Effect of an intensified individual nutrition therapy on serum metabolites in critically ill patients - A targeted metabolomics analysis of the ONCA study

Abstract

Purpose: The effect of medical nutrition on serum metabolomics has been poorly explored. The aim of the study was to investigate the relation between energy supply and metabolic profiles in critically ill patients.

Materials and methods: Twenty mechanically ventilated patients on enteral nutrition (EN) or enteral/parenteral nutrition (EN/PN) were randomized into two groups. One group received an individual energy supply based on indirect calorimetry (IC group, n = 9), the other group received a standard energy supply based on a formula, the standard care group (SC group, n = 11). Targeted metabolomics was performed in early-, late- and post-acute metabolic phase.

Results: Individual versus standard care energy supply resulted in a metabolite class separation between the IC and the SC group (P < 0.001). In the SC group concentrations of four glucogenic amino acids and three biogenic amines increased between the early- and late-acute metabolic phase (P < 0.05). The metabolomics pattern differed between the routes of nutrition administration (P < 0.01).

Conclusions: The amount of energy supply by EN or PN, besides other factors, seems to modulate serum metabolites. Nutrition therapy based on individualized energy supply is associated with a reduction of metabolites reflecting catabolism. Therefore, metabolomics could be a new tool to determine metabolic phases in critically ill patients.

Keywords: Critical illness; Indirect calorimetry; Medical nutrition; Nutrition therapy; Targeted metabolomics.