Exposure to even small doses of arsenic increases the risk of type 2 diabetes

Exposure to high doses of inorganic arsenic, which is mostly ingested through drinking water, is known to increase the risk of type 2 diabetes mellitus, but few studies have looked at exposure to smaller doses. Arsenobetaine—an organic arsenic compound mainly ingested through seafood—is excreted unchanged in urine and considered non-toxic, but this has not been tested in human studies⇑.

A population based health and nutrition survey (NHANES 2003-4) measured urine concentrations of arsenic compounds in 788 US adults. After adjustment for diabetes risk factors and seafood intake, people with type 2 diabetes had 26% (95% CI 2.0% to 56%) higher concentrations of total urine arsenic than people without diabetes, but concentrations of organic arsenic did not differ in the two groups, which confirms the notion that this type of arsenic is non-toxic in humans. When compared with people with the lowest total urinary arsenic concentrations, people with the highest concentrations had a 3.6-fold higher risk of type 2 diabetes.

The exposure to arsenic seen in the study may have been as little as three times less than the current US Environmental Protection Agency reference dose of 0.3 μg/kg body weight each day, say the editorialists (p 845). The association needs to be explored further in prospective studies, but in the meantime it seems prudent to minimise exposure to arsenic.

Better oxygen systems are feasible and save lives in poor settings

In five hospitals in Papua New Guinea the introduction of new oxygen equipment and a new protocol saved the lives of children with pneumonia. A before and after study compared outcomes in more than 11 000 children with pneumonia who were treated between 2001 and 2007. In 2005, oxygen concentrators and pulse oxymeters were introduced in these hospitals, as well as a protocol for detecting hypoxaemia and using oxygen. This protocol included measuring oxygen saturation in all children admitted …