Physiologic similarities and differences between COPD and asthma.
The structural and physiologic findings in asthma and COPD appear, on average, and in the extremes of presentation, to be easily distinguished. A closer inspection of the literature reveals that significant overlap exists in individual patients with respect to airway wall thickening and low-attenuation parenchymal regions on CT scans, and in reversibility, airway hyperresponsiveness, lung diffusion, resting and dynamic hyperinflation, lung elastic recoil, exercise response, and a "pharmaceutical volume reduction" effect following therapy with bronchodilators. In particular, the subgroup of COPD patients having an airway-dominant phenotype becomes indistinguishable from asthmatic subjects with reversible disease that evolves into an incompletely reversible pattern.
Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, 1211 Kaufmann Bldg, Pittsburgh, PA 15213, USA. sciurbafc@upmc.edu
Frank C
FC
Sciurba
D001249:Asthma / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology*; D017079:Exercise Tolerance / Q000502:physiology; D005541:Forced Expiratory Volume / Q000502:physiology; D014644:Genetic Variation / Q000235:genetics; D006801:Humans; D008170:Lung Compliance / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010641:Phenotype; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology*; D014797:Vital Capacity / Q000502:physiology