title: Reduced right frontal fractional anisotropy correlated with early elevated plasma LDL levels in obese young adults.
abstract: OBJECTIVE
  To investigate the underlying physiological mechanisms of the structural differences in gray matter (GM) and white matter (WM) associated with obesity in young Chinese adults.
  
  
  METHODS
  A total of 49 right-handed obese or overweight (n = 22, mean age 31.72±8.04 years) and normal weight (n = 27, mean age 29.04±7.32 years) Han Chinese individuals were recruited. All participants underwent voxel-based morphometry analysis of T1-weighted MRI and tract-based spatial statistics analysis of diffusion tensor imaging. Partial correlation analysis was performed between the physiological data obtained and the abnormal structural alterations.
  
  
  RESULTS
  In the OO group, GM atrophy occurred in the left prefrontal cortex, bilateral cingulate gyrus, and the right temporal lobe, while enlargement was observed in the bilateral putamen. WM atrophy was observed predominantly in the regions that regulate food intake, such as the bilateral basal ganglia, the right amygdala, and the left insula. The OO group exhibited lower fractional anisotropy (FA) in bilateral frontal corticospinal tracts and the right brainstem. Significant negative correlations were observed between FA values of those three clusters and BMI, and waist circumference, while the volume of bilateral putamen positively correlated with both BMI and waist circumference. High plasma LDL levels were correlated with low FA values in the right frontal corticospinal tract. Interestingly, the negative correlation was limited to male participants.
  
  
  CONCLUSIONS
  Obesity-related alterations of GM and WM volumes were observed predominantly in food reward circuit, which may motivate abnormal dietary intake. Further, early elevated plasma LDL might contribute to low right frontal FA values of male adults, which requires further demonstration by larger-scale and longitudinal studies.
authors.affiliation: Graduate School of Peking Union Medical College, Beijing, China; Beijing Institute of Geriatrics, Beijing Hospital, Beijing, China.
authors.forename: Baohui
authors.initials: B
authors.lastname: Lou
authors.affiliation: Graduate School of Peking Union Medical College, Beijing, China; Department of Radiology, Beijing Hospital, Beijing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Radiology, Beijing Hospital, Beijing, China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Luo
authors.affiliation: Philips Healthcare, Shanghai, China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Dai
mesh_terms: D000328:Adult; D016880:Anisotropy; D008078:Cholesterol, LDL / Q000097:blood*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009765:Obesity / Q000097:blood* / Q000473:pathology*; D012307:Risk Factors; D066127:White Matter / Q000473:pathology; D055815:Young Adult
chemical_list: D008078:Cholesterol, LDL