- TUESDAY, Aug. 19 (HealthDay News) — High levels of arsenic in
urine may be linked with a higher risk of developing type 2 diabetes,
researchers report.

The findings, published in the Aug. 20 issue of the Journal of the
American Medical Association, are the first to link low-level exposure
to arsenic with type 2 diabetes prevalence in the United States.

“This suggests that arsenic would play a role in the development of
diabetes,” said lead researcher Dr. Ana Navas-Acien, assistant professor
of environmental health science at the Bloomberg School of Public Health
at Johns Hopkins University. “But there clearly needs to be additional
research conducted because our study has certain limitations. We are
conducting those studies now, but that's going to take a few years.”

“This is a good base for future research but it's a small sample size
and doesn't look at dose-response,” added Rajat Sethi, assistant professor
of pharmaceutical sciences with the Texas A&M Health Science Center's
Irma Lerma Rangel College of Pharmacy, in Kingsville. “A lot of research
still needs to be done.”

Inorganic arsenic from natural mineral deposits contaminates much
drinking water. Individuals exposed to enough arsenic can develop cancer,
among other conditions, experts note.

According to background information in the study, about 13 million
people in the United States live in areas with a concentration of
inorganic arsenic in the public water supply that exceeds recommended
levels.

In animal studies, high concentrations of arsenic affected glucose and
insulin mechanism — key factors in type 2 diabetes.

And, epidemiologic studies in Taiwan, Bangladesh and Mexico, which have
relatively high levels of inorganic arsenic in drinking water, have
associated arsenic with the development of diabetes.

It's unclear, however, if lower levels of arsenic might have a similar
effect. In areas such as Taiwan and Bangladesh, arsenic levels in drinking
water are above 100 micrograms per liter, while in the United States the
safety standard is only 10 micrograms per liter.

“In terms of magnitude, people in Taiwan and Bangladesh are exposed to
at least 10 times higher levels compared to people in the U.S.,”
Navas-Acien said. “We were interested in investigating if arsenic exposure
at low and moderate levels could be related to diabetes.”

After analyzing 788 U.S. adults aged 20 or older, the study authors
found that people with type 2 diabetes had a 26 percent higher level of
total arsenic in their urine than participants without type 2 diabetes.

People with the highest levels of arsenic were almost 3.6 times more
likely to have diabetes than people with the lowest levels, the
researchers found.

Those with the highest levels of dimethylarsinate (a compound into
which inorganic arsenic is metabolized) had 1.5 times the risk of diabetes
as those with the lowest levels. This was after adjusting for organic
arsenic compounds such as arsenobetaine and arsenosugars, which come
primarily from seafood.

“When we adjusted for diabetes risk factors and for markers of seafood
intake, we found this moderate-to-strong relationship between arsenic and
the prevalence of diabetes,” Navas-Acien said.

In the United States, the main sources of inorganic arsenic are
contaminated drinking water and food. An estimated 8 percent of public
water supply systems in the United States may have arsenic levels higher
than 10 micrograms per liter while 14 percent may have levels exceeding 2
micrograms per liter, the researchers said.

“There are still many Americans with arsenic in drinking water at
levels above safety standards,” said Navas-Acien. “This reinforces how
important it is that all drinking water is below this standard. The good
news is that we can actually do something to eliminate arsenic from
water.”

Small, rural and semi-rural communities may be at especially high risk
for high arsenic levels in drinking water, Navas-Acien.

More information

For more on arsenic in the water supply, visit the U.S.
Environmental Protection Agency.