Preconception air pollution exposure and glucose tolerance in healthy pregnant women in a middle income country

Abstract

Background: The effect of preconception exposure to air pollution on glucose tolerance during pregnancy in developing and middle-income countries is under debate yet. Therefore, this study aimed to assess the relationship between exposure to ambient particulate matter (PM) and traffic indicators with glucose tolerance in healthy pregnant women in Sabzevar, Iran (2019). Methods: Accordingly, 250 healthy pregnant women with singleton pregnancies of 24-26 weeks of gestations were participated in our study. Land use regression (LUR) models were applied to estimate the annual mean of PM1, PM2.5 and PM10 at residential address. Traffic indicators, including distance from home to the nearest major road (DHMR) as well as total streets length in 100, 300 and 500m buffers around the home (TSL-100, 300 and 500) were calculated using the street map of Sabzevar. Oral glucose tolerance test (OGTT) was used to assess glucose tolerance during pregnancy. Multiple linear regression adjusted for relevant covariates was used to estimate the association of fasting blood glucose (FBG), 1-h and 2-h post-load glucose with PMs and traffic indicators. Results: Exposure to PM1, PM2.5 and PM10 was significantly associated with higher FBG concentration. Higher TSL-100 was associated with higher FBG and 1-h glucose concentrations. Each one interquartile range (IQR) increase in DHMR the levels of FBG and 1-h post-load glucose were decreased -3.42 mg/dL (95% confidence interval (CI): -4.47, -2.37, P-value < 0.01) and -4.65 mg/dL (95% CI: -8.03, -1.26, P-value < 0.01), respectively. Conclusion: We found higher preconception exposure to air pollution and exposure to air pollution during pregnancy were negatively associated with glucose tolerance during pregnancy in a middle income country.