Impact of bronchiectasis on the thoracoabdominal kinematics at rest and during exercise: a controlled cross-sectional study

<bold>Background:</bold> Non-cystic fibrosis bronchiectasis (NCFB) is a neglected respiratory disease that causes airway obstruction, and reduces ventilatory and exercise capacities; however, the thoracoabdominal asynchrony (TAA) during exercise in the NCFB patients is poorly known. <bold>Objectives:</bold> To assess TAA by optoelectronic plethysmography (OEP) in NCFB patients. <bold>Methods:</bold> Clinically stable patients aged 18-59 with NCFB diagnosis confirmed by computerized tomography with a smoke history of <10 pack-years were enrolled. Lung function, thoracoabdominal kinematics (TAK, by OEP), cardiopulmonary exercise test (CPET), and constant-load exercise test (CLET) were carried out during two hospital visits. On the first visit, patients performed a complete lung function test and CPET. On the second visit, patients performed the CLET (75%Wmax) and the TAK, simultaneously. Patients were assessed in three moments: at rest(T1), unloaded(T2), and CLET(T3). Age and anthropometric-matched individuals without NCFB underwent all the assessments. <bold>Results:</bold> Twenty-two NCFB patients (46±10.5years, 25.8±5.4kg/m2, VEF1 49.7±22.9%pred, peakVO2 19.9±5.6kg.ml-1.min-1) were evaluated. During T3, NCFB patients presented a reduced abdominal volume compared to controls. In addition, NCFB patients presented a TAA during T3 which was associated to airway obstruction (r=-0.56, p=0.01) and hyperinflation (r=0.6, p=0.003). <bold>Conclusions:</bold> Individuals with NCFB showed worse abdominal ventilation during exercise than controls. Furthermore, our results suggest that declining lung function is associated with increased asynchrony, and it is linked to worsening exercise capacity in this population.