Grim warning for Delhi residents as air pollution found to increase diabetes risk

"Till now, we have blamed the individual for an increase in diabetes by saying that, oh, you ate too much, you did not exercise, you had stress and so on," says Dr. V. Mohan, Chairman of Dr. Mohan's Diabetes Speciality Center and the Madras Diabetes Research Foundation at Chennai, India, one of the authors of a new study that has found a link between air pollution and diabetes. Until now, the concern and effort to safeguard oneself from air pollution was mainly to prevent the risk of cardiovascular diseases and respiratory infections. "Exposure to fine particulate matter has been associated with several cardiovascular and cardiometabolic diseases. However, such evidence mostly originates from low-pollution settings or cross-sectional studies, thus necessitating evidence from regions with high air pollution levels, such as India, where the burden of non-communicable diseases is high, say the group of Indian researchers who recently found a link between diabetes and air pollution.

A new study published in the BMJ Open Diabetes Research and Care has found association between ambient PM2.5 levels and fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c) and incident type 2 diabetes mellitus (T2DM) among a total of 12,064 participants in an adult cohort from urban Chennai and Delhi, India. "This is a seven-year study of over 12,000 residents in Delhi and Chennai, where we have found a link between PM2.5 particles and increased risk of type 2 diabetes," says Dr. V Mohan.

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"Till now, we have been thinking that the higher prevalence of diabetes in urban areas is due to increased obesity, less physical activity, and unhealthy diet with more carbohydrate, fat, calories, fat, etc. Of course, all these are more common in urban areas," says Dr. Mohan. "But now, this new study of ours shows that there could be yet another explanation for the higher prevalence of type 2 diabetes seen in urban areas. For the first time, we are showing in a large study in India that air pollution can also precipitate type 2 diabetes in those who are predisposed to it," he adds.

PM2.5 particulate matter, that can cause respiratory diseases, including chronic obstructive lung disease, asthma, emphysema and probably even lung cancer, can disturb the endocrine system as well. " In the case of diabetes, they can lead to, number one, reduced insulin secretion from the pancreatic beta cells. Number two, they can also produce insulin resistance both in the liver and in the muscle. As we know, reduced insulin secretion and increased insulin resistance are the two primary pathophysiological defects in type 2 diabetes. Now, with both of these getting affected due to the endocrine disruptor effect of the PM2.5 particulate matter, it is not a surprise, therefore, that the type 2 diabetes is now being linked to the air pollution," Dr. Mohan explains.

"Diabetes was until now mostly linked to lifestyle issues and genetic factors. This is alarming as pollution is a major issue in all the metropolitan cities especially Delhi. Particulate matter (PM2.5), a common pollutant, has been singled out as a major culprit. When inhaled, these tiny particles can infiltrate the bloodstream, triggering inflammation and oxidative stress throughout the body," says Dr Ashutosh Shukla, Medical Advisor and Senior Director – Internal Medicine, at Max Hospital, Gurugram. "Reducing exposure to air pollution is crucial for diabetes prevention. We can do this by using cleaner energy and better public transportation. Awareness and collective action are key in safeguarding our communities from the effects of polluted air on our health and well-being," he adds.

"Now, we know that the environment is also playing a role, and therefore, it becomes the duty of citizens and NGOs and also the government to try to reduce pollution. By doing this, not only the general health will improve, but perhaps non-communicable diseases like diabetes can also be prevented. Therefore, urgent steps have to be taken to control pollution in our large cities. While more studies need to be done to look at air pollution in different parts of the country, this study is pretty definitive because it talks about the risk of incident type 2 diabetes, it is a large sample size and also studied in two large cities of India, namely in New Delhi and in Chennai," Dr. Mohan says.