Association between selenium level and autism spectrum disorder in children and adolescents: a systematic review and meta-analysis

Qian Jingyu ^* jing fang Qiliang Li song wen qi

• Health Center, Beijing Children’s Hospital, Capital Medical University, Beijing, China

Studies assessing selenium (Se) levels in the blood and hair of children and adolescents to detect its relationship with autism spectrum disorder (ASD) have reported conflicting results. Therefore, we conducted this systematic review and meta-analysis to determine the association between Se levels in blood and hair specimens and ASD. We conducted a comprehensive search of the PubMed, Web of Science, Cochrane Library, and Embase databases, with the final update on March 21, 2024. The fixed-effects model was used when low to moderate heterogeneity (I 2 <50%) was observed; otherwise, a random-effects model was used. Twenty studies involving 1,188 patients with ASD and 1,194 healthy controls were included. The results showed a significant difference in the blood Se levels between children and adolescents with ASD and healthy controls (standardized mean difference [SMD]=-0.56, 95% confidence interval [CI]:-0.96 to -0.16, p=0.007, I 2 =92%). Regarding hair specimens, no significant difference was observed between children and adolescents with ASD and healthy controls (SMD=0.18, 95% CI: -0.57-0.93, p=0.64, I 2 =97%). The sources of high heterogeneity in blood specimens between the studies were sex, age, region, determination, and sampling type. Egger and Begger tests for blood and hair specimens showed no publication bias. In summary, this meta-analysis revealed that lower blood Se levels might be associated with ASD; however, our findings did not support an association between hair Se levels and ASD in children and adolescents.