Table 1 Characteristics of the study population
From: Smoking-associated DNA methylation markers predict lung cancer incidence
Characteristics | Training set | Validation set | ||||
|---|---|---|---|---|---|---|
Cases (N = 78) | Controls (N = 222) | p valueb | Cases (N = 65) | Controls (N = 235) | p valueb | |
No. (%)a | No. (%)a | No. (%)a | No. (%)a | |||
Age (years) | 64 (5.7) | 64 (6.1) | 64 (5.9) | 64 (6.3) | ||
Sex | ||||||
Male | 58 (74.4) | 167 (75.2) | 48 (73.9) | 169 (71.9) | ||
Female | 20 (25.6) | 55 (24.8) | 0.88 | 17 (26.1) | 66 (28.1) | 0.76 |
Smoking statusc | ||||||
Never smoker | 5 (6.5) | 86 (39.8) | 9 (13.9) | 100 (44.8) | ||
Former smoker | 29 (37.7) | 90 (41.7) | 26 (40.0) | 88 (39.5) | ||
Current smoker | 43 (55.8) | 40 (18.5) | <0.0001 | 30 (46.2) | 35 (15.7) | <0.0001 |
Body mass index (kg/m2)d | ||||||
Under weight (<18.5) | 1 (1.3) | 0 | 1 (1.6) | 1 (0.43) | ||
Normal weight (18.5–<25.0) | 25 (32.5) | 55 (24.8) | 19 (29.2) | 62 (26.4) | ||
Overweight (25.0–<30.0) | 29 (37.7) | 115 (51.8) | 32 (49.2) | 119 (50.6) | ||
Obesity (≥30.0) | 22 (28.5) | 52 (23.4) | 0.07 | 13 (20.0) | 53 (22.6) | 0.74 |
Educational levele | ||||||
Low | 59 (78.7) | 143 (65.3) | 57 (87.7) | 164 (71.6) | ||
Intermediate | 11 (14.7) | 41 (18.7) | 3 (4.6) | 35 (15.3) | ||
High | 5 (6.6) | 35 (16.0) | 0.06 | 5 (7.7) | 30 (13.1) | 0.02 |
Physical activityf | ||||||
Inactive | 18 (23.1) | 40 (18.0) | 25 (38.5) | 48 (20.6) | ||
Insufficient | 43 (55.1) | 95 (42.8) | 23 (35.4) | 115 (49.4) | ||
Sufficient | 17 (21.8) | 87 (39.2) | 0.02 | 17 (26.1) | 70 (30.0) | 0.01 |
Family history of cancerg | ||||||
No | 39 (52.0) | 132 (60.0) | 30 (47.6) | 132 (56.4) | ||
Yes | 36 (48.0) | 88 (40.0) | 0.23 | 33 (52.4) | 102 (43.6) | 0.21 |
Diabetesh | ||||||
Not prevalent | 64 (82.0) | 188 (85.1) | 50 (76.9) | 198 (84.3) | ||
Prevalent | 14 (18.0) | 33 (14.9) | 0.53 | 15 (23.1) | 37 (15.7) | 0.17 |
Cardiovascular disease | ||||||
Not prevalent | 60 (76.9) | 177 (79.7) | 44 (67.7) | 180 (76.6) | ||
Prevalent | 18 (23.1) | 45 (20.3) | 0.60 | 21 (32.3) | 55 (23.4) | 0.14 |
Systolic blood pressure (mmHg)i | 140 (18) | 140 (19) | 0.12 | 141 (17) | 141 (19) | 0.77 |
Total cholesterol (mg/dL)j | 205.6 (54.4) | 200.5 (58.7) | 0.48 | 236.1 (38.4) | 224.8 (43.6) | 0.03 |
Pack-yearsk | 39.2 (25.4) | 16.2 (20.2) | <0.0001 | 34.3 (22.6) | 13.4 (18.4) | <0.0001 |