Body Mass Index (BMI) Is Negatively Correlated with Adaptive Functioning in a Population of Children with Neurodevelopmental Disorders

Background:  Childhood obesity is a global epidemic that leads to both significant physical health problems, such as, diabetes and cardiovascular disease, as well as mental health and behavioral problems.  Both young children and adults with obesity have increased rates of internalizing and externalizing behaviors, and in children, the association seems to increase with age.  Children with neurodevelopmental conditions have at least a similar if not greater risk of obesity compared to the normal pediatric population.   Maladaptive behavior is a key feature of most neurodevelopmental disorders.  Identifying alternative factors external to the disorder itself that may compound this problem is worthwhile, especially given the limited management options.   Such behaviors greatly impact overall functioning, independence and quality of life.

Objectives:  To determine if body mass index (BMI) is associated with internalizing behavior, externalizing behavior, or adaptive skills.

Methods:  Data was drawn from the Province of Ontario Neurodevelopmental Disabilities (POND) Network, a large cohort of children with neurodevelopmental disabilities including autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), intellectual disability and obsessive compulsive disorder.  Internalizing and externalizing behavior was measured using the Child Behavior Checklist (CBCL).  Adaptive skills were measured using the Vineland Adaptive Behavior Scales (VABS).  The Pearson correlation was used to determine the correlation between BMI, internalizing behavior, externalizing behavior and adaptive functioning.

Results:  Complete data was available for 405 children with BMI values and externalizing and internalizing behavior scores.   Children with BMI and VABS data were 263.  The Pearson correlation demonstrated a significant negative correlation with the VABS Sum of Scores score (-0.381, p < 0.01) and total score (-0.244, p < 0.01).  There was no significant correlation between BMI and internalizing or externalizing behavior. 

Conclusions:  Elevated BMI is a risk factor for physical and mental health issues, and is already an important target in child health.   Our data demonstrate an association of increasing BMI with worse adaptive skills.  Further research is needed to more carefully explore this relationship.  However, adaptive skills may represent an important target to help reduce BMI, and subsequently obesity in this population.  Alternatively, reducing BMI may improve adaptive skills and overall independence.