Table 6.
Associations between quartiles of choline and betaine intake and breast cancer risk according to folate intake
| Methyl donors | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | P trend |
|---|---|---|---|---|---|
| Total choline | |||||
| Folate <242 μg/day | |||||
| No. cases/controls | 310/182 | 186/128 | 82/68 | 20/25 | 0.005 |
| Adjusted OR (95% CI)a | 1 | 0.76 (0.55–1.04) | 0.65 (0.43–0.99) | 0.46 (0.23–0.91) | |
| Folate ≥242 μg/day | |||||
| No. cases/controls | 11/19 | 41/74 | 59/135 | 98/176 | 0.970 |
| Adjusted OR (95% CI)a | 1 | 0.68 (0.27–1.72) | 0.56 (0.23–1.36) | 0.76 (0.32–1.84) | |
| P interaction | 0.437 | ||||
| Betaine | |||||
| Folate <242 μg/day | |||||
| No. cases/controls | 239/149 | 191/117 | 118/88 | 50/49 | 0.130 |
| Adjusted OR (95% CI)a | 1 | 1.11 (0.80–1.55) | 0.88 (0.60–1.28) | 0.68 (0.42–1.09) | |
| Folate ≥242 μg/day | |||||
| No. cases/controls | 21/51 | 57/87 | 60/113 | 71/153 | 0.756 |
| Adjusted OR (95% CI)a | 1 | 1.71 (0.86–3.38) | 1.38 (0.71–2.70) | 1.19 (0.62–2.29) | |
| P interaction | 0.670 | ||||
| Total choline + betaine | |||||
| Folate <242 μg/day | |||||
| No. cases/controls | 307/170 | 160/126 | 102/75 | 29/32 | |
| Adjusted OR (95% CI)a | 1 | 0.74 (0.53–1.02) | 0.80 (0.54–1.18) | 0.46 (0.26–0.81) | 0.011 |
| Folate ≥242 μg/day | |||||
| No. cases/controls | 13/31 | 44/76 | 74/128 | 78/169 | |
| Adjusted OR (95% CI)a | 1 | 1.50 (0.66–3.46) | 1.35 (0.61–2.98) | 1.06 (0.48–2.31) | 0.424 |
| P interaction | 0. 694 | ||||
a
Odds ratios were adjusted for occupation, body mass index, age at menarche, live births and age at first live birth, mother/sister/daughter with breast cancer, passive smoking, alcohol consumption, physical activity, total energy intake and study stage. CI, confidence interval; OR, odds ratio.