Quality of life is associated with physical activity and fitness in cystic fibrosis

Abstract

BackgroundHealth-related and disease-specific quality of life (HRQoL) has been increasingly valued as relevant clinical parameter in cystic fibrosis (CF) clinical care and clinical trials. HRQoL measures should assess – among other domains – daily functioning from a patient’s perspective. However, validation studies for the most frequently used HRQoL questionnaire in CF, the Cystic Fibrosis Questionnaire (CFQ), have not included measures of physical activity or fitness. The objective of this study was, therefore, to determine the cross-sectional and longitudinal relationships between HRQoL, physical activity and fitness in patients with CF.MethodsBaseline (n = 76) and 6-month follow-up data (n = 70) from patients with CF (age ≥12 years, FEV1 ≥35%) were analysed. Patients participated in two multi-centre exercise intervention studies with identical assessment methodology. Outcome variables included HRQoL (German revised multi-dimensional disease-specific CFQ (CFQ-R)), body composition, pulmonary function, physical activity, short-term muscle power, and aerobic fitness by peak oxygen uptake and aerobic power.ResultsPeak oxygen uptake was positively related to 7 of 13 HRQoL scales cross-sectionally (r = 0.30-0.46). Muscle power (r = 0.25-0.32) and peak aerobic power (r = 0.24-0.35) were positively related to 4 scales each, and reported physical activity to 1 scale (r = 0.29). Changes in HRQoL-scores were directly and significantly related to changes in reported activity (r = 0.35-0.39), peak aerobic power (r = 0.31-0.34), and peak oxygen uptake (r = 0.26-0.37) in 3 scales each. Established associates of HRQoL such as FEV1 or body mass index correlated positively with fewer scales (all 0.24 < r < 0.55).ConclusionsHRQoL was associated with physical fitness, especially aerobic fitness, and to a lesser extent with reported physical activity. These findings underline the importance of physical fitness for HRQoL in CF and provide an additional rationale for exercise testing in this population.Trial registrationClinicalTrials.gov, NCT00231686

The 1-Minute Sit-to-Stand Test in Adults With Cystic Fibrosis: Correlations With Cardiopulmonary Exercise Test, 6-Minute Walk Test, and Quadriceps Strength

“…5 Our findings are in line with this study and extend this association to measures of selfesteem, which is also compromised in CF. 30 These findings underline the importance of a high level of peak aerobic capacity as a contributor to psychological and sociological well-being.…”

“…5 Based on significant associations with quadriceps strength, 12,28 the STS test has been proposed as a simple measure of lower-limb strength. We expressed STS repetitions as a product of body weight because this factor clearly influences STS performance.…”

“…1 Importantly, exercise testing has a strong prognostic value in CF, 4 and reduced aerobic exercise capacity has been cross-sectionally and longitudinally associated with reduced health-related quality of life (HRQOL). 5 A cardiopulmonary exercise test (CPET) with gas exchange measurements is the accepted standard exercise test, with peak oxygen uptake (peak V O 2 ) as the primary outcome. However, many centers do not have the resources to include CPET on a routine basis, 6 mainly because CPET equipment is costly, labor intensive, and requires trained staff for supervision and interpretation.…”

Evaluation of functional capacity and level of physical activity in adolescent and adult patients with cystic fibrosis

“…In the present study, the BMI of patients with CF did not differ when they were categorized in different physical activity levels through the IPAQ questionnaire. In contrast with our findings, previous studies have shown that malnourishment in this population is associated with impairment of pulmonary function, loss of musculoskeletal muscles, fatigue, and reduction in physical and functional capacity 10,[22][23][24] . Furthermore, the classification through the IPAQ questionnaire did not distinguish patients in terms of pulmonary function, differently from what occurred when patients were categorized according to the 6MWD.…”

“…Additionally, they show a reduction in protein degradation, production of lactic acid, resistance to insulin and resting heart rate 8 . Stretching and aerobic exercises can also contribute to the improvement of posture and quality of life 9,10 . The assessment of the capacity to exercise in patients with CF is usually performed through the six-minute walk test (6MWT) or maximal effort test 11 .…”