الفهرس | Only 14 pages are availabe for public view |
Abstract There is an agreement amongst all professionals that autism is one of the most puzzling diseases. The increase of ASDs prevalence cannot be fully explained by advances in diagnostics or sudden genetic shifts. There is a growing consensus among scientists and clinicians that ASDs ensue from an interaction between biological vulnerability factors and environmental or iatrogenic insults. The aim of the present study was to measure the levels of toxic heavy metals in hair of an Egyptian sample of autistic children comparing them with age and sex matched controls, and correlating their levels with the clinical severity of the disease. This study comprised 140 children. They were classified into two groups. Group I (Autistic patients): It included 70 children diagnosed as having one of the autistic disorders according to the DSM-IV TR (2000) criteria. They were 57 males (81.4%) and 13 females (18.6%). Their ages ranged from 2.5 to 12 years with mean age 6.30, SD ± 2.2 years, and group II (Control group) which included 70 clinically healthy children of comparable age and sex. They were 58 males (82.9%) and 12 males (17.1%). Their ages ranged from 3 to 12 years with mean age 6.0., SD± 2.2 years. To all studied cases, full history, clinical examination, psychiatric evaluation and measurement of hair mercury, lead and aluminium levels were done. In the current study several risk factors for autism were evaluated. The results showed that 55.7% of the studied autistic patients were first order of birth, 58.6% of them were born by Cesarean section while 41.4% were vaginally delivered, and their mean birth weight was 3.2 + 0.6 kg. However On comparing between the studied autistic patients & the control group there was no statistically significant differences as regards the previously mentioned factors; p > 0.05 for all. The maternal age at conception was significantly higher in the autistic group than that of the controls (p < 0.01). The present study revealed that consanguinity rate was significantly higher in the autistic cases (n= 15) compared to controls (n= 5) (p < 0.05). On comparing between the autistic patients and controls as regards their maternal occupation, there was no statistically significant difference; p > 0.05. A delay in motor development among autistic patients was documented compared to their matched controls however it was not statistically significant; p = 0.091. Also failure of development of sphincteric control was significantly more encountered among the autistic patients (34.3%) compared to 8.6% in the controls (p = 0.001). The mean IQ of the studied cases (47.6 + 16.9) was significantly lower than that of the control group (95.7 + 4.3), meanwhile the anxiety & depression scores were significantly higher in the studied cases when compared to the control group (p < 0.001) The current study also revealed negative correlation between the IQ level and the severity of autism (measured by CARS & ATEC) which means that the higher the IQ level, the lower the severity of autism, whereas anxiety score and depression score showed a positive significant correlation with the severity of autism (measured by CARS & ATEC) meaning that the higher the autism severity, the higher the anxiety and depression scores. Also the IQ level showed a negative correlation with anxiety and depression scores. On comparing between the levels of heavy metals in hair of the autistic patients and the control group, levels were significantly higher among the studied cases than the control group (p < 0.001) however these levels were not correlated with autism severity. In the current study, the mean mercury level of the autistic patients (0.36 + 0.29) was significantly higher than that of the controls (0.27 + 0.22) with p = 0.015 The mean lead level of the autistic patients (3.13 + 1.78) was significantly higher than that of the controls (1.55 + 1.06) with p = 0.005. The mean aluminum level of the autistic patients (64.47 + 58.23) was significantly higher than that of the controls (16.11 + 10.62) with p = 0.0001. There was no significant difference in hair heavy metals concentrations among different autistic groups classified according to age. Several different sources of heavy metals exposure were evaluated. On comparing between the studied autistic patients & the control group as regards their maternal fish consumption during pregnancy, it was significantly higher than that of the controls (p < 0.01). Also there was statistically significant increase in mercury levels as fish consumption increased (p < 0.05). There was no statistically significant difference between the autistic cases and the controls as regards the maternal use of dental amulgum & the use of Anti-d; also there was no statistically significant difference between mercury level in autistic children in relation to maternal use of dental amalgam or the use of Anti-d (p > 0.05 for both). On comparing between the autistic patients & the control group as regards their house age, it was significantly higher in the autistic patients than that of the controls (p < 0.01). There was no statistically significant difference between the autistic patients & the control group as regards the presence of gasoline stations (p > 0.05) while there was statistically significant increase in lead levels with presence of nearby gasoline stations (p < 0.05). On comparing between the studied autistic patients & the control group in the current study as regards the passive smoking & the use of aluminum pans, the studied cases were significantly higher than that of the controls (p < 0.01). On studying the different clinical characteristics of the studied cases in the present study, they showed that hyperactivity was significantly higher in studied cases with higher mercury level (p < 0.05), meanwhile there was no statistically significant relationship between mercury level and other clinical characteristics among the studied cases (p > 0.05 for all). Also the reported results of the current study demonstrated that that there was no statistically significant relationship between either lead and aluminum level and the clinical characteristics of the studied cases (p > 0.05). |