Examining the Association Between Physical Activity and Sleep Quality in Children With Autism Spectrum Disorder Using Melatonin-mediated Mechanism Model: A Randomized Controlled Trial

Sleep disturbance is commonly found in children with autism spectrum disorder (ASD) and is often accompanied with family distress. Disturbed sleep may exacerbate the core symptoms of ASD including stereotypic behaviors, social interactions, and health problems. Therefore, it is important to develop effective intervention strategies to ameliorate the sleep disturbance in children with ASD. Traditionally, behavioral interventions and supplemental melatonin medication are used to improve their sleep quality. However, poor sustainability of behavioral intervention effects and use of other medications (e.g. antidepressants and stimulants) that metabolize melatonin may degrade the effectiveness of these interventions. Alternatively, previous research supported physical activity intervention as an effective treatment on sleep disturbance for typically developing children who suffered from sleep disturbance. It is therefore natural to extend the study to examine whether such intervention is also effective in children with ASD. This study aims to investigate whether physical activity intervention would be effective to improve sleep quality in children with ASD. Moreover, how physical activity impacts on sleep in children with ASD through melatonin-mediated mechanism model will also be investigated. According to this mechanism model, it is suggested that physical activity could affect circadian rhythm through altering melatonin level. Melatonin is generally lower in ASD children than in their typically developing counterparts and supplemental melatonin medication is often used to treat the sleep disturbance in this population. This study is a parallel-group randomized controlled trial comparing a 12-week jogging intervention and a control group receiving standard care in 32 children with ASD. The changes of four sleep parameters (sleep onset latency; sleep efficiency, wake after sleep onset and sleep duration) through objective actigraphic assessment and parental sleep logs will be monitored. To measure melatonin level, all participants will be instructed to collect a 24-h urinary sample. 6-sulfatoxymelatonin, a creatinine-adjusted morning urinary melatonin and representative for melatonin level, will be measured from the collected urine sample. All the assessments will be carried out before the intervention (T1), immediately after the 12 weeks of physical activity intervention or regular treatment (T2), and 12 weeks after post-intervention (T3) for examination of sustained intervention effect. The findings of this proposed study can provide information on the mechanism pathway that physical activity impacts on sleep in children with ASD, which will contribute to the design of an effective intervention to improve sleep quality for children with ASD.