Association between particulate matter (pm) 2.5 and the development of type 2 diabetes mellitus among women with a history of gestational diabetes mellitus
Gestational diabetes mellitus (GDM) increases the lifetime risk of developing type 2 diabetes mellitus (T2DM) in the mother; however, biological mechanisms remain relatively unknown, and known risk factors have shown to be incomplete. Both epidemiological and experimental research suggest that environmental exposure to particulate matter (PM2.5) may initiate and further progress chronic diseases such as T2DM. This study investigates the association between PM2.5 exposure and the risk of T2DM among women with a history of GDM. Associations between prevalent and incident T2DM with PM2.5 utilized two PM2.5 metrics: 1) annual average PM2.5 concentration and 2) annual average modeled PM2.5 exposure, calculated from daily PM2.5 concentration levels provided by the USRA/NASA Marshal Space Flight Center. Data from the Southern Community Cohort Study, who at recruitment reported a previous diagnosis of GDM, for whom T2DM, risk factor, and follow-up information were available, was provided. In total, 2403 participants were included in the analysis of prevalent T2DM, and 1036 participants were included in the analysis of incident T2DM. Associations between proximity to roadways and race with PM2.5 metrics were also conducted. Participants that live close to roadways were exposed to higher annual average PM2.5 concentrations and annual average modeled PM2.5 exposures. When stratified by race, non-Black participants were exposed to higher averages. After adjustment, a significant association was observed between annual average PM2.5 concentration and incident T2DM (hazards ratio (HR)= 1.022, 95% confidence interval (CI): 1.003, 1.040). No association was observed between annual average PM2.5 concentrations and prevalent T2DM. Annual average modeled PM2.5 exposure was not associated with either prevalent or incident T2DM. Results were partly consistent with previous literature. Additional studies with a greater range of air pollution exposures, including higher levels, additional pollutants, and more tailored exposure models, are warranted to investigate hypothesized associations.