Table 1 Demographic information for the discovery and replication cohorts stratified by sex
From: X chromosome-wide analysis identifies DNA methylation sites influenced by cigarette smoking
Variable | N (%) or mean (SD) | |||||
|---|---|---|---|---|---|---|
Twins I (n = 139) | Twins II (n = 78) | GSE50660 male (n = 327) | GSE50660 female (n = 137) | GSE42861 male (n = 95) | GSE42861 female (n = 238) | |
Current smoker | Â | Â | Â | Â | Â | |
 Yes | 47 (34 %) | 17 (22 %) | 15 (4.6 %) | 7 (5.1 %) | 23 (24 %) | 66 (28 %) |
 No | 92 (66 %) | 61 (78 %) | 312 (95 %) | 130 (95 %) | 72 (76 %) | 172 (72 %) |
Age | 55.7 (3.3) | 55.4 (3.3) | 54.6 (6.8) | 57.3 (5.9) | 55.5 (10.5) | 51.7 (11.7) |
BMI | 28.9 (4.3) | 29.7 (4.1) | NA | NA | NA | NA |