The status of chemical elements in the blood plasma of children with autism spectrum disorder in Tunisia: a case-control study

Abdominal pain caused by Tibetan medicine: A case report of lead poisoning

Nowadays, lead poisoning in children commonly occurs, but lead poisoning caused by the administration of Tibetan medicine is rarely reported. This report describes the diagnosis and management of lead poisoning in a 16-year-old girl presented with abdominal pain, vomiting, and anemia with limb numbness, who had a childhood history of epilepsy and took Tibetan medicine intermittently to control the symptoms. After admission into hospital, Computed tomography showed high-density shadows in the gastrointestinal tract. Video-Electroencephalography showed no signs of seizure. Reflux esophagitis was observed in gastroscopy. And no obvious abnormalities in the colonic mucosa through colonoscopy. Bone marrow smear test showed basophilic stippling in the erythrocytes. The blood and urine lead levels of 626 and 75.9 μg/L, respectively. We therefore considered lead poisoning, and the patient improved after chelation therapy. Due to its atypical clinical manifestations, lead poisoning is easily misdiagnosed. Thus, clinicians should pay more attention to this disease. When abdominal pain, anemia, and neurological symptoms are present, the possibility of lead poisoning should be considered.

Autism spectrum disorder: Cadmium and mercury concentrations in different biological samples, a systematic literature review and meta-analysis of human studies

The present study was conducted to investigate the differences in cadmium (Cd) and mercury (Hg) concentrations between children with autism spectrum disorder (ASD) and controls. In this systematic review and meta-analysis study, three thousand one hundred forty-five studies were collected from scientific databases including Web of Science, Scopus, PubMed, and Google Scholar from January 2000 to October 2022 and were investigated for eligibility. As a result, 37 studies published in the period from 2003 to 2022 met our inclusion criteria and were considered in the meta-analysis. The heterogeneity assumption was evaluated using the Chi-squared-based Q-test and I-squared (I2) statistics. The pooled estimates were shown in the forest plots with Hedges' g (95% confidence interval) values. The random effects model demonstrated that there is no significant difference in the blood (Hedges' g: 0.14, 95% CI: 0.45, 0.72, p > 0.05), hair (Hedges' g: 0.12, 95% CI: 0.26, 0.50, p > 0.05), and urinary (Hedges' g: 0.05, 95% CI: 0.86, 0.76, p > 0.05) Cd levels of the case group versus control subjects. Moreover, the pooled findings of studies showed no significant difference in the blood (Hedges' g: 1.69, 95% CI: 0.09, 3.48, p > 0.05), hair (Hedges' g: 3.42, 95% CI: 1.96, 8.80, p > 0.05), and urinary (Hedges' g: 0.49, 95% CI: 1.29 - 0.30, p > 0.05) Hg concentrations. The results demonstrated no significant differences in Hg and Cd concentrations in different biological samples of children with ASD compared to control subjects.

Clinical case analysis of 32 children aged 0-6 years with lead poisoning in Nanning, China

Lead is one of the heavy metals that is toxic and widely distributed in the environment, and children are more sensitive to the toxic effects of lead because the blood-brain barrier and immune system are not yet well developed. The objective of the study was to investigate the clinical characteristics of lead poisoning in children aged 0∼6 years in a hospital in Guangxi, and to provide scientific basis for the prevention and treatment of lead poisoning. We collected and analyzed the clinical data of 32 children with lead poisoning admitted to a hospital in Guangxi from 2010 to 2018. The results showed that most of the 32 cases presented with hyperactivity, irritability, poor appetite, abdominal pain, diarrhea, or constipation. The hemoglobin (HGB), mean corpusular volume (MCV), mean corpuscular hemoglobin (MCH), and hematocrit (HCT) of the lead-poisoned children were all decreased to different degrees and were below normal acceptable levels. Urinary β2-microglobulin was increased. Blood lead levels (BLL) decreased significantly after intravenous injection of the lead chelator, calcium disodium edetate (CaNa2-EDTA). In addition, HGB returned to normal levels, while MCV, MCH, and HCT increased but remained below normal levels. Urinary β2-microglobulin was reduced to normal levels. Therefore, in this cohort of children, the high-risk factors for lead poisoning are mainly Chinese medicines, such as baby powder. In conclusion, lead poisoning caused neurological damage and behavioral changes in children and decreased erythrocyte parameters, leading to digestive symptoms and renal impairment, which can be attenuated by CaNa2-EDTA treatment.

