Objective To analyze the systemic metabolic changes of patients with uncontrolled inflammation response after acute lung injury (ALI) happened.

Methods Traumatic patients with systemic inflammatory response syndrome (SIRS), ALI and acute respiratory distress syndrome (ARDS) were selected as subjects, the serum ¹H-NMR spectra were recorded on a Varian Unity INOVA-600 spectrometer and analyzed by pattern recognition analyses.

Results The partial least squares-discriminant analysis (PLS-DA) could distinguish the migration process of metabolic patterns from SIRS to ALI and even ARDS. Corresponding metabolite assignment indicated that NMR profiles responsible for SIRS discrimination were distributed in low chemical shift regions, mainly composed of ketogenic amino acids such as tyrosine and lysine, while δ1.02-2.50 and δ3.02-4.14 integral regions for ALI/ARDS patients, principally consisted of various proton signals of lactate, valine, arginine, glutamic acid, and other glycogenic amino acids, pyruvate, creatine, along with fatty acyl chains and glycerol backbone of lipids. Pathway enrichment analyses of metabolites revealed the occurrence of ALI/ARDS were mainly related to the activation of glycolysis, gluconeogenesis, pyruvate metabolism, glyceride metabolism, arginine metabolism, and primary bile acid synthesis. This result indicates that the systemic metabolic disorder of patients with acute lung injury caused by uncontrolled inflammatory response was characterized by hypercatabolism under hypoxia.

Conclusions The serum NMR-based metabonomic profiles could reflect the overall metabolic changes of patients after lung damage, which will contribute to surveillance and elucidation mechanism of ALI/ARDS.