Social, Genetic & Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK; Computational, Cognitive, and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
Neuroscience. 2013 Nov 12;252:109-17. doi: 10.1016/j.neuroscience.2013.07.015. Epub 2013 Aug 9.
Obesity and major depressive disorder (MDD) are highly prevalent and often comorbid health conditions. Both are associated with differences in brain structure and are genetically influenced. Yet, little is known about how obesity, MDD, and known risk genotypes might interact in the brain. Subjects were 81 patients with MDD (mean age 48.6 years) and 69 matched healthy controls (mean age 51.2 years). Subjects underwent 1.5T magnetic resonance imaging, genotyping for the fat mass and obesity associated (FTO) gene rs3751812 polymorphism, and measurements for body mass index (BMI). We conducted a whole brain voxelwise analysis using tensor-based morphometry (TBM) to examine the main and interaction effects of diagnosis, BMI and FTO genotype. Significant effects of BMI were observed across widespread brain regions, indicating reductions in predominantly subcortical and white matter areas associated with increased BMI, but there was no influence of MDD or FTO rs3751812 genotype. There were no significant interaction effects. Within MDD patients, there was no effect of current depressive symptoms; however the use of antidepressant medication was associated with reductions in brain volume in the frontal lobe and cerebellum. Obesity affects brain structure in both healthy participants and MDD patients; this influence may account for some of the brain changes previously associated with MDD. BMI and the use of medication should ideally be measured and controlled for when conducting structural brain imaging research in MDD.
肥胖症和重度抑郁症（MDD）是两种高发且常合并存在的健康问题。这两种疾病都与大脑结构的差异有关，并且受到遗传因素的影响。然而，目前对于肥胖症、MDD 和已知的风险基因型如何在大脑中相互作用，我们知之甚少。本研究的受试者包括 81 名患有 MDD（平均年龄 48.6 岁）的患者和 69 名匹配的健康对照者（平均年龄 51.2 岁）。受试者接受了 1.5T 磁共振成像、肥胖相关基因（FTO）rs3751812 多态性的基因分型以及体重指数（BMI）的测量。我们使用基于张量的形态测量学（TBM）进行了全脑体素分析，以研究诊断、BMI 和 FTO 基因型的主效应和交互效应。在广泛的大脑区域观察到 BMI 的显著影响，表明与 BMI 增加相关的主要是皮质下和白质区域的减少，但 MDD 或 FTO rs3751812 基因型没有影响。没有观察到显著的交互效应。在 MDD 患者中，目前的抑郁症状没有影响；然而，抗抑郁药物的使用与额叶和小脑的脑体积减少有关。肥胖症会影响健康参与者和 MDD 患者的大脑结构；这种影响可能解释了之前与 MDD 相关的一些大脑变化。在进行 MDD 的结构脑成像研究时，理想情况下应测量并控制 BMI 和药物使用情况。
