Table 1.
Baseline characteristics of colorectal cancer cases and controls in a nested case-control study within the ATBC Study
| Colorectal cancer cases (N=644) |
Controls (N=644) |
P-value | |||
|---|---|---|---|---|---|
| N | Value | N | Value | ||
| Age at baseline | 644 | 57 (5) | 644 | 57 (5) | 0.39 |
| Married | 644 | 530 (82) | 644 | 539 (84) | 0.46 |
| Education | 644 | 644 | 0.19 | ||
| <HS | 186 (29) | 216 (34) | |||
| Some college or technical school | 421 (65) | 396 (61) | |||
| College graduate | 37 (6) | 32 (5) | |||
| Height (cm) | 643 | 174.0 (6.0) | 644 | 173.7 (6.1) | 0.39 |
| Weight (kg) | 643 | 80.4 (12.6) | 644 | 78.9 (11.4) | 0.03 |
| Body mass indexa (kg/m2) | 643 | 26.5 (3.8) | 644 | 26.1 (3.4) | 0.06 |
| Heavy physical activity | |||||
| Leisure time | 644 | 39 (6) | 643 | 45 (7) | 0.49 |
| Occupational | 644 | 51 (8) | 644 | 64 (10) | 0.21 |
| Physical activity ≥3 times/weeka | 644 | 118 (18) | 644 | 120 (19) | 0.89 |
| Family history of colorectal cancer | 436 | 25 (6) | 485 | 22 (5) | 0.41 |
| Cigarettes per day | 644 | 19.4 (8.4) | 644 | 20 (9) | 0.93 |
| Years Smoked | 644 | 35.9 (8.3) | 644 | 35.9 (7.9) | 0.95 |
| Pack-years | 644 | 35.2 (17.5) | 644 | 35.4 (18.0) | 0.90 |
| Age at smoking initiation) | 644 | 19.6 (4.9) | 644 | 19 (4) | 0.11 |
| Aspirin use (% yes) | 489 | 70 (14) | 536 | 98 (18) | 0.09 |
| Supplement Use | 643 | 126 (20) | 643 | 125 (19) | 0.94 |
| Calcium | 637 | 64 (10) | 638 | 70 (11) | 0.59 |
| Vitamin D | 637 | 39 (6) | 638 | 52 (8) | 0.16 |
| Dietary Intake (per day) | |||||
| Energy (kcal) | 614 | 2691.5 (708.6) | 616 | 2668.3 (708.2) | 0.57 |
| Folate including supplements (µg) | 614 | 339.8 (98.7) | 616 | 340.2 (102.2) | 0.94 |
| Alcohol (g) | 614 | 18.8 (20.9) | 616 | 16.5 (20.3) | 0.05 |
| Serum biomarkers (µmol/L) | |||||
| Trimethylamine N-oxide (TMAO) | 644 | 4.8 (3.9) | 644 | 4.7 (3.9) | 0.51 |
| Median (25th–75th percentile) | 3.73 (2.61–5.46) | 3.6 (2.5–5.2) | |||
| Choline | 644 | 15.2 (15.2) | 644 | 10.4 (9.9) | <0.01* |
| Median (25th–75th percentile) | 10.24 (7.90–15.68) | 8.7 (7.0–10.5) | |||
| Carnitine | 644 | 34.2 (7.4) | 644 | 33.9 (7.2) | 0.40 |
| Median (25th–75th percentile) | 33.79 (29.91–38.23) | 33.5 (29.8–38.3) | |||
| Betaine | 644 | 33.08 (13.72) | 644 | 32.4 (11.2) | 0.33 |
| Median (25th–75th percentile) | 30.72 (25.05–38.54) | 30.6 (24.8–37.6) | |||
ATBC Study, The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. 2 participants had diagnoses of both colon and rectal cancers on the same date and only contribute once to these data. Values are number (percent) or mean (standard deviation) unless otherwise noted. P-values represent a t-test for difference in unadjusted means.
a
Leisure-time physical activity
*
P<0.0001