Chronic PM2.5 Exposure Poses a Higher Risk of Diabetes, CUHK and HKU Find

A study led by The Chinese University of Hong Kong’s Faculty of Medicine (CU Medicine) and The University of Hong Kong’s Faculty of Architecture, joining with other collaborators, revealed a clear association between ambient fine particulate matter (or PM2.5, refers to particulate matter 2.5 micrometres in diameter or smaller) and the prevalence of prediabetes and diabetes, at every life stage, particularly in adulthood compared to school age and adolescence, with a rise of risk for 29%.

Diabetes is closely linked to insulin, a hormone produced by the pancreas that regulates blood glucose levels by facilitating its absorption into body cells. Insulin resistance can lead to limited control of blood glucose levels, eventually resulting in diabetes. Whereas prediabetes is a medical condition marked by elevated blood glucose levels that do not yet meet the criteria for diabetes. The International Diabetes Federation projected that the number of adults globally living with prediabetes could double to as many as 730 million by 2045. Furthermore, a systematic review revealed that up to half of individuals with prediabetes progress to diabetes within five years of diagnosis.

The study found that inhalation of PM2.5 would result in systemic oxidative stress and inflammation, which are the key contributors to insulin resistance and increasing the risk of diabetes. With approximately 10% of the local population diagnosed with diabetes, as reported by the Hospital Authority, the medical and financial burdens associated with diabetes-related health issues are expected to rise. In 2023, the annual average PM2.5 concentration in the region exceeded the World Health Organization’s Air Quality Guidelines of 5 µg/m³ by 340% for general monitoring stations and 260% for roadside stations, highlighting the severity of PM2.5 pollution in Hong Kong. CAN is dedicated to advocating for improved local air quality, and this year, we have installed indoor air quality monitors at 19 sites across two districts. At six of these locations, PM2.5 levels surpassed the WHO safety standard over 60% of the time [1]. The air pollution and public health situation warrants attention.

Professor Martin Wong Chi-sang, senior co-corresponding author of the study, from The Jockey Club School of Public Health and Primary Care at CU Medicine, emphasized the importance of reducing PM2.5 exposure to mitigate the risks of prediabetes and diabetes. The study underscores the urgent need for effective air pollution control strategies to address and alleviate the growing burden of diabetes-related health issues, ultimately improving public health.

[1] CAN collected data on a minute-by-minute basis, while the WHO averaged measurements over 24 hours, with a standard of 15 µg/m³.

Reference
Yi, Y., Guo, C., Zheng, Y., Chen, S., Lin, C., Lau, A., Wong, M., & Bishai, D. (2024). Life Course Associations between Ambient Fine Particulate Matter and the Prevalence of Prediabetes and Diabetes: A Longitudinal Cohort Study in Taiwan and Hong Kong. Diabetes Care. https://doi.org/10.2337/dc24-1041