New analysis finds that millions of new cases of diabetes may be caused by not something you ingest in your mouth– but rather, by something you breathe.
Air pollution has been known to be associated with increased risk of diabetes; however, a knowledge gap exists to quantify the exact relationship.
Dr. Ziyad Al-Aly of Washington University and his colleagues decided to investigate further.
According to research published in The Lancet, the smallest particulate matter of pollution, known as “PM 2.5” has already been associated with increased risk of heart disease, lung disease, kidney disease, and other diseases, and has contributed to about 4.2 million premature deaths in 2015.
To look for a link between air pollution and type 2 diabetes, researchers studied data on 1.7 million U.S. veterans without diabetes. They compared PM 2.5 levels where they lived relative to their risk of getting diabetes during eight years. They singled out the effect of air pollution by taking other risk factors for developing diabetes into account.
They found that the study participant’s annual average daily PM 2.5 exposure ranged from 5 to 22.1 micrograms per cubic meter (mcg/m3) of air. A 10-point increase in PM 2.5 concentration was associated with a 15 percent higher risk of developing diabetes, and an 8 percent higher risk of death.
Globally, PM 2.5 contributed to about 3.2 million new cases of diabetes, and over 200,000 deaths from diabetes attributable to polluted air. They found the numbers varied among different geographies and was more heavily skewed towards low-income and lower-to-middle-income countries.
The authors point out several limitations to the study and note, “our study focused on quantitating the burden of diabetes associated with PM 2.5 exposure, however, evaluation of the burden of diabetes associated with exposure to other pollutants including carbon monoxide, nitrogen dioxide, and others should be undertaken in future research.”
In a related commentary, Dr. Gary O’Donovan of the Universidad de los Andes in Bogota, Colombia, and Dr. Carlos Cadena-Gaitan of the Universidad EAFIT in Medellin, call the findings a “call for action.” They say current study did not take into account other factors like physical activity.
“More research is required to determine the independent associations of physical activity and air pollution with diabetes and other non-communicable diseases, however, there is more than enough evidence to justify the implementation of policies and interventions that might actually increase physical activity and decrease air pollution,” they write.