title: Altered Regional Gray Matter Volume in Obese Men: A Structural MRI Study.
abstract: Obesity is associated with a number of health problems, especial insulin resistance and Type 2 diabetes. Our previous study showed that obese males had decreased neural activity in the orbital frontal cortex (OFC) and increased activity in the left putamen (Zhang et al., 2015b), which could indicate altered eating behaviors in obesity related to a hyper-functioning striatum and hypo-functioning inhibitory control. Accordingly, our goal of the current study was to determine whether there are alterations in the brain structures within these two neural systems in obese individuals. Twenty obese men (age: 20-28 years) and 20 age-matched lean male subjects were involved in the current study. Plasma glucose and insulin were tested during hunger state, and homeostasis model assessment of insulin resistance (HOMA-IR) was based on the blood samples. In the study, we used structural MRI and a voxel-based morphometry (VBM) method to investigate regional structures in obese subjects and find out whether there are correlations between the insulin and the brain structures. We found that obese men only showed a significantly increased gray matter volume (GMV) in the left putamen and that the GMV of the left putamen was positively correlated with body mass index, plasma insulin and HOMA-IR. The putamen is a core region participating in insulin signal regulation, and our results showed an abnormal GMV of the putamen is a core alternation in aberrant insulin. Furthermore, the GMV of the OFC was negatively correlated with hunger rating, despite there being no significant difference between the two groups in the OFC. In conclusion, the altered structure and function of the putamen could play important roles in obesity and aberrant insulin.
authors.affiliation: Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Shanghai, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Cancer Immunology and Biotherapy, Biotherapy Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer Tianjin, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Tian
authors.affiliation: Department of Anatomy, Tianjin Medical University Tianjin, China.
authors.forename: Derun
authors.initials: D
authors.lastname: Tian
authors.affiliation: Department of Medical Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Shanghai, China.
authors.forename: Jinhong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Anatomy, Tianjin Medical University Tianjin, China.
authors.forename: Qiming
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Chunshui
authors.initials: C
authors.lastname: Yu
authors.affiliation: Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Shanghai, China.
authors.forename: Chunbo
authors.initials: C
authors.lastname: Li
authors.affiliation: Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Shanghai, China.
authors.forename: Jijun
authors.initials: J
authors.lastname: Wang
keywords: functional MRI; gray matter volume; hunger rating; insulin; obesity; putamen