Table 5: Hazard ratios (HR) and 95% confidence intervals (CI) from time-dependent covariate analysis of the association of DXA-derived body fat with risk of incident, invasive breast cancer in postmenopausal women.

Quintiles for trend
12345

Average value:
Whole body fat mass
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.05
(0.76–1.44)
1.31
(0.97–1.77)
1.25
(0.92–1.70)
1.53
(1.13–2.07)
0.003
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.04
(0.75–1.44)
1.37
(1.00–1.86)
1.29
(0.93–1.78)
1.60
(1.16–2.21)
0.002
Whole body percent fat
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.00
(0.73–1.37)
1.33
(0.99–1.78)
1.06
(0.78–1.44)
1.47
(1.10–1.97)
0.01
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
0.99
(0.72–1.38)
1.37
(1.01–1.85)
1.08
(0.78–1.49)
1.52
(1.11–2.08)
0.01
Fat mass of trunk
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.24
(0.90–1.70)
1.21
(0.89–1.66)
1.46
(1.07–1.99)
1.82
(1.34–2.47)
<0.0001
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.33
(0.96–1.85)
1.29
(0.93–1.79)
1.64
(1.19–2.27)
2.07
(1.49–2.87)
<0.0001
Fat mass of right leg
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.05
(0.77–1.43)
1.23
(0.91–1.65)
1.21
(0.90–1.64)
1.69
(1.27–2.26)
0.0003
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
0.96
(0.70–1.32)
1.19
(0.88–1.61)
1.12
(0.82–1.54)
1.60
(1.18–2.16)
0.002
Fat mass of left leg
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.01
(0.74–1.38)
1.29
(0.96–1.73)
1.09
(0.81–1.48)
1.66
(1.25–2.21)
0.0008
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
0.92
(0.67–1.27)
1.25
(0.93–1.69)
1.00
(0.73–1.37)
1.55
(1.15–2.09)
0.005
Ratio of trunk fat mass to average of R and L leg fat mass
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.43
(1.06–1.93)
1.24
(0.91–1.68)
1.21
(0.89–1.65)
1.37
(1.01–1.87)
0.24
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.50
(1.10–2.04)
1.30
(0.94–1.79)
1.32
(0.95–1.82)
1.63
(1.18–2.25)
0.03

Value 2–4 years prior to diagnosis:
Whole body fat mass
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.18
(0.80–1.74)
0.86
(0.56–1.30)
1.03
(0.69–1.53)
1.55
(1.06–2.25)
0.07
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.16
(0.78–1.74)
0.94
(0.61–1.44)
1.04
(0.68–1.59)
1.67
(1.12–2.49)
0.04
Whole body percent fat
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.05
(0.70–1.56)
1.18
(0.81–1.73)
0.85
(0.56–1.28)
1.30
(0.89–1.90)
0.41
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.07
(0.71–1.61)
1.22
(0.82–1.81)
0.88
(0.57–1.36)
1.35
(0.90–2.02)
0.33
Fat mass of trunk
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.31
(0.88–1.93)
0.91
(0.60–1.40)
1.28
(0.86–1.90)
1.60
(1.08–2.36)
0.04
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.39
(0.93–2.09)
1.02
(0.66–1.59)
1.40
(0.92–2.14)
1.83
(1.21–2.79)
0.01
Fat mass of right leg
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.19
(0.81–1.76)
1.11
(0.75–1.65)
0.91
(0.60–1.39)
1.56
(1.07–2.26)
0.12
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.11
(0.75–1.66)
1.08
(0.72–1.61)
0.85
(0.55–1.32)
1.50
(1.02–2.22)
0.17
Fat mass of left leg
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.17
(0.79–1.74)
1.24
(0.84–1.82)
0.95
(0.63–1.44)
1.50
(1.03–2.19)
0.14
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.09
(0.73–1.62)
1.21
(0.82–1.80)
0.89
(0.58–1.36)
1.43
(0.96–2.13)
0.23
Ratio of trunk fat mass to average of R and L leg fat mass
 Age- and energy-adjusted HR (95% CI)1.00
Ref.
1.28
(0.87–1.90)
1.14
(0.76–1.70)
1.20
(0.81–1.78)
1.15
(0.77–1.72)
0.69
 Multivariable-adjusted HR (95% CI)a1.00
Ref.
1.33
(0.89–2.00)
1.21
(0.79–1.83)
1.29
(0.85–1.95)
1.37
(0.90–2.09)
0.22

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.