Table 2

 Odds ratios for colorectal cancer by categories of plasma folate and homocysteine

OR, odds ratio; CI, 95% confidence interval; Hcys, homocysteine.
*Folate quintile cut offs were for men: 5.1, 6.7, 8.1, and 11.3; and for women: 5.7, 7.4, 9.4, and 13.0 nmol/l.
†Adjusted for body mass index, current smoking, recreational and occupational physical activity, and alcohol intake (alcohol data were available for approximately two thirds of subjects).
‡Categories selected to explore a greater range of plasma folate concentrations.
§Homocysteine quintile cut offs were for men: 9.7, 10.9, 12.4, and 15.1; and for women: 8.8, 10.3, 12.0, and 14.1 μmol/l.
Folate quintiles* Q1 Q2 Q3 Q4 Q5 p Trend
    Cases/referents27/8650/8756/8651/8737/86
    Unadjusted OR (CI)1.001.85 (1.07–3.19)2.26 (1.29–3.95)1.97 (1.12–3.47)1.55 (0.85–2.85)0.173
    Adjusted OR† (CI)1.001.72 (0.99–3.03)2.00 (1.13–3.56)1.87 (1.04–3.36)1.34 (0.72–2.50)0.325
Folate categories‡ <5 nmol/l 5–8 nmol/l 8–12 nmol/l 12–15 nmol/l ⩾15 nmol/l p Trend
    Cases/referents20/6086/16276/12122/3717/52
    Unadjusted OR (CI)1.001.54 (0.88–2.70)1.86 (1.04–3.32)1.88 (0.89–3.96)1.10 (0.52–2.32)0.597
    Adjusted OR† (CI)1.001.52 (0.85–2.70)1.81 (0.99–3.29)1.71 (0.79–3.69)1.01 (0.47–2.19)0.734
Hcys quintiles§ Q1 Q2 Q3 Q4 Q5 p Trend
    Cases/referents39/8637/8854/8852/8844/86
    Unadjusted OR (CI)1.000.93 (0.54–1.56)1.33 (0.80–2.21)1.30 (0.77–2.19)1.12 (0.65–1.95)0.376
    Adjusted OR† (CI)1.000.87 (0.50–1.49)1.26 (0.75–2.11)1.27 (0.74–2.17)1.12 (0.63–1.99)0.354