Study links air pollution exposure to type 2 diabetes susceptibility

A study by researchers at Wayne State University links exposure to air pollution to an increased risk of type 2 diabetes. Their paper, published in the journal Diabetes, established a robust association between exposure to benzene, a prevalent airborne volatile organic compound, and insulin resistance in humans across all ages.

Marianna Sadagurski, Ph.D., associate professor at Wayne State University’s Institute of Environmental Health Sciences, was the lead author of the paper, “Microglia Mediate Metabolic Dysfunction From Common Air Pollutants Through NF-κB Signaling.”

“In our paper, we performed a meta-analysis where we collected data from different populations ranging from young adults to the elderly,” said Sadagurski. “We saw a significant correlation between the presence of benzene metabolites in people’s urine and increased index of insulin resistance.”

Sadagurski and her fellow researchers concluded that the microglial NF-κB pathway plays a critical role in chemical-induced metabolic disturbances, revealing a vital pathophysiological mechanism linking exposure to airborne toxicants and the onset of metabolic diseases.

“In this study, we exposed mice to benzene to see how it affects their blood glucose levels and energy expenditure,” said Sadagurski. “Our research revealed that within seven days of exposure, they developed high blood glucose insulin levels.”

Following exposure in mice, disruptions in energy homeostasis, accompanied by modifications in the hypothalamic transcriptome and alterations in insulin and immune signaling, were observed exclusively in males, leading to a surge in blood glucose levels.

The researchers noted that acute benzene exposure triggers hypothalamic insulin resistance and provokes an inflammatory shift associated with NF-κB pathway in the microglial transcriptome. Genetic ablation of this pathway in microglia, rescued metabolic phenotype in benzene-exposed mice.

The study was jointly led by postdoctoral fellow Lukas Debarba and graduate students in Biological Sciences, Hashan Jayarathne and Lucas Stilgenbauer as co-first authors. Other authors include Ana L. Terra dos Santos, Wayne State University; Lisa Koshko, Wayne State University; Sydney Scofield, Wayne State University; Ryan Sullivan, Wayne State University; Abhijit Mandal, University of Texas at El Paso; and Ulrike Klueh, Wayne State University.