Low-Level Air Pollution Increase Hyperglycemia Risk in Pregnancy: Study

A recent study published in the Environmental Science & Technology journal uncovered a significant connection between low-level air pollution exposure and increased hyperglycemia among pregnant individuals without pre-existing diabetes. The research highlighted the potential risks of air pollutants like PM2.5 (particulate matter) and NO2 (nitrogen dioxide) on blood glucose levels during pregnancy, even in the individuals considered medically low-risk.

The study focused on hemoglobin A1c (HbA1c) which reflects average blood glucose levels over the past three months. Elevated HbA1c levels are a concern as they indicate poor blood sugar control, which can lead to complications such as gestational diabetes mellitus (GDM). The research collected a total of 577 blood samples from 224 pregnant individuals by tracking HbA1c levels at 3 stages of pregnancy: early, mid, and late. The average HbA1c levels were recorded at 5.13% in early pregnancy, 4.97% in mid-pregnancy, and 5.43% in late pregnancy, indicating a U-shaped pattern of HbA1c levels across the pregnancy timeline.

Using high-resolution spatiotemporal models, the research estimated residential concentrations of PM2.5 and NO2 for each participant. They found that an interquartile range increase in 10-week NO2 exposure (approximately 8.0 parts per billion) was associated with a 0.09% increase in HbA1c levels throughout the pregnancy and a more substantial 0.18% increase in late pregnancy.

The findings of this study remained consistent even after adjusting for classic GDM risk factors like the maternal age, body mass index (BMI), and family history of diabetes. The association between air pollution and HbA1c levels was particularly pronounced during a critical window between the 8th and 14th weeks of gestation. Increased exposure to air pollutants during this period was linked to higher HbA1c levels at the 14th, 22nd, and 30th weeks of pregnancy. These outcomes illuminate the importance of minimizing exposure to air pollutants, particularly for pregnant individuals, to reduce the risk of adverse health outcomes like GDM.

Overall, the implications of these findings are particularly relevant for public health policies as they highlight the need for stricter air quality regulations to protect vulnerable populations, including pregnant people. Further research is imperative to fully understand the mechanisms behind this association towards recognizing and addressing the impact of environmental factors on maternal and fetal health.

Reference:

Lin, Y., Chen, R., Ge, Y., Brunner, J., Hopke, P. K., Miller, R. K., Thornburg, L. L., Stevens, T., Barrett, E. S., Harrington, D. K., Thurston, S. W., Murphy, S. K., O’Connor, T. G., Rich, D. Q., & Zhang, J. J. (2024). Exposure to Low-Level Air Pollution and Hyperglycemia Markers during Pregnancy: A Repeated Measure Analysis. In Environmental Science & Technology. American Chemical Society (ACS). https://doi.org/10.1021/acs.est.4c05612