Evaluating the contribution of the Glittre-ADL test in adults with cystic fibrosis

Abstract

Background and objectives: Cardiopulmonary and skeletal muscle impairment and poor physical activity are potential contributors to reduced functional capacity in cystic fibrosis (CF). The Glittre-ADL test (TGlittre) has great potential for clinical use in adult CF adults, as it meets the need for a comprehensive assessment of physical function using tasks similar to activities of daily living. This study aimed to evaluate the performance of TGlittre in CF adults compared to the 6-min walk test (6MWT) and, secondarily, to quantify the associations of their results with pulmonary function, muscle strength, and health-related quality of life (HRQoL).

Methods: This cross-sectional study evaluated 34 CF adults and compared them with 34 subjects from a control group. The participants underwent the following assessments: functional capacity using TGlittre and 6MWT; spirometry; respiratory muscle strength; handgrip strength (HGS); and HRQoL using the Cystic Fibrosis Questionnaire-Revised (CFQ-R).

Results: While CF patients showed a longer time to perform TGlittre compared to controls (134 (119-150) versus 107 (95-126) % of the predicted time p = 0.0002), no difference between these groups was observed in the 6MWT. When the second TGlittre was compared to the first TGlittre, there was a significant decrease in total time for both CF patients (p < 0.0001) and controls (p = 0.0001). TGlittre time correlated with 6MWT distance (6MWD) (r_s = -0.641, p < 0.0001), HGS (r_s = -0.364, p = 0.034), peripheral oxygen saturation at the end of the test (r_s = -0.463, p = 0.006) and the "digestive symptoms" domain of CFQ-R (r_s = 0.376, p = 0.028). TGlittre time was shorter in patients who engaged in regular physical activity (3.10 (2.49-3.39) min versus 3.28 (2.95-3.53) min, p = 0.016).

Conclusions: TGlittre is more effective than the 6MWT in detecting limitations during exercise. There is an important learning effect of TGlittre in adult CF patients. TGlittre time was correlated with 6MWD, HGS, oxygen saturation level, and the patient's level of physical activity.

Keywords: cystic fibrosis; exercise; pulmonary function testing; rehabilitation.