Alteration of whole-body protein kinetics according to severity of surgical trauma in patients receiving total parenteral nutrition

Abstract

This study was conducted to clarify the mechanisms of body nitrogen losses according to the severity of surgical trauma. Thirteen male patients who underwent operation for esophageal cancer (group E), and 11 men (who underwent gastric or colorectal surgeries (group GC) were studied. The measurement of whole-body protein turnover, synthesis, and breakdown were made preoperatively on the 3rd and 10th postoperative day with constant infusion of [15N]glycine during isocaloric and isonitrogenous total parenteral nutrition. Significant increases in the rates of whole-body protein turnover (flux) and breakdown were seen in group E on the 3rd postoperative day (p < 0.01, p < 0.01, respectively), whereas the increases were not significant in group GC. The rates of whole-body protein flux and breakdown were significantly greater in group E than group GC (p < 0.01, p < 0.01, respectively). The rate of protein synthesis significantly increased in group E (p < 0.05), but did not alter or slightly decreased in group GC. The rates of whole-body protein flux and breakdown in group E were still significantly greater on the 10th postoperative day than preoperatively. It was concluded that unchanged or slightly decreased rates of whole-body protein synthesis with slightly increased breakdown were seen in the group of patients who underwent gastric or colorectal surgery, whereas synthesis increased significantly with a greater increase of breakdown in patients receiving severe surgical procedures, esophagectomy for esophageal cancer.