Table 1.
Characteristics of the study population
| Cases | Controls | |
| (P2+DY; | (N1+P1; | |
| Characteristics | n = 203) | n = 203) |
| Mean age (years) | 59.3 | 59.3 |
| Mean body mass index | 25.2 | 27.4 |
| Mean waist:hip ratio | 2.1 | 2.4 |
| Menopausal status (n) | ||
| Premenopausal | 44 | 24 |
| Postmenopausal | 148 | 165 |
| Unknown | 11 | 14 |
| Mean age at menarche (years) | 13.0 | 12.7 |
| Mean age at menopause (years) | 47.7 | 47.0 |
| Number of children (n) | ||
| 0 | 31 | 16 |
| 1 | 27 | 26 |
| 2 | 96 | 82 |
| 3 | 34 | 47 |
| 4+ | 15 | 29 |
| Unknown | - | 3 |
| History of benign breast diseases (n) | ||
| No | 188 | 198 |
| Yes | 15 | 5 |
| Hysterectomy (n) | ||
| No | 141 | 152 |
| Yes | 60 | 49 |
| Unknown | 2 | 2 |
| HRT use (n) | ||
| Never | 106 | 131 |
| Past | 22 | 25 |
| Current | 73 | 43 |
| Unknown | 2 | 4 |
| Smoking (n) | ||
| Never | 121 | 120 |
| Past | 62 | 53 |
| Current | 20 | 30 |
HRT, hormone replacement therapy.