GLUTAMINE DIPEPTIDE-SUPPLEMENTED PARENTERAL-NUTRITION MAINTAINS INTESTINAL FUNCTION IN THE CRITICALLY ILL

Background/Aims: Long-term total parenteral nutrition is accompanied w ith mucosal atrophy and subsequent malabsorption syndrome. Current inf ormation attests the important role of glutamine in maintaining intest inal structure and function. The aim of this study was to investigate the effect of glutamine dipeptide supplementation on small intestinal absorption capacity during critical illness. Methods: Twelve intensive care unit patients were uniformly randomized to receive isonitrogenou s (0.26 g nitrogen.kg(-1).day(-1)) and isoenergetic (155 kJ.kg(-1).day (-1)) parenteral nutrition over 9 days. The control group received a c onventional amino acid solution (1.5 g amino acids.kg(-1).day(-1)), an d the test group received a complete amino acid solution containing th e dipeptide L-alanyl-L-glutamine (20 g/L). On days 8 and 9, a modified D-xylose test was performed. Results: Excretion of D-xylose during th e 5-hour test period was 7.4 +/- 1.1 g (test) vs. 3.8 +/- 0.9 g (contr ol) (P < 0.05). The 2-hour serum D-xylose concentration was 38.7 +/- 3 .0 (test) vs. 27.8 +/- 2.9 mg/100 mt (control) (P < 0.05). Kinetic eva luation showed higher maximum D-xylose blood concentration and higher values for the area under the curve with the peptide. Conclusions: The results strongly suggest that glutamine dipeptide-containing total pa renteral nutrition prevents intestinal atrophy and increased permeabil ity associated with glutamine-free parenteral nutrition.