Table 1. Associations between the Fatigue Severity Scale (FSS) score and participants’ characteristics
Variable
|
Value
|
rho
|
p value
|
W value
|
p value
|
Age, years
|
59.8 ± 10.0
|
−0.007
|
0.973
|
NA
|
NA
|
Sex, male/female
|
17/6
|
NA
|
NA
|
67.0
|
0.277
|
Height, m
|
1.66 ± 0.07
|
−0.082
|
0.712
|
NA
|
NA
|
Weight, kg
|
62.0 ± 9.0
|
0.210
|
0.337
|
NA
|
NA
|
Body mass index, kg·m−2
|
22.4 ± 3.3
|
0.173
|
0.430
|
NA
|
NA
|
Type of stroke, ischaemic/haemorrhagic
|
12/11
|
NA
|
NA
|
81.0
|
0.371
|
Side of motor paresis, right/left
|
11/12
|
NA
|
NA
|
63.0
|
0.877
|
Time since stroke, days
|
69.7 ± 30.2
|
−0.069
|
0.753
|
NA
|
NA
|
Comorbidities
|
|
|
|
|
|
Hypertension
|
11
|
NA
|
NA
|
69.5
|
0.853
|
Diabetes mellitus
|
5
|
NA
|
NA
|
34.5
|
0.455
|
FSS score, points
|
32 (27, 42)
|
NA
|
NA
|
NA
|
NA
|
GDS score, points
|
5 (2, 6)
|
NA
|
NA
|
NA
|
NA
|
Depressive symptoms (GDS score ≥ 5)
|
13
|
NA
|
NA
|
54.5
|
0.534
|
Mini-Mental State Examination score, points
|
28 (26, 30)
|
0.085
|
0.701
|
NA
|
NA
|
Stroke Impairment Assessment Set motor score, points
|
19 (12, 25)
|
−0.237
|
0.276
|
NA
|
NA
|
Functional Independence Measure motor score, points
|
77 (70, 89)
|
−0.140
|
0.524
|
NA
|
NA
|
Functional Independence Measure cognitive score, points
|
30 (28, 35)
|
0.029
|
0.895
|
NA
|
NA
|
Values are presented as mean ± standard deviation, median (interquartile range), or number.
rho, Spearman’s rank correlation coefficient; GDS, Geriatric Depression Scale; NA, not available.
Table 2. Correlations between the Fatigue Severity Scale score and cardiorespiratory variables during a symptom-limited graded exercise test and a submaximal constant-load exercise test
Variable
|
Value
|
Correlation analysis
|
|
|
rho (95% CI)
|
p value
|
At peak exercise during graded exercise
|
|
|
|
O2, mL·kg-1·min-1
|
18.0 ± 4.2
|
−0.264 (−0.618, 0.179)
|
0.224
|
CO, L·min-1
|
9.2 ± 1.4
|
−0.017 (−0.437, 0.409)
|
0.939
|
AVO2diff, mL·100 mL-1
|
12.2 ± 2.5
|
−0.106 (−0.506, 0.332)
|
0.632
|
E, L·min-1
|
43.4 ± 14.7
|
−0.011 (−0.432, 0.414)
|
0.959
|
Respiratory exchange ratio
|
0.99 ± 0.12
|
0.104 (−0.334, 0.504)
|
0.638
|
Oxygen uptake efficiency slope, mL·min-1·log(L·min-1)-1
|
1,354 ± 355
|
−0.401 (−0.705, 0.026)
|
0.058
|
At ventilatory threshold during graded exercise
|
|
|
|
O2, mL·kg-1·min-1
|
14.2 ± 2.9
|
−0.294 (−0.637, 0.148)
|
0.174
|
CO, L·min-1
|
7.8 ± 1.1
|
−0.105 (−0.505, 0.333)
|
0.634
|
AVO2diff, mL·100 mL-1
|
11.2 ± 1.9
|
−0.078 (−0.485, 0.357)
|
0.724
|
E, L·min-1
|
24.1 ± 6.9
|
−0.019 (−0.438, 0.407)
|
0.932
|
Respiratory exchange ratio
|
0.74 ± 0.08
|
0.021 (−0.405, 0.440)
|
0.923
|
At the onset of constant-load exercise
|
|
|
|
τ O2, sec
|
38.6 ± 10.1
|
0.530 (0.138, 0.778)
|
0.009
|
τCO, sec
|
45.3 ± 22.5
|
0.476 (0.067, 0.749)
|
0.022
|
τAVO2diff, sec
|
26.7 ± 7.7
|
0.215 (−0.228, 0.585)
|
0.324
|
τ E, sec
|
70.0 ± 15.1
|
0.234 (−0.210, 0.598)
|
0.283
|
Values are presented as mean ± standard deviation.
rho, Spearman’s rank correlation coefficient; O2, oxygen uptake; CO, cardiac output; AVO2diff, arterial-venous oxygen difference; E, minute ventilation; τ, the time constant.
Table 3. Associations of participants’ characteristics and the time constants of oxygen uptake (τ O2) and cardiac output (τCO)
Variable
|
τ O2
|
τCO
|
|
Correlation coefficient
(p value)
|
t value
(p value)
|
Correlation coefficient
(p value)
|
t value
(p value)
|
Age
|
r = 0.272
(0.209)
|
NA
|
r = 0.165
(0.451)
|
NA
|
Sex
|
NA
|
−0.160
(0.875)
|
NA
|
0.859
(0.400)
|
Height
|
r = −0.096
(0.662)
|
NA
|
r = 0.196
(0.371)
|
NA
|
Weight
|
r = 0.066
(0.766)
|
NA
|
r = −0.060
(0.786)
|
NA
|
Body mass index
|
r = −0.085
(0.699)
|
NA
|
r = 0.063
(0.774)
|
NA
|
Type of stroke
|
NA
|
−1.085
(0.290)
|
NA
|
−1.208
(0.241)
|
Side of motor paresis
|
NA
|
−0.657
(0.518)
|
NA
|
−0.714
(0.483)
|
Time since stroke
|
r = −0.007
(0.973)
|
NA
|
r = −0.164
(0.456)
|
NA
|
Comorbidities
|
|
|
|
|
Hypertension
|
NA
|
−1.377
(0.183)
|
NA
|
−0.836
(0.412)
|
Diabetes mellitus
|
NA
|
−1.665
(0.111)
|
NA
|
−1.161
(0.259)
|
Depressive symptoms (GDS score ≥ 5)
|
NA
|
0.083
(0.935)
|
NA
|
−0.880
(0.389)
|
Mini-Mental State Examination score
|
rho = 0.072
(0.744)
|
NA
|
rho = 0.162
(0.459)
|
NA
|
Stroke Impairment Assessment Set motor score
|
rho = −0.113
(0.608)
|
NA
|
rho = −0.193
(0.377)
|
NA
|
Functional Independence Measure motor score
|
rho = 0.017
(0.940)
|
NA
|
rho = −0.149
(0.498)
|
NA
|
Functional Independence Measure cognitive score
|
rho = −0.236
(0.278)
|
NA
|
rho = 0.332
(0.122)
|
NA
|
r, Pearson’s product-moment correlation coefficient; rho, Spearman’s rank correlation coefficient; GDS, Geriatric Depression Scale, NA, not available.