Researchers at the Helmholtz Zentrum München and the German Center for Diabetes Research (DZD) found that exposure to air pollution increases the risk of developing insulin resistance as a pre-diabetic state of type 2 diabetes. The findings have been published in the journal Diabetes.

“Whether the disease becomes manifest and when this occurs is not only due to lifestyle or genetic factors, but also due to traffic-related air pollution,” adds Annette Peters, professor and director of the Institute of Epidemiology II at Helmholtz Zentrum München and lead researcher of epidemiology at DZD.

The study involved collecting data of 3,000 participants from Augsburg and two adjacent rural counties. Researchers from German Diabetes Center Düsseldorf and the German Heart Centre also helped.

The participants were interviewed and had their blood samples taken.

The blood samples were needed to study the markers for insulin resistance and inflammation, as well as leptin. Participants without diabetes also had to undergo oral glucose tolerance test to find out if they have problems with glucose metabolism.

These data were then compared with the concentration of air pollutants in the area. The team found that pre-diabetics or people with impaired metabolism were especially vulnerable to the effects of air pollution.

The association between their blood marker levels and air pollutant concentrations is significant, says lead author Kathrin Wolf. Hence, the researchers concluded that air pollution increases the chances of developing type 2 diabetes.

The researchers lament that the air concentration allowed in the EU is still higher than what the World Health Organization (WHO) recommends. They suggest dropping the threshold. Aside from the increased diabetes risk, the team adds that reducing the allowed air pollutant concentration is also important to lower the incidence of respiratory problems.

The next step for the researchers is to study the influence of ultrafine particles. Knowing the exact risk factors for diabetes is integral to solve the problem of increasing incidence of diabetes.