ObjectiveTo evaluate the effect of N(2)-L-alanyl-L-glutamine (Ala-Glu) on perioperative insulin resistance in patients undergoing radical colon cancer operation.MethodsSixty ASA Ⅰ or Ⅱ patients of both sexes aged 35-75 yr with BMI of 18.5-25.0 kg/m2 undergoing redical colon cancer operation under general anesthesia were randomly divided into 3 groups ( n =20 each):control group(group C) ; vehicle group (group Ⅴ) and group Ala-Glu.Ala-Glu 22.5 ml/kg was administered iv at 24 h before and 1 h after operation in group AlaGlu,while in groups C and V equal volume of normal saline and vehicle were given iv instead of Ala-Glu.Venous blood samples were taken at 24 h before operation (T1),30 main before ( T2 ) and 3 h after induction of anesthesia (T3) and 1 and 24 h after operation (T4,T5 ) for determination of blood concentrations of glucose (BG),insulin ( INS)-,TNF-α and free fatty acid (FFA).Insulin resistance ( HOMA-IR =BG × INS ÷ 22.5) and insulin sensitivity index (ISI =1 ÷ (lgBG + lgINS) ) were calculated.The time when the patients passed flatus,the days of hospitali-zation after operation,and the incidence of insulin resistance were recorded.ResuitsAla-Glu significantly decreased blood concentrations of BG,INS,TNF-α,FFA and HOMA-IR and increased ISI in group Ala-Glu as compared with groups C and V.The patients passed flatus earlier after operation and postoperative hospital stay was shorter and the incidence of insulin resistance was lower in group Ala-Glu than in groups C and V.There was no significant difference in all the indexes between group C and group V.ConclusionN (2)-L-alanyl-L-glutamine can attenuate perioperative insulin resistance in patients undergoing colon cancer resection and is helpful to patient' s recovery,and the decrease in the concentrations of TNF-α and FFA may be involved in the mechanism.