NEURAL CORRELATES OF EXECUTIVE FUNCTIONING IN PEDIATRIC OBESITY: DIFFERENCES BETWEEN GIRLS AND BOYS

Obesity has been associated with brain structure alterations, brain functional connectivity deficits and executive functions (EF) impairment in both adults and children. However, their interrelationships and the existence of sex differences in EF, brain structure and connectivity in pediatric obesity remain understudied.
The present study investigates sex-dependent differences in 46 children (9 to 12 years-old) with obesity (19 girls) in working memory, cognitive flexibility, inhibitory control, planning abilities, and emotional regulation strategies using 6 neuropsychological tests and z scores to assess participants performances relative to normative data, brain structure using volumetric measures from T1-weighted images, and ROI-to-ROI whole-brain connectivity using resting-state fMRI data analyzed with the CONN Toolbox.
Relative to boys, girls differed significantly more from normative data on ToL rule violations (p=0.005).
Girls had greater amygdala volume (p=0.02), and boys had greater parietal lobule and supramarginal gyrus volumes than girls (both p=0.03). There was a stronger functional connectivity (p<0.001) between the right Heschl gyrus and the left temporal superior gyrus among boys; and a stronger connectivity (p<0.001) between 1) the left orbital part of the inferior frontal gyrus and the left inferior parietal gyrus, 2) the left rectus gyrus and the left precuneus, and 3) the right cerebellum lobule III and the left cerebellum lobule VIII among girls.
Overall, the present results suggest some sex-dependent differences in executive functioning, brain anatomy and brain connectivity. However, given that our study did not include a healthy-weight control group, no conclusion on the potential influence of obesity can be drawn.