[Association of microRNA expression before and after drug therapy with clinical symptoms in children with attention deficit hyperactivity disorder].

objectiveTo study the association of microRNA expression before and after drug therapy with clinical symptoms in children with attention deficit hyperactivity disorder (ADHD).

methodsA total of 80 previously untreated children with ADHD who were diagnosed from May 2017 to October 2018 were enrolled. The children who were willing to receive drug therapy were randomly divided into concerta-treated group with 31 children and strattera-treated group with 33 children. The children who were unwilling to receive treatment were enrolled as the untreated group with 16 children. A total of 60 children who underwent physical examination during the same period of time were enrolled as the healthy control group. SNAP-V score was determined at initial diagnosis and 3 and 6 months of follow-up. Serum samples were collected from the children with ADHD and the healthy control group. Quantitative real-time PCR was used to measure the relative expression of miR-4566-3p and miR-7641.

resultsThe repeated measures analysis of variance showed that the SNAP-V score of attention deficit symptoms were different among the two treatment groups and the untreated group at the first visit and 3 months and 6 months after treatment (P<0.05). There were significant differences in the relative expression of the two miRNAs among the two treatment groups and the healthy control group at the first visit and 3 months and 6 months after treatment (P<0.05). The SNAP-V score of attention deficit symptoms and the relative expression of the two miRNAs were different in different time points in the subjects (P<0.05). There were interactions between grouping and time factors in the SNAP-V score of attention deficit symptoms and the relative expression of the two miRNAs (P<0.05). The SNAP-V score of hyperactive impulsive symptoms was different in different time points in the two treatment groups and the untreated group (P<0.05), but the significant difference in the score was not observed between two treatment groups and the untreated group (P>0.05), and there was no interaction between the time factor and the grouping factor (P>0.05). The SNAP-V score of attention deficit symptoms was negatively correlated with the relative expression of miRNA-4655-3p and miRNA-7641 (r=-0.314, -0.495 respectively; P<0.05) in ADHD children after drug treatment.

conclusionsDrug therapy can significantly improve the clinical symptoms of children with ADHD. The expression of miR-4655-3p and miR-7641 in serum can be used as biomarkers for the diagnosis and outcome evaluation of ADHD.