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 chi2 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.