Mixed Heavy Metal Exposure During Pregnancy Induces GDM-like Metabolic Dysfunction Associated with Glycer-Ophospholipid Metabolic Reprogramming and Altered Insig1 Expression: A Multi-Omics Study in Rats

This study aimed to investigate whether mixed heavy metal exposure (lead, cadmium, manganese, and arsenic) during pregnancy induces gestational diabetes mellitus (GDM)-like phenotypes and to explore the associated molecular alterations. We examined the effects of exposure on metabolic disturbances using a Sprague-Dawley rat model exposed to low- and high-dose mixed heavy metals, with doses selected based on biomonitoring data. The results showed that high-dose mixed heavy metal exposure significantly increased blood glucose levels in rats, elevated the area under the curve (AUC) during the oral glucose tolerance test (OGTT), and induced insulin resistance and dyslipidemia. Concurrently, pathological examinations revealed hepatocyte steatosis, inflammatory cell infiltration, and mitochondrial abnormalities in liver tissues. Transcriptomic and metabolomic analyses identified significant disruption of the glycerophospholipid metabolic pathway following heavy metal exposure, suggesting the involvement of this pathway in the observed metabolic disturbances. Lasso regression analysis identified Insig1 as a candidate gene associated with lipid metabolic alterations, a finding subsequently validated by qPCR. Overall, mixed heavy metal exposure during pregnancy was associated with GDM-like metabolic abnormalities in rats. Disruption of glycerophospholipid metabolism and altered Insig1 expression likely contribute to these effects, providing molecular evidence linking mixed heavy metal exposure to gestational metabolic dysfunction.