Table 1.
Characteristics of individuals in the Polyp Prevention Trial of Aspirin and Folate who completed first year follow-up
| Characteristic | Adenoma occurrence | No adenoma occurrence | p-value** |
|---|---|---|---|
| No. of participants | 471 | 613 | |
| Age at baseline, mean ± SD (y) | 59.0 ± 9.3 | 56.2 ± 9.6 | <0.001# |
| Male Sex, No. (%) | 321 (68.2%) | 369 (60.2%) | 0.007 |
| Body-mass index > 30 kg/m2, No. (%) | 117 (24.9%) | 125 (20.4%) | 0.080 |
| Current cigarette smoker, No. (%) | 86 (18.5%) | 72 (11.8%) | 0.002 |
| Colorectal cancer in first-degree relative, No. (%) | 143 (37.1%) | 189 (37.4%) | 0.949 |
| Self identified as White, No. (%) | 412 (87.5 %) | 516 (84.2%) | 0.125 |
| Aspirin use at baseline, No. (%) | 291 (61.8%) | 358 (58.5%) | 0.274 |
| Aspirin Treatment Group¥, No. (%) | 300 (63.7%) | 421 (68.7%) | 0.085 |
| Folate Treatment Group, No. (%) | 221 (51.8%) | 280 (50.0%) | 0.584 |
| Baseline plasma folate, mean ± SD (nmol/L) | 21.9 (15.3%) | 24.4 (19.1%) | 0.025# |
| Baseline plasma B2, mean ± SD | 30.6 ± 56.8 | 27.7 ± 43.6 | 0.374# |
| Baseline plasma B6, mean ± SD | 76.3 ± 89.2 | 81.3 ± 86.8 | 0.378# |
| Baseline plasma B12, mean ± SD | 317.1 ± 141.3 | 333.7 ± 177.1 | 0.112# |
| Multivitamin use, No. (%) | 153 (32.6%) | 226 (37.1%) | 0.125 |
| Dietary intake | |||
| Dietary folate intake, mean ± SD (mg/day) | 317.9 ± 150.4 | 320.7 ± 162.4 | 0.772# |
| Total folate*, mean ± SD (mg/day) | 460.2 ± 309.5 | 461.9 ± 284.7 | 0.927# |
| Dietary vitamin B2 †, mean ± SD ((mg/day) | 30.6 ± 56.8 | 27.7 ± 43.6 | 0.729# |
| Total vitamin B6*, mean ± SD (mg/day) | 2.6 ± 2.2 | 2.5 ± 2.0 | 0.718# |
| Total vitamin B12 ‡, mean ± SD (mg/day) | 2.6 ± 5.8 | 2.5 ± 4.6 | 0.779# |
| Alcohol (drinks per day), No (%) | |||
| None | 121 (26.8%) | 206 (35.4%) | 0.006 |
| 1 or less | 223 (49.4%) | 271 (46.6%) | |
| 2 or more | 107 (23.7%) | 105 (18.0%) | |
| Adenoma Characteristics (at baseline)§ | |||
| Number (mean ± SD) | 1.7 ± 1.1 | 1.5 ± 0.9 | <0.001# |
| Large Adenomas (>1 cm), No. (%) | 107 (22.7%) | 140 (22.8%) | 0.962 |
| Villous histology, No. (%) | 60 (12.7%) | 93 (15.2%) | 0.254 |
| Proximal location, No. (%) | 248 (52.7%) | 244 (39.8%) | <0.001 |