Mercury and Autism Spectrum Disorder: Exploring the Link through Comprehensive Review and Meta-Analysis

Mercury (Hg) is a non-essential trace metal with unique neurochemical properties and harmful effects on the central nervous system. In this study, we present a comprehensive review and meta-analysis of peer-reviewed research encompassing five crucial clinical matrices: hair, whole blood, plasma, red blood cells (RBCs), and urine. We assess the disparities in Hg levels between gender- and age-matched neurotypical children (controls) and children diagnosed with autism spectrum disorder (ASD) (cases). After applying rigorous selection criteria, we incorporated a total of 60 case-control studies into our meta-analysis. These studies comprised 25 investigations of Hg levels in hair (controls/cases: 1134/1361), 15 in whole blood (controls/cases: 1019/1345), 6 in plasma (controls/cases: 224/263), 5 in RBCs (controls/cases: 215/293), and 9 in urine (controls/cases: 399/623). This meta-analysis did not include the data of ASD children who received chelation therapy. Our meta-analysis revealed no statistically significant differences in Hg levels in hair and urine between ASD cases and controls. In whole blood, plasma, and RBCs, Hg levels were significantly higher in ASD cases compared to their neurotypical counterparts. This indicates that ASD children could exhibit reduced detoxification capacity for Hg and impaired mechanisms for Hg excretion from their bodies. This underscores the detrimental role of Hg in ASD and underscores the critical importance of monitoring Hg levels in ASD children, particularly in early childhood. These findings emphasize the pressing need for global initiatives aimed at minimizing Hg exposure, thus highlighting the critical intersection of human-environment interaction and neurodevelopment health.

Does Lead Have a Connection to Autism? A Systematic Review and Meta-Analysis

Environmental pollutants, particularly toxic trace metals with neurotoxic potential, have been related to the genesis of autism. One of these metals that stands out, in particular, is lead (Pb). We conducted an in-depth systematic review and meta-analysis of peer-reviewed studies on Pb levels in biological materials retrieved from autistic children (cases) and neurotypical children (controls) in this work. A systematic review was conducted after the careful selection of published studies according to established criteria to gain a broad insight into the higher or lower levels of Pb in the biological materials of cases and controls, and the findings were then strengthened by a meta-analysis. The meta-analysis included 17 studies (hair), 13 studies (whole blood), and 8 studies (urine). The overall number of controls/cases was 869/915 (hair), 670/755 (whole blood), and 344/373 (urine). This meta-analysis showed significantly higher Pb levels in all three types of biological material in cases than in controls, suggesting a higher body Pb burden in autistic children. Thus, environmental Pb exposure could be related to the genesis of autism. Since no level of Pb can be considered safe, the data from this study undoubtedly point to the importance of regularly monitoring Pb levels in autistic children.

Zinc Status and Autism Spectrum Disorder in Children and Adolescents: A Systematic Review

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder, the prevalence of which has increased in children and adolescents over the years. Studies point to deficiency of trace elements as one of the factors involved in the etiology of the disorder, with zinc being one of the main trace elements investigated in individuals with ASD. The aim of this review is to summarize scientific evidence about the relationship between zinc status and ASD in children and adolescents. This review has been registered in the International Prospective Register of Systematic Reviews (registration number CRD42020157907). The methodological guidelines adopted were in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies were selected from an active investigation of the PubMed, Scopus, LILACS, and Google databases to search for observational studies. Fifty-two studies from twenty-two countries were included. The sample sizes ranged from 20 to 2635, and the participants ranged from 2 to 18 years old. Nine types of biological matrices were used, with hair, serum, and plasma being the most frequently used in the evaluation of zinc concentrations. Significant differences in zinc concentrations between the ASD and control groups were observed in 23 studies, of which 19 (36%) showed lower zinc concentrations in the ASD group. The classification of studies according to methodological quality resulted in high, moderate, and low quality in 10, 21, and 21 studies, respectively. In general, we did not observe a significant difference between zinc concentrations of children and adolescents with ASD compared to controls; however, studies point to an occurrence of lower concentrations of Zn in individuals with ASD. This review reveals that more prospective studies with greater methodological rigor should be conducted in order to further characterize this relation.

Association between heavy metals exposure (cadmium, lead, arsenic, mercury) and child autistic disorder: a systematic review and meta-analysis

Background

Studies have found that toxic heavy metals exposure could induce the generation of reactive oxygen species (ROS), and is of epigenetic effect, which might be associated with the occurrence of Autistic Disorder (ASD). This systematic review and meta-analysis aims to elucidate the association between exposure to 4 heavy metals, cadmium (Cd), lead (Pb), arsenic(As), and mercury (Hg), and the occurrence of ASD in children.

