The effect of L-alanyl-L-glutamine dipeptide supplemented total parenteral nutrition on infectious morbidity and insulin sensitivity in critically ill patients.

OBJECTIVE The aim of this study was to assess the clinical efficacy of alanine-glutamine dipeptide-supplemented total parenteral nutrition defined by the occurrence of nosocomial infections. Secondary parameters included Sequential Organ Failure Assessment score, hyperglycemia and insulin needs, intensive care unit and hospital length of stay, and 6-month mortality. DESIGN Multicenter, prospective, double-blind, randomized trial. SETTING Twelve intensive care units at Spanish hospitals. PATIENTS One hundred twenty-seven patients with Acute Physiology and Chronic Health Evaluation II score >12 and requiring parenteral nutrition for 5-9 days. INTERVENTION Patients were randomized to receive an isonitrogenous and isocaloric total parenteral nutrition or alanine-glutamine dipeptide-supplemented total parenteral nutrition. Nutritional needs were calculated: 0.25 g N/kg(-1)/d(-1) and 25 kcal/kg(-1)/d(-1). The study group received 0.5 g/kg(-1)/d(-1) of glutamine dipeptide and the control total parenteral nutrition group a similar amount of amino acids. Hyperglycemia was controlled applying an intensive insulin protocol with a target glycemia of 140 mg/dL. MEASUREMENTS AND MAIN RESULTS The two groups did not differ at inclusion for the type and severity of injury or the presence of sepsis or septic shock. Caloric intake was similar in both groups. Preprotocol analysis showed that treated patients with alanine-glutamine dipeptide-supplemented total parenteral nutrition had lesser nosocomial pneumonia, 8.04 vs. 29.25 episodes-‰ days of mechanical ventilation (p = .02), and urinary tract infections, 2.5 vs. 16.7 episodes-‰ days of urinary catheter (p = .04). Intensive care unit, hospital, and 6-month survival were not different. Mean plasmatic glycemia was 149 ± 46 mg/dL in the alanine-glutamine dipeptide-supplemented total parenteral nutrition group and 155 ± 51 mg/dL in the control total parenteral nutrition group (p < .04), and mean hourly insulin dose was 4.3 ± 3.3 IU in the alanine-glutamine dipeptide-supplemented total parenteral nutrition group and 4.7 ± 3.7 IU in control total parenteral nutrition group (p < .001). Multivariate analysis showed a 54% reduction of the amount of insulin for the same levels of glycemia in the alanine-glutamine dipeptide-supplemented total parenteral nutrition group. CONCLUSIONS Total parenteral nutrition supplemented with alanine-glutamine in intensive care unit patients is associated with a reduced rate of infectious complications and better glycemic control.