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Table 1 Demographic data and results

From: Decreased oxygen extraction during cardiopulmonary exercise test in patients with chronic fatigue syndrome

Female

 

CFS

CFI

Healthy

ANOVA

 

n=178

n=172

n=11

P

Age

(years)

37.3 ± 12.1

37.9 ± 12.3

42.2 ± 14.8

0.421

Weight

(kg)

69.5 ± 15.0

67.5 ± 13.1

68.6 ± 13.2

0.412

BSA

(m2)

1.81 ± 0.20

1.78 ± 0.18

1.79 ± 0.17

0.497

Haemoglobin

(mmol/l)

8.45 ± 0.55

8.46 ± 0.51

 

0.846

Rest

     

HR

(beats/min)

96.1 ± 14.9

93.5 ± 16.8

87.7 ± 11.1

0.113

V’O2

(ml/min/kg)

5.46 ± 0.99

5.41 ± 0.93

5.18 ± 0.98

0.635

O2 pulse

(ml/beat)

4.00 ± 0.85

3.95 ±0.82

4.09 ± 0.90

0.784

RER

 

0.86 ± 0.07

0.86 ± 0.07

0.81 ± 0.03

0.073

V’E/V’CO2

 

34.2 ± 4.3

34.3 ± 4.1

34.7 ± 3.0

0.924

SVI

(ml/m2)

42.8 ±7.0

42.3 ±7.6

43.4 ± 10.4

0.797

Cardiac index

(L/min/m2)

4.10 ± .081

3.97 ± 0.92

3.80 ± 0.95

0.294

O2 extraction

(ml/100ml)

6.48 ± 1.65

6.58 ± 1.72

6.96 ± 1.63

0.620

Anaerobic threshold

     

HR

(beats/min)

112.0 ± 15.6

112.3 ± 15.2

113.3 ± 8.7

0.955

V’O2

(ml/min/kg)

10.9 ± 2.6

11.6 ± 2.7

13.7 ± 3.6

0.001

O2 pulse

(ml/beat)

6.75 ± 1.63

6.95 ± 1.67

8.33 ± 2.31

0.009

RER

 

0.84 ± 0.07

0.85 ± 0.08

0.81 ± 0.06

0.216

V’E/V’CO2

 

29.7 ± 3.5

28.8 ± 3.5

27.6 ± 1.7

0.025

SVI

(ml/m2)

45.7 ± 7.9

45.0 ± 8.2

48.2 ± 11.8

0.382

Cardiac index

(L/min/m2)

5.12 ± 1.10

5.11 ± 1.21

5.52 ± 1.64

0.534

O2 extraction

(ml/100ml)

8.30 ± 2.08

8.77 ± 2.23

9.86 ± 2.37

0.019

Peak exercise

     

HR

(beats/min)

158.4 ± 19.3

159.6 ± 18.6

164.1 ± 11.3

0.250

V’O2

(ml/min/kg)

20.3 ± 5.0

22.2 ± 5.3

27.4 ± 7.2

0.000

V’O2/pred.

%

80.6 ± 17.9

83.1 ± 18.0

105.4 ± 18.8

0.000

O2 pulse

(ml/beat)

8.89 ± 2.17

9.26 ± 2.08

11.36 ± 2.89

0.001

RER

 

1.16 ± 0.10

1.18 ± 0.10

1.20 ± 0.11

0.094

V’E/V’CO2

 

30.2 ± 3.7

29.7 ± 3.7

27.9 ± 2.4

0.103

SVI

(ml/m2)

45.9 ±7.9

45.4 ± 8.3

47.6 ± 11.2

0.797

Cardiac index

(L/min/m2)

7.33 ± 1.77

7.39 ± 1.78

7.87 ± 1.96

0.618

O2 extraction

(ml/100ml)

10.83 ± 2.80

11.62 ± 2.90

13.45 ± 2.72

0.001

Slope

     

ΔQ’/ΔV’O2

(L/L)

7.35 ± 2.40

6.80 ± 1.99

5.85 ± 1.23

0.012

Male

     
  

CFS

CFI

Healthy

ANOVA

  

n=25

n=51

n=7

P

Age

(years)

