Correlates of variability in endurance shuttle walk test time in patients with chronic obstructive pulmonary disease

PLoS One. 2021 Apr 21;16(4):e0249786. doi: 10.1371/journal.pone.0249786. eCollection 2021.

Abstract

Background: The endurance shuttle walk test (ESWT) is used to evaluate exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). The recommended pre-intervention tolerated duration (Tlim) is between 3-8 minutes for optimal interpretation of treatment effects. However, this window may be exceeded and factors determining ESWT Tlim are not completely understood. Therefore, we aimed to determine whether pulmonary function, physical and incremental shuttle walk test (ISWT) performance measures are associated with ESWT Tlim in COPD patients.

Methods: Assessment data from patients eligible for pulmonary rehabilitation was retrospectively analyzed. Inclusion criteria were: diagnosis of COPD and complete data availability regarding ESWT and ISWT. Patients performed an ESWT at 85% of ISWT speed and were divided into three groups (ESWT Tlim: <3 minutes, 3-8 minutes, >8 minutes). Subject characteristics, severity of complaints, pulmonary function, physical capacity and activity, exercise tolerance and quadriceps muscle strength were evaluated.

Results: 245 COPD patients (FEV1 38 (29-52)% predicted) were included. Median ESWT Tlim was 6.0 (3.7-10.3) minutes, 41 (17%) patients walked <3 minutes and 80 (33%) patients walked >8 minutes. Body mass index, maximal oxygen consumption, Tlim on constant work rate cycle test, physical activity level, maximal ISWT speed, dyspnoea Borg score at rest and increase of leg fatigue Borg score during ISWT independently predicted Tlim in multivariate regression analysis (R2 = 0.297, p<0.001).

Conclusion: This study reported a large variability in ESWT Tlim in COPD patients. Secondly, these results demonstrated that next to maximal ISWT speed, other ISWT performance measures as well as clinical measures of pulmonary function, physical capacity and physical activity were independent determinants of ESWT Tlim. Nevertheless, as these determinants only explained ~30% of the variability, future studies are needed to establish whether additional factors can be used to better adjust individual ESWT pace in order to reduce ESWT Tlim variability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Exercise Tolerance*
  • Female
  • Forced Expiratory Volume / physiology
  • Humans
  • Male
  • Middle Aged
  • Oxygen Consumption*
  • Pulmonary Disease, Chronic Obstructive / metabolism
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Quadriceps Muscle / metabolism
  • Quadriceps Muscle / physiopathology
  • Respiratory Function Tests / methods*
  • Retrospective Studies
  • Walk Test / methods*

Grants and funding

The BASES consortium is financially supported by Lung Foundation, the Netherlands (#5.1.18.232). Dr. F.M.E. Franssen received support in the form of grants and personal fees from AstraZeneca, personal fees from Boehringer Ingelheim, personal fees from Chiesi, personal fees from GlaxoSmithKline, grants and personal fees from Novartis, personal fees from TEVA, outside the submitted work. Dr. B. van den Borst received support in the form of personal lecture fees from AstraZeneca and Boehringer Ingelheim bv. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.