چکیده (انگلیسی):

Background:We see patients who present with spirometry airflow limitation despite their forced expiratory volume in
one second (FEV1) as well as forced vital capacity (FVC) to be supernormal (FEV1/FVC < 70%, both the %FEV1and the %
FVC≧100%) in asymptomatic healthy non-smokers. Based on previous studies, we hypothesized these spirometry
conditions (results measured with spirometry) could be suitably used as a practical surrogate marker of pulmonary
dysanapsis: the condition of disproportionate but physiologically normal growth between airways and lung parenchyma.
Methods:We compared the conventional surrogate marker of dysanapsis, maximum mid-expiratory flow to FVC
(MMF/FVC), in SUBJECTS (FEV
1/FVC < 70%, both the %FEV1and the %FVC≧100% in healthy non-smokers) (n = 25),
in EMPHYSEMA (CT confirmed pulmonary emphysema, same spirometry results with SUBJECTS) (n = 55), and in
CONTROLS(age-andheight-matched,normalspirometry results) (n = 25). Next we added imaging analysis to
evaluate the relationship between the cross sectional airway luminal area (X-Ai) and the lung volume results
among the three groups.
Results:The MMF/FVC was significantly lower in SUBJECTS and in EMPHYSEMA compared to CONTROLS. However,
percent predicted peak expiratory flow (%PEFR) was significantly lower only in SUBJECTS and not in EMPHYSEMA
compared to CONTROLS. The ratio of the X-Ai of the trachea and right apical bronchus to lung volume was significantly
lower in SUBJECTS compared to CONTROLS.
Conclusion:The simple spirometry conditions in SUBJECTS are highly suggestive of practical surrogate marker of
pulmonary dysanapsis. Awareness of this concept would help to attenuate the risk of overdiagnosis of obstructive
pulmonary disease.