Table 4: Hazard ratios (HR) and 95% confidence intervals (CI) for the association of body mass index, waist circumference, and waist-hip ratio with risk of incident, invasive breast cancer in postmenopausal women.

Quintiles for trend
12345

Body mass index
 Cases8089102102129
 Person-years25,40925,46825,05824,86824,109
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.13
(0.83–1.53)
1.31
(0.98–1.76)
1.33
(0.99–1.79)
1.74
(1.31–2.31)
<0.0001
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.15
(0.84–1.57)
1.41
(1.04–1.91)
1.43
(1.05–1.95)
1.97
(1.45–2.68)
<0.0001

Waist circumference
 Cases8974100108131
 Person-years27,18723,19025,01425,40124,332
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
0.98
(0.72–1.43)
1.22
(0.91–1.63)
1.30
(0.98–1.72)
1.68
(1.28–2.21)
<0.0001
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.00
(0.72–1.37)
1.27
(0.94–1.72)
1.44
(1.07–1.94)
1.97
(1.46–2.65)
<0.0001

Waist : hip ratio
 Cases8510310288124
 Person-years 26,31525,47225,13924,48023,655
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.26
(0.95–1.69)
1.26
(0.94–1.68)
1.12
(0.83–1.51)
1.61
(1.22–2.13)
0.004
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.39
(1.02–1.87)
1.46
(1.08–1.98)
1.30
(0.94–1.78)
1.91
(1.41–2.58)
0.0001

Adjusted 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.