Rôle de l’impulsivité dans la relation entre surpoids et TDAH chez l’enfant : étude exploratoire des caractéristiques cliniques, neuropsychologiques et neurobiochimiques

Abstract

ObjectivesRelationship between Attention Deficit Hyperactivity Disorder (ADHD) and obesity in adults and children had previously been established in research studies. Brain imaging studies pointed out the important role of the prefrontal region in both ADHD and obesity. However, the underlying link between ADHD and obesity is not well understood. The hypothesis that impulsivity could play a role has been explored in clinical studies of ADHD and Binge Eating Disorders or Loss of Control Eating, with contradictory results. Our study aims to compare children with ADHD and obesity to children with ADHD and normal weight. We propose to compare these two populations with clinical, neuropsychological and brain spectroscopy investigation, focusing specifically on impulsivity items. MethodTen children presenting overweight or obesity were selected from a larger population of children with ADHD (5–12y) and paired with regard to gender and age with ten children with ADHD and normal weight from the same population. Conners Rating scales version parents (CPRS) and teachers (CTRS), Conners’ Continuous Performance Test II (CPT-II), and Magnetic Resonance Spectroscopy (MRS) metabolites in five regions of interest (left and right prefrontal, left and right striatal and left cerebellum regions) were measured for all the children. For MRS, ratio to creatinine levels of following metabolites were measured: glycerophosphocholine+phosphocholine/creatinine (GPC+PCh/Cr), glutamate+glutamine (Glu+Gln/Cr), myoinositol (mI/Cr) et N-acétylaspartate+N-acétylaspartylglutamate (NAA+NAAG/Cr). ResultsHyperactivity/Impusivity and Conners Global Index (CGI) subscales of Conners rating scales showed a higher rate of impulsivity in children with ADHD and obesity as compared to children with ADHD and normal weight. Neuropsychological results were comparable in the two groups. Finally, MRS showed a higher GPC+PCh/Cr ratio in right prefrontal cortex in children with ADHD and obesity as compared to children with ADHD and normal weight. ConclusionsOur results are concordant with the hypothesis that impulsivity could be the link between obesity and ADHD in a population of children with ADHD. The right prefrontal regions seem to be areas of interests that need more research in the study of the link between obesity and ADHD.