Bone Health and Physical Activity in Children With Autism Spectrum Disorder

Abstract

Objectives. The overall objectives were to synthesize and update the evidence of bone health in children with autism spectrum disorder (ASD), synthesize the evidence of moderate-to-vigorous physical activity (MVPA) in children with ASD vs. typically developing children (TDC), and assess the feasibility and efficacy of an animal-assisted physical activity (PA) intervention in children with ASD. Methods. I performed two meta-analyses to compare imaged bone properties and MVPA between children with ASD and TDC. I used site-specific MANCOVAs to test bone strength, area and mass differences at distal and shaft sites of radius and tibia between male children with ASD (n=15) and TDC (n=81) and explored mediating effects of PA, selected nutrients, grip strength and long jump distance on bone differences. I assessed the feasibility and efficacy of a pilot animal-assisted PA intervention in children with ASD (n=20). Results. Compared to TDC, the first meta-analysis indicated 0.7-1.0 SD lower areal bone mineral density, and the qualitative analysis suggested deficits in bone mass, micro-architecture and strength in children with ASD. Our comparison suggested 9-18% lower bone strength, structure, and mass at the distal tibia and the shaft sites of radius and tibia in male children with ASD when compared to TDC. Long jump distance accounted for 40-51% of the variance in bone strength and structure deficits at the tibia. The second meta-analysis indicated that children with ASD spent 30 minutes less in daily MVPA and had 4 times the odds of not meeting the recommended daily MVPA. The animal-assisted PA intervention was feasible, and children with ASD had 13% more minutes of light PA and 22% lower sedentary time in sessions with the therapy dog. Conclusion. My thesis provided evidence of bone deficits in children with ASD, partly explaining the higher risk of fracture in individuals with ASD. The evidence also suggested that lower PA and muscle performance may contribute to bone deficits in children with ASD. Future PA intervention may benefit from the evidence of feasibility and efficacy of the animal-assisted PA interventions to optimize bone health and development in children with ASD.