Okudzhava Liana, Heldmann Marcus, Münte Thomas F
Department of Neurology, University of Lübeck, Lübeck, Germany.
Department of Psychology, University of Lübeck, Lübeck, Germany.
Obes Rev. 2022 Mar;23(3):e13388. doi: 10.1111/obr.13388. Epub 2021 Dec 14.
Obesity is a major global health problem leading to serious complications. It has been consistently associated with alterations in brain structure. Diffusion tensor imaging is used to examine brain white matter microstructure by assessing the dynamics of water diffusion in white matter tracts. Fractional anisotropy and mean diffusivity are two parameters measuring the directionality and rate of diffusion, respectively. Changes in these indices associated with obesity have been previously reported in numerous fiber tracts. This systematic review investigates microstructural white matter alterations in obesity using diffusion tensor imaging. A computerized search was performed in PubMed, Web of Science, and Livivo databases. Based on the inclusion/exclusion criteria, 31 cross-sectional studies comparing individuals with obesity and lean controls were identified. The studies included mixed-gender samples of children, young, middle-aged, and older adults. The majority of included studies reported decreased fractional anisotropy and increased mean diffusivity associated with elevated body mass index, suggesting white matter abnormalities. Nevertheless, a pattern of alterations is inconsistent across studies. This could be explained by several potential biases assessed by the National Institute of Health quality assessment tool. Furthermore, a direct assessment of body fat is recommended for a more accurate characterization of the brain-body relationship.
肥胖是一个导致严重并发症的主要全球健康问题。它一直与脑结构改变有关。扩散张量成像用于通过评估白质束中水扩散的动力学来检查脑白质微观结构。分数各向异性和平均扩散率是分别测量扩散方向性和速率的两个参数。先前已在许多纤维束中报道了与肥胖相关的这些指标的变化。本系统评价使用扩散张量成像研究肥胖中的微观结构白质改变。在PubMed、科学网和Livivo数据库中进行了计算机化检索。根据纳入/排除标准，确定了31项比较肥胖个体和瘦对照的横断面研究。这些研究包括儿童、青年、中年和老年人的混合性别样本。大多数纳入研究报告，与体重指数升高相关的分数各向异性降低和平均扩散率增加，提示白质异常。然而，各研究之间的改变模式并不一致。这可以通过美国国立卫生研究院质量评估工具评估的几种潜在偏倚来解释。此外，建议直接评估体脂，以便更准确地表征脑-体关系。
