Table 6.
Hazard ratios (HR) and 95% confidence intervals (CI) from time-dependent covariate analysis of the association of body mass index, waist circumference, and waist-hip ratio with risk of incident, invasive breast cancer in postmenopausal women.
| Quintiles | P for trend | |||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | ||
| Average value: | ||||||
| Body mass index | ||||||
| Age- and energy-adjusted HR (95% CI) | 1.00 Ref. |
1.05 (0.76–1.44) |
1.20 (0.89–1.63) |
1.18 (0.87–1.61) |
1.60 (1.19–2.14) |
0.0012 |
| Multivariable-adjusted HR (95% CI) a | 1.00 Ref. |
1.05 (0.75–1.45) |
1.29 (0.94–1.76) |
1.25 (0.90–1.71) |
1.74 (1.27–2.40) |
0.0004 |
| Waist circumference | ||||||
| Age- and energy-adjusted HR (95% CI) | 1.00 Ref. |
0.89 (0.64–1.22) |
0.99 (0.73-1.34) |
1.28 (0.96–1.71) |
1.56 (1.17–2.07) |
<0.0001 |
| Multivariable-adjusted HR (95% CI)a | 1.00 Ref. |
0.90 (0.65–1.25) |
1.02 (0.74–1.40) |
1.43 (1.05–1.94) |
1.80 (1.32–2.45) |
<0.0001 |
| Waist : hip ratio | ||||||
| Age- and energy-adjusted HR (95% CI) | 1.00 Ref. |
1.24 (0.91–1.69) |
1.12 (0.82–1.53) |
1.23 (0.91–1.68) |
1.48 (1.10–2.00) |
0.02 |
| Multivariable-adjusted HR (95% CI)a | 1.00 Ref. |
1.38 (0.99–1.91) |
1.28 (0.92–1.78) |
1.46 (1.06–2.03) |
1.79 (1.30–2.47) |
0.0007 |
|
| ||||||
| Value 2–4 years prior to diagnosis: | ||||||
| Body mass index | ||||||
| Age- and energy-adjusted HR (95% CI) | 1.00 Ref. |
0.96 (0.63–1.46) |
1.06 (0.71–1.59) |
0.97 (0.64–1.47) |
1.43 (0.97–2.10) |
0.08 |
| Multivariable-adjusted HR (95% CI)a | 1.00 Ref. |
0.97 (0.63–1.50) |
1.16 (0.77–1.77) |
1.07 (0.69–1.65) |
1.64 (1.08–2.49) |
0.02 |
| Waist circumference | ||||||
| Age- and energy-adjusted HR (95% CI) | 1.00 Ref. |
0.82 (0.51–1.30) |
0.61 (0.37–0.99) |
0.92 (0.60–1.42) |
1.27 (0.84–1.90) |
0.17 |
| Multivariable-adjusted HR (95% CI)a | 1.00 Ref. |
0.88 (0.55–1.41) |
0.64 (0.38–1.07) |
1.08 (0.69–1.71) |
1.53 (0.98–2.37) |
0.03 |
| Waist : hip ratio | ||||||
| Age- and energy-adjusted HR (95% CI) | 1.00 Ref. |
1.15 (0.72–1.84) |
0.94 (0.57–1.52) |
0.99 (0.62–1.60) |
1.38 (0.89–2.14) |
0.24 |
| Multivariable-adjusted HR (95% CI)a | 1.00 Ref. |
1.23 (0.76–2.00) |
1.06 (0.64–1.75) |
1.14 (0.70–1.88) |
1.66 (1.04–2.63) |
0.05 |
aAdjusted for age at enrollment, education, ethnicity, family history of breast cancer, age at menarche, age at first full-term birth, parity, age at menopause, oral contraceptive use, duration of hormone therapy, previous breast biopsy, physical activity, alcohol intake, pack-years of smoking, intake of energy, and randomization status.