A new study confirms that prolonged exposure to high levels of arsenic increases the risk of developing type 2 diabetes.
- A new study in mice confirms the link between arsenic exposure and type 2 diabetes.
- However, only male mice exposed to arsenic in drinking water developed diabetes. This was not the case for females.
- Females could be protected by female sex hormones.
Studies in Bangladesh and Mexico – where endemic levels of arsenic above safe limits have been observed – have shown an association between exposure to the element and type 2 diabetes. Works of Cornell University confirm that high levels of arsenic increase the risk of developing the disease. However, only men seem to be affected by this risk factor.
The results of this new research were presented in the journal Environmental Health OutlookDecember 27, 2023.
Diabetes type 2: chronic exposure to arsenic increases the risk
To better understand the link between arsenic and type 2 diabetes, researchers at Cornell University worked with laboratory mice genetically modified with a human gene allowing them to express a enzyme present in humans, called AS3MT and intended to metabolize arsenic. These rodents as well as unmodified specimens were exposed for a month to doses of arsenic in drinking water that were non-lethal, but sufficient to potentially promote type 2 diabetes. Their liver and white adipose tissue were then analyzed.
The results showed that male mice exposed to arsenic had increased expression of genes linked to insulin resistance, as well as a biomarker called miR-34a strongly associated with insulin resistance in type 2 diabetes and other metabolic diseases. This phenomenon was not observed in females or “control” animals.
“This suggests that miR-34a is potentially a way to screen individuals who live in areas where arsenic levels are endemic.”explains first author Jenna Todero in a communicated. “If you have a high rate of miRNA-34ayou may be at risk of developing type 2 diabetes or other metabolic dysfunction.“
Arsenic and diabetes: females could be protected byestradiol
The new study also allowed the team to identify the role of the transcription factor (protein that regulates genes, Editor’s note) Klf11present in the liver, in protection against diabetes. Analyzes showed that it was absent in humanized male mice exposed to arsenic. However, these rodents had characteristics of diabetes such as insulin resistance and high fasting blood sugar. Once again, the genetically modified females and the control group did not present this particularity, nor these signs of diabetes.
“It was really exciting, because we showed that genes that are very important for things like regulating glucose or lipid metabolism appear to be targets for Klf11“adds Jenna Todero.
In mice “humanized” femalesresearchers found evidence of elevated expression of genes that support insulin sensitivity. “We saw the opposite effect in women, where the expression of genes promoting insulin sensitivity and glucose absorption increased.”indicates the expert. She says previous work suggests that estradiol, a female sex hormone, may play a role in the differences observed between females and males exposed to arsenic.
The works of Cornell University warn of the potential risks of arsenic exposure for the development of type 2 diabetes, particularly in men.
