Nutritional status and cytokine-related protein breakdown in elderly patients with gastrointestinal malignancies

BACKGROUND: Age-related factors affecting cytokine-related whole-body protein breakdown and their relation to clinical outcomes in cancer patients were investigated. METHODS: For assessment of protein-calorie malnutrition and protein breakdown, the creatinine height index (CHI) and daily urinary excretion of 3-methylhistidine (3-MH) were measured in 70 patients with gastrointestinal malignancies. Perioperative cytokine profile was evaluated to assess its relation to perioperative protein catabolism. RESULTS: In elderly patients, daily 3-MH excretion during the stable preoperative period decreased with the increase of tumor interleukin (IL)-6 production, suggestive of the activation of a metabolic compensation mechanism. However, these patients showed significant increases in postoperative 3-MH excretion in accord with perioperative systemic IL-6 response, and this deterioration of the compensating mechanism seemed to be associated with poor clinical outcome. An increase in 3-MH excretion under surgical stress was positively correlated with postoperative consumption of IL-6 soluble receptor (sR) in elderly patients with nutritional depletion. CONCLUSIONS: In elderly cancer patients with protein-calorie malnutrition, metabolic compliance against intrinsic IL-6 may be compensated for in the preoperative stable period, but deteriorate from surgical insults. This mechanism might involve increased affinity of IL-6 with IL-6sR under surgical stress.