Exposure to traffic fumes can set children on the road to diabetes, a study has shown.
Living near a busy road and increased levels of pollution from cars and lorries significantly raised the risk of insulin resistance in 10-year-olds, scientists found.
The condition, which reduces the body’s ability to control blood sugar with the hormone insulin, is a recognised precursor of type 2 diabetes.
Researchers in Germany looked at the effect of two kinds of traffic pollution on 397 children.
Blood tests were taken and measurements made of pollution emissions in areas where the children lived.
For every defined step-rise in levels of nitrogen dioxide (NO2) and sooty particulate matter (PM) from diesel exhausts, the risk of insulin resistance increased by 17 per cent and 19 per cent respectively. The risk also rose by seven per cent every 500 metres closer to a major road a child lived.
Study leader Joachim Heinrich, from the German Research Centre for Environmental Health in Neuherberg, said: “To our knowledge, this is the first prospective study that investigated the relationship of long-term traffic-related air pollution and insulin resistance in children.
“Insulin resistance levels tended to increase with increasing air pollution exposure, and this observation remained robust after adjustment for several confounding factors, including socioeconomic status, BMI (body mass index, a measurement relating height and weight) and passive smoking.”
The findings appear in the latest edition of the journal Diabetologia.
Previous research has linked air pollution, especially sooty particulates, with heart disease and premature death.
However, studies looking at associations between long-term exposure to traffic pollution and type 2 diabetes in adults have been inconclusive.
“Oxidative stress caused by exposure to air pollutants may play a role in the development of insulin resistance,” Heinrich said.
“In addition, some studies have reported that short-term and long-term increases in particulate matter and nitrogen dioxide exposure lead to elevated inflammatory biomarkers, another potential mechanism for insulin resistance.”
The children’s progress will be monitored for 15 years.