Association of body mass index and its classifications with gray matter volume in individuals with a wide range of body mass index group: A whole-brain magnetic resonance imaging study

Shinsuke Hidese; Miho Ota; Junko Matsuo; Ikki Ishida; Yuuki Yokota; Kotaro Hattori; Yukihito Yomogida; Hiroshi Kunugi

doi:10.3389/fnhum.2022.926804

Association of body mass index and its classifications with gray matter volume in individuals with a wide range of body mass index group: A whole-brain magnetic resonance imaging study

Front Hum Neurosci. 2022 Sep 8:16:926804. doi: 10.3389/fnhum.2022.926804. eCollection 2022.

Authors

Shinsuke Hidese^{1

2}, Miho Ota^{1

3}, Junko Matsuo^{1

4}, Ikki Ishida^{1

2}, Yuuki Yokota^{1

5}, Kotaro Hattori^{1

6}, Yukihito Yomogida^{1

7}, Hiroshi Kunugi^{1

2}

Affiliations

¹ Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan.
² Department of Psychiatry, Teikyo University School of Medicine, Itabashi-ku, Japan.
³ Department of Neuropsychiatry, Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
⁴ Department of Psychiatry, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Japan.
⁵ Department of Behavioral Medicine, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Japan.
⁶ Medical Genome Center, National Center of Neurology and Psychiatry, Kodaira, Japan.
⁷ Araya Inc., Minato-ku, Japan.

Abstract

Aim: To examine the association of body mass index (BMI) [kg/m²] and its classifications (underweight [BMI < 18.5], normal [18.5 ≤ BMI < 25], overweight [25 ≤ BMI < 30], and obese [BMI ≥ 30]) with brain structure in individuals with a wide range of BMI group.

Materials and methods: The participants included 382 right-handed individuals (mean age: 46.9 ± 14.3 years, 142 men and 240 women). The intelligence quotient was assessed using the Japanese Adult Reading Test. Voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) were performed to analyze the association of BMI and its classifications with gray and white matter structures, respectively.

Results: According to VBM, BMI was significantly and negatively correlated with the bilateral cerebellum exterior volumes. In group comparisons, the right cerebellum exterior volume was significantly lower in the overweight or obese group than in the underweight or normal group, while the bilateral cuneus and calcarine cortex, left cuneus, and left precuneus volume was significantly lower in the underweight group than in the non-underweight group. Sex-related stratification analyses for VBM revealed that BMI was significantly and negatively correlated with the bilateral cerebellum exterior volumes only in women. In group comparisons, the left cerebellum exterior volume was significantly lower in obese women than in non-obese women. The left thalamus proper and the right cerebellum exterior volumes were significantly lower in overweight or obese group than in underweight or normal group in men and women, respectively. The bilateral cuneus and calcarine cortex, left cuneus and carcarine cortex, and bilateral cuneus volume was significantly lower in underweight men than in non-underweight men. In contrast, there were no notable findings on DTI.

Conclusion: Our results suggest association of continuous BMI, being overweight or obese, and being underweight with decreased gray matter volume in individuals with a wide range of BMI group. Furthermore, sex-related differences are seen in the association of BMI and its classifications with regional gray matter volume reductions. Abnormally high or low BMIs may have a negative influence on regional gray matter volumes.

Keywords: BMI; body mass index; gray matter volume (GMV); magnetic resonance imaging; obese; overweight; underweight.