Applied nutritional investigationEffects of oral glutamine during abdominal radiotherapy on chronic radiation enteritis: A randomized controlled trial

- Glutamine has been proposed as a nutrient with potential protective effects against the toxicity induced either by chemoradiotherapy, but few trials have studied this effect.
- The administration of oral glutamine during abdominal radiotherapy was related with the development of gastrointestinal symptoms.
- One year after finishing radiotherapy, the patients who received glutamine referred significant changes in stool frequency and characteristics.
- Glutamine was not related to better nutritional outcomes compared with placebo.

ObjectiveGlutamine has been proposed as a preventive treatment for toxicity related to cancer therapies. The aim of this study was to test the efficacy of glutamine in the prevention of radiation enteritis.MethodsA randomized, double-blind, controlled trial was performed including 69 patients who were assigned to receive either glutamine (Gln, 30 g/d) or placebo while they were receiving abdominal radiotherapy. Patients were re-evaluated 1 y after completion of treatment. The presence of chronic enteritis was assessed using the Radiation Therapy Oncology Group scale. Nutritional status was evaluated using subjective global assessment, weight, and bioimpedance. Relative risk (RR) and its confidence interval (CI) were also calculated.ResultsThe trial initially included 69 patients (34 Gln, 35 placebo), but 11 patients were lost during follow-up (4 Gln, 7 placebo; P = 0.296). Chronic enteritis was developed by 14 % of patients: Gln 16.7 % versus placebo 11.1% (RR = 1.33; 95 % CI, 0.35-5.03; P = 0.540). Most cases of enteritis were grade I (75 %), with no differences between groups. The stool frequency increased after radiotherapy in patients who received Gln (from 1 ± 1 to 2 ± 2 stools per day, P = 0.012), but remained unchanged with placebo (1 ± 1 stools per day, P = 0.858; difference between groups P = 0.004). There were no differences between the two groups in terms of weight, fat mass, or fat-free mass index, or between patients with enteritis and those without intestinal toxicity.ConclusionsChronic enteritis is a relatively infrequent phenomenon, and Gln administration during radiotherapy does not exert a protective effect.