Table 1. Baseline characteristics of participants in the Nurses' Health Study (1990)a.
| Variable | Cases (n = 757) | Controls (n = 757) | P |
|---|---|---|---|
| Age at blood draw, year | 56.9 (6.8) | 56.8 (6.7) | 0.24 |
| Body mass index, kg/m2 | 25.9 (4.7) | 25.4 (4.5) | 0.01 |
| Physical activity, MET-hours/week | 14.7 (16.8) | 16.9 (25.2) | 0.14 |
| Colorectal cancer in a parent or sibling, % | 17 | 15 | 0.20 |
| History of lower gastrointestinal endoscopy, % | 33 | 32 | 0.61 |
| Postmenopausal, % | 84 | 84 | 0.70 |
| Current use of menopausal hormone therapy, %b | 42 | 48 | 0.09 |
| Current multivitamin use, % | 37 | 38 | 0.60 |
| Regular aspirin use (≥2 tablets/week), %c | 39 | 43 | 0.14 |
| Regular NSAID use (≥2 tablets/week), %d | 19 | 21 | 0.36 |
| Current smoker, % | 14 | 10 | 0.01 |
| Alcohol consumption, g/d | 5.6 (10.2) | 4.9 (8.6) | 0.78 |
| Calcium intake, mg/d | 1001 (519) | 1035 (484) | 0.06 |
| Dietary AHEI score | 44.0 (9.1) | 45.0 (8.9) | 0.03 |
| Plasma biomarker levels, median (IQR)e | |||
| MIC-1, ng/L | 609 (494-783) | 595 (488-741) | 0.04 |
| CRP, mg/L | 1.91 (0.90-4.04) | 1.56 (0.75-3.62) | 0.01 |
| IL-6, ng/L | 0.96 (0.62-1.59) | 0.96 (0.59-1.58) | 0.55 |
| sTNFR-2, μg/L | 2.68 (2.30-3.16) | 2.64 (2.30-3.10) | 0.07 |
| Time of diagnosis since blood draw, month | 118 (57) | - | |
| Size of adenoma, mm | 14.4 (9.8) | - | |
| Multiple (≥2) adenoma, % | 34 | - | |
| Adenoma location, % | |||
| Proximal colon | 28 | - | |
| Distal colon | 41 | - | |
| Rectum | 13 | - | |
| Multiple adenomas in ≥2 locations | 18 | - | |
| Histology of adenoma, % | |||
| Tubular | 38 | - | |
| Tubulovillous, villous or high-grade dysplasia (CIS) | 62 | - | |
Abbreviations: AHEI, Alternative Healthy Eating Index; CIS, carcinoma in situ; CRP, C-reactive protein; IL-6, interleukin-6; IQR, inter-quartile range; MET, metabolic equivalent; MIC-1, macrophage inhibitory cytokine-1; NSAID, non-steroidal anti-inflammatory drug; sTNFR-2, soluble tumor necrosis factor receptor 2.
a
Mean (standard deviation) is presented for continuous variables unless otherwise specified.
b
Percentage is among postmenopausal women only.
c
Regular use is defined as ≥2 standard (325-mg) tablets of aspirin per week.
d
Regular use is defined as ≥2 tablets of NSAIDs per week.
e
The number of pairs of subjects with missing measurements: 19 for MIC-1, 3 for CRP, and 24 for IL-6.