Abstract
PURPOSE: To determine the differences of metabolites and metabolic pathways between patients with proliferative diabetic retinopathy (PDR) and without diabetes (nondiabetic controls) in plasma and vitreous, respectively, and to characterize the relationship between plasma and vitreous metabolic profiles. METHODS: Liquid chromatography/tandem mass spectrometry technology was performed to distinct metabolite profiles of plasma and vitreous. A total of 139 plasma samples from 88 patients with PDR and 51 nondiabetic controls, as well as 74 vitreous samples from 51 patients with PDR and 23 nondiabetic controls, were screened. Pathway analysis was performed using MetaboAnalyst 5.0. Pearson correlation analysis was used to investigate the correlation of metabolites in vitreous and plasma. RESULTS: After adjusting for age, fasting blood glucose, and urea, in vitreous metabolomes, a total of 76 features distinguished patients with PDR from controls. Fifteen differential metabolites were found in plasma metabolites. Pantothenate and CoA biosynthesis was the common metabolic pathway altered in both plasma and vitreous. Aromatic amino acid metabolism pathways were dysregulated in vitreous of PDR. For four metabolic features, there were positive correlations between vitreous and plasma. CONCLUSIONS: Despite great differences between the metabolic profiles of plasma and vitreous in PDR cases, there are also similarities in the change of metabolites and metabolic pathways. Exploring the relationship of metabolomics between vitreous and plasma may help provide new understanding of the mechanism of PDR.