Examining the Impact of Physical Activity on Sleep Quality in Children with Autism through Melatonin-Mediated Model: A RCT

Background: Sleep disturbance is commonly found in children with autism spectrum disorder (ASD) and is often accompanied by 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 sleep disturbance in children with ASD. Traditionally, behavioral interventions and supplemental melatonin medication are used to improve sleep quality. However, the 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 as an effective intervention for treating sleep disturbance in typically developing (TD) children. It is therefore natural to extend the study to examine whether such intervention is also effective in children with ASD.

Objectives: In the present study, we aimed to investigate whether physical activity is an effective intervention to improve sleep quality for children with ASD. Moreover, we also investigated how physical activity impacts on sleep in children with ASD through a melatonin-mediated mechanism model. According to this model, it is suggested that physical activity could affect circadian rhythm by altering melatonin levels. Melatonin levels are generally lower in children with ASD than in their typically developing counterparts and supplemental melatonin medication is often used to treat sleep disturbance in this population.

Methods: We conducted a parallel-group randomized controlled trial of 28 child participants with ASD that compared a jogging intervention group and a control group receiving standard care. We have monitored the changes of their sleep quality as depicted by four sleep parameters (sleep onset latency, sleep efficiency, wake after sleep onset and sleep duration) through objective actigraphic assessment and parental sleep logs. To measure melatonin level, all participants were instructed to collect a 24-h urine sample. 6-sulfatoxymelatonin, a creatinine-adjusted morning urinary melatonin representative of the participant’s melatonin levels, were measured from the sample. All assessments were carried out before the intervention (T1) and immediately after the 12 weeks of physical activity or regular treatment (T2).

Results: The present study revealed a significant improvement between T1 and T2 in sleep efficiency, sleep onset latency and sleep duration in the intervention group (all ps < .05) but not in the control group (all ps >.05). More significantly, there was a significant increase of the urinary 6-sulfatoxymelatonin (ng/ml) (p <.05) between T1 and T2 in the intervention group (4.65±5.27 vs 8.09±5.24) but not in the control group (3.31±4.87 vs 4.09±3.38) (p> .05).

Conclusions: The findings of this proposed study provided an insight to the mechanism by which physical activity impacts on sleep in children with ASD, which may ultimately lead to the design of an effective intervention to improve the sleep quality of children with ASD.