[The effect of chemotherapy on energy and nitrogen balance in patients with hematologic neoplasms]

Energy balance and nitrogen balance were evaluated within the opening week of standard induction chemotherapy in 26 haematooncological patients. The patients were uncomplicated in good nutritional status and nutritional requirements were covered by oral diet under the daily assistance of specially trained dietary nurse. Resting energy expenditure (REE) measured by indirect calorimetry under standard circumstances was elevated to 113.1% of predicted value by Harris-Benedict equation. We found a significant decrease in REE to 106.1% of predicted value (p < 0.01) on day 7 after the beginning of induction chemotherapy. Total energy requirements calculated on the basis of measured REE were not elevated during chemotherapy and mean energy balance was balanced. On the other hand mean nitrogen balance was markedly negative during chemotherapy even on the second day of treatment (-6.9 gN/day, cumulative nitrogen balance -28.0 gN/5 days). The negativity correlated will with markedly elevated urinary nitrogen output but worse with nitrogen intake in the diet. Significant correlation was found between the negativity of cumulative nitrogen balance for the whole period of follow up and the magnitude of decrease in REE after chemotherapy (r = 0.74, p < 0.01). This dependence may give evidence of the decay of tumor mass as the main factor of changes shown. Findings described here may support the assumption that energy requirements of haematooncological patients in good nutrition status during chemotherapy may be covered by oral diet even though this usually does not prevent the negativity of nitrogen balance.