Table 5a.
Cross-classification by weight change, body mass index at age 20 years (BMI20) and hormone replacement therapy (HRT) with the same BMI and HRT status as reference
| Postmenopausal (n = 66 479/ca = 3409)b | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Never HRT users (n = 33 531) |
Ever HRT users (n = 32 948) |
|||||||||||||||
| BMI20 <25 kg/m2 ca = 939 |
BMI20 ≥25 kg/m2 ca = 430 |
BMI20 <25 kg/m2 ca = 1 412 |
BMI20 ≥25 kg/m2 ca = 628 |
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| Weight change (kg) | Cases (n) | HRa | 95% CI | Cases (n) | HR | 95% CI | Cases (n) | HR | 95% CI | Cases (n) | HR | 95% CI | ||||
| <–2.5 | 28 | 0.91 | 0.64 | 1.30 | 60 | 0.88 | 0.60 | 1.28 | 50 | 0.94 | 0.68 | 1.29 | 64 | 1.07 | 0.67 | 1.73 |
| ±2.5 | 81 | 1.00 | Ref. | 53 | 1.00 | Ref. | 111 | 1.00 | Ref. | 76 | 1.00 | Ref. | ||||
| 2.51–5 | 60 | 1.14 | 0.88 | 1.47 | 44 | 0.92 | 0.64 | 1.32 | 119 | 1.16 | 0.92 | 1.46 | 73 | 1.39 | 0.91 | 2.11 |
| 5.1–10 | 183 | 1.23 | 0.98 | 1.54 | 73 | 0.81 | 0.59 | 1.10 | 347 | 1.23 | 1.01 | 1.51 | 134 | 1.30 | 0.90 | 1.86 |
| 10+ | 587 | 1.52 | 1.24 | 1.86 | 200 | 1.05 | 0.80 | 1.37 | 785 | 1.31 | 1.08 | 1.58 | 281 | 1.33 | 0.95 | 1.87 |
a
Stratified by centre and age at recruitment (categorical 5-year interval) and adjusted for weight at age 20 years, height, age at menarche, age at first pregnancy, education, alcohol consumption, smoking status, physical activity and use of oral contraceptives.
b
Out of 71 751 postmenopausal women at cohort entry, 66 479 women had informaton on BMI at age 20 years and HRT. Out of 4891 postmenopausal breast-cancer cases, 3409 breast-cancer cases had information on BMI at age 20 years and HRT.
95% CI, 95% confidence interval; HR, hazard ratio.