Methods

We searched PubMed, Web of Science, Embase, and Cochrane Library, from their inception to October 2022, for epidemiological investigations that explore the association between exposure to Cd, Pb, As, or Hg and the occurrence of child ASD.

Results

A total of 53 studies were included, involving 5,054 individuals aged less than 18 (2,533 ASD patients and 2,521 healthy controls). Compared with the healthy controls, in hair and blood tests, concentrations of the 4 heavy metals were significantly higher in the ASD group than in the healthy control group, and the differences in Pb, arsenic and Hg were statistically significant (P < 0.05). In the urine test, concentrations of arsenic and Hg were significantly higher in the ASD group than in the healthy control group (P < 0.05), while the results of Cd and Pb were opposite to those of arsenic and Hg (P > 0.05). Subgroup analysis for geographic regions showed that ASD patients in Asia and Europe had higher concentrations of the 4 heavy metals, compared with the healthy controls, in which the differences in Pb, arsenic, and Hg were statistically significant (P < 0.05), while in North America, the healthy controls had higher Cd, arsenic, and Hg concentrations (P > 0.05).

Conclusion

Compared with the healthy control group, the ASD group had higher concentrations of Cd, Pb, arsenic, and Hg. These 4 heavy metals play different roles in the occurrence and progression of ASD. Moreover, there is significant heterogeneity among the included studies due to controversies about the study results among different countries and regions and different sources of detection materials. The results of this study firmly support the policies to limit heavy metals exposure, especially among pregnant women and young children, so as to help reduce the incidence of ASD.

Hair Trace Elements and Mineral Content in Moroccan Children with Autism Spectrum Disorder: a Case-Control Study

The prevalence of autism spectrum disorder (ASD) around the world continues to increase while the pathophysiology remains insufficiently elucidated. Genetics, environment, and epigenetic changes are often implicated. Abnormal level in trace elements and minerals is among environmental factors assumed to be involved. The purpose of this article is to assess hair concentrations of toxic and essential elements in children with ASD and children with neurotypical development in the city of Marrakech. Two hundred and twenty-seven children (107 with ASD and 120 controls) aged 3 to 14 years old were recruited. The results of analysis by ICP-MS showed a significant decrease in hair levels of copper, zinc, iron, and selenium (25%, 13%, 17%, 11%) of children with ASD. The most significantly reduced concentrations in children with ASD are that of manganese by 34%. Hair aluminum level was significantly elevated by 29% in ASD compared to controls. Multiple linear regression analysis revealed that copper, selenium, and iron content in hair were significantly inversely associated with ASD, similarly, hair aluminum content was significantly associated with ASD. Adjusted model for demographic parameters increased the predictive ability of the model, father's age was a significant predictor. In addition, ASD and gender were significant predictors of hair levels of aluminum, selenium, and manganese.These results support the hypothesis of the disparity of trace elements and minerals levels in children with ASD and highlight the potential interest of micronutrient supplementation in the eventual improvement of ASD symptoms. Future research should explore the pathophysiology of these micronutrient deficiencies.

Blood and hair copper levels in childhood autism spectrum disorder: a meta-analysis based on case-control studies

OBJECTIVES

The association between copper levels and autism spectrum disorder (ASD) has been a controversial topic. This study investigated relationship between copper levels and ASD.

CONTENT

The following databases are searched until April 2022: PubMed, EMBASE and Web of Science. Combined effect size standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated with Stata 12.0. In this meta-analysis, 29 case-control studies were included, which included 2,504 children with ASD and 2,419 healthy controls. The copper levels in hair (SMD: -1.16, 95% CI: -1.73 to -0.58) was significantly lower in ASD children than healthy controls. The copper levels in blood (SMD: 0.10, 95% CI: -0.12 to 0.32) not significantly compare ASD with controls.

SUMMARY AND OUTLOOK

Copper may be associated with the development of ASD in children.

Trace Element Changes in the Plasma of Autism Spectrum Disorder Children and the Positive Correlation Between Chromium and Vanadium

Existing data demonstrate a significant correlation between autism spectrum disorder (ASD) and the status of biologically essential and toxic trace elements. However, there is still a lack of data on the steady state of trace elements in ASD. We performed a case-control study to explore the association between the risk of ASD and 23 trace elements in plasma. The results showed that children with ASD had considerably decreased lithium (Li), manganese (Mn), selenium (Se), barium (Ba), mercury (Hg), and tin (Sn) levels when compared to their age- and sex-matched controls. Meanwhile, children with ASD had considerably increased plasma chromium (Cr) and vanadium (V) concentrations. We also divided each group into subgroups based on age and gender and created element-related networks for each subgroup. We detected significant element correlations within or between subgroups, as well as changes in correlations that included all elements examined. Finally, more element correlations were observed among males, which may open a new avenue for understanding the complicated process behind the sex ratio of children with ASD. Overall, our data revealed a novel relationship between elements and ASD, which may extend current understanding about ASD.

