A new study entitled “Ventilatory response to exercise in adolescents with cystic fibrosis and mild-to-moderate airway obstruction,” published this week in SpringerPlus, tested the ventilatory response to exercise in a sample of adolescents with a diagnosis of cystic fibrosis (CF) and to compare the results with a matched healthy sample. The study helps to shed light on the exercise capabilities of those with the disease, which is crucial to maintaining health.
Evidence shows that in patients with CF the peak of oxygen uptake is limited, because of the limitations in respiration, cardiovascular, and peripheral muscle functions that CF causes. Furthermore, in these patients, non-pulmonary factors, such as low muscle mass, impaired skeletal muscle function, and centrally mediated oxygen delivery, appear to limit the capacity to perform exercise.
Due to progressive airflow obstruction, as reflected by a decreased FEV1 and dynamic hyperinflation, adolescents with CF develop a low breathing pattern at rest and during exercise, which can be accompanied by a decreased ventilatory capacity and concomitant reduced VO2peak. Children and adolescents with CF with static hyperinflation at rest appear to be more disposed to ventilatory limitations during exercise, which appears to be associated with decreased exercise performance.
During exercise, recent evidence shows that patients with CF have an exercise limitation due to multifactorial causes and that there is correlation with FEV1 and nutritional and inflammatory status, but also with the magnitude of the overall ventilatory response during exercise.
In this study, the team of researchers from the Netherlands examined an exercise database of 22 randomly selected adolescents (mean age 14.3 years) with mild to moderate CF. The aim was to describe the ventilatory response with a progressive cardiopulmonary exercise test (CPET) and to also assess the ventilatory response for carbon dioxide exhalation. The sample was sex and aged matched with a population of healthy controls.
The study found no differences in breathing patterns between CF patients and healthy controls. However, the CF patients had lower minute ventilation, and the ratio for estimated ventilatory dead space ventilation was higher for the CF group, compared to the healthy adolescents.
Findings from this study revealed that during progressive exercise up to maximal exhaustion, while adolescents with mild to moderate airway obstruction due to CF had an exaggerated ventilatory response (high VE/WR ratio values), this was adequate for CO2 exhalation (normal VE/VCO2-slope and PETCO2 values), suggesting that in spite of limitations, exercise is indeed possible for those with the disease.