Table 3.

Association between percentage SFRP methylation and selected demographic, lifestyle, and dietary variables in the rectum and right colon

CountsOverallRectumRight colon
NT/NL/NRMeana (SE)PbMeana (SE)PbMeana (SE)PbPc
Age, y
 Q1 (30–52)107/107/10619.3 (0.4)0.00120.5 (0.5)0.00118.0 (0.5)0.0010.60
 Q2 (53–58)96/94/9620.5 (0.5)21.3 (0.6)19.7 (0.6)
 Q3 (59–64)93/92/9223.0 (0.5)24.5 (0.7)21.6 (0.6)
 Q4 (65–78)92/92/9126.1 (0.6)27.4 (0.7)24.8 (0.8)
Sex
 Male246/244/24422.2 (0.3)0.7523.3 (0.4)0.9321.1 (0.4)0.530.52
 Female142/141/14222.0 (0.4)23.4 (0.5)20.6 (0.5)
Race
 White325/322/32422.1 (0.3)0.000523.3 (0.3)0.00320.9 (0.4)0.010.009
 African American22/22/2119.7 (0.6)21.0 (0.9)18.4 (1.1)
 Hispanic22/22/2223.7 (1.2)23.0 (1.5)24.4 (1.4)
 Other19/19/1923.3 (1.3)26.6 (1.5)20.1 (1.5)
Smoking
 Never164/164/16321.9 (0.4)0.9923.5 (0.5)0.7520.2 (0.5)0.650.11
 Former163/162/16322.4 (0.4)23.2 (0.5)21.6 (0.5)
 Current60/58/5821.9 (0.6)23.2 (0.9)20.6 (0.8)
Alcohol
 Never123/123/12222.7 (0.5)0.3023.9 (0.6)0.2821.4 (0.7)0.540.88
 1 per day85/83/8521.8 (0.3)23.1 (0.4)20.5 (0.4)
 2+ per day165/164/16321.8 (0.6)22.9 (0.7)20.8 (0.6)
Treatment
 Placebo190/187/18922.3 (0.4)0.4723.8 (0.5)0.1720.9 (0.5)0.880.21
 Folate198/198/19621.9 (0.3)22.9 (0.4)21.0 (0.4)
Treatment
 Placebo128/126/12721.6 (0.4)0.7822.6 (0.5)0.3020.6 (0.5)0.670.64
 Aspirin 81137/137/13622.6 (0.5)23.9 (0.5)21.1 (0.6)
 Aspirin 325123/122/12222.2 (0.5)23.4 (0.6)20.9 (0.6)
Multivitamin used
 No256/255/25322.4 (0.4)0.1123.7 (0.4)0.1421.2 (0.5)0.310.71
 Yes130/130/13021.7 (0.3)22.8 (0.4)20.6 (0.4)
Dietary folate, μg/d
 Q1 (78.08–205.86)94/94/9321.9 (0.5)0.5823.3 (0.6)0.4620.6 (0.5)0.770.73
 Q2 (205.87–277.3)94/93/9422.3 (0.5)23.2 (0.6)21.4 (0.8)
 Q3 (277.31–373.65)94/93/9321.7 (0.6)22.8 (0.7)20.6 (0.6)
 Q4 (376.17–1,285.59)93/91/9222.5 (0.5)24.0 (0.6)21.1 (0.7)
Dietary protein, g/d
 Q1 (17.00–44.91)94/93/9322.7 (0.5)0.00523.6 (0.6)0.1021.7 (0.7)0.0040.40
 Q2 (45.15–60.32)94/92/9422.9 (0.5)23.8 (0.6)22.0 (0.7)
 Q3 (60.70–78.71)94/94/9322.0 (0.5)23.7 (0.6)20.4 (0.6)
 Q4 (78.82–144.62)93/92/9220.8 (0.5)22.1 (0.6)19.6 (0.6)

Abbreviations: NT, total individuals; NL, total individuals with samples in the rectum; NR, total individuals with samples on the right side.

  • aMeans are adjusted for age, sex, randomized folate treatment assignment, smoking status, alcohol intake, and adenoma occurrence during the 3-year randomized period.

  • bP value for trend.

  • cP for interaction between colorectal location and variables in the table.

  • dMultivitamins used during the trial did not contain folic acid.