术前口服碳水化合物对胃癌术后胰岛素抵抗影响的机制研究

Effects of preoperative oral carbohydrate on postoperative insulin resistance in radical gastrectomy patients

目的评价胃癌患者术前口服碳水化合物对术后胰岛素抵抗的影响并探讨其可能机制。方法将2011年4—10月连续入院且符合入组标准的60例胃癌患者按照随机双盲原则分为口服碳水化合物组和口服安慰剂组，术前4h监测患者静息能量消耗（REE）及呼吸商，并抽取空腹血，测定血糖、胰岛素及三酰甘油，麻醉前2—3h口服500ml碳水化合物（或安慰剂），2组患者均在硬膜外加静脉复合全身麻醉下行根治性远端胃癌切除术，开腹即刻及关腹前取腹直肌组织并固定，术后即刻抽血测定血糖、胰岛素及三酰甘油，并监测术后BEE及呼吸商，比较2组患者手术前后胰岛素抵抗指数、三酰甘油、REE及呼吸商的变化，透射电镜观察2组患者腹直肌线粒体超微结构变化。结果共48例患者完成试验（口服碳水化合物组和口服安慰剂组各24例），口服安慰剂组和口服碳水化合物组术后胰岛素抵抗指数分别为12．68±3．13和5．67±1．40（t=6．646，P=0．003）；静息能量分别为（1458±169）、（1341±110）kcal／d（t=2．851，P=0．046）；呼吸商分别为0．73±0．42和0．79±0．22（t=6．546，P=0．041）；血三酰甘油水平分别为（0．53±0．24）、（1．04±0．97）g／L（t=2．542，P=0．006）；腹直肌线粒体损伤指数分别为1．14±0．33和0．92±0．19（t=2．730，P=0．028），差异均有统计学意义。口服安慰剂组术后线粒体较术前明显肿胀，嵴膜不清晰。结论术前口服碳水化合物可降低胃癌根治术患者术后胰岛素抵抗，减少静息能量消耗，改善物质代谢；可能机制与口服碳水化合物促进胰岛素释放，保护线粒体功能有关。

Objective To investigate the effects and mechanism of postoperative insulin resistance in gastrectomy patients with preoperative oral carbohydrate. Methods From April to October 2011, 60 consecutive gastric cancer patients met inclusion criteria were divided into oral carbohydrate group and placebo group by randomized double-blind principles. Resting energy expenditure （REE）, fasting blood glucose, insulin and triglyceride level were detected in 4 hours preoperatively. The 500 ml carbohydrate or placebo were administrated orally 2-3 hours before anaesthesia. Two group patients underwent radical distal subtotal gastrectomy under epidural compounded intravenous anesthesia. After laparotomy and before the abdomen was closed, a piece of rectus abdominis was taken and fixed in 3% glutaraldehyde. REE, fasting blood glucose, insulin and triglyceride level were detected immediately after surgery. The changes of insulin resistance index, blood triglycerides level, REE and respiratory quotient were compared pre and post-operatively. The changes of rectus abdominis mitochondrial ultrastructure were observed by transmission electron microscopy respectively. Results There were 48 patients （34 males and 14 females） completed the trial. The 24 and 24 patients in oral placebo and carbohydrate groups respectively. In oral placebo group, post-operative insulin resistance index, REE, respiratory quotient, serum triglyceride level and the rectus abdominis mitochondrial damage index were 12. 68 s 3.13, （1458 s 169） kcal/d, 0. 73 s 0. 42, （0.53 ±0.24） g,/L and 1.14±0.33, respectively. And the above items were 5.67 ± 1.40, （1341 ± 110） kcalfd, 0. 79 ±0. 22, （1.04 ±0. 97） g/L and 0. 92 s0. 19 in oral carbohydrate groups respectively.All difference was statistically significant （ t = 6. 646, 2. 851, 6. 546, 2. 542 and 2. 730, all P 〈 0. 05 ）. Oral placebo group showed a markedly swollen mitochondria, steep membrane was not clear, mitoehondria appeared vacuolated changes. Conclusions Preoperative oral carbohydrate could reduce the insulin resistance and REE, improve the material metabolism status in radical gastrectomy patients. The possible mechanisms should be related to promotion of insulin release and protection of mitochondrial function.