Searching the Blood Lead Level in Children with Attention Deficit Hyperactivity Disorder: A Case-control Study in Tehran, Iran

Abstract

Background: Attention deficit hyperactivity disorder (ADHD) is a common behavioral problem in children. Identifying the associated risk factors of ADHD is very important for the prognosis and early diagnosis of the disease. Here, we evaluated the association between lead exposure and growth indexes in children with ADHD. Materials and Methods: This case-control study was conducted on 30 children with ADHD and 50 healthy subjects. The patient’s age was between 5-12 years. Demographic and clinical information of children were recorded. Blood lead levels were measured in all samples by atomic absorption spectrometry. Results: Children with ADHD had significantly higher mean BMI than the control group (16.54 ± 2.8 kg/m2 vs. 14.82 ± 1.68 kg/m2; p=0.001). The mean of blood lead in children with ADHD was significantly higher than the normal group (10.58 ± 8.06 μg/dl vs. 7.52 ± 2.26 μg/dl; p=0.01). Multiple logistic analysis revealed one unit increase in BMI was associated with a higher risk of ADHD by 1.5 times (P=0.005; OR = 1.50), while one unit increase in blood lead level increased the risk of ADHD by 1.15 times (P=0.03, OR=1.15). Conclusion: Higher BMI and blood lead concentration are risk factors for ADHD among Iranian children.