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发表在8月28日《PNAS》杂志上题为'肥胖的神经行为相关性很大程度上是可遗传的'(Neurobehavioral correlates of obesity are largely heritable)这项研究中，蒙特利尔神经研究所和医院( Neuro )的研究人员对1200个参与者的磁共振成像( MRI )和认知测试数据进行了检查。
他们发现，体重指数(BMI，体重/身高的平方，单位kg/㎡。成人的正常BMI数值：18.5-23.9；过重：24-27；肥胖：28-32；非常肥胖：高于32)较高的人表现出认知灵活性、延迟满足能力、视觉空间能力和语言记忆能力降低。他们还发现，体重指数增加的人倾向于左前额叶皮质较厚、右前额叶皮质较薄。先前的研究表明，右前额叶皮层的损伤会导致进食量增加。
此外，BMI较高的受试者左侧杏仁核的体积也有所增加。已有研究表明，杏仁核对食物信号起着一定的反应。他们还减少了内嗅-旁海马结构的体积，后者与情景记忆和语境调节有关。这表明了一种模式，在这种模式下，容易肥胖的人对视觉食物线索更敏感，并且即使在考虑饮食的负面效应（比如体重增加）时，仍然难以抗拒这些食物。
鉴于许多受试者是兄弟姐妹（包括异卵双胞胎和同卵双胞胎），这使得研究人员能够确定这些特征的遗传性，以及通过体重指数(BMI)来衡量的肥胖。使用统计学方法，研究人员发现许多认知和神经特征与肥胖有遗传联系。这表明遗传在肥胖中的作用至少部分通过大脑解剖和认知功能表现出来。
“这项研究将有助于制定干预措施来帮助肥胖患者。” 该研究的主要作者、爱沙尼亚塔尔图大学神经和心理学研究所的研究员Uku Vainik说，“例如，通过认知训练来改变神经行为因素，以提高人们抵抗食物的能力，可能会有希望。”
研究人员补充道，干预不应该仅仅集中在饮食上，还应该承认肥胖与神经行为有着基因上的联系。这种干预可能有助于人们保持苗条身材，即便他们有遗传特征。”
“这项工作为人类的体重在一定程度上受认知、决策和动机等高级大脑系统的控制这一理论提供了支持。此外，这些调节食物摄入的大脑系统中的个体差异似乎具有适度的遗传性。”资深作者Alain Dagher总结。
原始出处： Uku Vainik, Travis E. Baker, Mahsa Dadar, et.al.Neurobehavioral correlates of obesity are largely heritable. PNAS August 28, 2018 Abstract Recent molecular genetic studies have shown that the majority of genes associated with obesity are expressed in the central nervous system. Obesity has also been associated with neurobehavioral factors such as brain morphology, cognitive performance, and personality. Here, we tested whether these neurobehavioral factors were associated with the heritable variance in obesity measured by body mass index (BMI) in the Human Connectome Project (n = 895 siblings). Phenotypically, cortical thickness findings supported the “right brain hypothesis” for obesity. Namely, increased BMI is associated with decreased cortical thickness in right frontal lobe and increased thickness in the left frontal lobe, notably in lateral prefrontal cortex. In addition, lower thickness and volume in entorhinal-parahippocampal structures and increased thickness in parietal-occipital structures in participants with higher BMI supported the role of visuospatial function in obesity. Brain morphometry results were supported by cognitive tests, which outlined a negative association between BMI and visuospatial function, verbal episodic memory, impulsivity, and cognitive flexibility. Personality–BMI correlations were inconsistent. We then aggregated the effects for each neurobehavioral factor for a behavioral genetics analysis and estimated each factor’s genetic overlap with BMI. Cognitive test scores and brain morphometry had 0.25–0.45 genetic correlations with BMI, and the phenotypic correlations with BMI were 77–89% explained by genetic factors. Neurobehavioral factors also had some genetic overlap with each other. In summary, obesity as measured by BMI has considerable genetic overlap with brain and cognitive measures. This supports the theory that obesity is inherited via brain function and may inform intervention strategies. 关爱父母 关注阿尔茨海默病 |
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