AIR pollution is a "significant" contributor to type 2 diabetes around the world - triggering more than three million new cases a year, according to new research. Even low pollution levels can pose a health risk, suggests the study.
The findings raise the possibility that reducing pollution may lead to a drop in diabetes cases in heavily polluted countries such as India and even less polluted ones.
Diabetes is one of the fastest growing diseases, affecting more than 420 million people worldwide.
The main drivers of diabetes include eating an unhealthy diet, a couch potato lifestyle, and obesity.
But the new research, published in The Lancet Planetary Health indicates the extent to which outdoor air pollution plays a role.
Study senior author Dr Ziyad Al-Aly, an Assistant Professor of medicine at Washington University School of Medicine in the United States, said: "Our research shows a significant link between air pollution and diabetes globally.
"We found an increased risk, even at low levels of air pollution currently considered safe by the U.S. Environmental Protection Agency (EPA) and the World Health Organisation (WHO).
"This is important because many industry lobbying groups argue that current levels are too stringent and should be relaxed.
"Evidence shows that current levels are still not sufficiently safe and need to be tightened."
While growing evidence has suggested a link between air pollution and diabetes, researchers have not attempted to quantify that burden until now.
Dr Al-Aly said: "Over the past two decades, there have been bits of research about diabetes and pollution.
"We wanted to thread together the pieces for a broader, more solid understanding."
To evaluate outdoor air pollution, the researchers looked at particulate matter, airborne microscopic pieces of dust, dirt, smoke, soot and liquid droplets.
Previous studies have found that such particles can enter the lungs and invade the bloodstream, contributing to major health conditions such as heart disease, stroke, cancer and kidney disease.
In diabetes, pollution is thought to reduce insulin production and trigger inflammation, preventing the body from converting blood glucose into energy that the body needs to maintain health.
The overall risk of pollution-related diabetes is tilted more toward lower-income countries
Overall, the researchers estimated that pollution contributed to 3.2 million new diabetes cases globally in 2016, which represents about 14 per cent of all new diabetes cases globally that year.
They also estimated that 8.2 million years of healthy life were lost in 2016 due to pollution-linked diabetes, representing about 14 per cent of all years of healthy life lost due to diabetes from any cause.
The Washington University team, in collaboration with scientists at the Veterans Affairs' Clinical Epidemiology Centre, examined the relationship between particulate matter and the risk of diabetes by first analysing data from 1.7 million U.S. veterans who did not have histories of diabetes.
The researchers linked that patient data with the EPA's land-based air monitoring systems as well as space-borne satellites operated by the National Aeronautics and Space Administration (NASA).
They used several statistical models and tested the validity against controls such as ambient air sodium concentrations, which have no link to diabetes, and lower limb fractures, which have no link to outdoor air pollution, as well as the risk of developing diabetes, which exhibited a strong link to air pollution.
They then sifted through all research related to diabetes and outdoor air pollution and devised a model to evaluate diabetes risk across various pollution levels.
Finally, they analysed data from the Global Burden of Disease study, which is conducted annually with contributions from researchers worldwide.
The data helped to estimate annual cases of diabetes and healthy years of life lost due to pollution.
The researchers also found that the overall risk of pollution-related diabetes is tilted more toward lower-income countries such as India that lack the resources for environmental mitigation systems and clean-air policies.
For instance, poverty-stricken countries facing a higher diabetes-pollution risk include Afghanistan, Papua New Guinea and Guyana, while richer countries such as France, Finland and Iceland experience a lower risk.
In the United States, the EPA's pollution threshold is 12 micrograms per cubic metre of air, the highest level of air pollution considered safe for the public, as set by the Clean Air Act of 1990 and updated in 2012.
However, using mathematical models, Dr Al-Aly's team established an increased diabetes risk at 2.4 micrograms per cubic metre of air.
Based on VA data, among a sample of veterans exposed to pollution at a level of between 5 to 10 micrograms per cubic metre of air, about 21 per cent developed diabetes.
When that exposure increases to 11.9 to 13.6 micrograms per cubic metre of air, about 24 per cent of the group developed diabetes.
A three per cent difference may appear small, but the researchers said that it represents an increase of 5,000 to 6,000 new diabetes cases per 100,000 people in a given year.
Last October, The Lancet Commission on pollution and health published a report outlining knowledge gaps on pollution's harmful health effects.
One of its recommendations was to define and quantify the relationship between pollution and diabetes.
https://www.express.co.uk/life-style/health/981552/diabetes-type-2-pollution-health-risk-new-research
They also estimated that 8.2 million years of healthy life were lost in 2016 due to pollution-linked diabetes, representing about 14 per cent of all years of healthy life lost due to diabetes from any cause.
The Washington University team, in collaboration with scientists at the Veterans Affairs' Clinical Epidemiology Centre, examined the relationship between particulate matter and the risk of diabetes by first analysing data from 1.7 million U.S. veterans who did not have histories of diabetes.
The researchers linked that patient data with the EPA's land-based air monitoring systems as well as space-borne satellites operated by the National Aeronautics and Space Administration (NASA).
They used several statistical models and tested the validity against controls such as ambient air sodium concentrations, which have no link to diabetes, and lower limb fractures, which have no link to outdoor air pollution, as well as the risk of developing diabetes, which exhibited a strong link to air pollution.
They then sifted through all research related to diabetes and outdoor air pollution and devised a model to evaluate diabetes risk across various pollution levels.
Finally, they analysed data from the Global Burden of Disease study, which is conducted annually with contributions from researchers worldwide.
The data helped to estimate annual cases of diabetes and healthy years of life lost due to pollution.
The researchers also found that the overall risk of pollution-related diabetes is tilted more toward lower-income countries such as India that lack the resources for environmental mitigation systems and clean-air policies.
For instance, poverty-stricken countries facing a higher diabetes-pollution risk include Afghanistan, Papua New Guinea and Guyana, while richer countries such as France, Finland and Iceland experience a lower risk.
In the United States, the EPA's pollution threshold is 12 micrograms per cubic metre of air, the highest level of air pollution considered safe for the public, as set by the Clean Air Act of 1990 and updated in 2012.
However, using mathematical models, Dr Al-Aly's team established an increased diabetes risk at 2.4 micrograms per cubic metre of air.
Based on VA data, among a sample of veterans exposed to pollution at a level of between 5 to 10 micrograms per cubic metre of air, about 21 per cent developed diabetes.
When that exposure increases to 11.9 to 13.6 micrograms per cubic metre of air, about 24 per cent of the group developed diabetes.
A three per cent difference may appear small, but the researchers said that it represents an increase of 5,000 to 6,000 new diabetes cases per 100,000 people in a given year.
Last October, The Lancet Commission on pollution and health published a report outlining knowledge gaps on pollution's harmful health effects.
One of its recommendations was to define and quantify the relationship between pollution and diabetes.
https://www.express.co.uk/life-style/health/981552/diabetes-type-2-pollution-health-risk-new-research