Diabetes due to car exhaust

Air pollution increases the likelihood of insulin resistance

05/13/2013

Car exhaust emissions increase the risk of insulin resistance in children, according to the latest study by the research team led by Elisabeth Thiering and Joachim Heinrich from the Helmholtz Center for Health and the Environment. With the increased likelihood of insulin resistance, the risk of developing type 2 diabetes is likely to increase later in life, the researchers report in the journal „Diabetologia“.

According to the scientists, previous studies have already linked traffic-related air pollution with particulate matter and nitrogen dioxide to numerous health risks such as the increased likelihood of respiratory diseases, atherosclerosis (arteriosclerosis) or acute cardiovascular diseases. There was already some evidence of a possible increase in the risk of diabetes from the exhaust fumes, but the results of previous scientific studies were in part contradictory and mostly related to adults, Heinrich and colleagues explained the reasons for their current investigation. Their results are disturbing: children exposed to increased air pollution showed increased insulin resistance, even though they had not previously had diabetes.

Nearly 400 children were tested for insulin resistance
Together with scientists from the Universities of Augsburg, Leipzig and Dusseldorf, the Technical University of Munich as well as the Ludwig-Maximilian-University Munich and the Marien-Hospital in Wesel, Joachim Heinrich evaluated the data of 397 ten-year-old children from the regions around Munich and Wesel. The researchers use the available data from the cohort studies „Lisa Plus“ and „GINIplus“. They formed a randomized experimental group and invited the nearly 400 participants to a blood test. The air pollution at the place of residence of the children was calculated on the basis of the distance to the main traffic routes and the traffic there. Subsequently, the researchers identified the so-called HOMA index, which reflects insulin resistance. To avoid bias, the data were adjusted for socioeconomic factors and other influences, such as passive smoking.

Car exhaust significantly increases the risk of insulin resistance
During the evaluation, the researchers found that the cells of children who were exposed to high levels of air pollution, increased insulin resistance. Thus, the probability of insulin resistance in children increased by about 19 percent when the particulate matter increased by ten micrograms per cubic meter of air. In terms of nitrogen dioxide concentration, the result was similarly dramatic. An increase in concentration of more than ten micrograms per cubic meter of air would increase the risk of insulin resistance by 17 percent. In general, the proximity to the busy main roads has shown a crucial role in insulin resistance, the researchers report. For children living near a busy street, the risk of insulin resistance per 500 meters closer to the street increased by about seven percent.

Relationship between the increase in diabetes and car exhaust?
Although the researchers emphasized that their results do not provide any information on the actual risk of childhood diabetes later in life. But Joachim Heinrich explained equally, the results would support the thesis, „that the development of diabetes in adulthood is related to environmental factors of earlier stages of life.“ In fact, air pollution may play a far more significant role in the observed increase in diabetes than previously thought. After all, with increasing traffic levels, particulate matter pollution and nitrogen dioxide concentrations in the air, especially in the cities, had risen for years. Only in the recent past have some cities taken countermeasures, such as the establishment of an environmental zone, to significantly reduce particulate matter pollution. Also with regard to the cardiovascular diseases and respiratory diseases, which are associated with the high exhaust emissions, certainly a good decision, although this was heavily criticized by many drivers initially. (Fp)