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Table 1 Background characteristics of the chronic fatigue syndrome (CFS) group and the healthy control (HC) group in the present study

From: Whole blood gene expression in adolescent chronic fatigue syndrome: an exploratory cross-sectional study suggesting altered B cell differentiation and survival

 

CFS group (n = 29)

HC group (n = 18)

p valuee

Background markers

 Female gender. Number, %

18

62

11

61

0.948

 Scandinavian ethnicity. Number, %

29

100

17

95

0.383

 Age (years). Mean, SD

15.1

1.4

14.7

1.4

0.335

 Body mass index (kg/m2). Mean, SD

20.2

3.4

19.4

1.9

0.317

 Disease duration (months). Median, range

12

4–60

n/a

  

 Adheres to the Fukuda criteria of CFSa. Number, %

20

69

n/a

  

 Adheres to the Canada 2003-criteria of CFSb. Number, %

11

38

n/a

  

Immune markers

 Blood leukocytes (cells × 109/L). Mean, SD

6.0

2.0

5.5

1.0

0.370

 Blood neutrophils (cells × 109/L). Mean, SD

3.1

1.6

2.8

0.7

0.462

 Blood lymphocytes (cells × 109/L). Mean, SD

2.2

0.7

2.1

0.5

0.626

 Blood monocytes (cells × 109/L). Mean, SD

0.48

0.19

0.42

0.10

0.146

 Blood eosinophils (cells × 109/L). Mean, SD

0.18

0.11

0.17

0.07

0.787

 Blood basophils (cells × 109/L). Mean, SD

0.02

0.04

0.02

0.04

0.681

 Serum C-reactive protein (mg/L). Median, IQR

0.40

0.89

0.32

0.28

0.405

 Plasma interleukin-1β (pg/mL). Mean, SD

3.0

2.1

2.3

1.5

0.223

 Plasma interleukin-6 (pg/mL). Mean, SD

10.0

7.5

7.2

4.3

0.158

 Plasma tumor necrosis factor (pg/mL). Mean, SD

63

40

47

29

0.161

Neuroendocrine markers

 Plasma norepinephrine (pmol/L). Mean, SD

2067

835

1530

358

0.004

 Plasma epinephrine (pmol/L). Mean, SD

362

131

284

74

0.012

 Plasma cortisol (nmol/L). Mean, SD

334

151

349

202

0.782

 Urine norepinephrine/creatinine ratio (nmol/mmol). Mean, SD

14.5

6.5

10.9

3.6

0.033

 Urine epinephrine/creatinine ratio (nmol/mmol). Mean, SD

1.7

1.1

1.6

0.9

0.657

 Urine cortisol/creatinine ratio (nmol/mmol). Median, IQR

4.4

3.3

4.5

2.8

0.605

 Heart rate variability, RMSSD (ms). Mean, SDc

83

50

n/a

  

 Heart rate variability, LF power (abs). Median, IQRd

541

1068

844

1729

0.445

 Heart rate variability, HF power (abs). Median, IQRd

919

2557

1009

1414

0.666

 Heart rate variability, LF/HF-ratio. Mean, SDd

0.83

0.59

0.90

0.41

0.774

Clinical markers

 Inflammatory symptoms (total score). Mean, SDd

2.1

0.8

1.3

0.5

0.010

 Symptoms of post-exertional malaise (total score). Median, IQRd

4.0

1.5

1.0

0.4

<0.001

 Chalder fatigue questionnaire (total score). Mean, SDd

20.4

5.2

6.8

4.9

<0.001

 Moods and feelings questionnaire (total score). Mean, SDd

20.6

10.8

3.9

3.8

<0.001

 Spielberger state-trait anxiety questionnaire (trait subscore). Mean, SDd

46

9.1

32

3.2

<0.001

 Steps per day (number). Mean, SDd

4698

2622

11,282

4670

0.005

  1. Italics indicate a statistically significant p-value
  2. n/a not applicable, SD standard deviation, IQR interquartile range, RMSSD square root of the mean squared differences of subsequent RR-intervals in the ECG, LF low-frequency power of heart rate variability, HF high-frequency power of heart rate variability
  3. aCf. Ref. [88]
  4. bCf. Ref. [89]
  5. cIn the present study, no data were obtained from the healthy control group
  6. dIn the present study, data were obtained from eight healthy controls only
  7. eBased upon t test, Mann–Whitney test or Fisher exact test as appropriate