Table 1 Individual characteristics of the study population
|  | Males n = 551 | Females n = 654 |
|---|---|---|
Age [years, mean (SD)]* | 20.98 (2.09) | 20.35 (1.74) |
Height [cm, mean (SD)]* | 179.75 (9.93) | 166.80 (5.58) |
BMI (body mass index) [kg/m2, mean (SD)]* | 23.99 (2.73) | 20.57 (2.21) |
Year of education [n (%)]* | ||
 1st and 2nd | 219 (39.8) | 316 (48.3) |
 3rd | 144 (26.1) | 181 (27.7) |
 4th and over | 188 (34.1) | 157 (24) |
Physical exercise* | ||
 Less than 2 h weekly | 246 (44.6) | 390 (59.6) |
 3–7 h weekly | 194 (35.2) | 195 (29.8) |
 More than 1 h daily | 103 (18.7) | 40 (6.1) |
Smoking status [n (%)]* | ||
 Nonsmoker | 272 (49.4) | 368 (56.3) |
 Current | 279 (50.6) | 286 (43.7) |
 <10 cigarettes daily | 78 (14.2) | 106 (16.2) |
 10–19 cigarettes daily | 98 (17.8) | 100 (15.3) |
 ≥20 cigarettes daily | 83 (15.1) | 62 (9.5) |
Age of starting smoking [years, n (%)] | ||
 ≤14 | 16 (2.9) | 17 (2.6) |
 15–16 | 57 (10.3) | 58 (8.9) |
 17–18 | 110 (20) | 106 (16.2) |