Table 3.
Hazard ratios and 95% CI for the association of baseline DXA‐derived body fat measures and incident, ER‐positive breast cancer in postmenopausal women
| Cases/person‐years | Age‐adjusted HR (95% CI)a | Multivariable‐adjusted HR (95% CI)b | Multivariable‐adjusted HR (95% CI)c | Multivariable‐adjusted HR (95% CI)d | Multivariable‐adjusted HR (95% CI)e | |
|---|---|---|---|---|---|---|
| Whole body fat mass (kg) | ||||||
| Per SD increase | 1.16 (1.06‐1.26) | 1.22 (1.11‐1.33) | 1.28 (1.02‐1.59) | 1.18 (1.00‐1.39) | 1.19 (1.08‐1.31) | |
| Octilesf | ||||||
| 1 | 46/19708.8 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 48/19867.8 | 1.04 (0.69‐1.55) | 1.12 (0.75‐1.68) | 1.11 (0.73‐1.68) | 1.11 (0.74‐1.68) | 1.10 (0.73‐1.66) |
| 3 | 55/19672.6 | 1.20 (0.81‐1.71) | 1.32 (0.86‐1.96) | 1.35 (0.89‐2.05) | 1.31 (0.87‐1.97) | 1.29 (0.87‐1.91) |
| 4 | 58/19883.7 | 1.25 (0.85‐1.84) | 1.40 (0.95‐2.07) | 1.43 (0.94‐2.19) | 1.38 (0.91‐2.09) | 1.35 (0.91‐1.99) |
| 5 | 76/20054.6 | 1.63 (1.13‐2.35) | 1.90 (1.31‐2.75) | 1.96 (1.28‐3.02) | 1.86 (1.22‐2.83) | 1.81 (1.24‐2.64) |
| 6 | 66/19388.8 | 1.47 (1.01‐2.14) | 1.72 (1.17‐2.52) | 1.79 (1.11‐2.87) | 1.65 (1.04‐2.60) | 1.60 (1.08‐2.37) |
| 7 | 65/19189.0 | 1.48 (1.01‐2.15) | 1.75 (1.19‐2.57) | 1.84 (1.08‐3.14) | 1.69 (1.03‐2.77) | 1.64 (1.10‐2.44) |
| 8 | 70/18698.0 | 1.67 (1.15‐2.42) | 2.06 (1.40‐3.02) | 2.22 (1.14‐4.35) | 1.96 (1.10‐3.50) | 1.93 (1.30‐2.86) |
| P for trend | <.001 | <.001 | .003 | .007 | <.001 | |
| Whole body fat percent | ||||||
| Per SD increase | 1.13 (1.03‐1.24) | 1.19 (1.09‐1.31) | 1.12 (0.97‐1.29) | 1.11 (0.98‐1.26) | 1.17 (1.06‐1.29) | |
| Octilesf | ||||||
| 1 | 48/20332.0 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 51/19801.3 | 1.09 (0.74‐1.62) | 1.17 (0.78‐1.73) | 1.10 (0.74‐1.64) | 1.12 (0.75‐1.66) | 1.14 (0.77‐1.70) |
| 3 | 66/20265.4 | 1.38 (0.95‐2.00) | 1.55 (1.07‐2.26) | 1.44 (0.98‐2.12) | 1.43 (0.97‐2.10) | 1.49 (1.02‐2.17) |
| 4 | 61/20071.8 | 1.29 (0.88‐1.88) | 1.48 (1.01‐2.16) | 1.33 (0.89‐1.99) | 1.32 (0.88‐1.96) | 1.40 (0.95‐2.06) |
| 5 | 68/19718.9 | 1.46 (1.01‐2.11) | 1.72 (1.18‐2.50) | 1.51 (1.01‐2.26) | 1.49 (0.99‐2.22) | 1.60 (1.10‐2.35) |
| 6 | 61/18786.2 | 1.38 (0.95‐2.02) | 1.62 (1.10‐2.38) | 1.38 (0.90‐2.12) | 1.37 (0.90‐2.09) | 1.51 (1.02‐2.24) |
