Medical comorbidities in autistic children: prevalence, sex-specific clustering, and network patterns at diagnosis in a Chilean cohort.

Medical comorbidities are common in autistic children, yet patterns of co-occurrence at diagnosis-particularly in under-researched regions-remain poorly characterized. We examined the prevalence, distribution, temporal trends, and sex-specific clustering of medical comorbidities at ASD diagnosis in a large Chilean cohort. We performed a retrospective chart review of 544 children diagnosed with ASD between 2015 and 2023 at a specialized pediatric neurodevelopmental center. Comorbidities were identified through standardized caregiver interviews, clinical examination, anthropometric assessment, and clinician-verified medical record review. Analyses included prevalence estimates, temporal trends, and sex-stratified exploratory network analysis. At least one comorbidity was present in 90% of children. The most frequent were insomnia (61%), overweight (52%), allergic rhinitis/atopic dermatitis (28%), and constipation (27%). Underweight prevalence declined significantly over time (from 11% to 5%; p = 0.028), whereas other conditions remained stable. Exploratory network analysis showed high connectivity in both sexes, with denser clustering in girls. In boys, insomnia, overweight, constipation, and allergic disorders formed the main cluster; in girls, allergic disorders remained central, while underweight showed more limited connectivity within the network. Demographic characteristics did not differ between children with and without additional medical conditions.

conclusionMedical comorbidities are highly prevalent at the time of ASD diagnosis, with distinct sex-specific co-occurrence patterns that may guide early screening priorities. These findings support systematic, multidisciplinary assessment during the diagnostic process and highlight the need for longitudinal, multicenter studies to validate comorbidity clusters and clarify their developmental trajectories. WHAT IS KNOWN: • Autistic children frequently have medical comorbidities such as sleep, nutritional, gastrointestinal, and allergic disorders. • The prevalence of individual comorbidities is documented, but patterns of co-occurrence at diagnosis-particularly in Latin American cohorts-remain understudied. WHAT IS NEW: • In a large Chilean cohort of autistic children, 90% had ≥1 clinician-verified medical comorbidity at ASD diagnosis. • Sex-stratified exploratory network analysis showed a shared central cluster (insomnia, overweight, constipation, and ARAD), with higher overall connectivity in girls; underweight and epilepsy showed more limited connectivity at diagnosis.