Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth College, United States; Department of Pediatrics, Geisel School of Medicine at Dartmouth College, United States.
Department of Nutrition and Food Sciences, University of Rhode Island, Kingston, RI 02881, United States.
Appetite. 2017 Oct 1;117:321-329. doi: 10.1016/j.appet.2017.07.009. Epub 2017 Jul 13.
Polymorphisms in the Fat Mass and Obesity Associated (FTO) gene are robustly associated with overweight and obesity among children, although the underlying mechanisms are poorly understood. We tested if appetitive traits partially mediated the association between FTO genotype and increased BMI among a sample of US preadolescents. Data were from 178 unrelated 9-10 year olds who participated in an experimental study between 2013 and 2015. Children's DNA was isolated from buccal swabs, and the rs9939609 SNP in the FTO gene was genotyped. Children's age- and sex-adjusted BMI z-scores were computed using height and weight measured at the laboratory. Parents completed the Child Eating Behavior Questionnaire that includes three validated scales of habitual appetitive traits related to drive and regulation: satiety responsiveness, enjoyment of food and food responsiveness. Structural equation modeling was used to assess if those traits mediated the relationship between FTO and BMI z-score. The sample of children was 48.9% male and 91.0% non-Hispanic white. FTO distribution was in Hardy Weinberg equilibrium, and 16.3% of participants were homozygous for the high-risk allele. Mean BMI z-score was greatest among those with the high-risk genotype (ANOVA P < 0.01). In separate structural equation models adjusted for the child's sex and maternal education, decreased satiety responsiveness and increased food responsiveness each partially mediated the positive association between the high-risk genotype and increased BMI z-score (P-value for each indirect effect <0.05). Continued research is needed to better understand how other known genetic obesity risk factors may impact appetitive traits among children.
肥胖相关基因（FTO）多态性与儿童超重和肥胖密切相关，尽管其潜在机制尚不清楚。我们检测了在一项美国青少年前样本中，食欲特征是否部分介导了 FTO 基因型与 BMI 增加之间的关联。数据来自于 2013 年至 2015 年期间参与一项实验研究的 178 名无亲缘关系的 9-10 岁儿童。从口腔拭子中提取儿童的 DNA，并对 FTO 基因中的 rs9939609 SNP 进行基因分型。利用实验室测量的身高和体重计算出儿童的年龄和性别调整后的 BMI z 分数。父母完成了儿童饮食行为问卷，其中包括三个与驱动力和调节相关的习惯性食欲特征的验证量表：饱腹感反应、食物享受和食物反应性。结构方程模型用于评估这些特征是否在 FTO 和 BMI z 分数之间的关系中起中介作用。该儿童样本中 48.9%为男性，91.0%为非西班牙裔白人。FTO 分布处于 Hardy Weinberg 平衡，16.3%的参与者为高风险等位基因纯合子。高风险基因型组的平均 BMI z 分数最高（方差分析 P < 0.01）。在分别调整了儿童性别和母亲教育的结构方程模型中，饱腹感反应降低和食物反应性增加都部分介导了高风险基因型与 BMI z 分数增加之间的正相关关系（每种间接效应的 P 值<0.05）。需要进一步研究以更好地了解其他已知的遗传肥胖风险因素如何影响儿童的食欲特征。
