Table 3.

Combined and interactive effects between OPRM1 methylation and environmental factors in breast cancer.

Environment factors	Combined effects			Interactive effects
	Hypomethylation	Hypermethylation	P-value	ORi (95%CI)	P-value
		OReg (95%CI)
Vegetable (g/day)
≥500	1.000	1.706 (1.046–2.781)		1.000
<500	1.303 (0.701–2.424)	2.829 (1.751–4.572)	0.000	0.786 (0.381–1.618)	0.513
Garlic (time/week)
≥1	1.000	2.066 (1.149–3.712)		1.000
<1	2.601 (1.365–4.955)	5.762 (3.208–10.350)	0.000	0.932 (0.442–1.966)	0.854
Soybean (time/week)
≥1	1.000	1.857 (1.265–2.727)		1.000
<1	1.811 (0.674–4.864)	5.592 (2.905–10.764)	0.000	0.601 (0.191–1.897)	0.386
Pork (time/week)
<1	1.000	1.851 (0.743–4.612)		1.000
≥1	1.834 (0.774–4.346)	3.628 (1.593–8.262)	0.002	1.069 (0.397–2.875)	0.895
Poultry (g/week)
≥1	1.000	2.825 (1.648–4.840)		1.000
<1	2.901 (1.544–5.452)	4.173 (2.415–7.210)	0.000	1.964 (0.946–4.075)	0.070
Milk (times/week)
≥3	1.000	2.445 (1.271–4a.703)		1.000
<3	3.409 (1.544–6.020)	5.166 (2.774–9.618)	0.000	1.443 (0.657–3.170)	0.361
Regular sportsa (time/week)
≥1	1.000	2.151 (1.211–3.822)		1.000
<1	2.300 (1.218–4.344)	4.114 (2.357–7.181)	0.000	1.203 (0.576–2.514)	0.623
Psychological stress score b
≤15	1.000	2.368 (1.099–5.103)		1.000
>15	2.972 (1.398–6.321)	5.340 (2.634–10.829)	0.000	0.759 (0.319–1.806)	0.533

OR_eg: OR_{genetic&environment}, combined effects of methylation and environmental factors.

OR_i: OR_interaction, interactive effects of methylation and environmental factors.

^aRegular sports, regular physical exercise such as walking, running, fitness exercise, swimming, and jumping rope.

^bPsychological stress score was evaluated using psychosocial stress survey for groups (PSSG).

Bold values indicate significance after Bonferroni correction, the P-value after Bonferroni correction is 0.05/16 = 0.003125.