Table 3 Interaction of the MTHFR C677T polymorphism and cigarette smoking or alcohol drinking

1.0 (reference)

-

1.0 (reference)

-

228/147

2.23 (1.64 - 3.03)

<0.01

3.03 (2.12 - 4.34)

<0.01

1.39 (0.78 - 2.46)

0.28

1.95 (0.99 - 3.84)

0.05**

81/23

5.06 (3.02 - 8.47)

<0.01

6.16 (3.48 - 10.9)

<0.01

Crude P_interaction = 0.21 and adjusted P_interaction = 0.93

Appropriate drinkers

Excessive drinkers

OR (95% CI)

Cases/

OR (95% CI)

Crude

P

Adjusted*

P

Controls

Crude

P

Adjusted*

P

1.0 (reference)

-

1.0 (reference)

-

226/151

2.07 (1.52 - 2.81)

<0.01

1.97 (1.38 - 2.82)

<0.01

2.56 (1.52 - 4.31)

<0.01

2.46 (1.37 - 4.43)

<0.01

58/24

3.34 (1.97 - 5.66)

<0.01

3.09 (1.64 - 5.81)

<0.01

Crude P_interaction = 0.22 and adjusted P_interaction = 0.30