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Diabetes Research
08.09.2016

Risk Factor Air Pollution

Exposure to air pollution at the place of residence increases the risk of developing insulin resistance as a pre-diabetic state of type 2 diabetes. Scientists of Helmholtz Zentrum München, in collaboration with colleagues of the German Center for Diabetes Research (DZD), reported these results in the journal ‘Diabetes’.

Map of modelled PM 2.5 concentration in the Augsburg area

Modelled PM 2.5 concentration in the Augsburg area. Source: Helmholtz Zentrum München using data of GeoBasis-DE / BKG 2016

“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,” said Professor Annette Peters, director of the Institute of Epidemiology II at Helmholtz Zentrum München and head of the research area of epidemiology of the DZD.

For the current study, she and her colleagues in collaboration with German Diabetes Center Düsseldorf and the German Heart Centre analyzed the data of nearly 3,000 participants of the KORA study who live in the city of Augsburg and two adjacent rural counties. All individuals were interviewed and physically examined. Furthermore, the researchers took fasting blood samples, in which they determined various markers for insulin resistance and inflammation. In addition, leptin was examined as adipokine which has been suggested to be associated with insulin resistance. Non-diabetic individuals underwent an oral glucose tolerance test to detect whether their glucose metabolism was impaired.

The researchers compared these data with the concentrations of air pollutants at the place of residence of the participants, which they estimated using predictive models based on repeated measurements at 20 sites (for particle measurements) and at 40 sites (for nitrogen dioxide measurements) in the city and in the rural counties.

“The results revealed that people who already have an impaired glucose metabolism, so-called pre-diabetic individuals, are particularly vulnerable to the effects of air pollution,” said Dr. Kathrin Wolf, lead author of the study. “In these individuals, the association between increases in their blood marker levels and increases in air pollutant concentrations is particularly significant! Thus, over the long term – especially for people with impaired glucose metabolism – air pollution is a risk factor for type 2 diabetes.”

Dirtier than the WHO allows

The authors are also concerned that the concentrations of air pollutants, though below EU threshold values, are still above the proposed guidelines of the World Health Organization (WHO). As a consequence, they demand changes in government policy: “Lowering the threshold for acceptable air pollution levels would be a prudent step,” said Dr. Alexandra Schneider, who was also involved in the study. “We are all exposed to air pollution. An individual reduction by moving away from highly polluted areas is rarely an option.” Moreover, the association between increased exposure to air pollution and respiratory and cardiovascular diseases has now been clearly established.

Next, the scientists want to investigate the influence of ultrafine particles. “Diabetes will be a main focus of our research, also in this context. A precise knowledge of the risk factors is crucial for counteracting the increasing incidence of diabetes,” said Peters, looking to the future.

Further Information

Background:
A previous study of Helmholtz Zentrum München from 2013 showed that ultrafine particulate air pollution increases the risk of insulin resistance in childhood. In a meta-analysis from 2015 the same authors concluded that there is an association between long-term exposure to air pollutants and the development of type 2 diabetes.

Original Publication:
Wolf, K. et al. (2016). Association between long-term exposure to air pollution and biomarkers related to insulin resistance, subclinical inflammation and adipokines.
Diabetes, doi: 10.2337/db15-1567

The Helmholtz Zentrum München, the German Research Center for Environmental Health, pursues the goal of developing personalized medical approaches for the prevention and therapy of major common diseases such as diabetes and lung diseases. To achieve this, it investigates the interaction of genetics, environmental factors and lifestyle. The Helmholtz Zentrum München is headquartered in Neuherberg in the north of Munich and has about 2,300 staff members. It is a member of the Helmholtz Association, a community of 18 scientific-technical and medical-biological research centers with a total of about 37,000 staff members. 

The Institute of Epidemiology II (EPI II) focuses on the assessment of environmental and lifestyle risk factors which jointly affect major chronic diseases such as diabetes, heart disease and mental health. Research builds on the unique resources of the KORA cohort, the KORA myocardial infarction registry, and the KORA aerosol measurement station. Aging-related phenotypes have been added to the KORA research portfolio within the frame of the Research Consortium KORA-Age. The institute’s contributions are specifically relevant for the population as modifiable personal risk factors are being researched that could be influenced by the individual or by improving legislation for the protection of public health. 

For almost 30 years, the Cooperative Health Research in the Region of Augsburg (KORA) has been examining the health of thousands of citizens in Augsburg and environs. The aim of the project is to increase understanding of the impact of environmental factors, behaviour and genes on human health. The KORA studies focus on matters relating to the development and progression of chronic diseases, in particular myocardial infarction and diabetes mellitus. To that end, research is conducted into risk factors arising from lifestyle factors (including smoking, diet and exercise), environmental factors (including air pollution and noise) and genetics. Questions relating to the use and cost of health services are examined from the point of view of health services research. 

The German Center for Diabetes Research (DZD) is a national association that brings together experts in the field of diabetes research and combines basic research, translational research, epidemiology and clinical applications. The aim is to develop novel strategies for personalized prevention and treatment of diabetes. Members are Helmholtz Zentrum München – German Research Center for Environmental Health, the German Diabetes Center in Düsseldorf, the German Institute of Human Nutrition in Potsdam-Rehbrücke, the Paul Langerhans Institute Dresden of the Helmholtz Zentrum München at the University Medical Center Carl Gustav Carus of the TU Dresden and the Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the Eberhard-Karls-University of Tuebingen together with associated partners at the Universities in Heidelberg, Cologne, Leipzig, Lübeck and Munich.