Markers related to oxidative stress in peripheral blood in children with autism spectrum disorder

Abstract

BackgroundOxidative stress in the brain contributes to neuronal damage in genetically susceptible children, which might be involved in the pathophysiology of autism spectrum disorder(ASD). However, clinical data were inconsistent. The goal of this study was to investigate whether oxidative stress markers (vitamin A and vitamin E concentrations and leukocyte mitochondrial DNA copy number and telomere length) in peripheral blood are related to ASD in Chinese children aged 6–9 years. MethodSixty seven individuals with ASD and 134 sex- and age-matched neurotypical controls participated. The relative mitochondrial DNA copy number (mtDNAcn) and telomere length of leukocytes in peripheral blood were measured using quantitative real-time polymerase chain reaction. The vitamin A and vitamin E concentrations in plasma were determined using reversed-phase high-performance liquid chromatography. ResultsASD group had a higher leukocyte mtDNAcn (1.36 ± 0.49 vs. 1.03 ± 0.24, p < 0.001) and vitamin E concentration (5.79 ± 1.70 ng/ml vs. 5.30 ± 0.96 ng/ml, p = 0.044) than the control group, but no significant differences in vitamin A concentration and leukocyte telomere length were detected between groups. Leukocyte mtDNAcn in the highest tertile increased the risk of ASD by 4.259 times (odds ratio:4.259, 95% confidence interval: 1.427–12.707, p = 0.009) compared with the lowest tertile after adjustment for confounders, and a significant dose–response relationship between mtDNAcn and ASD risk was observed (p-trend = 0.032). ConclusionsChildren with ASD had higher levels of leukocyte mtDNAcn.