Table 1 Distribution of baseline characteristics for 4,769 women from Diet, Cancer, and Health cohort
Total N = 4,769 | Mammographic density | ||
|---|---|---|---|
Mixed/dense N = 2,705 | Fatty N = 2,064 | ||
Baseline characteristics | |||
Mean (SD) age (years) | 56.2 (4.4) | 55.4 (4.3) | 57.2 (4.4) |
Menopausal, n (%) | 3,930 (82.4) | 2,147 (79.4) | 1,783 (86.4) |
Mean (SD) BMI (kg/m2) | 25.9 (4.7) | 24.6 (3.9) | 27.6 (5.1) |
Obese, n (%) | 792 (16.6) | 249 (9.2) | 543 (26.3) |
Short education (≤7 years), n (%) | 1660 (34.8) | 816 (30.2) | 844 (40.9) |
Medium education (8–10 years), n (%) | 2355 (49.4) | 1369 (50.6) | 986 (47.8) |
Long education (>10 years), n (%) | 754 (15.8) | 520 (19.2) | 234 (11.3) |
Alcohol use, n (%) | 4,610 (96.7) | 2623 (97.0 ) | 1987 (96.3) |
Mean (SD) alcohol use in users (g/day) | 13.9 (16.6) | 14.8 (16.4) | 12.8 (16.8) |
Never smoked, n (%) | 1814 (38.0) | 1025 (37.9) | 789 (38.2) |
Previously smoked, n (%) | 993 (20.8) | 548 (20.3) | 445 (21.6) |
Current smoker, n (%) | 1962 (41.1) | 1132 (41.8) | 830 (40.2) |
Mean (SD) duration of smoking in ever smokers (years) | 30.2 (11.8) | 29.4 (11.6) | 31.1 (11.9) |
Mean (SD) smoking intensity in ever smokers (g/day) | 10.0 (9.6) | 10.2 (9.7) | 9.7 (9.4) |
Physically active, n (%) | 2370 (49.7) | 1384 (51.2) | 986 (47.8) |
Nulliparious, n (%) | 662 (13.9) | 455 (16.8) | 207 (10.0) |
History of benign breast tumor, n(%) | 603 (12.6) | 429 (15.9) | 174 (8.4) |
Ever used HRT | 2295 (48.1) | 1,398 (51.7) | 897 (43.5) |
Mean (SD) duration of HRT use in ever users (years) | 5.6 (6.2) | 5.6 (6.2) | 5.6 (6.2) |
Air pollution exposure at residential address | |||
Mean (SD) baseline NOx (1-year mean 1993/97) | 46.1 (42.4) | 45.7 (41.5) | 46.7 (43.5) |
Mean (SD) NOx since 1971 (ca. 25-year mean 1971-1993/97) | 41.5 (30.7) | 41.0 (30.0) | 42.1 (31.6) |
Mean (SD) baseline NO2 (1-year mean 1993/97) | 23.0 (8.3) | 23.0 (8.2) | 23.1 (8.4) |
Mean (SD) NO2 since 1971 (ca. 25-year mean 1971-1993/97) | 21.2 (6.2) | 21.1 (6.0) | 21.3 (6.3) |