GLS and diabetes mellitus: Further exploration of the potential metabolic regulation changes of ECs in diabetes revealed that quantitative analysis of various metabolites involved in intracellular glutamine metabolism, glycolysis, and TCA cycle across different treatment groups showed that when HUVECs were exposed to HGHF conditions, intracellular glutamine levels increased, while glutamate levels significantly decreased, which seems to be ascribed to the suppression of GLS1 expression and viability by HGHF.