| 7 | 66/19058.1 | 1.47 (1.01‐2.13) | 1.75 (1.19‐2.56) | 1.44 (0.93‐2.21) | 1.36 (0.88‐2.11) | 1.63 (1.11‐2.40) |
| 8 | 63/18429.5 | 1.47 (1.01‐2.15) | 1.80 (1.23‐2.65) | 1.39 (0.86‐2.23) | 1.26 (0.78‐2.03) | 1.70 (1.15‐2.51) |
| P for trend | .019 | .001 | .275 | .446 | .012 | |
| Trunk fat mass (kg) | ||||||
| Per SD increase | 1.15 (1.05‐1.25) | 1.21 (1.11‐1.33) | 1.22 (1.01‐1.47) | 1.18 (0.98‐1.42) | 1.18 (1.07‐1.31) | |
| Octilesf | ||||||
| 1 | 40/20173.2 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 60/20018.3 | 1.51 (1.01‐2.25) | 1.65 (1.10‐2.46) | 1.66 (1.10‐2.49) | 1.64 (1.09‐2.47) | 1.63 (1.09‐2.44) |
| 3 | 61/19814.0 | 1.55 (1.04‐2.31) | 1.76 (1.18‐2.63) | 1.74 (1.15‐2.64) | 1.76 (1.15‐2.68) | 1.72 (1.15‐2.58) |
| 4 | 46/19722.3 | 1.17 (0.77‐1.79) | 1.35 (0.88‐2.08) | 1.36 (0.86‐2.14) | 1.35 (0.85‐2.14) | 1.31 (0.85‐2.02) |
| 5 | 78/19994.8 | 1.95 (1.33‐2.86) | 2.32 (1.58‐3.42) | 2.35 (1.52‐3.62) | 2.32 (1.48‐3.62) | 2.23 (1.50‐3.32) |
| 6 | 68/19243.0 | 1.79 (1.21‐2.64) | 2.18 (1.46‐3.25) | 2.21 (1.38‐3.54) | 2.16 (1.33‐3.53) | 2.07 (1.37‐3.13) |
| 7 | 61/18792.0 | 1.65 (1.11‐2.47) | 2.02 (1.35‐3.04) | 2.06 (1.22‐3.46) | 1.97 (1.15‐3.39) | 1.88 (1.22‐2.88) |
| 8 | 70/18705.7 | 1.95 (1.32‐2.87) | 2.45 (1.64‐3.66) | 2.51 (1.34‐4.66) | 2.43 (1.29‐4.59) | 2.31 (1.51‐3.53) |
| P for trend | .001 | <.001 | .005 | .011 | <.001 | |
| Fat mass of right leg (kg) | ||||||
| Per SD increase | 1.15 (1.06‐1.26) | 1.19 (1.09‐1.30) | 1.12 (0.98‐1.29) | 1.12 (1.00‐1.25) | 1.19 (1.09‐1.30) | |
| Octilesf | ||||||
| 1 | 42/18797.8 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 56/19409.6 | 1.30 (0.87‐1.94) | 1.33 (0.89‐1.98) | 1.27 (0.85‐1.91) | 1.29 (0.86‐1.93) | 1.33 (0.89‐1.99) |
| 3 | 49/19702.3 | 1.13 (0.75‐1.70) | 1.15 (0.76‐1.74) | 1.11 (0.73‐1.68) | 1.07 (0.71‐1.63) | 1.12 (0.74‐1.69) |
| 4 | 63/19992.4 | 1.43 (0.97‐2.11) | 1.49 (1.01‐2.21) | 1.41 (0.94‐2.12) | 1.40 (0.94‐2.09) | 1.49 (1.00‐2.20) |
| 5 | 65/20047.8 | 1.47 (0.99‐2.17) | 1.58 (1.07‐2.33) | 1.47 (0.98‐2.22) | 1.46 (0.98‐2.18) | 1.56 (1.06‐2.31) |
| 6 | 64/19433.4 | 1.50 (1.02‐2.22) | 1.60 (1.08‐2. 36) | 1.46 (0.96‐2.23) | 1.44 (0.96‐2.18) | 1.58 (1.06‐2.33) |
| 7 | 73/20249.2 | 1.64 (1.12‐2.41) | 1.80 (1.22‐2.64) | 1.61 (1.04‐2.48) | 1.58 (1.05‐2.39) | 1.78 (1.21‐2.62) |
| 8 | 72/18830.8 | 1.79 (1.22‐2.62) | 1.99 (1.34‐2.93) | 1.65 (0.99‐2.75) | 1.64 (1.05‐2.57) | 1.95 (1.32‐2.89) |
