Leukocyte DNA methylation and colorectal cancer among male smokers

Table 1 Characteristics of cases and controls n (%)

	Controls (n = 219)	Cases (n = 221)	P1
Age of randomization (mean) (yr)	58 (54-62)	58 (54-61)	0.7
ATBC			0.33
Placebo	62 (28)	48 (22)
Β-carotene	56 (26)	60 (27)
VitE	49 (22)	62 (28)
Both	52 (24)	51 (23)
Family history of CRC	6 (3)	6 (3)	0.98
Smoking age (mean) (yr)	20 (17-22)	19 (17-20)	0.18
Smoking years (mean) (yr)	36 (30-42)	37 (31-42)	0.26
BMI (kg/m2)			0.03
< 25	80 (36)	75 (34)
25-29.9	113 (52)	99 (45)
≥ 30	26 (12)	47 (21)

¹P from T-test for continuous variables or χ² test for categorical variables. CRC: Colorectal cancer; ATBC: α-tocopherol, β-carotene; BMI: Body mass index.