Researchers found that children living in areas with higher levels of air pollution, for example from exhaust fumes, are more likely to develop insulin resistance, a precursor to type 2 diabetes, by the age of 10.
Previous studies have shown that women in heavily polluted areas tend to have smaller babies, and low birth weight is known to raise the risk of type 2 diabetes, providing a possible explanation for the figures.
Air pollutants could also react with fats and proteins to cause cell damage or lead to higher levels of inflammation in the body, both of which could lead to insulin resistance, researchers said.
Scientists from Helmholtz Zentrum in Munich studied blood samples from 397 10-year-olds and estimated each child’s average daily exposure to pollution from exhaust fumes.
Results showed that children living in areas with higher levels of pollutants such as nitrogen dioxide in the air were significantly more likely to develop insulin resistance.
For every additional 500m in proximity between a child’s home and the nearest main road, the chance of their developing insulin resistance increased by seven per cent, according to findings published in the Diabetologia journal.
The researchers plan to follow up with the same children in 15 years to examine whether those who moved to cleaner areas saw any change in their condition.
Dr Joachim Heinrich, one of the study’s authors, said: “Whether the air pollution-related increased risk for insulin resistance in school-age has any clinical significance is an open question so far. However, 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.”
Frank Kelly, Professor of Environmental Health at King’s College London, who was not involved in the study, said children are more vulnerable to air pollution because their lungs are larger in relation to their body and have weaker defences against invading particles.
The findings are “especially relevant for cities in the UK such as London which regularly exceeds current EU limit values for NO2,” he added.
Dr Matthew Hobbs, head of research at Diabetes UK, said: “Although this article suggests that there may be a link between exposure to air pollution during childhood and the risk of developing Type 2 diabetes, previous research showed no consistent pattern between the two.
“This new work is based on a number of models and assumptions and has only looked at a relatively small number of children. As a result, a lot more research is needed before any firm conclusions can be drawn about this possible link.”