Children exposed to air pollution over a long period of time have a higher risk of developing insulin resistance, a precursor to diabetes, according to a press release from a team of researchers in Germany.

The team, which published a study in the journal Diabetologica, says that while previous studies have found links between air pollution exposure and conditions like heart disease and atherosclerosis, the studies of links between air pollution and diabetes have been less consistent. In this study, the researchers collected blood samples from 397 10 year-old children, and estimated their exposures to air pollution by analyzing car emissions, population density, and land use in the areas where they lived. They found that the children with greater exposure to air pollution had statistically significantly higher insulin levels than the children living in lower-pollution areas, the press release says.

"There is some evidence that air pollution is associated with lower birthweight and growth restrictions ... which are known risk factors for type 2 diabetes," says co-author Joachim Heinrich in the statement. "Thus, one may speculate that lower birthweight is an intermediate step or 'phenotype' between air pollution and insulin resistance. However, we found no evidence to suggest that this may be true in our cohort of children, all of whom had birthweights above 2.5kg."

The researchers plan to continue following up with the children in the study, and are looking for ways to study how their findings might translate to adults. "The results of this study support the notion that the development of diabetes in adults might have its origin in early life including environmental exposures," Heinrich adds.