To measure components of TDEE in adolescents with CF and normal lung function compared with controls, and to determine whether ECA can be improved by diet and exercise.
Clinically stable CF subjects (aged 9–13, n = 12) and age- and gender-matched controls (n = 13) had repeated measurements of TDEE by FHRM, REE, and maximal cardiopulmonary exercise testing (CPET) during a 6-week exercise and diet program.
While the mean REE was similar in both groups, ECA was significantly lower in CF adolescents as compared to controls (p = 0.02). During CPET, maximal exercise in CF was characterized by hyperventilation, which was unrelated to ventilation–perfusion mismatching. There were no changes in REE after dietary intervention.
ECA in CF adolescents with normal lung function is lower when compared to healthy controls. These findings support the hypothesis that clinically stable patients with CF have inefficient energy metabolism or alternatively conserve energy during activities of daily living.