Background
Methods
Study design and participants
Study protocol
Patients’ characteristics
Characteristic (n = 17) | Value | Range |
---|---|---|
Age (years) | 62.7 ± 10.4 | 41.0–78.0 |
Sex, n (%) | ||
Male | 9 (52.9 %) | |
Female | 8 (47.1 %) | |
Height (cm) | 169.5 ± 6.6 | 160.0–183.0 |
Body mass (kg) | 72.3 ± 10.0 | 57.5–90.0 |
Body mass index (kg/m2) | 25.2 ± 3.2 | 20.2–33.1 |
Type of stroke, n (%) | ||
Ischaemic | 15 (88.2 %) | |
Haemorrhagic | 2 (11.8 %) | |
Hemiparetic side, n (%) | ||
Left | 7 (41.2 %) | |
Right | 10 (58.8 %) | |
Stage, n (%) | ||
Sub-acute | 6 (35.3 %) | |
Chronic | 11 (64.7 %) | |
Days post stroke, | 485.3 (535.5) | 21–1810 |
median (IQR) | 350 (788) | |
FAC | 3.6 ± 2.1 | 0–5 |
NIHSS | 3.1 ± 3.2 | 0–11 |
MMSE score | 28.1 ± 2.3 | 21–30 |
Modified Rankin Scale | ||
0–2 | 12 (70.6 %) | |
3 | 1 (5.9 %) | |
4–5 | 4 (23.5 %) | |
Comorbidities, n (%) | ||
Hypertension | 9 (52.9 %) | |
Diabetes mellitus | 1 (5.9 %) | |
Dyslipidemia | 4 (23.5 %) | |
None | 4 (23.5 %) | |
Antihypertensive medications, n (%) | ||
β-blocker | 2 (11.9 %) | |
ACE inhibitors | 3 (17.6 %) | |
Calcium channel blockers | 3 (17.6 %) | |
None | 9 (52.9 %) |
Cardiopulmonary fitness assessment
Outcome measures
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Peak oxygen uptake, denoted V'O2peak. This was determined as the maximum of a 15-breath average during the ramp phase.
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Peak heart rate, HRpeak: the highest value of HR during the ramp phase.
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Peak respiratory exchange ratio, RERpeak: the 15-breath average at the time of V'O2peak.
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Peak work rate, WRpeak. This was calculated as the highest work rate achieved.
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Oxygen uptake at the ventilatory anaerobic threshold VAT (V'O2VAT): the method for determination of VAT is summarized below.
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Oxygen uptake at the respiratory compensation point RCP (V'O2RCP), described below.
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Rating of perceived exertion (RPE) for dyspnea and leg effort at the time of peak exercise (Borg CR10) [25].
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Heart rate at the VAT (HRVAT) and heart rate at the RCP (HRRCP).
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The value of the ventilatory equivalent of oxygen (V'E/V'O2) at VAT and ventilatory equivalent of carbon dioxide (V'E/V'CO2) at RCP, where V'E is minute ventilation and V'CO2 is carbon dioxide output, and the slope of V'E-vs-V'CO2 from the start of the ramp phase to the RCP.
