| 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 |