Table 1.
Age-standardized characteristics of participants prior to blood draw by study
| Characteristic | Nurses’ Health Studies
|
Women’s Health Study
|
||
|---|---|---|---|---|
| Cases N=222 | Controls N=584 | Cases N=74 | Controls N=243 | |
| Age at blood draw (years)a | 52.0 (7.8) | 51.6 (8.0) | 55.4 (7.7) | 55.4 (7.5) |
| Age at RA diagnosis (years)a | 60.5 (9.9) | NR | 61.3 (7.7) | NR |
| Time to RA onset (years)a | 8.5 (4.9) | NR | 5.8 (2.5) | NR |
| Seropositive (RF and/or anti-CCP) % | 59 | NR | 58 | NR |
| Radiographic changesb | 23 | NR | 23 | NR |
| Smoking status % | ||||
| Never | 44 | 49 | 35 | 49 |
| Past | 42 | 36 | 57 | 42 |
| Current | 15 | 14 | 8 | 8 |
| Body mass index (kg/m2) | 26.1 (5.1) | 25.0 (4.3) | 26.1 (5.9) | 25.7 (5.0) |
| Average alcohol intake (g/day) | 4.4 (6.2) | 5.6 (8.3) | 5.7 (10.9) | 5.4 (10.2) |
| Husband/partner’s education % | ||||
| <4 years of college | 36 | 33 | ||
| 4-year college | 26 | 27 | ||
| Graduate school | 22 | 25 | ||
| Missing/Not applicable | 16 | 15 | ||
| Median family income % | ||||
| <$40,000 | 12 | 11 | ||
| $40,000 – $49,999 | 20 | 20 | ||
| $50,000 – $64,999 | 31 | 31 | ||
| $65,000 – $79,999 | 20 | 19 | ||
| $80,000+ | 18 | 19 | ||
| Menopausal status % | ||||
| Premenopausal | 36 | 36 | 24 | 26 |
| Postmenopausal, No HT use | 23 | 25 | 16 | 13 |
| Postmenopausal, HT use | 31 | 29 | 40 | 40 |
| Menopausal status unknown | 11 | 11 | 20 | 22 |
| IL-6 (pg/ml) | 1.6 (1.7) | 1.4 (1.4) | 2.3 (2.8) | 2.1 (2.5) |
| sTNFRII (pg/ml) | 2427 (716) | 2406 (757) | 2320 (666) | 2200 (585) |
| Median leukocyte telomere lengthc | 0.62 | 0.59 | 0.24 | 0.21 |
Mean (standard deviation) unless otherwise stated
a
Value is not age-adjusted
b
Erosions or periarticular osteopenia consistent with RA
c
Different protocol and calibrator DNA used in Nurses’ Health Studies vs. Women’s Health Study