Long-term exposure to pollution from city traffic may increase children’s insulin resistance, a risk factor for Type 2 diabetes, says a new study in the European journal, Diabetologia.
However, local health experts say urban dwellers shouldn’t pack their bags and move to the country just yet.
German researchers measured changes in insulin resistance by comparing insulin and glucose measurements at birth to insulin and glucose measurements at age 10 for 397 children. Eighty-two percent of the children lived in the major metropolitan area of Munich, Germany, and 18 percent lived in the smaller city of Wesel.
Researchers evaluated how much polluted air affected a child’s body chemistry by measuring the levels of nitrogen dioxide, and amounts of particles emitted into the air by vehicles and other forms of industrialization at the children’s home addresses.
Researchers adjusted their findings by taking into account the education levels of the children’s parents, the children’s pubertal status, their exposure to second-hand smoke, and body mass index or measure of body fat. Researchers found an increase of insulin resistance of about 17 percent.
Dr. Joachim Heinrich, the corresponding author of the study, said via email that the research was inspired by the “studies in adults which suggested an association between air pollution exposure and Type 2 diabetes.”
Heinrich noted that all participants were Caucasian. They are planning a follow-up study when the children turn 15.
There is a good reason for that age as a follow-up, according to Dr. Steven Shapiro, chairman of the department of pediatrics at Abington Memorial Hospital. “I see 10-year-olds and they all look the same, and then when they’re 15, one’s fat and one’s 6 foot 9 inches,” he said. “Pediatrics is a dynamic specialty in that the child is changing all the time.”
Shapiro said that lots of things besides air pollution can cause insulin resistance. One is poor diet.
Shapiro said genetics can also affect how a person’s pancreas functions and the effectiveness of lifestyle remedies like proper diet and exercise.
Genetics was not considered in the German research even though, in general, a child has a risk of one in seven for developing Type 2 diabetes if one parent develops the disease before the age of 50, says the American Diabetes Association, which notes that Type 2 is also “the most common form of diabetes.”
Dr. Lorraine Katz, a pediatric endocrinologist who has led several national diabetes studies at the Children’s Hospital of Philadelphia, said air pollution is an interesting factor to consider because “we do see higher rates of Type 2 diabetes among urban populations, and specifically populations in poverty.”
However, Katz said she wanted to know about the family histories with diabetes for each of the children studied in the German project.
In her article, “Diabetes and Race,” in the American Journal of Public Health, Arleen Marchia Tuchman writes that 100 years ago, diabetes was considered the “Jewish disease.” In the 1930s, the validity of this link began to be challenged publically, and more so after “the extremes to which the Nazis had taken racial notions of disease and degeneracy.”
By the mid-1950s, the link between Jews and diabetes disappeared, writes Tuchman, but “in the 21st century, the role of race in medicine remains contentious.”
So while an American reviewer may be asking for more family information, perhaps given their nation’s history, German researchers are painfully aware of using genetics as a telltale sign.
Heinrich said more information about the children will be included in their follow-up study, but didn’t specify what information.