From a previous population-based study 450 subjects were examined with spirometry and IOS and answered a questionnaire on respiratory symptoms and diseases.
Seventy-seven subjects were Q+, of whom 34 also were G+. Q+/G鈭?subjects (n聽=聽43) reported respiratory symptoms more frequently (35-40%vs 8-14%) but had higher FEV1 (100%vs 87%) than Q鈭?G+ subjects (n聽=聽90), p聽<聽0.05 for both comparisons. Q+ subjects had higher pulmonary resistance and lower pulmonary reactance than Q鈭?subjects (p聽<聽0.01 for all comparisons). The same pattern was seen both in G+ subjects ((Q+/Q鈭? R5 0.39/0.32, R5-R20 0.10/0.07, X5 0.13/0.09, AX 0.55/0.27, p聽<聽0.05 for all) and G鈭?subjects ((Q+/Q鈭? R5 0.35/0.29, R5-R20 0.08/0.06, X5 0.10/0.08, AX 0.31/0.19 p聽<聽0.05 for all) except for R20 (adjusted for gender and age).
Self-reported chronic bronchitis or emphysema or COPD was associated with higher pulmonary resistance and lower pulmonary reactance measured by IOS, both among subjects with and without COPD according to GOLD criteria. IOS may have the potential to detect pathology associated with COPD earlier than spirometry.