Poster #26 - Effects of overweight or obesity on brain gray matter volumes of individuals with autism spectrum disorder

• In Event: 2-001 - Poster Session 1 during Breakfast

Abstract

Background: Autism spectrum disorder (ASD) is a developmental disorder characterized by restricted repetitive behaviors and impairments in communication and social interaction. Individuals with ASD appear to have a higher prevalence of overweight and obesity (OWOB) compared to individuals without ASD. However, the effects of co-existence of the two conditions on brain gray matter have not been studied.
Methods: Phenotypic and T1-weighted structural magnetic resonance imaging (MRI) data shared via the Autism Brain Imaging Data Exchange (ABIDE) I and II initiatives were accessed. Records of individuals (i.e. both children and adults) with biologically plausible body mass indices (BMI) were identified and their structural MRI data were downloaded. Structural data was analyzed with FSL-VBM, an optimized voxel-based morphometry (VBM) protocol carried out with tools available in the FMRIB Software Library (FSL). Group-level analyses were performed to compare the groups with 1) ASD but not OWOB, 2) OWOB but not ASD and 3) both conditions, with the group without ASD or OWOB (i.e. controls) using a factorial regression model controlling for sex, age and study site using the Threshold-free Cluster Enhancement option in the randomise function in FSL (i.e. a permutation-based approach).
Results: BMI was available for 89 individuals in the ABIDE I phase and 115 individuals in the ABIDE II phase (age 10.61±5.58 [range 5.12, 49.00] years, 168 male, 107 with ASD, 51 with OWOB; 6 study sites). VBM analyses revealed significant global increase in gray matter volumes volume in individuals with ASD compared to controls (P < 0.001, FWER). Presence of OWOB was associated with a significant increase in gray matter volumes in a cluster that included bilateral occipital pole, lingual gyrus and the intracalcarine cortex (P = 0.029, FWER). All other comparisons were not significant. However, compared to controls, a trend of decreased gray matter volumes were noted in bilateral inferior frontal gyrus, anterior insula, planum temporale, hippocampus- amygdala complex, and several regions in the occipital cortex in the group with both ASD and OWOB (P = 0.066, FWER).
Conclusions: Our findings highlight the trend of reductions in gray matter volumes in brain regions that are involved in regulation of executive functions, language, introceptive awareness, affect regulation and visual information processing for individuals with both ASD and OWOB. Further exploration of behavioral, neuropsychological, and functional neuroimaging correlates of the coexistence of ASD and OWOB is warranted to fully appreciate the impact of the observed trends.

Authors

• Chanaka Nadeeshan Kahathuduwa, Texas Tech University, Department of Human Development and Family Studies
  Presenting Author

• Rebecca Beights, Texas Tech University, Department of Human Development and Family Studies

• Blake West, Texas Tech University, Department of Human Development and Family Studies

• Wonjung Oh, Texas Tech University, Department of Human Development and Family Studies

• Ann Mastergeorge, Texas Tech University