| dc.description.abstract | Objectives: We aimed to explore physiological responses to the six-minute walk test (6MWT)
and assess computed tomographic (CT) features of the lungs and thigh muscle in order to
determine contributors to dyspnea intensity and exercise limitation in dyspneic and nondyspneic
subjects with GOLD-1 COPD and controls.
Methods: We compared Borg dyspnea ratings, ventilatory responses to 6MWT, and CT-measures
of emphysema, airway lumen caliber, and cross-sectional area of the thigh muscle (RTMCT-CSA)
in 19 dyspneic, 22 non-dyspneic, and 30 control subjects.
Results: Dyspneic subjects walked less and experienced greater exertional breathlessness than
non-dyspneic (105 m less and 2.4 Borg points more, respectively) and control subjects (94 m
less and 2.6 Borg points more, respectively (P < 005 for all comparisons). At rest, dyspneic
subjects had significant greater expiratory airflow obstruction, air trapping, ventilation/perfusion
mismatch, burden of emphysema, narrower airway lumen, and lower RTMCT-CSA than
comparison subjects. During walking dyspneic subjects had a decreased inspiratory capacity | |
