Abstract
BACKGROUND: Ventilatory parameters obtained during exercise predict survival in several chronic diseases; however, long-term changes in exercise ventilatory parameters in patients with cystic fibrosis (CF) have yet to be examined and potential differences between sexes in CF are unknown. PURPOSE: We sought to examine the change in exercise ventilatory parameters over time in patients with CF and determine if the change is different between sexes. METHODS: Exercise capacity (VO(2) peak) and exercise ventilatory parameters (V(E)/VO(2) peak, V(E)/VCO(2) peak, and V(E)/VCO(2) slope) were determined from a maximal cardio-pulmonary test on a cycle ergometer on two visits separated by 39 ± 16 months in 20 patients with CF (10 female, 10 male). RESULTS: No differences between sexes were observed at visit 1 (all p > 0.05). Overall, exercise ventilatory parameters significantly (p < 0.05) deteriorated between visits, with no change (p > 0.05) in VO(2) peak. Moreover, compared to males, female patients exhibited greater deteriorations in V(E)/VO(2) peak (p = 0.001), V(E)/VCO(2) peak (p = 0.002), and V(E)/VCO(2) slope (p = 0.016) between visits. CONCLUSIONS: These data in patients with CF indicate that exercise ventilatory parameters decline over time despite no change in VO(2) peak, and female patients exhibit a more rapid deterioration compared to males.