁和 17 岁时的 BMI。根据父母的报告，双胞胎被分为高学历（父母双方均为高中毕业生）、混合学历（一方父母为毕业生，另一方不是）和低学历（父母双方均未毕业）三组。采用双生子分析方法，对不同教育程度下 BMI 变化的遗传和环境影响进行建模。在高学历父母的 11-12 岁儿童中，BMI 的遗传率为 85-87%，而如果父母的教育程度较低或混合水平，则遗传率为 61-68%。如果父母的教育程度较低或混合水平，会发现共同环境效应（即家庭成员共享的环境因素的影响）（17-22%），但如果父母的教育程度较高，则不会发现这种效应。随着父母教育程度的提高，男孩（从 22%降至 3%）和女孩（从 17%降至 10%）在 14 岁时 BMI 的共同环境方差在高学历家庭中下降，而男孩的遗传率从 63%增加到 78%，但女孩的遗传率没有变化。在所有父母教育程度的组别中，17 岁时 BMI 的共同环境成分消失，遗传率更大。总之，在高学历家庭中，共同环境不会影响青少年 BMI 的变化，但在低学历家庭中则会产生影响。这表明，干预和预防运动可以有效地针对那些父母教育程度较低的家庭。
