An elevated anxiety level among prepubertal autistic boys with non-treatment-seeking functional gastrointestinal disorders: A case-control study

Abstract

Children with autism commonly suffer from comorbid functional gastrointestinal disorders (FGID) and anxiety. The raised prevalence of both conditions in autism suggests complex reciprocal relationships, which are seldom explored in non-treatment-seeking FGID. The relationships between subtypes of FGID and anxiety are also unclear. This study recruited boys with autism and age-matched typically developing (TD) boys, aged 4-11 years, who were not actively seeking help for gastrointestinal problems. Their parents completed the Rome IV Diagnostic Questionnaires for Pediatric FGID. Four groups of children with and without autism/FGID were identified and compared on their anxiety level using the Spence children's anxiety scale. In 69 boys with autism and 69 age-matched TD boys, FGID were identified in 22 and 16 boys, respectively. ANCOVA demonstrated a significant interaction effect of autism and FGID on anxiety (F[1, 129] = 5.43, p = 0.021), while conditional logistic regression identified an interaction effect of autism and anxiety on the odds of FGID (OR 1.038, 95% CI 1.002-1.075, p = 0.038). Explorative post hoc analysis showed higher anxiety in functional nausea and vomiting disorder (p = 0.033) and functional abdominal pain disorder (p = 0.029) among boys with autism than TD boys with the same respective subtypes of FGID. In summary, among prepubertal boys with autism, the presence of FGID that are non-treatment-seeking in nature, has a significantly stronger association with higher levels of anxiety than TD boys. The strength of association may be more prominent in subtypes of FGID. Possible pathomechanisms including the underlying microbiota spectra and inflammatory paths should be explored in future studies. LAY SUMMARY: Anxiety and gastrointestinal problems are common symptoms in autism. Given that gut health could be linked to emotions, their association in young boys with autism was studied. The presence of nausea vomiting, or abdominal pain were associated with raised anxiety among boys with autism, yet this was not observed in typically developing boys. This suggests that anxiety among autistic children could be partly explained by the presence of FGID.

Keywords: abdominal pain; anxiety; autism; constipation; functional gastrointestinal disorder; gut-brain axis; nausea.