The Impact of Alanyl‐Glutamine on Clinical Safety, Nitrogen Balance, Intestinal Permeability, and Clinical Outcome in Postoperative Patients: A Randomized, Double‐Blind, Controlled Study of 120 Patients

Purpose: To evaluate the impact of alanyl‐glutamine (Ala‐Gln)‐supplemented parenteral nutrition (PN) on clinical safety, nitrogen balance, intestinal permeability, and clinical outcome in postoperative patients. Methods: One hundred twenty patients undergoing major abdominal surgery were enrolled. Protocol was approved and informed consent obtained. A double‐blind protocol was designed as used in Europe. The clinical safety and outcome were observed for 60 patients in 2 centers (30 each). Sixty patients from 2 additional centers (30 each) were observed for clinical safety, nitrogen balance, intestinal permeability, and clinical outcome. All patients received isonitrogenous (0.20 g/kg body wt per day) and isocaloric (30 kcal/kg body wt per day) parenteral nutrition. The study group received Ala‐Gln (Dipeptiven, Fresenius Kabi, Bad Homberg, Germany) 0.50 g/kg per day. Clinical chemistry variables, plasma amino acids profile, nitrogen balance, intestinal permeability (lactulose/mannitol ratio [L/M ratio]) were measured; hospital stay and infection rate were monitored. Statview was used for analysis of variance (ANOVA) or χ 2 tests. Data were expressed as means ± SD, and the significance level was p <.05. Results: The patients in both groups were comparable prior to the operation. Vital signs and clinical chemical parameters were similar between groups. L/M ratio was 0.047 ± 0.029 in control and 0.058 ± 0.049 in study group before the operation (AOD‐3). The L/M ratio was 0.132 ± 0.081 in the control group, and 0.097 ± 0.063 in study group on the seventh postoperative day. The difference of L/M ratio between groups was significant (p =.02). The cumulative nitrogen balance values were ‐5 ± 162 mg/kg for 6 days in control and 144 ± 145 mg/kg for 6 days in study group (p =.0004). All the patients recovered without incision infection. However, there were 3 cases that had infection‐related complications in the control group; the difference was not significant between groups. The hospital stay in the study group was 12.5 days, which was 4 days less than that of the control group (p =.02). Conclusions: Ala‐Gln‐supplemented PN was clinically safe, had better nitrogen balance, and maintained intestinal permeability in postoperative patients. The clinical outcome of the patients in study group was better; it was significantly different from the control group. (Journal of Parenteral and Enteral Nutrition 23:S62‐S66, 1999)