Early-life chemical exposome and gut microbiome development: African research perspectives within a global environmental health context

The gut microbiome of neonates, infants, and toddlers (NITs) is very dynamic, and only begins to stabilize towards the third year of life. Within this period, exposure to xenobiotics may perturb the gut environment, thereby driving or contributing to microbial dysbiosis, which may negatively impact health into adulthood. Despite exposure of NITs globally, but especially in Africa, to copious amounts and types of xenobiotics - such as mycotoxins, pesticide residues, and heavy metals - little is known about their influence on the early-life microbiome or their effects on acute or long-term health. Within the African context, the influence of fermented foods, herbal mixtures, and the delivery environment on the early-life microbiome are often neglected, despite being potentially important factors that influence the microbiome. Consequently, data on in-depth understanding of the microbiome-exposome interactions is lacking in African cohorts. Collecting and evaluating such data is important because exposome-induced gut dysbiosis could potentially favor disease progression.

Exposure to multiple metals and the risk of dyslexia - A case control study in Shantou, China

Environmental heavy metal exposure has been considered to be the risk factor for neurodevelopmental disorders in children. However, the available data on the associations between multiple metals exposure and the risk of dyslexia in China are limited. The purpose of our study was to examine the associations between urinary metal concentrations and Chinese dyslexia risk. A total of 56 Chinese dyslexics and 60 typically developing children were recruited. The urinary concentration of 13 metals were measured by inductively coupled plasma-mass spectrometer (ICP-MS). Binary logistic regression and the Probit extension of Bayesian kernel machine regression (BKMR-P) were used to explore the associations between multiple metal exposure and the risk of Chinese dyslexia. Our results indicated that Co, Zn and Pb were significantly associated with Chinese dyslexia in the multiple-metal exposure model. After adjusting the covariates, a positive association was observed between Pb and the risk of Chinese dyslexia, with the odds ratio (OR) in the highest quartiles of 6.81 (95%CI: 1.07-43.19; p-trend = 0.024). Co and Zn were negatively associated with the risk of Chinese dyslexia. Compared to the lowest quartile, the ORs of Co and Zn in the highest quartile are 0.13 (95%CI: 0.02-0.72; p-trend = 0.026) and 0.18 (95%CI: 0.04-0.88; p-trend = 0.038), respectively. In addition, BKMR-P analysis indicated that with the cumulative level across Co, Zn and Pb increased, the risk of Chinese dyslexia gradually declined and then rebounded, albeit non-significantly, and Pb was the major contributor in this association. In general, the urinary concentrations of Co, Zn and Pb were significantly associated with Chinese dyslexia. More prospective studies are needed to confirm the health effects of multiple metals exposure in children with Chinese dyslexia.

Hair levels of heavy metals and essential elements in Chinese children with autism spectrum disorder

BACKGROUND

Disproportional heavy metals and essential elements were reported in children with autism spectrum disorder (ASD) that is obscure in etiology. Inevitably, the association is biased by diet and environmental factors.

METHODS

Fifty pairs, one with ASD and the other living together from the same special school with cerebral palsy (CP), were recruited in Hangzhou (China), aged from 2 to 11 years old (74.0 % male). All samples were divided into two subgroups: preschool-aged (2-5 years old) and school-aged (6-10 years old). Heavy metals (As, Hg, Pb) and essential elements (Al, Ca, Cu, Mg, Mn, Zn) in hair were quantified by inductively coupled plasma mass spectrometry analysis and flame atomic absorption spectroscopy.

RESULTS

The children with ASD generally had lower hair levels of Mn (ASD 0.124 μg/g, CP 0.332 μg/g, P = 0.001) compared to the children with CP. After stratification for age, there were no significant differences detected in preschool-aged group. In school-aged group, the results exhibited the children with ASD had higher hair Pb (1.485 μg/g, 0.690 μg/g, P = 0.007) and Cu/Zn ratio (0.092, 0.060, P = 0.003), while hair Hg (0.254 μg/g, 0.353 μg/g, P = 0.016)、Mn (0.089 μg/g, 0.385 μg/g, P = 0.002)、Mg (17.81 μg/g, 24.53 μg/g, P = 0.014) and Zn (100.15 μg/g, 135.83 μg/g, P = 0.007) showed an opposite pattern.

CONCLUSIONS

These results suggest an imbalance of Mn in Chinese children with ASD.