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. P rotocol was approved and informed consent obtained. A double-blind protocol was designed as used in Europe. The clinical safety and outcome were obser ved for 60 patients in 2 centers (30 each). Sixty patients from 2 additiona l centers (30 each) were observed for clinical safety, nitrogen balance, in testinal permeability, and clinical outcome. All patients received isonitro genous (0.20 g/kg body wt per day) and isocaloric (30 kcal/kg body wt per d ay) parenteral nutrition. The study group received Ala-Gln (Dipeptiven, Fre senius Kabi, Bad Homberg, Germany) 0.50 g/kg per day. Clinical chemistry va riables, plasma amino acids profile, nitrogen balance, intestinal permeabil ity (lactulose/mannitol ratio [L/M ratio]) were measured; hospital stay and infection rate were monitored. Statview was used for analysis of variance (ANOVA) or chi(2) tests. Data were expressed as means +/-SD, and the signif icance level was p < .05. Results: The patients in both groups were compara ble prior to the operation. Vital signs and clinical chemical parameters we re similar between groups. L/M ratio was 0.047 +/- 0.029 in control and 0.0 58 +/- 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 an the seventh postoperative day. The difference of L/M ratio between group s 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 st udy group (p =.0004). All the patients recovered without incision infection . However, there were 3 cases that had infection-related complications in t he control group; the difference was not significant between groups. The ho spital stay in the study group was 12.5 days, which was 4 days less than th at of the control group (p = .02). Conclusions: Ala-Gln-supplemented PN was clinically safe, had better nitrogen balance, and maintained intestinal pe rmeability in postoperative patients, The clinical outcome of the patients in study group was better; it was significantly different from the control group.