Table 1.
Baseline characteristics of study subjects within the Nurses’ Health Study (NHS) and the Health Professionals Follow-up Study (HPFS)
| Baseline characteristics | Women (NHS) | Men (HPFS) | ||||
|---|---|---|---|---|---|---|
| Case patients (n = 152) |
Control individuals (n = 297) |
P | Case patients (n = 155) |
Control individuals (n = 296) |
P | |
| Mean age at blood draw (SD)*, y | 58.5 (6.7) | 58.5 (6.6) | − | 66.2 (8.4) | 66.2 (8.4) | − |
| Fasting at time of blood draw†, % | 69 | 70 | .84 | 52 | 53 | .93 |
| Mean body mass index (SD), kg/m2 | 25.2 (4.7) | 24.7 (4.4) | .32 | 26.1 (2.9) | 25.3 (2.8) | .02 |
| Mean physical activity, MET-hours per week (SD) | 15.2 (17.7) | 14.8 (16.6) | .60 | 32.1 (27.2) | 30.4 (26.8) | .70 |
| Mean pack-years of smoking before age 30 y among ever-smoker (SD) | 7.3 (7.0) | 6.1 (4.7) | .41 | 10.1 (6.3) | 9.1 (6.4) | .23 |
| Never smoker, % | 44 | 49 | .31 | 39 | 45 | .22 |
| Colorectal cancer in a parent or sibling, % | 16 | 15 | .93 | 21 | 14 | .04 |
| Current multivitamin use, % | 35 | 38 | .55 | 48 | 51 | .55 |
| Regular aspirin use (≥2 tablets/wk), % | 22 | 29 | .12 | 35 | 41 | .26 |
| Current hormone replacement therapy, % | 22 | 16 | .12 | − | − | − |
| History of previous lower endoscopy, % | 14 | 17 | .52 | 54 | 64 | .03 |
| Mean daily intake (SD) | ||||||
| Total calorie, kcal/d | 1.7 (0.46) | 1.7 (0.44) | .52 | 2.1 (0.58) | 2.0 (0.49) | .10 |
| Red meat, serving/d | 0.68 (0.34) | 0.63 (0.31) | .75 | 0.62 (0.40) | 0.56 (0.33) | .13 |
| Processed meat, serving/d | 0.29 (0.27) | 0.27 (0.26) | .56 | 0.38 (0.49) | 0.33 (0.32) | .93 |
| Calcium, mg/d | 922 (350) | 972 (362) | .20 | 917 (331) | 952 (366) | .52 |
| Folate, µg/d | 398 (172) | 415 (185) | .48 | 495 (204) | 529 (238) | .45 |
| Alcohol, g/d | 5.0 (7.0) | 6.0 (9.2) | .67 | 13.4 (16.3) | 10.8 (12.4) | .08 |
| Plasma 25-hydroxyvitamin D, median (IQR), ng/mL | 24.2 (17.5–29.5) | 25.9 (19.2–30.8) | .17 | 27.2 (22.2–33.1) | 27.8 (21.8–33.7) | .96 |
| Plasma adiponectin, median (IQR), µg/mL | 7.9 (5.0–10.8) | 8.2 (5.7–10.6) | .45 | 5.0 (3.0–7.0) | 5.6 (3.7–7.9) | .003 |
| Plasma adiponectin, tertile cutpoints based on controls, µg/mL | 6.7 and 10.0 (batch 1); 6.6 and 9.3 (batch 2) |
4.2 and 6.7 | ||||
| Plasma adiponectin, tertiles | .14 | .06 | ||||
| Tertile 1, No. | 63 | 102 | 60 | 98 | ||
| Tertile 2, No. | 46 | 101 | 53 | 94 | ||
| Tertile 3, No. | 43 | 94 | 42 | 104 | ||
* Age is one of the matching variables. HPFS = Health Professionals Follow-up Study; IQR = interquartile range; MET = metabolic equivalent task; NHS = Nurses’ Health Study; SD = standard deviation.
† Hours since last meal ≥ 8.