Increased resting energy expenditure in malnourished patients with cystic fibrosis

Two recent studies (Shepherd 1988, Buchwals 1988) suggest that the malnutrition of CF may be associated with an energy-requiring defect leading to increased resting energy expenditure (REE). We investigated REE in relation to lean body mass (LBM) in 8 malnourished children with CF prior to the insertion of a gastrostomy tube. Two groups of age-matched (N1, n = 6) and weight-matched (N2, n = 5) healthy children served as controls. REE was measured by indirect calorimetry (Deltatrac Metabolic Monitor, Datex Instruments, Finland); FFM was determined by means of bioelectric impedance (BIA 103, RJL Systems, Detroit, U.S.A.). Malnourished patients with CF had higher expenditures than predicted by the Harris-Benedict equation (+32.7%). REE per kg LBM per day was markedly increased (+38.5%) compared to weight-matched controls. These results suggest that malnourished patients with CF have higher energy requirements than would be expected by the use of standard equations for caloric expenditure.