Relationship between body mass index and gray matter volume in 1,428 healthy individuals

Objective: To investigate any correlation between BMI and brain gray matter volume, we analyzed 1,428 healthy Japanese subjects by applying volumetric analysis and voxel-based morphometry (VBM) using brain magnetic resonance (MR) imaging, which enables a global analysis of brain structure without a priori identification of a region of interest.Methods and Procedures: We collected brain MR images from 690 men and 738 women, and their height, weight, and other clinical information. The collected images were automatically normalized into a common standard space for an objective assessment of neuroanatomical correlations in volumetric analysis and VBM with BMI.Results: Volumetric analysis revealed a significant negative correlation in men (P < 0.001, adjusting for age, lifetime alcohol intake, history of hypertension, and diabetes mellitus), although not in women, between BMI and the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume. VBM revealed that, in men, the regional gray matter volume of the bilateral medial temporal lobes, anterior lobe of the cerebellum, occipital lobe, frontal lobe, precuneus, and midbrain showed significant negative correlations with BMI, while those of the bilateral inferior frontal gyri, posterior lobe of the cerebellum, frontal lobes, temporal lobes, thalami, and caudate heads showed significant positive correlations with BMI.Discussion: Global loss and regional alterations in gray matter volume occur in obese male subjects, suggesting that male subjects with a high BMI are at greater risk for future declines in cognition or other brain functions.

目的：为了研究体重指数（BMI）与脑灰质体积之间的任何相关性，我们通过应用基于体素的形态测量学（VBM）和体积分析对1428名健康的日本受试者进行了分析，使用脑部磁共振（MR）成像，这种成像能够在不预先确定感兴趣区域的情况下对脑结构进行全面分析。 方法和步骤：我们收集了690名男性和738名女性的脑部MR图像以及他们的身高、体重和其他临床信息。收集到的图像被自动归一化到一个通用的标准空间，以便在体积分析和与BMI相关的VBM中对神经解剖学相关性进行客观评估。 结果：体积分析显示，在男性中（在校正年龄、终生酒精摄入量、高血压病史和糖尿病后，P < 0.001），BMI与代表颅内体积中灰质体积百分比的灰质比率之间存在显著的负相关，而在女性中则不存在这种相关性。VBM显示，在男性中，双侧内侧颞叶、小脑前叶、枕叶、额叶、楔前叶和中脑的局部灰质体积与BMI呈显著负相关，而双侧额下回、小脑后叶、额叶、颞叶、丘脑和尾状核头部的灰质体积与BMI呈显著正相关。 讨论：肥胖男性受试者出现灰质体积的整体减少和局部改变，这表明BMI较高的男性受试者未来认知或其他脑功能下降的风险更大。