Does Glutamine Promote Benefits for Patients With Diabetes Mellitus Scheduled for Cardiac Surgery?

BackgroundWe hypothesised, that perioperative use of N(2)-l-alanyl-l-glutamine confers cardioprotection and improves insulin resistance in diabetic patients with coronary artery disease operated under cardiopulmonary bypass.MethodsThis double-blind, placebo-controlled, randomised study included 64 patients with diabetes mellitus type 2 who were scheduled for on-pump coronary artery bypass graft surgery. The protocol group (32 patients) and the control group (32 patients) glutamine (0.4 g/kg/day of 20% solution of N(2)-l-alanyl-l-glutamine (“Dipeptiven®” Fresenius Kabi, Germany)) and placebo (0.9% NaCl), respectively. Perioperative concentration of troponin I in plasma was considered as the primary end-point. Whereas the secondary end-points were insulin resistance, insulin sensitivity, β-cell function, blood glucose, plasma triglycerides and free fatty acids concentrations. Insulin resistance, insulin sensitivity and β-cell function were measured using HOMA equation. Thermodilution method was used to measure haemodynamics in all the patients.ResultsNo differences have been found in perioperative dynamics of troponin I, insulin resistance, insulin sensitivity, β-cell function, blood glucose, plasma triglycerides free fatty acids concentrations and haemodynamics.ConclusionOur results have failed to confirm the cardioprotective properties and modulatory effect on perioperative insulin resistance that are thought to be attributable to parenteral glutamine administration in dose 0.4 g/kg/day among cardiac patients with DM operated on under CPB.