Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC/UAM, Madrid, Spain.
J Cereb Blood Flow Metab. 2020 Nov;40(11):2135-2151. doi: 10.1177/0271678X20941263. Epub 2020 Jul 23.
Obesity is a current threat to health care systems, affecting approximately 13% of the world's adult population, and over 18% children and adolescents. The rise of obesity is fuelled by inadequate life style habits, as consumption of diets rich in fats and sugars which promote, additionally, the development of associated comorbidities. Obesity results from a neuroendocrine imbalance in the cerebral mechanisms controlling food intake and energy expenditure, including the hypothalamus and the reward and motivational centres. Specifically, high-fat diets are known to trigger an early inflammatory response in the hypothalamus that precedes weight gain, is time-dependent, and eventually extends to the remaining appetite regulating regions in the brain. Multiple magnetic resonance imaging (MRI) and spectroscopy (MRS) methods are currently available to characterize different features of cerebral obesity, including diffusion weighted, T and volumetric imaging and H and C spectroscopic evaluations. In particular, consistent evidences have revealed increased water diffusivity and T values, decreased grey matter volumes, and altered metabolic profiles and fluxes, in the brain of animal models and in obese humans. This review provides an integrative interpretation of the physio-pathological processes associated with obesity development in the brain, and the MRI and MRS methods implemented to characterize them.
肥胖是当前对医疗保健系统的威胁，影响了全球约 13%的成年人口，以及超过 18%的儿童和青少年。肥胖的增加是由不良的生活方式习惯引起的，因为摄入富含脂肪和糖的饮食会促进相关合并症的发展。肥胖是由于大脑控制食物摄入和能量消耗的神经内分泌平衡失调引起的，包括下丘脑和奖励和动机中心。具体来说，高脂肪饮食已知会引发下丘脑的早期炎症反应，该反应先于体重增加，是时间依赖性的，最终会扩展到大脑中剩余的食欲调节区域。目前有多种磁共振成像（MRI）和光谱（MRS）方法可用于描述大脑肥胖的不同特征，包括扩散加权、T 和容积成像以及 H 和 C 光谱评估。特别是，一致的证据表明，动物模型和肥胖人群的大脑中，水扩散系数和 T 值增加，灰质体积减少，代谢谱和通量改变。本综述综合解释了与大脑中肥胖发展相关的生理病理过程，以及用于描述这些过程的 MRI 和 MRS 方法。
