Table 1.
Characteristics of the study population (n = 1243).
| Characteristic | Control (n = 410)a | Case Group I (n = 191)b | Case Group II (n = 642)c | Subgroup I (n = 122)d | Subgroup II (n = 340)e | Subgroup III (n = 311)f | Subgroup IV (n = 611)g |
|---|---|---|---|---|---|---|---|
| Age (mean ± SD) | 29.90 ± 3.61 | 29.19 ± 3.91 | 29.11 ± 4.51 | 29.39 ± 4.86 | 29.15 ± 4.54 | 29.11 ± 4.59 | 29.13 ± 4.45 |
| BMI (mean ± SD)h | 23.77 ± 2.94 | 23.23 ± 2.92 | 23.27 ± 3.11 | 23.48 ± 3.13 | 23.14 ± 3.11 | 23.12 ± 3.12 | 23.26 ± 3.14 |
| Smoking status [n (%)] | |||||||
| Never smoker | 186 (45.4) | 84 (44.0) | 305 (47.5) | 48 (39.3) | 142 (41.8) | 127 (40.8) | 294 (48.1) |
| Ever smoker | 224 (54.6) | 107 (56.0) | 337 (52.5) | 74 (60.7) | 198 (58.2) | 184 (59.2) | 317 (51.9) |
| Current smoker | 199 (48.5) | 90 (47.1) | 288 (44.9) | 66 (54.1) | 169 (49.7) | 155 (49.8) | 268 (43.9) |
| Former smoker | 25 (6.1) | 17 (8.9) | 49 (7.6) | 8 (6.6) | 29 (8.5) | 29 (9.3) | 49 (8.0) |
| Pack-years (mean ± SD)f | 4.58 ± 4.70 | 5.28 ± 4.15 | 5.33 ± 5.80 | 5.92 ± 7.79 | 5.30 ± 6.04 | 5.43 ± 6.23 | 5.25 ± 5.81 |
| Drinking status [n (%)] | |||||||
| Never drinker | 187 (45.6) | 99 (51.8) | 290 (45.2) | 56 (45.9) | 148 (43.8) | 137 (44.1) | 274 (44.8) |
| Ever drinker | 223 (54.4) | 92 (48.2) | 387 (60.3) | 66 (54.1) | 192 (56.5) | 174 (55.9) | 337 (55.2) |
| Current drinker | 211 (51.5) | 74 (38.7) | 292 (45.5) | 53 (43.3) | 163 (47.9) | 147 (47.3) | 280 (45.8) |
| Former drinker | 12 (2.9) | 18 (9.4) | 95 (14.8) | 13 (10.7) | 29 (8.5) | 27 (8.7) | 57 (9.3) |
SD, standard deviation; BMI, body mass index.
aProven fertility men with semen volume ≥ 2 ml, sperm concentration ≥20 × 106/ml, sperm number per ejaculum ≥40 × 106/ml and sperm motility ≥50% motile sperm.
bIdiopathic infertile men with all four semen parameters at or above the WHO reference value.
cIdiopathic infertile men with at least one of the abnormal semen parameters (semen volume, sperm concentration, sperm number per ejaculum and sperm motility).
dIdiopathic infertile men with semen volume < 2 ml.
eIdiopathic infertile men with sperm concentration <20 × 106/ml.
fIdiopathic infertile men with sperm number per ejaculum <40 × 106/ml.
gIdiopathic infertile men with sperm motility <50% motile sperm.
hBMI: kg/m2.