Air pollution increases risk of insulin resistance in children

May 9, 2013

New research shows that growing up in areas where air pollution is increased raises the risk of insulin resistance (the prescursor to diabetes) in children. The research is published in Diabetologia, the journal of the European Association for the Study of Diabetes (EASD), and is by Elisabeth Thiering and Joachim Heinrich, Helmholtz Zentrum München, Neuherberg, Germany, and colleagues.

Previous studies have identified links between and other chronic conditions such as atherosclerosis and heart disease. However to date, that have examined associations between long-term exposure to traffic-related air pollution and in adults are inconsistent, and studies on in children are scarce. Thus this new study sought to explore the possible association between air pollution and insulin resistance in children.

"Although toxicity differs between air pollutants, they are all considered potent oxidisers that act either directly on lipids and proteins or indirectly through the activation of intracellular oxidant pathways," says Heinrich.

" caused by exposure to air pollutants may therefore play a role in the development of insulin resistance. In addition, some studies have reported that short-term and long-term increases in particulate matter and nitrogen dioxide (NO2) exposure lead to elevated inflammatory biomarkers, another potential mechanism for insulin resistance."

In this new study, fasting blood samples were collected from 397 10-year-old children within a follow-up of two prospective German studies. Individual-level exposures to traffic-related air pollutants at their birth address were estimated by analysing emission from road traffic in the neighbourhood, population density and land use in the area, and the association between air pollution and insulin resistance was calculated using a model adjusted for several possible confounders including socioeconomic status of the family, birthweight, pubertal status and BMI. Models were also further adjusted for second-hand smoke exposure at home.

The researchers found that in all crude and adjusted models, levels of insulin resistance were greater in children with higher exposure to air pollution. Insulin resistance increased by 17% for every 10.6 µg/m3 (2 standard deviations [SDs] from the mean) increase in ambient nitrogen dioxide (NO2) and 19% for every 6 µg/m3 (2 SDs) increase in particulate matter of up to 10 μm in diameter. Proximity to the nearest major road increased insulin resistance by 7% per 500 metres. All the findings were statistically significant.

Heinrich says: "There is some evidence that air pollution is associated with lower birthweight and growth restrictions—also shown previously in one of the cohorts of the present study—which are known risk factors for type 2 diabetes. Thus, one may speculate that lower birthweight is an intermediate step or 'phenotype' between air pollution and insulin resistance. However, we found no evidence to suggest that this may be true in our cohort of children, all of whom had birthweights above 2.5kg."

He concludes: "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 and passive smoking."

Currently, the 15 year follow-up of both cohorts is ongoing and the authors are planning to investigate how their findings translate into older age during or after puberty. "Moving from a polluted neighbourhood to a clean area and vice versa would allow us to explore the persistence of the effect related to perinatal exposure and to evaluate the impact of exposure to increased air pollution concentration later in life," says Heinrich. "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."

Explore further: Exposure to traffic-related air pollution linked to autism

Related Stories

Exposure to traffic-related air pollution linked to autism

January 8, 2013
(HealthDay)—Exposure to traffic-related air pollution, including nitrogen dioxide and particulate matter less than 2.5 and 10 micrometers in diameter (PM2.5 and PM10), during gestation and the first year of life is associated ...

Long-term exposure to fine particles of traffic pollution increases risk of heart disease

April 18, 2013
The association between road traffic and heart disease has been suggested in several studies. In 2012 a large prospective cohort study from Denmark showed that traffic noise was significantly associated with risk of heart ...

Exposure to traffic air pollution in infancy impairs lung function in children

October 12, 2012
Exposure to ambient air pollution from traffic during infancy is associated with lung function deficits in children up to eight years of age, particularly among children sensitized to common allergens, according to a new ...

Road traffic pollution as serious as passive smoke in the development of childhood asthma

March 21, 2013
New research conducted in 10 European cities has estimated that 14% of chronic childhood asthma is due to exposure to traffic pollution near busy roads.

Gene variants link to insulin resistance based on diet

April 28, 2013
(HealthDay)—Variants of insulin receptor substrate 1 (IRS1) are associated with insulin resistance and metabolic syndrome, but only under particular dietary conditions, according to a study published online April 17 in ...

Air pollution and hardening of arteries

April 23, 2013
Long term exposure to air pollution may be linked to heart attacks and strokes by speeding up atherosclerosis, or "hardening of the arteries", according to a study by U.S. researchers published in this week's PLOS Medicine.

Recommended for you

Scientists discover a new way to treat type 2 diabetes

July 21, 2017
Medication currently being used to treat obesity is also proving to have significant health benefits for patients with type 2 diabetes. A new study published today in Molecular Metabolism explains how this therapeutic benefit ...

Alzheimer's drug cuts hallmark inflammation related to metabolic syndrome by 25 percent

July 20, 2017
An existing Alzheimer's medication slashes inflammation and insulin resistance in patients with metabolic syndrome, a potential therapeutic intervention for a highly dangerous condition affecting 30 percent of adults in the ...

Diabetes or its precursor affects 100 million Americans

July 19, 2017
Almost one-third of the US population—100 million people—either has diabetes or its precursor condition, known as pre-diabetes, said a government report Tuesday.

One virus may protect against type 1 diabetes, others may increase risk

July 11, 2017
Doctors can't predict who will develop type 1 diabetes, a chronic autoimmune disease in which the immune system destroys the cells needed to control blood-sugar levels, requiring daily insulin injections and continual monitoring.

Diabetes complications are a risk factor for repeat hospitalizations, study shows

July 7, 2017
For patients with diabetes, one reason for hospitalization and unplanned hospital readmission is severe dysglycemia (uncontrolled hyperglycemia - high blood sugar, or hypoglycemia - low blood sugar), says new research published ...

Researchers identify promising target to protect bone in patients with diabetes

July 7, 2017
Utilizing metabolomics research techniques, NYU Dentistry researchers investigated the underlying biochemical activity and signaling within the bone marrow of hyperglycemic mice with hopes of reducing fracture risks of diabetics

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

JessicaH
not rated yet May 09, 2013
I'm sure there are other correlations not mentioned here including poverty, poor diet, lower education levels,etc.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.