Davis C, Patte K, Zai C, Kennedy J L
Kinesiology and Health Sciences, York University, Toronto, ON, Canada.
Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
Nutr Diabetes. 2017 May 22;7(5):e279. doi: 10.1038/nutd.2017.24.
BACKGROUND/OBJECTIVES: Oxytocin (OXT) is an evolutionarily ancient neuropeptide with strong links to affiliative and prosocial behaviors, and the management of stress. Increases in OXT also tend to decrease food intake, especially of sweet carbohydrates. The social correlates of low OXT levels mesh with the social deficits and stress proneness identified in interpersonal models of overeating, as well as the increased appetite for highly palatable foods typically seen in chronic overeaters. The objectives of this study were to investigate links between polymorphisms of the oxytocin receptor (OXTR) gene and overeating, and to examine OXTR links with relevant endophenotypes of overeating related to reward and stress sensitivity, and to food preferences.
SUBJECT/METHODS: The sample comprised 460 adults between the ages of 25 and 50 years recruited from the community, and representing a broad range of body weights. Overeating, reward and punishment sensitivity, and food preferences, were quantified as composite variables using well-validated questionnaires. In addition, seven single-nucleotide polymorphisms (rs237878, rs237885, rs2268493, rs2268494, rs2254298, rs53576, rs2268498) of the OXTR gene were genotyped.
Analyses identified a four-marker haplotype that was significantly related to food preferences. Individual genotype analyses also found that at least one of the markers was related to each of the phenotypic variables. In addition, an empirically derived structural equation model linking genetic and phenotype variables produced a good fit to the data.
The results of this preliminary study have demonstrated that OXTR variation is associated with overeating, and with endophenotypic traits such as sweet and fatty food preferences, and reward and punishment sensitivity. In general, the genetic findings also favor the view that overeating may be associated with relatively low basal OXT levels.
背景/目的：催产素（OXT）是一种在进化上古老的神经肽，与亲和及亲社会行为以及压力管理密切相关。催产素水平升高也往往会减少食物摄入量，尤其是甜碳水化合物的摄入量。低催产素水平的社会关联与暴饮暴食人际模型中所确定的社会缺陷和压力易感性相契合，也与慢性暴饮暴食者中常见的对高适口性食物的食欲增加相契合。本研究的目的是调查催产素受体（OXTR）基因多态性与暴饮暴食之间的联系，并检查OXTR与与奖励和压力敏感性以及食物偏好相关的暴饮暴食相关内表型之间的联系。
对象/方法：样本包括从社区招募的460名年龄在25至50岁之间的成年人，代表了广泛的体重范围。使用经过充分验证的问卷将暴饮暴食、奖励和惩罚敏感性以及食物偏好量化为复合变量。此外，对OXTR基因的七个单核苷酸多态性（rs237878、rs237885、rs2268493、rs2268494、rs2254298、rs53576、rs2268498）进行基因分型。
分析确定了一种与食物偏好显著相关的四标记单倍型。个体基因型分析还发现，至少有一个标记与每个表型变量相关。此外，一个基于经验得出的将遗传和表型变量联系起来的结构方程模型与数据拟合良好。
这项初步研究的结果表明，OXTR变异与暴饮暴食以及诸如对甜食和高脂肪食物的偏好、奖励和惩罚敏感性等内表型特征有关。总体而言，遗传研究结果也支持暴饮暴食可能与相对较低的基础催产素水平有关的观点。
