Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, United Kingdom.
Am J Clin Nutr. 2012 Mar;95(3):633-9. doi: 10.3945/ajcn.111.023671. Epub 2012 Jan 25.
The behavioral susceptibility model proposes that inherited differences in traits such as appetite confer differential risk of weight gain and contribute to the heritability of weight. Evidence that the FTO gene may influence weight partly through its effects on appetite supports this model, but testing the behavioral pathways for multiple genes with very small effects is not feasible. Twin analyses make it possible to get a broad-based estimate of the extent of shared genetic influence between appetite and weight.
The objective was to use multivariate twin analyses to test the hypothesis that associations between appetite and weight are underpinned by shared genetic effects.
Data were from Gemini, a population-based birth cohort of twins (n = 4804) born in 2007. Infant weights at 3 mo were taken from the records of health professionals. Appetite was assessed at 3 mo for the milk-feeding period by using the Baby Eating Behaviour Questionnaire (BEBQ), a parent-reported measure of appetite [enjoyment of food, food responsiveness, slowness in eating (SE), satiety responsiveness (SR), and appetite size (AS)]. Multivariate quantitative genetic modeling was used to test for shared genetic influences.
Significant correlations were found between all BEBQ traits and weight. Significant shared genetic influence was identified for weight with SE, SR, and AS; genetic correlations were between 0.22 and 0.37. Shared genetic effects explained 41-45% of these phenotypic associations.
Differences in weight in infancy may be due partly to genetically determined differences in appetitive traits that confer differential susceptibility to obesogenic environments.
行为易感性模型提出，食欲等特质的遗传差异赋予了体重增加的不同风险，并有助于体重的遗传性。FTO 基因可能通过其对食欲的影响部分影响体重，这支持了该模型，但测试具有非常小影响的多个基因的行为途径是不可行的。双胞胎分析使人们有可能对食欲和体重之间遗传影响的共享程度进行广泛的估计。
本研究旨在使用多变量双胞胎分析来检验以下假设，即食欲和体重之间的关联是由共同的遗传效应支撑的。
数据来自 Gemini，这是一个基于人群的双胞胎出生队列（n=4804），于 2007 年出生。3 个月大时的婴儿体重来自健康专业人员的记录。在母乳喂养期，通过使用婴儿进食行为问卷（BEBQ）评估 3 个月大时的食欲，这是一种父母报告的食欲衡量指标，包括对食物的享受、食物反应性、进食速度（SE）、饱腹感反应（SR）和食欲大小（AS）。使用多变量定量遗传建模来检验共同遗传影响。
发现 BEBQ 所有特征与体重之间均存在显著相关性。在 SE、SR 和 AS 方面，体重存在显著的共同遗传影响；遗传相关性在 0.22 到 0.37 之间。共同遗传效应解释了这些表型关联的 41-45%。
婴儿期体重的差异可能部分归因于食欲特征的遗传差异，这些差异赋予了对肥胖环境的不同易感性。
