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Abstract Reports on attention deficit hyperactivity disorder have uniformly indicated high rates of behavioral problems including lower intelligence, poorer academic skills, increased motor activity and is strongly associated with learning disabilities [(Gorden (1991) and Klein and Mannuzza (1991)]. Although a considerable amount of work has been appeared on the role of raised blood lead level as causative factor in the development of hyperactivity, little work has been carried out on the rest of metals. In an attempt to elucidate the role of the elements lead, Cd, Mn, Zn and Cu in the development of hyperactivity and to investigate any possible relationship between hyperactivity, Intelligence quotient and serum lipid levels, the present work was conducted. A large pool of healthy primary school children of Giza province were clinically examined to select the study subjects. The chosen sample included 38 children whose ages ranged between 7 and 12 years, 28 were hyperactive and 10 normals served as controls. The incidence of hyperactivity in some primary schools of Giza province was found to be 0.96%. In the present work a child was diagnosed hyperactive if he achieved a score greater than or equal to 50 per cent on both Conners Abbreviated Teacher Rating Scale (ATRS) and Mother hyperactivity rating scale (Werry-Wiess Peters Activity Scale After Omitting School Behavior). All subjects were submitted to the following investigations: 1) Good enough test was applied to the children for calculation of IQ. 2) Anthropometric measurements were performed to assess grov.th of hyperactive children. 3) Blood lead: Blood samples were analyzed for lead concentration using flameless atomic absorption spectro- photometer (high graphite analysis). 4) Serum Cd, Mn, Zn and Cu: Serum elements were assayed usmg atomic absorption spectrophotometer (Zeiss FMD3) 5) Serum lipids:Serum cholesterol and triglycerides were determined by enzymatic colorimetric method. The results obtained can be summarized as follows: The present results revealed that the Teacher rating scale % is highly correlated with the Mother rating scale %. On comparison between anthropometric measurements of control and hyperactive children, our results showed no statistical significance. Thus, there is no associated growth slow-down due to hyperactivity disorder. Blood lead concentration was significantly higher. The mean value ±. SEM in the hyperactive group was 17.79 ±. 1.35 ug/dl compared to 13.63 ±. 1.29 ug/dl in the control group (P<O.OS). Elevated blood lead in the hyperactive group is positively correlated ·with hyperactivity i.e. Teacher and Mother rating scale %. It is worthy to note that 9 out of 28 hyperactive children had blood lead level above 24 ug/dl which may be considered in the toxic range compared to non in the control group. Although blood lead reflects only recent exposure, however at reasonable constant levels of environmental lead exposure it has been shown that blood lead concentration are fairly stable. Cadmium, is an important environmental hazard. Cd may retard the development of certain neuro-chemicals which may have long-term implication on the brain functions. In the present work serum Cd rose significantly in the hyperactive group compared to the control group. This rise is highly significant (P < 0.001 ). The concentration of serum cadmium in the hyperactive group also correlated well \Vith hyperactivity i.e. Teacher and Mother rating scale %. Serum Mn in the hyperactive group of the present work was not changed when compared to the non- hyperactive group. Other investigators found that there was a raised manganese level in hyperactivity and learning disabled children and this they related to the possible use of infant formula, many of which contain high manganese levels up to one hundred times the level found in human milk. Insignificant change was also found in serum Zn and Cu between hyperactive and control group. There is no correlation between hyperactivity and IQ on one side and serum Mn, Zn and Cu on the other. The results presented in our study revealed that the mean value for IQ of the control group was significantly higher when compared to the hyperactive group which was in the low average range of normal intelligence. Also a significant negative correlation was found between IQ and elevated blood lead and elevated serum Cd of the hyperactive children. It is concluded that raised blood lead as well as cadmium are associated with lower intelligence and increased hyperactivity of children in Giza province. Our results showed no statistical significant change between total cholesterol in hyperactive and control groups. Also, there was no correlation between serum cholesterol on one side and hyperactivity or IQ on the other. However serum triglyceride increased significantly in the present hyperactive group. Also serum triglyceride was positively correlated with hyperactivity elevated blood lead and serum cadmium. Thus changes in blood lipid levels may indicate subclinical trace elements poisoning. |