Body Fat and Breast Cancer Risk in Postmenopausal Women: A Longitudinal Study
Table 3
Hazard ratios (HR) and 95% confidence intervals (CI) for the association of DXA-derived body fat measured at baseline with risk of incident, invasive breast cancer in postmenopausal women.
Quintiles
for trend
1
2
3
4
5
Whole body fat mass
Cases
77
87
112
106
121
Person-years
25,490
25,188
25,404
24,935
24,511
Age- and energy-adjusted HR (95% CI)
1.00 Ref.
1.14 (0.84–1.56)
1.47 (1.10–1.96)
1.42 (1.06–1.91)
1.69 (1.27–2.25)
0.0001
Multivariable-adjusted HR (95% CI)a
1.00 Ref.
1.18 (0.86–1.62)
1.57 (1.16–2.13)
1.47 (1.08–2.02)
1.88 (1.38–2.57)
<0.0001
Whole body percent fat
Cases
81
96
112
100
114
Person-years
25,730
25,157
25,137
25,141
24,364
Age- and energy-adjusted HR (95% CI)
1.00 Ref.
1.21 (0.90–1.62)
1.41 (1.06–1.88)
1.26 (0.94–1.69)
1.50 (1.13–1.99)
0.007
Multivariable-adjusted HR (95% CI)a
1.00 Ref.
1.21 (0.89–1.64)
1.48 (1.10–1.99)
1.28 (0.94–1.75)
1.60 (1.18–2.18)
0.004
Fat mass of trunk
Cases/person-years
79
94
97
106
127
Person-years
25,770
25,353
25,252
24,689
24,466
Age- and energy-adjusted HR (95% CI)
1.00 Ref.
1.21 (0.89–1.63)
1.24 (0.92–1.67)
1.41 (1.05–1.88)
1.74 (1.31–2.31)
<0.0001
Multivariable-adjusted HR (95% CI)a
1.00 Ref.
1.31 (0.96–1.78)
1.34 (0.98–1.83)
1.56 (1.15–2.14)
2.05 (1.50–2.79)
<0.0001
Fat mass of right leg
Cases
81
86
107
109
120
Person-years
24,666
25,231
25,522
25,276
24,835
Age- and energy-adjusted HR (95% CI)
1.00 Ref.
1.05 (0.78–1.43)
1.30 (0.98–1.74)
1.34 (1.01–1.79)
1.53 (1.15–2.04)
0.0008
Multivariable-adjusted HR (95% CI)a
1.00 Ref.
1.00 (0.73–1.36)
1.26 (0.93–1.69)
1.29 (0.95–1.74)
1.53 (1.14–2.07)
0.001
Fat mass of left leg
Cases
78
91
109
101
124
Person-years
24,586
25,501
25,321
25,386
24,736
Age- and energy-adjusted HR (95% CI)
1.00 Ref.
1.14 (0.84–1.54)
1.38 (1.03–1.85)
1.28 (0.95–1.72)
1.64 (1.24–2.19)
0.0004
Multivariable-adjusted HR (95% CI)a
1.00 Ref.
1.05 (0.77–1.43)
1.33 (0.99–1.79)
1.19 (0.87–1.62)
1.63 (1.21–2.20)
0.0007
Ratio of trunk fat mass to average of R and L leg fat mass
Cases
74
117
104
104
104
Person-years
25,932
25,391
25,388
24,864
23,955
Age- and energy-adjusted HR (95% CI)
1.00 Ref.
1.61 (1.20–2.15)
1.43 (1.06–1.93)
1.45 (1.08–1.96)
1.51 (1.12–2.04)
0.04
Multivariable-adjusted HR (95% CI)a
1.00 Ref.
1.68 (1.25–2.28)
1.51 (1.10–2.06)
1.60 (1.17–2.18)
1.77 (1.29–2.42)
0.004
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.
