Crude and adjusted HR of general and central adiposity indicators
| Age-adjusted HR (95% CI) | Model 1 HR (95% CI) | Model 2 HR (95% CI) | |
| BMI groups at 20 years | |||
| Cases/total | 857/16 055 | 457/8825 | NA |
| Underweight | 0.93 (0.73 to 1.15) | 0.97 (0.71 to 1.34) | – |
| Normal weight | 1.00 | 1.00 | |
| Overweight | 0.83 (0.63 to 1.01) | 0.81 (0.55 to 1.21) | – |
| Obese | 0.94 (0.51 to 1.76) | 0.42 (0.10 to 1.68) | – |
| Linear model (per kg/m2) | 0.98 (0.96 to 1.00) | 0.98 (0.94 to 1.01) | – |
| P for trend (linear model) | 0.123 | 0.168 | – |
| BMI groups at enrolment | |||
| Cases/total | 901/17 003 | 476/9241 | 453/8781 |
| Underweight | 0.54 (0.27 to 1.09) | 0.49 (0.16 to 1.55) | 0.32 (0.08 to 1.30) |
| Normal weight | 1.00 | 1.00 | 1.00 |
| Overweight | 1.27 (1.10 to 1.47) | 1.28 (1.05 to 1.56) | 1.34 (1.09 to 1.65) |
| Obese | 1.32 (1.08 to 1.62) | 1.18 (0.88 to 1.59) | 1.27 (0.91 to 1.76) |
| Linear model (per kg/m2) | 1.03 (1.02 to 1.04) | 1.03 (1.00 to 1.05) | 1.04 (1.02 to 1.07) |
| P for trend (linear model) | 0.021 | 0.001 | |
| Waist circumference at enrolment | |||
| Case/total | 776/14 476 | 483/9334 | 380/7377 |
| Waist circumference (per 5 cm) | 1.05 (1.02 to 1.09) | 1.06 (1.01 to 1.11) | 1.07 (1.01 to 1.14) |
| Skirt size at enrolment | |||
| Case/total | 911/16 906 | 479/9197 | 447/8552 |
| ≤10 | 1.00 | 1.00 | 1.00 |
| 12 | 1.95 (1.29 to 2.96) | 2.06 (1.12 to 3.78) | 1.92 (1.04 to 3.54) |
| 14 | 2.02 (1.34 to 3.03) | 2.43 (1.35 to 4.39) | 2.45 (1.35 to 4.43) |
| 16 | 2.31 (1.54 to 3.48) | 2.74 (1.51 to 4.97) | 2.87 (1.58 to 5.22) |
| 18 | 2.32 (1.52 to 3.55) | 2.67 (1.43 to 4.98) | 2.74 (1.45.5.15) |
| ≥20 | 2.57 (1.66 to 3.97) | 3.21 (1.70 to 6.08) | 3.06 (1.58 to 5.93) |
| Linear model (per 2 unit) | 1.09 (1.05 to 1.15) | 1.12 (1.06 to 1.19) | 1.14 (1.06 to 1.22) |
| P for trend (linear model) | <0.001 | <0.001 | <0.001 |
| Blouse size at enrolment | |||
| Case/total | 873/16 222 | 459/8834 | 428/8206 |
| ≤10 | 1.00 | 1.00 | 1.00 |
| 12 | 1.56 (1.13 to 2.17) | 2.04 (1.24 to 3.36) | 2.11 (1.26 to 3.53) |
| 14 | 1.59 (1.16 to 2.20) | 2.13 (1.30 to 3.48) | 2.25 (1.36 to 3.75) |
| 16 | 1.74 (1.25 to 2.42) | 2.20 (1.33 to 3.64) | 2.39 (1.42 to 4.03) |
| 18 | 1.57 (1.09 to 2.26) | 2.02 (1.16 to 3.52) | 2.21 (1.24 to 3.96) |
| ≥20 | 2.11 (1.46 to 3.03) | 2.63 (1.50 to 4.61) | 2.92 (1.60 to 5.32) |
| Linear model (per 2 unit) | 1.08 (1.03 to 1.12) | 1.08 (1.01 to 1.14) | 1.10 (1.03 to 1.18) |
| P for trend (linear model) | 0.001 | 0.019 | 0.005 |
Model 1: adjusted for age, education levels, parity, age at first birth, age of menarche, use of HRT, use of OC, family history of breast cancer, dietary pattern, walking (hours/day).
Model 2: model 1+BMI at 20 years.
BMI, body mass index; HRT, hormone replacement therapy; OC, oral contraceptive.