Serum levels of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in children with autism spectrum disorder.

Objectives: To study the serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) in children with autism spectrum disorder (ASD) and their association with the core symptoms of ASD.

Methods: A total of 150 ASD children aged 2-7 years (ASD group) and 165 healthy children matched for age and sex (control group) who were recruited at the outpatient service of Chongqing Health Center for Women and Children were enrolled as subjects. Autism Behavior Checklist (ABC) and Childhood Autism Rating Scale (CARS) were used to evaluate the core symptoms of the ASD children. Chemiluminescence was used to measure the serum levels of IGF-1 and IGFBP-3 in both groups.

Results: The ASD group had a significantly lower serum level of IGF-1 than the control group (<0.05). The children with severe ASD had significantly lower serum levels of IGF-1 and IGFBP-3 than those with mild-to-moderate ASD (<0.001). For the children aged 2-3 years, the ASD group had a significantly lower serum level of IGF-1 than the control group (<0.05). Boys had a significantly lower serum level of IGF-1 than girls in both ASD and control groups (<0.05). The serum levels of IGF-1 and IGFBP-3 were negatively correlated with the total score of CARS (=-0.32 and -0.40 respectively, <0.001).

Conclusions: The reduction in serum IGF-1 level in early childhood may be associated with the development of ASD, and the serum levels of IGF-1 and IGFBP-3 are associated with the core symptoms of ASD children.