Substrate fuel kinetics in enterally fed traumapatients supplemented with ornithine alpha ketoglutarate

Abstract

Background: Ornithine-α-ketoglutarate (OKG) is apromising anticatabolic agent and themechanisms of its potential use in trauma patients are not clearly understood. Aim: To determine the altered whole-body protein, lipid and glucose substrate kinetics in trauma victims in the early flow-phase of injury when they were fed enterally with or without OKG. Methods: Fourteen adult, multiple trauma patients who were highly catabolic and hypermetabolic werestudied. Whole-body protein ( 15N glycine), fat (2 stage glycerol infusion) and glucose ( 3H glucose) kinetics (t/o) and plasma parameters were measured (A) within 48–60 h after injury before starting nutritional support and then (B) after 4 days of enteral feeding. Group A (n=7, control) received a defined enteral formula (Two Cal HN, 1.4 times BEE calories) and Group B (n=7, OKG) received same isonitrogenous diet replacing 2.62gN/d from the enteral diet by OKG-N (20g OKG/d). Results: (Mean±SEM): Protein turnover is significantly ( P≤0.05) increased in OKG treated patients(4.68±0.15 vs 3.90±0.23, gP/kg/day) and glycerol turnover is decreased (0.87±0.16 vs 1.46±0.16, μ mole/kg/min). Glucose turnover is not changed. Significant ( P≤0.05) increases in circulating plasma levels of hormones (insulin, 44.2±8.4 vs 15.7±5.0 uIU/ml, growth hormone 1.68±0.33 vs 0.92±0.16, ng/ml and IGF-1, 106±13 vs 75±18, ng/ml) and free amino acids (glutamine, 383±20 vs 306±25, Proline, 203±18 vs 146±13 and ornithine, 164±27 vs 49±5 μ mole/l) are found in OKG treated patients, compared to non OKG patients. Conclusion: Increased hormone secretion due to OKG and the rapid interaction between the metabolites of OKG at the intermediary metabolism level may be responsible for altered substrate fuel kinetics.