Biological Trace Element Research (2023) 201:627–635
Who are the super cool authors?
Gang Zhao, Si‑jin Liu, Xin‑yu Gan, Jun‑ru Li, Xiao‑xue Wu, Si‑yan Liu, Yi‑si Jin, Ke‑rang Zhang, and Hong‑mei Wu
What is the study about?
The study aims to explore the levels of trace elements in the whole blood and urine samples of autistic children and compare them to sex-and age-matched typical development children. The study also attempts to investigate the possible relationship between trace elements levels and autistic behaviors in children with ASD to explore the etiology of ASD and provide a theoretical basis for treatment.
The trace elements that were analyzed in this study include Chromium, Manganese, Cobalt, Zinc, Arsenic, Selenium, Molybdenum, Cadmium, Stannum, Stibium, Mercury, Titanium, and Plumbum (aka Lead).
What background research is there on this topic?
Previous research has explored associations between trace elements and autism spectrum disorder (ASD). One study found a relationship between levels of Molybdenum in hair and cognitive function in ASD, while another study reported inconsistent associations between certain trace elements and ASD in hair samples. Similarly, research examining blood and urine samples has found inconsistent associations between toxic metals and ASD.
Other studies have reported significant correlations between trace element levels and behavioral and symptom severity in ASD. Additionally, researchers have explored the relationship between trace element levels and oxidative stress and inflammation in children with ASD, uncovering associations between certain trace elements and these processes.
What methods were used in this study?
Autism Assessments
In this study, researchers utilized three different assessment tools to evaluate autistic behaviors, including the Autism Behavior Checklist (ABC), Childhood Autism Rating Scale (CARS), and Children Neuropsychological and Behavior Scale (CNBS). The ABC is a 57-item scale that screens and diagnoses autism in children aged 2 months to 28 years, assessing five domains including sensory, relating, body/object use, language, and social/self-help. Meanwhile, the CARS is a 15-item scale that definitively diagnoses autism and distinguishes the severity of autistic symptomatology in children over the age of 2 years. Finally, the CNBS is a standardized tool that assesses children’s cognitive abilities and behavior, including both positive and negative behaviors. By utilizing these assessment tools, the authors aimed to investigate potential correlations between trace element levels and core behaviors of autism.
Urine and Blood Samples
Urine samples were collected in the morning on an empty stomach and diluted with a nitric acid solution before being analyzed. Blood samples were collected through the cubital venous and stored in vacuum blood collection tubes. The concentrations of trace elements in these samples were analyzed using inductively coupled plasma mass spectrometry, a highly sensitive and accurate technique for measuring trace elements in biological samples.
What were the findings?
Whole Blood Concentrations of Trace Elements
Researchers found that children with autism spectrum disorder (ASD) had significantly higher concentrations of certain trace elements in their blood compared to healthy controls. Specifically, higher concentrations of molybdenum, cadmium, tin, and lead were found in the whole blood of ASD cases compared to control subjects.
Urine Concentrations of Trace Elements
No significant differences were observed in trace element concentrations in urine samples between the two groups.
Correlation between Trace Element Levels and Autism
The researchers also examined the correlation between trace element levels and autistic behaviors using various assessment tools to measure cognitive ability, behavior, and symptom severity.
1. There were two significant positive correlations observed between two trace elements and total scores on the Autism Behavior Checklist (ABC). Stibium and Thallium were the trace elements positively correlated with total scores on the ABC test.
2. Additionally, Molybdenum levels were negatively correlated with total scores on the Childhood Autism Rating Scale (CARS) test.
3. The study also revealed significant negative correlations between two trace elements and certain CNBS domains. Specifically, Manganese levels were negatively correlated with language and total scores (TS), and Molybdenum levels were negatively correlated with fine motor and total scores (TS).
4. On the other hand, two significant positive correlations were found: Zinc levels were positively correlated with gross motor and language, and Selenium levels were positively correlated with gross motor and total scores (TS).
What other research is related to these findings?
Trace element imbalance and oxidative stress are discussed in relation to nervous system impairment and biological malfunctions associated with autism spectrum disorder (ASD). The excessive exposure to certain metallic elements, such as cadmium, tin, and lead, may lead to impairments in nervous system development through oxidative stress.
Previous research has explored the link between trace element levels and oxidative stress and inflammation in children with ASD. One study investigated this relationship and found significant associations between some trace elements and these processes. Other studies have found that exposure to Plumbum in children can lead to irreversible morphological and molecular changes in the nervous system, resulting in a range of neurodevelopmental disorders including ASD.
The paper suggests that trace element imbalance may contribute to generating oxidative stress and biological malfunctions associated with ASD.
What were the limitations of the study?
The study had a small sample size, with only 60 participants from the same region of China, and did not assess dietary patterns, making it unclear if differences in trace element concentrations were due to environmental exposure, diet, or other factors. The lack of diversity in the sample also limits the generalizability of the findings. The study only analyzed trace elements in whole blood and urine, and did not investigate other biomarkers or potential confounding variables. Further research is needed to address these limitations and gain a better understanding of the relationship between trace elements and ASD.
What should future research look into?
The authors suggest that more research into the relationship between these elements and diet, environmental exposure, and metabolism is necessary. Future research should also investigate the association between trace elements and core symptoms of ASD.
Can I find the study somewhere online?
Absotootly. Right here.
The Causes of Autism 