Arsenic in Water May Have Diabetes Link

(August 20, 2008) - Having a water supply with higher levels of arsenic may increase your chances of developing diabetes. (Read about "Diabetes") In a study involving a representative sample of U.S. adults, higher levels of arsenic in the urine appear to be associated with increased prevalence of type 2 diabetes, according to a report in JAMA.

Arsenic from inorganic sources is highly toxic and causes cancer in humans, according to background information in the article. Millions of individuals worldwide are exposed to drinking water contaminated with inorganic arsenic, including 13 million Americans whose public water supply contains more than the U.S. Environmental Protection Agency standard of 10 micrograms per liter. Exposure to high concentrations of the element in drinking water and in the workplace has been shown to be associated with diabetes, but little is known about the effect of lower levels on diabetes risk. In contrast, arsenobetaine - an organic arsenic compound derived eating seafood - is considered non-toxic.

Researchers studied 788 adults age 20 and older who had their urine tested for arsenic levels. Overall, 7.7 percent of the participants had type 2 diabetes. After adjusting for diabetes risk factors and biomarkers of seafood intake, participants with type 2 diabetes had a 26 percent higher level of total arsenic in their urine than those without the disease. Levels of arsenobetaine were similar between the two groups.

The researchers found that participants in the top one-fifth of total urine arsenic levels (16.5 micrograms per liter) had 3.6 times the odds of having type 2 diabetes as those in the lowest one-fifth (3.0 micrograms per liter). They also found that those in the top one-fifth of dimethylarsinate levels (6.0 micrograms per liter) had 1.5 times the odds as those in the lowest one-fifth (2.0 micrograms per liter). Dimethylarsinate is a compound into which inorganic arsenic is metabolized before excretion.