ENERGY AND SUBSTRATE METABOLISM IN PATIENTS WITH CHRONIC EXTENSIVE GRAFT-VERSUS-HOST DISEASE

Abstract

Allogeneic stem cell transplantation is frequently complicated by graft-versus-host disease (GVHD). Weight loss is one of the characteristic features of GVHD. The etiology of weight loss in GVHD is not completely understood. We measured resting energy expenditure (REE) and substrate oxidation rates by indirect calorimetry in patients with stable chronic extensive GVHD under immunosuppressive therapy (n=13) and sex-, age-, height-, and weight-matched healthy controls (n=13) in order to evaluate metabolic changes in these patients. Measurements were done on day 518+/-261 after allogeneic stem cell transplantation in the postabsorptive state. Serum concentrations of glucagon, norepinephrine, tumor necrosis factor-alpha, interleukin-6, and free fatty acids were determined. Patients showed a maximum weight loss of 22% during their course of GVHD; nevertheless, they regained 15% of total body weight (TBW) during successful treatment of GVHD. Indirect calorimetry showed an increase in REE per kilogram of TBW (patients, 21.8+/-3.1 kcal/kg TBW/day; controls, 19.9+/-2 kcal/kg TBW/day; P<0.05). Respiratory quotient (patients, 0.79+/-0.04, controls, 0.86+/-0.04; P<0.005) and non-protein respiratory quotient (0.78+/-0.05 and 0.87+/-0.05, respectively; P<0.005) were decreased in patients. GVHD patients had elevated serum glucagon and norepinephrine concentrations, whereas tumor necrosis factor-alpha and interleukin-6 were in the normal range. Patients with chronic extensive GVHD show an increase in REE and alterations in fat and carbohydrate oxidation rates. These changes seem to be the result of increased action of glucagon and norepinephrine.