Maximal mid-expiratory flow detects early lung disease in α1-antitrypsin deficiency

Research output: Contribution to journalArticle

Authors

  • James Stockley
  • Asem M Ismail
  • Siân M Hughes
  • Ross Edgar
  • Robert A Stockley

External organisations

  • Dept of Lung Function and Sleep, University Hospital Birmingham, Birmingham, UK.
  • College of Medical and Dental Sciences, The University of Birmingham
  • Respiratory Medicine, University Hospital Birmingham, Birmingham, UK.
  • Institute of Inflammation and Ageing, Centre for Translational Inflammation Research, University of Birmingham, Birmingham, UK e.sapey@bham.ac.uk.

Abstract

Pathological studies suggest that loss of small airways precedes airflow obstruction and emphysema in chronic obstructive pulmonary disease (COPD). Not all α1-antitrypsin deficiency (AATD) patients develop COPD, and measures of small airways function might be able to detect those at risk. Maximal mid-expiratory flow (MMEF), forced expiratory volume in 1 s (FEV1), ratio of FEV1/forced vital capacity (FVC), health status, presence of emphysema (computed tomography (CT) densitometry) and subsequent decline in FEV1 were assessed in 196 AATD patients. FEV1/FVC, FEV1 % predicted and lung densitometry related to MMEF % pred (r2=0.778, p<0.0001; r2=0.787, p<0.0001; r2=0.594, p<0.0001, respectively) in a curvilinear fashion. Patients could be divided into those with normal FEV1/FVC and MMEF (group 1), normal FEV1/FVC and reduced MMEF (group 2) and those with spirometrically defined COPD (group 3). Patients in group 2 had worse health status than group 1 (median total St George’s Respiratory Questionnaire (SGRQ) 23.15 (interquartile range (IQR) 7.09–39.63) versus 9.67 (IQR 1.83–22.35); p=0.006) and had a greater subsequent decline in FEV1 (median change in FEV1 −1.09% pred per year (IQR −1.91–0.04% pred per year) versus −0.04% pred per year (IQR −0.67–0.03% pred per year); p=0.007). A reduction in MMEF is an early feature of lung disease in AATD and is associated with impaired health status and a faster decline in FEV1.

Details

Original languageEnglish
Article number1602055
JournalThe European respiratory journal
Volume49
Issue number3
Publication statusPublished - 1 Mar 2017

ASJC Scopus subject areas