Statistical analysis
Results
General observations
TB1 (mean ± SD) | TB2 (mean ± SD) | p-value | MD | 95%CI | SDD | 95 % LoA | CoV (%) | ICC (95 % CI) | |
---|---|---|---|---|---|---|---|---|---|
Absolute V'O2peak (mL/min) | 1130.5 ± 349.4 | 1156.4 ± 376.6 | 0.60 | 25.8 | −77.4, 129.1 | 200.8 | −0.26x̄, 0.26x̄ | 11.6 | 0.85 (0.64, 0.94) |
Relative V'O2peak (mL/kg/min) | 15.7 ± 4.7 | 16.0 ± 4.9 | 0.65 | 0.3 | −1.1, 1.7 | 2.8 | −0.26x̄, 0.26x̄ | 11.6 | 0.84 (0.61, 0.94) |
HRpeak (beats/min) | 120.9 ± 26.3 | 124.2 ± 25.2 | 0.26 | 3.2 | −2.6, 9.0 | 11.3 | −18.9, 25.3 | 6.9 | 0.90 (0.76, 0.96) |
HRpeak% of APMHR | 78.0 ± 15.0 | 80.1 ± 13.6 | 0.26 | 2.04 | −1.6, 5.7 | 7.2 | −12.1, 16.2 | 6.9 | 0.87 (0.69, 0.95) |
RERpeak | 1.06 ± 0.09 | 1.08 ± 0.08 | 0.10 | 0.02 | −0.01, 0.52 | 0.06 | −0.1, 0.1 | 4.1 | 0.78 (0.49, 0.91) |
WRpeak (W) | 28.0 ± 12.4 | 29.0 ± 13.3 | 0.36 | 1.07 | 1.4, 3.5 | 4.6 | −7.9, 10.1 | 13.4 | 0.94 (0.83, 0.98) |
Absolute V'O2VAT (mL/min) (n = 16) | 575.4 ± 105.9 | 635.5 ± 177.3 | 0.045 | 60.1 | −1.4, 118.9 | 110.2 | −0.34x̄, 0.34x̄ | 14.5 | 0.67 (0.27, 0.87) |
Relative V'O2VAT (mL/kg/min) | 8.0 ± 1.6 | 8.8 ± 2.4 | 0.050 | 0.8 | 0.0, 1.6 | 1.5 | −0.34x̄, 0.34x̄ | 14.5 | 0.68 (0.29, 0.88) |
V'O2VAT% of V'O2peak (%) | 50.3 ± 9.4 | 53.1 ± 9.1 | 0.27 | 2.8 | −2.4, 8.2 | 10 | −16.8, 22.4 | 15.4 | 0.41 (−0.07, 0.74) |
HRVAT (beats/min) (n = 15) | 89.5 ± 9.3 | 91.9 ± 9.7 | 0.17 | 2.4 | −1.1, 6.0 | 6.5 | −10.3, 15.1 | 5.5 | 0.76 (0.44, 0.91) |
HRVAT % of HR reserve | 32.6 ± 9.2 | 35.1 ± 11.5 | 0.33 | 2.5 | −2.8, 7.8 | 9.5 | −16.1, 21.1 | 19.5 | 0.58 (0.13, 0.84) |
HRVAT % of APMHR | 57.3 ± 5.4 | 58.8 ± 5.2 | 0.20 | 1.5 | −0.9, 3.8 | 4.3 | −0.62x̄, 0.62x̄ | 5.5 | 0.67 (0.28, 0.87) |
Absolute V'O2RCP (mL/min) (n = 12) | 956.5 ± 197.9 | 1002.9 ± 179.4 | 0.33 | 46.3 | −54.1, 146.6 | 157.9 | −263.2, 355.8 | 11.6 | 0.65 (0.17, 0.88) |
Relative V'O2RCP (mL/kg/min) | 13.4 ± 2.5 | 14.1 ± 2.5 | 0.28 | 0.7 | −0.7, 2.1 | 2.1 | −3.4, 4.8 | 11.6 | 0.77 (0.24, 0.87) |
V'O2RCP% of V'O2peak (%) | 77.2 ± 8.8 | 82.1 ± 6.8 | 0.035 | 4.9 | 0.4, 9.5 | 7.1 | −9.0, 18.8 | 8.3 | 0.50 (−0.02, 0.82) |
HRRCP (beats/min) (n = 11) | 112.5 ± 18.2 | 113.6 ± 17.7 | 0.42 | 1.1 | −5.3, 7.4 | 9.4 | −17.3, 19.5 | 5.8 | 0.87 (0.59, 0.96) |
HRRCP % of HR reserve | 70.2 ± 16.2 | 73.6 ± 10.8 | 0.48 | 3.5 | −7.0, 14.0 | 15.6 | −27.1, 34.1 | 18.4 | 0.37 (−0.28, 0.78) |
