Kaur Sonya S, Gonzales Mitzi M, Eagan Danielle E, Goudarzi Katyoon, Tanaka Hirofumi, Haley Andreana P
Department of Psychology, The University of Texas at Austin, 108 E. Dean Keeton, Stop A8000, Austin, TX, 78712, USA.
Imaging Research Center, The University of Texas at Austin, Austin, TX, USA.
Brain Imaging Behav. 2015 Dec;9(4):737-43. doi: 10.1007/s11682-014-9330-z.
Metabolic Syndrome (MetS), the clustering of obesity, high blood pressure, and disordered glucose and lipid/lipoprotein metabolism within a single individual, is associated with poorer cognitive function. It has been hypothesized that cognitive impairment in MetS occurs primarily within the context of inflammation. MetS risk factors are also associated with thinning of the cerebral cortex. However, the mechanisms by which MetS and inflammation affect the brain are poorly understood. The present study used statistical mediation to examine the relationship between MetS risk factors, cortical thickness in a priori regions of interest (ROIs) and inflammation. ROIs were chosen from the previous literature. Forty-three adults between the ages of 40 and 60 years underwent a health screen, neuropsychological testing and structural magnetic resonance imaging. Serum levels of pro-inflammatory markers (interleukin 1, interleukin 2, interleukin 6 and C-Reactive Protein) were measured using enzyme-linked immunosorbent assays. A higher number of MetS risk factors were associated with thinning in the inferior frontal ROI (β = -0.35, p = 0.019) as well as higher levels of serum interleukin 2 (β = 0.31, p = 0.04). A higher level of serum interleukin 2 was also associated with reduced thickness in the inferior frontal gyrus (β = -0.41, p = 0.013). After accounting for the effects of interleukin 2, the number of MetS risk factors was no longer associated with cortical thickness in the inferior frontal gyrus indicating successful statistical mediation. The results indicate a potentially important role for inflammation in linking MetS to cortical thinning and cognitive vulnerability.
代谢综合征（MetS）是指在个体内肥胖、高血压以及葡萄糖和脂质/脂蛋白代谢紊乱同时存在的情况，它与较差的认知功能相关。据推测，代谢综合征中的认知障碍主要发生在炎症背景下。代谢综合征的危险因素也与大脑皮层变薄有关。然而，代谢综合征和炎症影响大脑的机制尚不清楚。本研究采用统计中介分析来检验代谢综合征危险因素、先验感兴趣区域（ROI）的皮质厚度与炎症之间的关系。感兴趣区域是从前文文献中选取的。43名年龄在40至60岁之间的成年人接受了健康筛查、神经心理学测试和结构磁共振成像。使用酶联免疫吸附测定法测量血清促炎标志物（白细胞介素1、白细胞介素2、白细胞介素6和C反应蛋白）的水平。更多的代谢综合征危险因素与额下回感兴趣区域的变薄有关（β = -0.35，p = 0.019），同时也与血清白细胞介素2水平升高有关（β = 0.31，p = 0.04）。血清白细胞介素2水平升高也与额下回厚度减小有关（β = -0.41，p = 0.013）。在考虑了白细胞介素2的影响后，代谢综合征危险因素的数量与额下回的皮质厚度不再相关，表明统计中介分析成功。结果表明炎症在将代谢综合征与皮质变薄和认知易损性联系起来方面可能具有重要作用。