41.6 ± 12.3

41.8 ± 9.9

49.4 ± 13.8

0.215

Weight

(kg)

88.9 ± 15.7

80.0 ± 12.8

94.3 ± 13.9

0.005

BSA

(m2)

2.12 ± 0.21

2.02 ± 0.17

2.19 ± 0.16

0.016

Haemoglobin

(mmol/l)

9.34 ± 0.66

9.53 ± 0.56

 

0.263

Rest

     

HR

(beats/min)

89.5 ± 15.8

88.4 ± 15.1

79.4 ± 16.2

0.303

V’O2

(ml/min/kg)

5.08 ± 0.81

5.51 ± 0.90

4.57 ± 0.79

0.093

O2 pulse

(ml/beat)

5.24 ± 1.20

5.01 ± 0.94

5.56 ± 1.47

0.025

RER

 

0.84 ± 0.07

0.88 ± 0.08

0.87 ± 0.04

0.226

V’E/V’CO2

 

33.6 ± 4.4

34.4 ± 5.7

36.5 ± 3.0

0.436

SVI

(ml/m2)

43.4 ± 8.0

45.9 ± 6.9

41.2 ± 6.7

0.182

Cardiac index

(L/min/m2)

3.86 ± 0.83

4.05 ±0.96

3.31 ± 1.02

0.152

O2 extraction

(ml/100ml)

6.96 ± 1.76

6.70 ± 1.68

8.20 ± 2.82

0.124

Anaerobic threshold

     

HR

(beats/min)

103.6 ± 14.6

107.0 ± 14.3

102.1 ± 19.2

0.529

V’O2

(ml/min/kg)

11.8 ± 2.8

13.4 ± 3.3

13.7 ± 3.1

0.093

O2 pulse

(ml/beat)

9.97 ± 2.50

9.92 ± 2.49

12.8 ± 3.5

0.025

RER

 

0.84 ± 0.09

0.87 ± 0.06

0.86 ± 0.08

0.250

V’E/V’CO2

 

28.0 ± 3.6

26.2 ± 3.0

27.3 ± 3.1

0.089

SVI

(ml/m2)

47.5 ± 8.9

51.3 ± 7.0

45.7 ± 6.4

0.049

Cardiac index

(L/min/m2)

4.95 ± 1.09

5.48 ± 1.07

4.77 ± 1.44

0.082

O2 extraction

(ml/100ml)

9.86 ± 2.02

9.74 ± 3.09

13.0 ± 4.32

0.025

Peak exercise

     

HR

(beats/min)

154.6 ± 19.4

160.5 ± 20.6

151.4 ± 16.2

0.328

V’O2

(ml/min/kg)

24.0 ± 7.2

28.9 ± 7.1

27.3 ± 3.7

0.019

V’O2/pred.

%

73.9 ± 17.5

83.4 ± 19.2

96.2 ± 11.4

0.011

O2 pulse

(ml/beat)

13.5 ± 3.0

14.2 ± 3.0

17.1 ± 3.0

0.023

RER

 

1.19 ±0.11

1.24 ± 0.12

1.29 ± 0.06

0.100

V’E/V’CO2

 

28.9 ± 5.2

27.9 ± 3.8

29.2 ± 4.0

0.537

SVI

(ml/m2)

47.4 ± 10.5

50.4 ± 9.4

44.4 ± 8.6

0.182

Cardiac index

(L/min/m2)

7.44 ±2.13

8.02 ± 2.07

6.45 ±1.81

0.136

O2 extraction

(ml/100ml)

13.66 ± 3.31

14.63 ± 4.38

19.52 ± 6.53

0.008

Slope

     

ΔQ’/ΔV’O2

(L/L)

5.84 ± 1.82

5.38 ± 1.63

4.01 ± 1.26

0.043

  1. Demographic data and results of cardiopulmonary exercise tests in patients with chronic fatigue syndrome, idiopathic chronic fatigue and healthy humans during rest, at the anaerobic threshold and maximal workload. BSA: body surface area, HR: heart rate, V’O2: oxygen uptake, V’O2/pred.: oxygen uptake as percentage of predicted, SVI stroke volume index, ΔQ’/ΔV’O2: increase of cardiac output relative to the increase of oxygen uptake.