HRRCP % of APMHR | 71.3 ± 12.1 | 71.9 ± 11.7 | 0.72 | 0.7 | −3.2, 4.6 | 5.8 | −10.7, 12.1 | 5.8 | 0.89 (0.64, 0.97) |
RPE dyspnea | 5.1 ± 2.0 | 5.2 ± 2.7 | 0.93 | 0.1 | −0.8, 0.9 | 1.7 | −3.2, 3.4 | 28.4 | 0.76 (0.44, 0.91) |
RPE leg effort | 6.8 ± 2.1 | 7.5 ± 1.6 | 0.23 | 0.8 | −0.3, 1.8 | 2 | −3.1, 4.7 | 29.5 | 0.41 (−0.04, 0.73) |
V'E/V'O2 at VAT | 31.8 ± 4.8 | 32.8 ± 5.0 | 0.28 | 0.9 | −0.8, 2.7 | 3.3 | −5.6, 7.4 | 7.3 | 0.77 (0.48, 0.91) |
V'E/V'CO2 at RCP | 33.8 ± 3.7 | 33.8 ± 3.7 | 0.91 | 0.1 | −1.2, 1.3 | 2.0 | −3.9, 4.0 | 4.5 | 0.87 (0.60, 0.96) |
V'E-vs-V'CO2 slope to RCP | 32.2 ± 4.8 | 33.0 ± 5.5 | 0.36 | 0.8 | −1.0, 2.6 | 2.8 | −4.7, 6.3 | 6.1 | 0.85 (0.58,0.96) |
6 MWD (n = 12) | 502.5 ± 113.4 | 528.3 ± 113.1 | 0.010 | 25.8 | 7.5, 44.1 | 28.7 | −30.5, 82.1 | 5.6 | 0.95 (0.65, 0.99) |
TB2 | TF | MD (95 % CI) (TF-TB2) | p-value | % changes (95 % CI) | |
---|---|---|---|---|---|
Absolute V'O2peak (mL/min) | 1156.4 ± 376.6 | 1170.0 ± 397.5 | 13.6 (−102.9, 130.2) | 0.81 | 2.8 (−6.3, 11.9) |
Relative V'O2peak (mL/kg/min) | 16.0 ± 4.9 | 16.2 ± 5.0 | 0.2 (−1.3, 1.6) | 0.80 | 2.8 (−6.3, 11.9) |
HRpeak (beats/min) | 124.2 ± 25.2 | 124.5 ± 23.5 | 0.4 (−4.7, 5.4) | 0.88 | 0.9 (−3.1, 5.0) |
RERpeak | 1.08 ± 0.08 | 1.08 ± 0.10 | 0.001 (−0.02, 0.03) | 0.89 | 0.2 (−2.3, 2.6) |
WRpeak (W) (n = 16) | 29.0 ± 13.3 | 30.0 ± 14.0 | 1.0 (−1.8, 3.8) | 0.46 | 2.6 (−7.3, 12.6) |
Absolute V'O2VAT (mL/min) (n = 16) | 637.4 ± 173.3 | 569.3 ± 151.3 | −68.1 (−107.5, −28.7) | 0.002 | −9.6 (−15.1, 4.0) |
Relative V'O2VAT (mL/kg/min) | 8.8 ± 2.3 | 7.9 ± 2.0 | −0.9 (−1.5, −0.4) | 0.002 | −9.6 (−15.1, 4.0) |
HRVAT (beats/min) | 93.8 ± 11.5 | 91.1 ± 7.4 | −2.6 (−6.8, 1.5) | 0.20 | −2.1 (−6.2, 2.0) |
Absolute V'O2RCP (mL/min) (n = 11) | 1018.7 ± 179.1 | 1055.4 ± 199.4 | 36.7 (−80.4, 153.7) | 0.50 | 4.5 (−5.9, 14.9) |
Relative V'O2RCP (mL/kg/min) | 14.2 ± 2.5 | 14.7 ± 2.5 | 0.5 (−1.0, 1.9) | 0.48 | 4.5 (−5.9, 14.9) |
HRRCP (beats/min) | 118.2 ± 16.8 | 116.8 ± 19.0 | −1.3 (−8.8, 6.1) | 0.69 | −1.0 (−7.7, 5.7) |
RPE dyspnea | 5.2 ± 2.7 | 4.5 ± 1.9 | −0.7 (−1.9, 0.5) | 0.25 | −0.7 (−25.2, 23.8) |
RPE leg effort | 7.5 ± 1.6 | 6.1 ± 2.2 | −1.4 (−2.8, −0.2) | 0.028 | −16.4 (−32.4, 0.4) |
V'E/V'O2 at VAT (n = 16) | 32.4 ± 4.6 | 32.4 ± 4.2 | 0.1 (−1.2, 1.3) | 0.93 | 0.5 (−3.2, 4.3) |
V'E/V'CO2 at RCP (n = 11) | 33.7 ± 3.8 | 33.5 ± 4.4 | −0.1 (−1.7, 1.4) | 0.86 | −0.4 (−5.2, 4.5) |
V'E-vs-V'CO2 slope to RCP (n = 11) | 32.8 ± 5.7 | 32.0 ± 4.6 | −0.8 (−3.4, 1.9) | 0.53 | −1.3 (−8.4, 5.8) |
6MWD (n = 12) | 528.3 ± 113.1 | 526.7 ± 114.5 | −1.7 (−26.1 to 22.8) | 0.89 | 0.1 (−5.0 to 5.2) |