Total energy expenditure in stable patients with cystic fibrosis

Background and aims: Undernutrition is a common problem in patients with cy stic fibrosis and is associated with a poor prognosis. The two aims of this study were to assess and compare the two main field techniques in the meas urement of total energy expenditure and, secondly, to assess total energy e xpenditure in stable patients and compare with healthy controls. Methods: Resting energy expenditure was measured using indirect calorimetry and total energy expenditure was measured using 24-h heart rate (HR) metho dology and doubly isotopically labelled water. Results. Seventeen patients, mean age 23 years and FEV(1)52% predicted and thirteen controls were recruited. Resting energy expenditure was higher in patients 0.24 (0.03) MJ/kg Fat-Free Mass (FFM) compared to controls 0.22 (0 .02) MJ/kg FFM, P=0.02. Twenty-four hour heart rate underestimated total en ergy expenditure, 9.49 (1.85) MJ/day in patients compared to 11.69 (2.79) M J/day using doubly labelled water. There was no difference in total energy expenditure in patients and controls using both methods, 11.69 (2.79) MJ/da y compared to 11.38 (2.71) MJ/day using doubly isotopically labelled water. Conclusions: In clinically stable young adult patients with moderately seve re respiratory disease total energy expenditure is comparable to that an a control population despite in increase in resting energy expenditure and bo th 24-h HR and doubly isotopically labelled water are suitable for use in p atients with cystic fibrosis. (C) 2001 Harcourt Publishers Ltd.