Serum aluminum level and its relation to serum trace elements in children with attention deficit hyperactivity disorders

ABSTRACT

Attention deficit hyperactivity disorder [ADHD] is the most common neurobehavioral disorder of childhood. Despite this disorder is increasing in prevalence, it is still controversial and its etiology is not fully known. There is increasing awareness of the role that metals1 minerals play in health and disease. Aluminum is one of the most abundant metals in the environment. It contributes very significantly to nervous diseases by affecting diverse functions, so a clear need exists for active work on the environmental causes of ADHD. This motivated us to carry out this research to find the possible role of aluminum in ADHD and its effect on the level of essential trace elements known to affect behavior and attention in children [iron, zinc and copper]. This study was conducted on twenty children [12 boys and 8 girls] aged 4-8 years diagnosed with attention deficit hyperactivity disorder according to DSM-IV criteria. Twenty age and sex matched normal children were included in the study as control group. All were subjected to psychometric assessment using Conner's rating scale and standard cognitive assessment intelligence scale. Serum aluminum, calcium, iron, zinc, and copper were measured using spectrophotometric techniques. The results proved that patients with ADHD showed statistically highly significant increase in serum levels of aluminum [p= 0.002] and significant lowering of serum calcium [p= <0.001], iron [p= <0.001], and zinc [p=0.01] as compared to controls. Serum levels of copper were lower in ADHD children than controls but the difference was not statistically significant [p=0, 29]. Correlation between studied variables revealed significant proportional correlation between Conner's rating score and serum levels of aluminum and significant inverse correlation between it and serum levels of calcium, iron and zinc. As regards IQ, there was inverse correlation between serum aluminum and total, verbal and performance IQ score and there was significant direct correlation between serum zinc levels and total, verbal and performance IQ. Serum levels of iron were proportionally correlated to both verbal and performance score while calcium was correlated to performance score only. When correlating serum levels of aluminum with calcium and studied trace elements levels, serum aluminum levels were inversely correlated to serum levels of iron, calcium, and zinc. There was no significant correlation between serum levels of aluminum and serum levels of copper. Mean serum level of aluminum was significantly higher in those patients living in industrial areas as compared to those living in non-industrial areas