PMID- 28794622
OWN - NLM
STAT- MEDLINE
DCOM- 20180508
LR  - 20181113
IS  - 1178-2005 (Electronic)
IS  - 1176-9106 (Print)
IS  - 1176-9106 (Linking)
VI  - 12
DP  - 2017
TI  - The association of tidal EFL with exercise performance, exacerbations, and death 
      in COPD.
PG  - 2179-2188
LID - 10.2147/COPD.S138720 [doi]
AB  - BACKGROUND: Tidal expiratory flow limitation (EFL(T)) is frequently found in 
      patients with COPD and can be detected by forced oscillations when within-breath 
      reactance of a single-breath is >/=0.28 kPa.s.L(-1). The present study explored the 
      association of within-breath reactance measured over multiple breaths and EFL(T) 
      with 6-minute walk distance (6MWD), exacerbations, and mortality. METHODS: In 425 
      patients, spirometry and forced oscillation technique measurements were obtained 
      on eight occasions over 3 years. 6MWD was assessed at baseline and at the 3-year 
      visit. Respiratory symptoms, exacerbations, and hospitalizations were recorded. A 
      total of 5-year mortality statistics were retrieved retrospectively. We grouped 
      patients according to the mean within-breath reactance [Formula: see text], 
      measured over several breaths at baseline, calculated as mean inspiratory-mean 
      expiratory reactance over the sampling period. In addition to the established 
      threshold of EFL(T), an upper limit of normal (ULN) was defined using the 97.5th 
      percentile of [Formula: see text], of the healthy controls in the study; 6MWDs 
      were compared according to [Formula: see text], as normal, >/= ULN < EFL(T), or >/= 
      EFL(T). Annual exacerbation rates were analyzed using a negative binomial model 
      in the three groups, supplemented by time to first exacerbation analysis, and 
      dichotomizing patients at the ULN. RESULTS: In patients with COPD and baseline 
      [Formula: see text] below the ULN (0.09 kPa.s.L(-1)), 6MWD was stable. 6MWD 
      declined significantly in patients with [Formula: see text]. Worse lung function 
      and more exacerbations were found in patients with COPD with [Formula: see text], 
      and patients with [Formula: see text] had shorter time to first exacerbation and 
      hospitalization. A significantly higher mortality was found in patients with 
      [Formula: see text] and FEV(1) >50%. CONCLUSION: Patients with baseline [Formula: 
      see text] had a deterioration in exercise performance, more exacerbations, and 
      greater hospitalizations, and, among those with moderate airway obstruction, a 
      higher mortality. [Formula: see text] is a novel independent marker of outcome in 
      COPD.
FAU - Aarli, Bernt Boegvald
AU  - Aarli BB
AD  - Department of Clinical Science, University of Bergen.
AD  - Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.
FAU - Calverley, Peter Ma
AU  - Calverley PM
AD  - Clinical Science Centre, University Hospital Aintree, Liverpool, UK.
FAU - Jensen, Robert L
AU  - Jensen RL
AD  - LDS Hospital, Pulmonary Division, Salt Lake City, UT, USA.
FAU - Dellaca, Raffaele
AU  - Dellaca R
AD  - TBM-Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico 
      di Milano University, Milano, Italy.
FAU - Eagan, Tomas Ml
AU  - Eagan TM
AD  - Department of Clinical Science, University of Bergen.
AD  - Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.
FAU - Bakke, Per S
AU  - Bakke PS
AD  - Department of Clinical Science, University of Bergen.
FAU - Hardie, Jon A
AU  - Hardie JA
AD  - Department of Clinical Science, University of Bergen.
LA  - eng
PT  - Journal Article
DEP - 20170726
PL  - New Zealand
TA  - Int J Chron Obstruct Pulmon Dis
JT  - International journal of chronic obstructive pulmonary disease
JID - 101273481
SB  - IM
MH  - Adult
MH  - Aged
MH  - Disease Progression
MH  - *Exercise Tolerance
MH  - Female
MH  - Forced Expiratory Volume
MH  - Hospitalization
MH  - Humans
MH  - Kaplan-Meier Estimate
MH  - Lung/*physiopathology
MH  - Male
MH  - Middle Aged
MH  - Oscillometry
MH  - Prognosis
MH  - Pulmonary Disease, Chronic 
      Obstructive/diagnosis/mortality/*physiopathology/therapy
MH  - *Pulmonary Ventilation
MH  - Retrospective Studies
MH  - Risk Factors
MH  - Spirometry
MH  - Time Factors
MH  - Vital Capacity
MH  - Walk Test
PMC - PMC5536237
OTO - NOTNLM
OT  - 6-minute walk test
OT  - COPD
OT  - exacerbations
OT  - forced oscillation technique
OT  - mortality
OT  - reactance
COIS- Disclosure The authors report no conflicts of interest in this work.
EDAT- 2017/08/11 06:00
MHDA- 2018/05/09 06:00
PMCR- 2017/07/26
CRDT- 2017/08/11 06:00
PHST- 2017/08/11 06:00 [entrez]
PHST- 2017/08/11 06:00 [pubmed]
PHST- 2018/05/09 06:00 [medline]
PHST- 2017/07/26 00:00 [pmc-release]
AID - copd-12-2179 [pii]
AID - 10.2147/COPD.S138720 [doi]
PST - epublish
SO  - Int J Chron Obstruct Pulmon Dis. 2017 Jul 26;12:2179-2188. doi: 
      10.2147/COPD.S138720. eCollection 2017.