Exercise responses are related to structural lung damage in CF pulmonary disease

Abstract

Introduction: Early detection of lung disease is a primary objective in monitoring patients with Cystic Fibrosis (CF); High-Resolution-Computed-Tomography (HRCT) assesses structural damage. Spirometry and cardiopulmonary exercise testing are used for functional evaluation of CF lung disease.

Aim: To evaluate the deterioration of exercise testing parameters over a 2-year period compared to the change of spirometry and HRCT parameters among CF patients.

Methods: Twenty-eight CF patients were evaluated with HRCT, spirometry, and exercise testing; 15 had two assessments with an interval of 2 years. Correlation analyses between Bhalla score parameters and functional measures were performed.

Results: Twenty-eight patients with CF (mean age 14.9 years, mean forced expiratory volume in 1 sec [FEV1 ] 83.2%) were evaluated. FEV1 was not found to change significantly in the 2-year period (P = 0.612). Both mean Bhalla score and mean peak oxygen consumption (VO2 peak %) deteriorated significantly (P = 0.014 and P = 0.026, respectively). VO2 peak and respiratory equivalents for O2 and CO2 at peak exercise were found to be significant predictors of Bhalla score (r = -0.477, P = 0.010; r = 0.461, P = 0.018; r = 0.402; P = 0.042, respectively). Anaerobic threshold was associated with changes in Bhalla score over the following 2 years.

Conclusions: Exercise testing is more sensitive than spirometry to detect structural changes in CF lungs. Pediatr Pulmonol. 2016; 51:914-920. © 2016 Wiley Periodicals, Inc.

Keywords: HRCT; cardiopulmonary exercise testing; children; cystic fibrosis; spirometry.