The role of atmospheric pollutants in type 2 diabetes prevalence across Italy

Background and aims: Ambient air pollution (AP) has been linked to increased risk of type 2 diabetes (T2D). This study examines the association between long-term AP exposure and T2D prevalence in Italy from 2006 to 2023. Materials and methods: The correlation between T2D prevalence, AP exposure, and health-related determinants (BMI, household members, smoking, education level, income, exercise, daily con sumption of pasta, bread, and vegetables) was assessed using multi ple linear and stepwise regression models. Simulations were run with three predictor configurations: 1) health-related indicators only, 2) AP only, 3) both. The AP considered are nitrogen oxide (NO), nitro gen dioxide (NO2), ozone (O3), formaldehyde (HCHO), carbon mon oxide (CO), nitric acid (HNO3), ethane (C2H6), propane (C3H8), isoprene (C5H8), hydroxyl radical (OH), peroxyacetyl nitrate (PAN), particulate matter (PM10, PM2.5), temperature, and water vapor content. T2D prevalence, health, and socioeconomic data were pro vided by the Italian National Institute of Statistics (ISTAT). AP data were acquired from the Copernicus Atmosphere Monitoring Service (CAMS) using the ECMWF Atmospheric Composition Reanalysis 4 (EAC4) dataset (REF EA1). Results: T2D prevalence increased from 4.4% in 2006 to over 6% in 2023. Figure 1 shows measured diabetes prevalence in Italy and three model simulations. Using only health-related indicators, the linear regression model reproduced measurements with R of 0.9444, identifying education level as the most significant predictor. Using only AP, the correlation coefficient between modeled and observed T2D prevalence increased to 0.9993, suggesting AP significantly improve trend description. The stepwise model identified NO2 as the most relevant predictor. When considering both health-related indicators and AP, model performance improved (R = 0.9997), with C2H6 as the most relevant predictor. Conclusion: Exposure to NO2 and C2H6 shows a strong association with rising T2D prevalence in Italy, outperforming health-related predictors. Air pollution thus emerges as a key determinant of the national diabetes burden.