RT Journal Article
SR Electronic
T1 Reduced FEV<sub>1</sub>/FVC and FEV<sub>1</sub> in the Normal Range as a Physiological Variant
JF Respiratory Care
FD American Association for Respiratory Care
SP 570
OP 575
DO 10.4187/respcare.06131
VO 64
IS 5
A1 dos Santos Andreata, Luciana
A1 Soares, Maria Raquel
A1 Pereira, Carlos AC
YR 2019
UL http://rc.rcjournal.com/content/64/5/570.abstract
AB BACKGROUND: Healthy individuals without respiratory symptoms can sometimes present with low FEV1/FVC. The objective of this study was to characterize and compare subjects without symptoms and with reduced FEV1/FVC but normal FEV1 with subjects with mild obstructive lung disease.METHODS: Fifty healthy subjects with FEV1/FVC below the fifth percentile of reference values (normal variants) were compared with 52 subjects with asthma and 48 subjects with COPD who had similar FEV1/FVC.RESULTS: Subjects without symptoms were more likely to be male, younger, and taller, and to have higher FVC%, FEV1%, mid expiratory flow, and terminal flow than subjects with obstructive disease. A receiver operating characteristic curve analysis determined that the best separation between the groups was provided by age &lt; 55 y, height ≥ 167 cm, and FVC &gt; 105%. A logistic regression analysis confirmed that male sex, age, FVC%, and FEF75 (Forced expiratory flow in 75% of forced vital capacity) were significant factors for discriminating subjects without symptoms from those with obstructive lung disease.CONCLUSIONS: A reduced FEV1/FVC may be a normal finding in younger-to-middle age male subjects with an FVC% value above the mean predicted value, especially when terminal flow is within the normal range.