Nov. 11 2016

Link Between Arsenic Exposure and a Cause of Type 1 Diabetes

Arsenic found in the environment may have some association with the development of type 1 diabetes in youth under 18, according to researchers at Columbia University’s Mailman School of Public Health.  They found that low plasma concentrations of Inorganicarsenic compared with other forms of arsenic were associated with both a higher odds and a higher prevalence of type 1 diabetes. Although studies have connected arsenic and diabetes in adults, this is one of the first to look at arsenic’s possible relationship with diabetes in children and teenagers. The findings are published online in the journal Diabetes Care.

“We found that arsenic metabolism characterized by the relative proportions of inorganic arsenic and methylated arsenic species in plasma, was associated with type 1 diabetes in children and adolescents who participated in Diabetes in Youth Case Control (SEARCH-CC), a study designed to assess risk factors in youth for diabetes type 1 and type 2,” said Maria Grau-Perez, MS, a biostatistician in the Department of Environmental Health Sciences at the Mailman School, and first author.

Grau-Perez and colleagues used biospecimens gathered from counties around Columbia, South Carolina and Denver, Colorado as part of a larger SEARCH for Diabetes in Youth Case Control study. They evaluated 688 participants under the age of 22; 429 with type 1 diabetes, 85 with type 2 diabetes, and 174 control participants.

According to Grau-Perez and senior author Ana Navas-Acien, MD, PhD, professor of Environmental Health Sciences, arsenic was studied for several reasons. It may impair the immune system, pre-natural exposure may alter the microbiome in early childhood and increase the susceptibility to type 1 diabetes, and pancreatic B-cells are targets in humans, animals and in vitro models for a variety of types of arsenic.

Inorganic arsenic is a toxicant and carcinogen that naturally occurs in groundwater and rice, grains and some juices. Blood samples from youths living around Columbia and Denver were used because they were more likely to be exposed to low levels of inorganic arsenic in the drinking water compared to rural youths living in other areas of the U.S., noted the authors.

The sample included a smaller number of type 2 diabetes cases and, therefore, the authors could not evaluate the association between arsenic and type 2 diabetes. The placebo-controlled study also looked at the interaction between arsenic and folate and vitamin B-12. “In our analyses, the association between methylated arsenic species and type 1 diabetes was stronger for participants with higher folate levels,” said Navas-Acien.

“Our findings provide novel evidence that links arsenic and diabetes in youth and support the need for additional research,” the researchers concluded.