Table 1.
Subject characteristics.
| Subject Characteristics | ME/CFS (n = 106) | Controls (n = 91) | p-Value * | |
|---|---|---|---|---|
| Sex | Female | 75 | 69 | 0.42 |
| Male | 31 | 22 | ||
| Age | Mean ± SD | 47.8 ± 13.7 | 47.0 ± 14.1 | 0.78 |
| Median (Range) | 51.0 (21.6–70.0) | 50.6 (21.2–68.2) | ||
| Race and Ethnicity | White and not Hispanic | 93 | 85 | 0.40 |
| Hispanic | 6 | 3 | ||
| Not White and not Hispanic | 7 | 3 | ||
| Site of Collection | Incline Village, NV | 23 | 17 | 0.30 |
| Miami, FL | 15 | 5 | ||
| New York, NY | 17 | 19 | ||
| Salt Lake City, UT | 32 | 32 | ||
| Palo Alto, CA | 19 | 19 | ||
| Season of Collection | Winter | 33 | 14 | 0.004 |
| Spring | 72 | 70 | ||
| Summer | 1 | 7 | ||
| sr-IBS Comorbidity † | Yes | 35 | 3 | <0.001 |
| No | 71 | 88 | ||
| BMI | Mean ± SD | 26.1 ± 5.2 | 25.2 ± 4.7 | 0.31 |
| Median (Range) | 25.0 (18.1–41.2) | 25.1 (16.9–38.7) | ||
| Duration of ME/CFS ‡ | Mean ± SD | 15.0 ± 9.8 | n/a | n/a |
| Median (Range) | 14.4 (1.2–44.2) | n/a | ||
| ≥3 years | 92 | n/a | ||
| <3 years | 8 | n/a | ||
| SF-36 Scales § Median (IQR) |
Emotional Limitations | 83.3 (0.0–100.0) | 100.0 (100.0–100.0) | <0.001 |
| Emotional Well-being | 72.0 (56.0–84.0) | 88.0 (80.0–92.0) | <0.001 | |
| General Health | 20.0 (15.0–30.0) | 90.0 (75.0–95.0) | <0.001 | |
| Pain | 45.0 (22.5–66.25) | 90.0 (90.0–100.0) | <0.001 | |
| Physical Functioning | 35.0 (20.0–55.0) | 100.0 (95.0–100.0) | <0.001 | |
| Physical Limitations | 0.0 (0.0–0.0) | 100.0 (100.0–100.0) | <0.001 | |
| Social Functioning | 22.5 (10.0–45.0) | 100.0 (90.0–100.0) | <0.001 | |
| Vitality | 5.0 (0.0–20.0) | 80.0 (70.0–85.0) | <0.001 | |
| MFI Scales || Median (IQR) |
General Fatigue | 91.7 (71.9–100.0) | 16.7 (4.2–33.3) | <0.001 |
| Mental Fatigue | 62.5 (45.8–75.0) | 12.5 (0.0–35.4) | <0.001 | |
| Physical Fatigue | 87.5 (66.7–100.0) | 12.5 (4.2–20.8) | <0.001 | |
| Reduced Activity | 79.2 (58.3–95.8) | 4.2 (2.1–29.2) | <0.001 | |
| Reduced Motivation | 45.8 (29.2–66.7) | 12.5 (4.2–25.0) | <0.001 | |
SD: standard deviation; IQR: interquartile range; ME/CFS: myalgic/encephalomyelitis/chronic fatigue syndrome. * For categorial variable, p-values were derived from Chi-squared tests; for continuous variables, p-values were derived from Wilcoxon rank-sum tests. † Prior physician diagnosed irritable bowel syndrome, self-reported on the questionnaire. ‡ Only 90 responses were received for this item. § 36-Item Short Form Health Survey; scored on a 0–100 scale with 0 = poor health status and 100 = excellent health status. || Multidimensional Fatigue Inventory; scored on 0–100 scale with 0 = no fatigue and 100 = maximal fatigue.