Lead Exposure in Infancy and Subsequent Growth in Beninese Children

Lead poisoning as a differential diagnosis in pediatric patients with chronic abdominal pain: a case-control study in Tehran-Iran

BACKGROUND

Chronic abdominal pain is a potential symptom of lead poisoning, which is often challenging to diagnose. This case-control study aimed to evaluate blood lead levels in pediatric patients with chronic abdominal pain.

METHODS

The case-control study was conducted on 190 pediatrics who presented to the Children's Medical Center Hospital clinics, Tehran between April 2021- 2023. The children were divided into two groups: the case group, consisting of 81 patients with chronic abdominal pain, and the matched control group; 109 children without any gastrointestinal symptoms. The statistical analysis of the data was performed using STATA 16. A multiple logistic regression model was used to assess the association of different independent variables with chronic abdominal pain.

RESULTS

There was no significant difference between mean (± standard deviation [SD]) of age (8.80(2.7) years vs. control group: 9.23(3.9) years), sex, and BMI (16.55(4.6) vs. 17.32(4.7)) of the patients with chronic abdominal pain (case group) and the control group, whereas the mean weight was remarkably low in patients with chronic abdominal pain: 27.25(± 12.1) kg vs. 31.70(± 14.7) kg (P value = 0.028). Fifty-nine percent of children with chronic abdominal pain had serum lead levels ≥ 10 µg/dL. The mean (SD) of blood lead levels was statistically high in the case group: 11.09 (± 5.35) µg/dL vs. control group: 8.26 (± 5.01) µg/dL) (P value ≤ 0.05). The appetite level was significantly low in the case group: 3.8 (± 2.5) vs. control group 5.4 (± 1.3).

CONCLUSIONS

Lead poisoning could be a possible cause of children's chronic abdominal pain. Regarding the high rate of lead poisoning in children exerting appropriate measures to reduce their exposure to lead is necessary.

Neurotoxic effects of heavy metal pollutants in the environment: Focusing on epigenetic mechanisms

The pollution of heavy metals (HMs) in the environment is a significant global environmental issue, characterized by its extensive distribution, severe contamination, and profound ecological impacts. Excessive exposure to heavy metal pollutants can damage the nervous system. However, the mechanisms underlying the neurotoxicity of most heavy metals are not completely understood. Epigenetics is defined as a heritable change in gene function that can influence gene and subsequent protein expression levels without altering the DNA sequence. Growing evidence indicates that heavy metals can induce neurotoxic effects by triggering epigenetic changes and disrupting the epigenome. Compared with genetic changes, epigenetic alterations are more easily reversible. Epigenetic reprogramming techniques, drugs, and certain nutrients targeting specific epigenetic mechanisms involved in gene expression regulation are emerging as potential preventive or therapeutic tools for diseases. Therefore, this review provides a comprehensive overview of epigenetic modifications encompassing DNA/RNA methylation, histone modifications, and non-coding RNAs in the nervous system, elucidating their association with various heavy metal exposures. These primarily include manganese (Mn), mercury (Hg), lead (Pb), cobalt (Co), cadmium (Cd), nickel (Ni), sliver (Ag), toxic metalloids arsenic (As), and etc. The potential epigenetic mechanisms in the etiology, precision prevention, and target therapy of various neurodevelopmental disorders or different neurodegenerative diseases are emphasized. In addition, the current gaps in research and future areas of study are discussed. From a perspective on epigenetics, this review offers novel insights for prevention and treatment of neurotoxicity induced by heavy metal pollutants.