Evaluation of lead levels in children with chronic constipation

Introduction Many causes such as anatomical, genetic and motor activity disorders, faulty habits and environmental heavy metal exposure are held responsible for the etiology of constipation. Lead is the most blamed metal among environmental heavy metal exposures and lead exposure is among the preventable causes of constipation. In this study, it was aimed to determine lead exposure and exposure sources in children with and without chronic constipation, to determine blood and hair lead levels of children with constipation and to compare them with healthy children, to investigate the relationship between blood and hair lead levels, and to evaluate the place of lead exposure in the etiology of constipation. Material and Method In this cross-sectional study, two groups were formed as the case group and control group. The case group included 84 children aged 3-18 years, who applied to the Bezmialem Vakıf University Pediatric Gastroenterology and Hepatology Clinic with the complaint of constipation between 01.01.2022 and 01.03.2023. An equal number of children who were planned to have blood tests for different reasons and who did not have complaint of constipation or chronic diseases formed the control group. We ruled out the presence of organic and metabolic diseases in all study participants through a thorough history-taking and physical examination. Written informed consent was obtained from the parents of the children participating in the study. Patients who did not agree to participate in the study were excluded from the study. Demographic information forms were created for the patients whose hair and blood samples were taken and; some information such as the age of the houses where the patients live, the history of the renovations in their houses, how their drinking water is supplied, the presence of a factory in the vicinity, and the history of smoking in the family were recorded. In this study, blood and hair samples were collected and the transfer process of blood and hair samples was performed according to international instructions. Blood samples were analyzed by AAS method in Acıbadem Labmed Clinical Laboratory; hair samples were analyzed by ICP-MS method in the Forensic Toxicology Laboratory of Istanbul University-Cerrahpasa Institute of Forensic Medicine and Legal Medicine. Results The case group included 84 children aged 3-18 years with chronic constipation. The control group consisted of 84 healthy children matched for age and sex. While there were 46 boys (54.8%) and 38 girls (45.2%) in the case group consisting of 84 children, there were 45 boys (53.6%) and 39 girls (46.4%) in the control group consisting of 84 children. The mean age of the case group was 7.21; the mean age of the control group was 7.23. xiv In this study, the mean blood lead level of the children with constipation was found as 3.66 μg/dl, and the mean hair lead level was 1.26 μg/g, while the mean blood lead level of the children in the control group was 1.61 μg/dl, and the mean hair lead level was 0.88 μg/g. The blood lead levels of the children with constipation were found to be significantly higher than the blood lead level of children from the control group, while there was no significant difference between the hair lead levels of the two groups. It was found that blood lead level of 48.8% of the children with constipation and 4.8% of the children in the control group had above the blood lead reference value (BLRV) which is 3.5 μg/dl. As a result, children with constipation are 10 times more likely to have a blood lead level above the blood lead reference value (BLRV) than the control group. In this study, it was observed that blood lead levels were not affected by gender and children's age, while it was observed that hair lead levels were higher in girls than boys, and therefore it was affected by gender. While no significant correlation was found between the blood lead level and the age of the children, a significant negative low-grade correlation was found between the hair lead level and the age (p<0.001, rs=0.3). When the relationship between blood lead levels and hair lead levels was examined, no statistically significant relationship was found between them. When the correlation between the age of the house and the lead levels were examined, it was found that there was a positive relationship between them. Consequently, as the age of the house increases, the blood and hair lead levels also increase. In this study, lead exposure sources such as drinking water, home renovation history, parental smoking status, and presence of an industrial establishment close to the home were investigated, but no statistically significant relationship was found between blood and hair lead levels and these sources. Conclusion and Recommendations According to the results of this study, these following steps should be applied in patients with the complaint of constipation: lead exposure should be measured, risk factors for lead exposure should be questioned, and lead level should be measured in children whose constipation etiology could not be clarified. Exogenous lead particles adhering to the hair may cause the hair lead level to be affected by gender and age. For this reason, blood lead levels are more useful than hair lead levels in measuring lead exposure. Thus, children with lead exposure can be diagnosed early and lead exposure can be prevented, especially before neurological adverse effects occur. Key words:Constipation, lead, blood lead level, hair lead level