Table 1 Sample demographics
| Sample set 1 | Sample set 2 | ||||||
|---|---|---|---|---|---|---|---|
| Characteristics |
All samples N = 729 |
Low mammographic density N = 295 |
High mammographic density N = 295 |
Karma normal N = 139 |
All samples N = 600 |
Low mammographic density N = 300 |
High mammographic density N = 300 |
| Mean (SD) | |||||||
| Age, years | 53.6 (9.5) | 52.9 (9.5) | 52.9 (9.5) | 56.5 (9.1) | 54.2 (9.6) | 54.2 (9.6) | 54.2 (9.6) |
| BMI, kg/m2 | 24.4 (3.1) | 24.4 (2.6) | 24.2 (2.6) | 25.2 (4.5) | 24.1 (2.7) | 24.2 (2.7) | 24.1 (2.7) |
| Absolute breast dense area, cm2 | 35.4 (29.3) | 17.0 (13.9) | 56.6 (30.0) | 29.4 (22.1) | 37.3 (31.2) | 15.7 (12.5) | 58.9 (29.4) |
| Absolute volumetric breast density, cm3 | 72.0 (43.6) | 33.9 (10.0) | 108.5 (36.2) | 75.3 (32.4) | 73.0 (49.5) | 33.4 (10.8) | 112.5 (40.7) |
| Age at menarche, years | 13.1 (1.5) | 13.0 (1.5) | 13.2 (1.5) | 13.1 (1.4) | 13.1 (1.4) | 13.1 (1.4) | 13.1 (1.3) |
| Age at first birth, years | 27.5 (5.4) | 27.5 (5.3) | 28.2 (5.7) | 26.2 (4.8) | 27.8 (5.2) | 27.4 (5.1) | 28.3 (5.3) |
| Age at menopause, years | 50.2 (5.5) | 50.3 (5.8) | 50.0 (5.1) | 50.3 (5.6) | 49.6 (5.3) | 49.2 (5.4) | 50.1 (5.2) |
| Number (percent) | |||||||
| Nulliparous | 86 (11.9) | 18 (6.1) | 51 (17.3) | 17 (12.7) | 103 (17.2) | 37 (12.3) | 66 (22.0) |
| Menopausal status | |||||||
| Premenopausal | 337 (46.4) | 140 (47.5) | 157 (53.2) | 40 (29.4) | 268 (44.7) | 129 (43.0) | 139 (46.3) |
| Postmenopausal | 389 (53.6) | 155 (52.5) | 138 (46.8) | 96 (70.6) | 332 (55.3) | 171 (57.0) | 161 (53.7) |
| HRT use ever | |||||||
| No | 527 (79.0) | 233 (79.0) | 243 (82.4) | 96 (71.6) | 488 (81.3) | 241 (80.3) | 247 (82.39 |
| Yes | 152 (21.0) | 62 (21.0) | 52 (17.6) | 38 (28.4) | 112 (18.7) | 59 (19.7) | 53 (17.7) |