Document Type : Original Article
Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Metabolic Disease Research Center, Qazvin University of Medical Sciences, Qazvin, Iran
Department of Community Medicine, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran
Preventive Medicine and Public Health Research Center (PMPHRC), Iran University of Medical Sciences, Tehran, Iran
Background: The six-minute walk test (6MWT) is a suitable tool for the assessment of functional capacity in patients with chronic pulmonary diseases. This study aimed to assess the clinical determinants of the six-minute walk distance (6MWD), exercise-induced desaturation (EID), and pretest saturation of arterial oxygen (SataO2) in patients with diffuse non-cystic fibrosis (CF) bronchiectasis.
Materials and Methods: In this cross-sectional study, a total of 57 clinically stable patients with diffuse non-CF bronchiectasis were enrolled. Anthropometric measurements (body mass index [BMI], mid-arm muscle circumference [MAMC], and triceps skinfold thickness [TSF]), spirometric indices (forced expiratory volume in one second [FEV1], forced vital capacity [FVC], and FEV1/FVC ratio), imaging assessment (CT scan), and bacteriological sputum studies were performed, and then, 6MWT was carried out.
Results: The mean 6MWD was measured to be 447.11±94.59 m. The average walked distance in patients with severe, moderate, and mild bronchiectasis was 427.73±92.07, 439.63±102.65, and 485.87±80.47 m, respectively, with no significant difference. The pretest SataO2 was 88.92±5.59%, 93.75±3.36%, and 94.87±2.88% in the severe, moderate, and mild bronchiectasis groups (P<0.001). A significant inverse correlation was observed between the distance walked and BMI (r=-0.434, P=0.001).
Conclusion: The predictors of 6MWD in stable non-CF bronchiectasis patients were FVC, SataO2 at rest, BMI, and MAMC. The FEV1, FEV1/FVC, and BMI were independent predictors of SataO2 at rest. The extension of bronchiectasis was the only predictor of EID during the test.