Associations of Reduced Ambient PM2.5 Level With Lower Plasma Glucose Concentration and Decreased Risk of Type 2 Diabetes in Adults: A Longitudinal Cohort Study

Abstract

<p>It remains unknown whether reduced air pollution levels can prevent type 2 diabetes mellitus. In this study, we investigated the associations between dynamic changes in long-term exposure to ambient fine particulate matter, defined as particulate matter with an aerodynamic diameter ≤2.5 μm (PM_2.5), and changes in fasting plasma glucose (FPG) levels and incidence of type 2 diabetes. A total of 151,398 adults (ages ≥18 years) were recruited in Taiwan between 2001 and 2014. All participants were followed up for a mean duration of 5.0 years. Change in PM_2.5 (ΔPM_2.5) was defined as the value at a follow-up visit minus the corresponding value at the immediately preceding visit. The PM_2.5 concentration in Taiwan increased during 2002–2004 and began to decrease in 2005. Compared with participants with little or no change in PM_2.5 exposure, those with the largest decrease in PM_2.5 had a decreased FPG level (β = −0.39, 95% confidence interval: −0.47, −0.32) and lower risk of type 2 diabetes (hazard ratio = 0.86, 95% confidence interval: 0.80, 0.93). The sensitivity analysis and analyses stratified by sex, age, body mass index, smoking, alcohol drinking, and hypertension generally yielded similar results. Improved PM_2.5 air quality is associated with a better FPG level and a decreased risk of type 2 diabetes development.</p>