Table 1.

Baseline characteristics of study subjects by adenoma recurrence

CharacteristicAdenoma recurrenceNo adenoma recurrenceP
No. participants392 (45.0)479 (55.0)
Mean age at baseline (SD), y59.1 (9.4)56.2 (9.5)<0.001*
Male sex, n (%) 270 (68.9)289 (60.3)0.01
Colorectal cancer in first-degree relative, n (%)117 (37.6)148 (38.1)0.91
NSAID use at baseline, n (%) 319 (81.4)379 (79.1)0.41
Multivitamin use at baseline, n (%) 134 (34.2)183 (38.2)0.22
Race/Ethnicity, n (%)
    White346 (88.3)408 (85.2)0.18
    African American23 (5.9)25 (5.2)
    Hispanic16 (4.1)27 (5.6)
    Other7 (1.8)19 (4.0)
BMI, kg/m2
    <25104 (26.6)161 (33.7)0.08
    25-<30191 (48.9)212 (44.4)
    ≥3096 (24.6)105 (22.0)
Current cigarette smoker, n (%)72 (18.5)51 (10.7)0.00
Mean dietary intake (SD), kcal/day1,645 (697)1,614 (612)0.49*
Mean dietary folate intake (SD),* μg/day316 (144)327 (158)0.31*
Mean total folate intake (SD), μg/day452 (256)466 (249)0.41*
Mean baseline plasma folate (SD), nmol/L22.1 (15.3)25.3 (19.4)0.01
Mean baseline plasma B12 (SD), pmol/L322 (144)337 (179)0.15
Mean baseline plasma B6 (SD), nmol/L77.8 (90.8)84.1 (90.6)0.01
Mean plasma Hcy at baseline (SD), μmol/L10.1 (3.1)9.6 (2.8)0.04
Alcohol use at baseline, n (%)278 (72.8)297 (64.7)0.01
Caffeine use at baseline, n (%)366 (95.8)428 (93.3)0.11
History of high cholesterol at baseline, n (%)§142 (36.3)147 (30.8)0.08
History of hypertension at baseline, n (%)§97 (24.7)120 (25.1)0.92
Lifetime adenomas at baseline, mean (SD)2.8 (2.6)2.0 (1.7)<0.001
Number of baseline adenomas, mean (SD)1.7 (1.1)1.5 (0.9)<0.001
Advanced adenomas at baseline, n (%)
    0248 (70.5)315 (70.3)0.97
    ≥1104 (29.6)133 (29.7)
MTHFR 677 C>T genotype
    CC178 (47.2)197 (44.0)0.35
    CT166 (44.0)199 (44.4)
    TT33 (8.8)52 (11.6)
MTHFR 1298 A>C genotype
    AA174 (46.0)234 (52.1)0.22
    AC169 (44.7)179 (39.9)
    CC35 (9.3)36 (8.0)

Abbreviation: NSAID, nonsteroidal anti-inflammatory drugs.

  • *Two sample t-test.

  • χ2 test.

  • Nonparametric Wilcoxon rank sum test.

  • §Self-reported from the risk factor questionnaire.

  • Advanced adenoma was defined as a ≥25% villous component, large adenoma (≥1 cm), advanced dysplasia, carcinoma in situ, or invasive cancer.