Iron supplementation ineffective for insomnia in ASD children

Ferrous sulphate does not appear to ease insomnia among children with autism spectrum disorders (ASD), reports a new study.

Researchers enrolled 20 children with ASD who were not responsive to sleep education. Participants were randomly assigned to receive either 3 mg/kg/day of ferrous sulphate (n=9; mean age, 6.0±3.1 years; 66.7 percent male) or placebo (n=11; mean age, 5.7±2.8 years; 100 percent male). The primary outcome was improvement in sleep onset latency (SOL) and wake after sleep onset (WASO), both measured using actigraphy.

The trial ran for 3 months, during which time the ferrous sulphate group showed a decrease in SOL by only 11.0 minutes compared with their placebo counterparts. This failed to reach statistical significance (95 percent confidence interval [CI], –28.4 to 6.4; p=0.22).

Similarly, ferrous sulphate cut WASO by only 7.7 minutes relative to placebo (95 percent CI, –22.1 to 6.6; p=0.29). Mean ferritin levels in the participants were unrelated to both SOL (p=0.42) and WASO (p=0.50).

On the other hand, iron supplementation significantly improved overall condition severity, as determined by the Sleep Clinical Global Impression score (p=0.047). This was not reflected in the Children’s Sleep Habits Questionnaire, which further showed no significant difference between ferrous sulphate and placebo in terms of sleep outcomes.

“The aetiology of insomnia in children with ASD is multi-factorial and multiple aetiologies may impact individual sleep difficulties,” said researchers. “While treatment with iron may be helpful for some individuals with ASD and should be initiated in those with low iron stores, our findings support larger trials to address the efficacy of iron supplementation in this population.”