PMID- 34032813
OWN - NLM
STAT- MEDLINE
DCOM- 20211028
LR  - 20211028
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 16
IP  - 5
DP  - 2021
TI  - Cardiodynamic variables measured by impedance cardiography during a 6-minute walk 
      test are reliable predictors of peak oxygen consumption in young healthy adults.
PG  - e0252219
LID - 10.1371/journal.pone.0252219 [doi]
LID - e0252219
AB  - Accurate prediction of aerobic capacity is necessary to guide appropriate 
      exercise prescription. It is common to use 6-minute walk distance (6MWD) to 
      predict peak oxygen uptake (VO2peak) in the clinical environment. The aim of this 
      study was to determine whether prediction of VO2peak can be improved by the 
      inclusion of cardiovascular indices derived by impedance cardiography (ICG) 
      during the 6MWT. A total of 62 healthy university students aged 21+/-1 years 
      completed in separate days, a cardiopulmonary exercise test (CPET) and two 6MWTs 
      (30 min apart), during which heart rate (HR), stroke volume (SV) and cardiac 
      output (CO) were measured by ICG (PhysioFlow(R) PF07 EnduroTM). The CPET was 
      conducted with the Ergoselect 200 Ergoline and oxygen consumption measured by a 
      MasterScreenTM CPX breath-by-breath metabolic cart. Multiple regression analyses 
      were conducted to generate VO2peak prediction equations using 6MWD with, or 
      without the cardiovascular indices recorded at the end of the best performed 6MWT 
      as predictor variables. The mean peak HR (bpm), SV (ml) and CO (L/min) recorded 
      during 6MWT were 156+/-18, 95.6+/-9, 15+/-2.8 and during CPET were 176+/-16, 91.3+/-8, 
      16.2+/-2.7, respectively. Analyses revealed the following VO2peak prediction 
      equation: VO2peak = 100.297+(0.019x6MWD)+(-0.598xHR6MWT)+(-1.236xSV6MWT) + (8.671 
      x CO6MWT). This equation has a squared multiple correlation (R2) of 0.866, 
      standard error of the estimate (SEE) of 2.28 mL/kg/min and SEE:VO2peak (SEE%) of 
      7.2%. Cross-validation of equation stability using predicted residual sum of 
      squares (PRESS) statistics showed a R2 (Rp2), SEE (SEEp) and SEEp% of 0.842, 2.38 
      mL/kg/min and 7.6% respectively. The minimal shrinkage of R2 implied regression 
      model stability. Correlation between measured and predicted VO2peak using this 
      equation was strong (r = 0.931, p<0.001). When 6MWD alone was used as the 
      predictor for VO2peak, the generated equation had a lower R2 (0.549), and a 
      higher SEE (4.08 mL/kg/min) and SEE% (12.9%). This is the first study which 
      included cardiac indices during a 6MWT as variables for VO2peak prediction. Our 
      results suggest that inclusion of cardiac indices measured during the 6MWT more 
      accurately predicts VO2peak than using 6MWD data alone.
FAU - Liu, Fang
AU  - Liu F
AD  - Department of Rehabilitation, Shenzhen Second People's Hospital, The First 
      Affiliated Hospital of Shenzhen University Health Science Centre, Shenzhen, 
      China.
FAU - Tsang, Raymond C C
AU  - Tsang RCC
AUID- ORCID: 0000-0002-9251-6236
AD  - Department of Physiotherapy, MacLehose Medical Rehabilitation Centre, Hong Kong, 
      China.
FAU - Jones, Alice Y M
AU  - Jones AYM
AUID- ORCID: 0000-0003-3682-619X
AD  - School of Health and Rehabilitation Sciences, The University of Queensland, 
      Queensland, Australia.
FAU - Zhou, Mingchao
AU  - Zhou M
AD  - Department of Rehabilitation, Shenzhen Second People's Hospital, The First 
      Affiliated Hospital of Shenzhen University Health Science Centre, Shenzhen, 
      China.
FAU - Xue, Kaiwen
AU  - Xue K
AD  - School of Rehabilitation Sciences, The Shandong University of Traditional Chinese 
      Medicine, Shandong, China.
FAU - Chen, Miaoling
AU  - Chen M
AD  - Department of Rehabilitation, Shenzhen Second People's Hospital, The First 
      Affiliated Hospital of Shenzhen University Health Science Centre, Shenzhen, 
      China.
FAU - Wang, Yulong
AU  - Wang Y
AD  - Department of Rehabilitation, Shenzhen Second People's Hospital, The First 
      Affiliated Hospital of Shenzhen University Health Science Centre, Shenzhen, 
      China.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20210525
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
SB  - IM
MH  - Adult
MH  - Cardiography, Impedance/*methods
MH  - Exercise Test
MH  - Female
MH  - Humans
MH  - Male
MH  - Oxygen Consumption/physiology
MH  - Regression Analysis
MH  - Walk Test
MH  - Young Adult
PMC - PMC8148309
COIS- The authors have declared that no competing interests exist.
EDAT- 2021/05/26 06:00
MHDA- 2021/10/29 06:00
PMCR- 2021/05/25
CRDT- 2021/05/25 13:56
PHST- 2021/03/25 00:00 [received]
PHST- 2021/05/12 00:00 [accepted]
PHST- 2021/05/25 13:56 [entrez]
PHST- 2021/05/26 06:00 [pubmed]
PHST- 2021/10/29 06:00 [medline]
PHST- 2021/05/25 00:00 [pmc-release]
AID - PONE-D-21-09792 [pii]
AID - 10.1371/journal.pone.0252219 [doi]
PST - epublish
SO  - PLoS One. 2021 May 25;16(5):e0252219. doi: 10.1371/journal.pone.0252219. 
      eCollection 2021.