A study of more than 21,000 Europeans has found that PM10 pollution and changing temperatures are associated with higher HbA1c levels in people without diagnosed diabetes.
A European study has linked air pollution and temperature swings to higher blood sugar levels in people who have not been diagnosed with diabetes, adding to evidence that environmental conditions may shape metabolic health long before disease develops. Published in Environment International, the research analysed data from 21,259 people across nine European research groups, including 5,464 participants from the GCAT-IGTP study in Spain, and focused on glycated haemoglobin, or HbA1c, the marker doctors use to estimate average blood sugar over the previous two to three months.
The researchers found that exposure to higher levels of pollution, particularly PM10 particles, was associated with elevated HbA1c. They also reported that greater temperature and more variable temperatures were linked to higher readings, suggesting that heat and fluctuating weather may play a role alongside air quality. According to the study team, the patterns point to interactions between these environmental factors, although the work did not show that pollution or changing temperatures directly cause diabetes.
The findings also indicate that the benefits of cleaner air may be greater in warmer conditions. In scenario analysis, the researchers suggested that improving air quality could coincide with lower HbA1c levels, while some climate-related temperature changes could have the opposite effect. The study did not find a consistent relationship between green space and HbA1c, and it did not directly test the biological pathways involved, although the authors said inflammation and insulin resistance may help explain the link.
Natàlia Blay, a postdoctoral researcher at GCAT and co-author of the paper, said: “This study highlights the association between air pollution, temperature variability and HbA1c levels in people who have not yet developed diabetes. Including temperature in this approach is particularly relevant in the current context of climate change, where environmental exposures cannot be understood in isolation.” The study was carried out as part of EXPANSE, a European project examining how urban environmental exposures affect health, and was led by researchers at the Swiss Tropical and Public Health Institute and the University of Basel with support from the Germans Trias i Pujol Research Institute.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
