Living in areas with polluted air increases the risk of type 2 diabetes, to the point that 14% of cases occurring in the world could be related to this cause. This is stated in a study by Washington University of Saint Louis published by Lancet Planetary Health. We discuss it with Dr. Cesare Berra, Head of the Metabolic Diseases Section of the Diabetology Unit at Humanitas.
Smog and diabetes: what is the relationship?
Type 2 diabetes mellitus (also called non-insulin-dependent diabetes mellitus) or adult diabetes, is a metabolic disease, characterized by high blood sugar in a context of insulin-resistance and relative insulin-deficiency. Unlike type 1 diabetes mellitus, where there is an absolute deficiency of insulin due to the destruction of the Langerhans Islands of the pancreas, this disease accounts for about 90% of cases of diabetes, with the remaining 10% are mainly due to type 1 diabetes mellitus and gestational diabetes.
Researchers at Washington University of Saint Louis analyzed the data of 1.7 million people followed on average for 8.5 years, comparing their state of health with the rates of pollution recorded by the control units in the vicinity of their residences. The data showed a strong correlation between pollution and diabetes: about 21% of those exposed to a level of smog between 5 and 10 micrograms per cubic meter developed the disease, while for those between 12 and 14 the percentage was 24%. The highest risk was then compared with diabetes data from around the world.
According to the authors of the study, pollution would contribute to the onset of at least 3.2 million cases of type 2 diabetes per year and the risk is higher for lower-income countries, such as India or Afghanistan, which can in no way mitigate the effects.
The opinion of Humanitas
Type 2 diabetes is a pathology or rather a set of different syndromes with polyfactorial genesis, i.e. the causes can really be many, both genetic and environmental. “This study focuses on an environmental cause so far little investigated, showing how pollution can also become part of the many causes that generate type 2 diabetes – said Dr. Berra. In addition to diet and nutrition, what other risk factors come into play in the onset of this disease? Family history first of all, then obesity and overweight, suffering from hypertension, previous history of abnormal blood sugar levels, diabetes that developed during pregnancy.
There is a simple algorithm called diabetes risk score based on 8 points (age, BMI, waist circumference, physical activity, proper diet, intake of antihypertensive drugs, family history and altered blood sugar) that helps in identifying those at greater risk. In these subjects, in addition to recommending a check of blood tests at least once a year, emphasis should be placed on lifestyle changes to prevent the presence of the disease.