title: Diagnostic and prognostic utility of mid-expiratory flow rate in older community-dwelling persons with respiratory symptoms, but without chronic obstructive pulmonary disease.
abstract: BACKGROUND
  The maximal expiratory flow at 50 % of the forced vital capacity (MEF50) is the flow where half of forced vital capacity (FVC) remains to be exhaled. A reduced MEF50 has been suggested as a surrogate marker of small airways disease. The diagnostic and prognostic utility of this easy to assess spirometric variable in persons with respiratory symptoms, but without COPD is unclear.
  
  
  METHODS
  We used data from the UHFO-COPD cohort in which 405 community-dwelling persons aged 65 years or over, and a general practitioner's diagnosis of chronic obstructive pulmonary disease (COPD) underwent pulmonary function testing and echocardiography. In total 161 patients had no COPD according to the spirometric GOLD criteria. We considered MEF50 as reduced if < 60 % of predicted.
  
  
  RESULTS
  Of the 161 patients without COPD (mean age 72 ± 5.7 years; 35 % male; follow-up 4.5 ± 1.1 years), 61 (37.9 %) had a reduced MEF50. They were older, had more pack-years of smoking, more respiratory symptoms, and used more frequently inhaled medication than the remaining 100 subjects. A reduced MEF50 was nearly twice as often associated with newly detected heart failure (HF) at assessment (29.5 % vs. 15.6 %, p = 0.045). In age-and sex-adjusted Cox regression analysis, a reduced MEF50 was significantly associated with episodes of acute bronchitis (hazard ratio 2.54 95 % confidence interval (1.26; 5.13) P = 0.009), and in trend with pneumonia (2.14 (0.98; 4.69) P = 0.06) and hospitalizations for pulmonary reasons (2.28 (0.93; 5.62) P = 0.07).
  
  
  CONCLUSIONS
  In older community-dwelling persons with pulmonary symptoms but without COPD, a reduced MEF50 may help to uncover unrecognized HF, and identify those at a higher risk for episodes of acute bronchitis, pneumonia and hospitalizations for pulmonary reasons. Echocardiography and close follow-up should be considered in these patients.
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. Gueder_G@ukw.de.|Department of Internal Medicine I, Cardiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany. Gueder_G@ukw.de.|Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany. Gueder_G@ukw.de.
authors.forename: Gülmisal
authors.initials: G
authors.lastname: Güder
authors.affiliation: Department of Internal Medicine I, Cardiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany. Brenner_S@ukw.de.|Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany. Brenner_S@ukw.de.
authors.forename: Susanne
authors.initials: S
authors.lastname: Brenner
authors.affiliation: Department of Internal Medicine I, Cardiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany. Stoerk_S@ukw.de.|Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany. Stoerk_S@ukw.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Störk
authors.affiliation: Medical Mission Hospital, Department of Internal Medicine, Respiratory Medicine and Cardiology, Würzburg, Germany. matthias.held@missioklinik.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Held
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. B.D.L.Broekhuizen@umcutrecht.nl.
authors.forename: Berna D L
authors.initials: BD
authors.lastname: Broekhuizen
authors.affiliation: Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht, The Netherlands. J.W.J.Lammers@umcutrecht.nl.
authors.forename: Jan-Willem J
authors.initials: JW
authors.lastname: Lammers
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. A.W.Hoes@umcutrecht.nl.
authors.forename: Arno W
authors.initials: AW
authors.lastname: Hoes
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. F.H.Rutten@umcutrecht.nl.
authors.forename: Frans H
authors.initials: FH
authors.lastname: Rutten
mesh_terms: D000368:Aged; D004452:Echocardiography / Q000706:statistics & numerical data; D045853:Exhalation / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive; D012129:Respiratory Function Tests / Q000706:statistics & numerical data; D012140:Respiratory Tract Diseases / Q000175:diagnosis* / Q000503:physiopathology; D014797:Vital Capacity / Q000502:physiology*