Abstract 191

Resting Energy Expenditure (REE) is increased in CF however little is known about Total Energy Expenditure(TEE). The aim of this study was to compare REE and TEE in stable patients with CF to healthy controls. Fourteen clinically stable patients with CF aged between 14-35 and 11 age, sex and body size matched controls were studied. REE was assessed by open circuit indirect calorimetry using a face mask. TEE was measured by a 24 hour heart-rate method. Physical Activity Levels (PAL) were assessed by calculating TEE/REE. REE was higher in patients 33.1kcal/kg/day(5.5 ) compared to controls 29.6(2.1). There was no difference between TEE in patients and controls: 40.1kcal/kg/day(6.9) and 42kcal/kg/day(6.2) respectively. Physical activity levels were significantly lower in patients compared to controls: 1.2(0.1) and1.5(0.3), p=0.01. In clinically stable patients with CF with moderate respiratory disease REE is increased but TEE is not different when compared to healthy controls. There is a significant decrease in physical activity levels in patients with CF.