Table I.
Demographic and clinical characteristics of CFS and non-CFS twins
| Characteristic | CFS Twin n = 13 | Non-CFS Twin n = 13 |
|---|---|---|
| Current age, mean years (SD) | 45.4 (10.0) | 45.4 (10.0) |
| Married, number | 10 | 9 |
| High school completion, number | 7 | 9 |
| Body mass index, mean kg/m2 (SD) | 30.1 (7.2) | 29.7 (6.1) |
| Lifetime major depression, number | 3 | 2 |
| Current major depression, number | 0 | 0 |
| Menopause *, number | 6 | 4 |
| Tender points, mean number (SD)1 | 17.5 (1.0) | 10.8 (5.6) |
| Fibromyalgia**, number1 | 9 | 1 |
| Duration of CFS, years (SD) | 9.2 (3.7) | -- |
| Age at onset of CFS, mean years (SD) | 36.8 (3.7) | -- |
One non-CFS twin was missing menopause status;
**
Fibromyalgia defined as widespread pain and ≥11 tender points; SD = standard deviation;
1
p<.05