The association between air pollution and three types of diabetes: An umbrella review of systematic reviews and meta-analyses.

BACKGROUND

Despite numerous meta-analyses showing an association between air pollutants and diabetes, there is considerable heterogeneity between studies.

OBJECTIVES

This study aims to evaluate the cumulative evidence regarding the association between air pollution and type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and gestational diabetes mellitus (GDM) through systematic reviews and meta-analyses.

METHODS

Following the PRISMA 2020 guidance, a comprehensive review across three databases, including Web of Science, Embase, and PubMed, from inception to September 30, 2024. The quality of the included systematic reviews was assessed using the AMSTAR 2 tool. The research protocol has been registered in PROSPERO (CRD42024594953).

RESULTS

A total of 19 meta-analyses were identified in this review, including two articles investigating the impact of air pollution on T1DM, nine on T2DM, and ten on GDM. Due to limited data, no significant relationship between air pollution and T1DM was found. There is evidence that exposure to particulate matter (PM2.5 and PM10) may significantly increase the risk of T2DM. However, meta-analyses concerning GDM exhibit a less consistent association between air pollution and GDM risk, which varies by pollutant and duration of exposure.

CONCLUSION

Results suggest that exposure to air pollution may increase diabetes risk to some extent, particularly for T2DM. However, due to limited available studies, further prospective cohort studies are warranted to elucidate the role of air pollutants in diabetes, particularly for T1DM. Additionally, understanding potential mechanisms by which air pollution affects diabetes is crucial for future investigations.