| P for trend | .001 | <.001 | .022 | .013 | <.001 | |
| Fat mass of left leg (kg) | ||||||
| Per SD increase | 1.14 (1.05‐1.25) | 1.18 (1.08‐1.29) | 1.09 (0.95‐1.26) | 1.10 (0.99‐1.24) | 1.18 (1.08‐1.29) | |
| Octilesf | ||||||
| 1 | 45/18976.4 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 53/19360.2 | 1.16 (0.78‐1.73) | 1.19 (0.80‐1.78) | 1.13 (0.76‐1.69) | 1.15 (0.77‐1.71) | 1.19 (0.80‐1.77) |
| 3 | 53/19605.3 | 1.15 (0.77‐1.71) | 1.18 (0.79‐1.76) | 1.12 (0.75‐1.67) | 1.10 (0.74‐1.65) | 1.16 (0.78‐1.73) |
| 4 | 60/20000.1 | 1.28 (0.87‐1.89) | 1.35 (0.92‐2.00) | 1.24 (0.83‐1.85) | 1.25 (0.85‐1.86) | 1.35 (0.92‐2.00) |
| 5 | 70/19877.7 | 1.51 (1.04‐2.19) | 1.61 (1.10‐2.34) | 1.44 (0.97‐2.13) | 1.45 (0.98‐2.14) | 1.58 (1.08‐2.30) |
| 6 | 66/19865.6 | 1.42 (0.97‐2.08) | 1.53 (1.04‐2.24) | 1.32 (0.88‐2.00) | 1.35 (0.90‐2.01) | 1.51 (1.03‐2.21) |
| 7 | 70/20007.7 | 1.50 (1.03‐2.19) | 1.63 (1.12‐2.39) | 1.36 (0.89‐2.08) | 1.39 (0.93‐2.09) | 1.62 (1.11‐2.37) |
| 8 | 67/18770.2 | 1.57 (1.07‐2.29) | 1.73 (1.18‐2.55) | 1.28 (0.78‐2.12) | 1.35 (0.86‐2.12) | 1.70 (1.16‐2.51) |
| P for trend | .003 | .001 | .123 | .070 | .001 | |
| Ratio of trunk fat mass to average of R and L leg fat mass | ||||||
| Octilesf | ||||||
| 1 | 45/20171.1 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 56/20416.0 | 1.22 (0.83‐1.81) | 1.31 (0.88‐1.95) | 1.23 (0.82‐1.83) | 1.21 (0.81‐1.81) | 1.26 (0.85‐1.88) |
| 3 | 82/20251.7 | 1.81 (1.26‐2.60) | 1.97 (1.37‐2.84) | 1.78 (1.23‐2.59) | 1.74 (1.20‐2.54) | 1.86 (1.28‐2.70) |
| 4 | 69/19707.1 | 1.57 (1.08‐2.29) | 1.76 (1.20‐2.57) | 1.55 (1.05‐2.30) | 1.51 (1.02‐2.24) | 1.63 (1.11‐2.41) |
| 5 | 52/19678.6 | 1.18 (0.79‐1.75) | 1.35 (0.90‐2.01) | 1.16 (0.76‐1.76) | 1.13 (0.74‐1.72) | 1.22 (0.81‐1.85) |
| 6 | 64/19144.2 | 1.50 (1.02‐2.19) | 1.72 (1.17‐2.54) | 1.50 (1.01‐2.24) | 1.41 (0.94‐2.14) | 1.54 (1.03‐2.31) |
| 7 | 50/18960.8 | 1.18 (0.79‐1.76) | 1.37 (0.91‐2.07) | 1.17 (0.77‐1.79) | 1.09 (0.70‐1.69) | 1.20 (0.78‐1.85) |
| 8 | 66/18133.7 | 1.64 (1.12‐2.39) | 1.95 (1.32‐2.88) | 1.67 (1.12‐2.51) | 1.48 (0.96‐2.28) | 1.61 (1.05‐2.49) |
| P for trend | .218 | .150 | .271 | .767 | .406 | |
| Fat mass index (kg/m2) | ||||||
| Continuous per SD increase | 1.12 (1.03‐1.22) | 1.19 (1.09‐1.29) | 1.20 (0.92‐1.57) | 1.10 (0.94‐1.28) | 1.16 (1.06‐1.27) | |
| Octilesf | ||||||
| 1 | 44/19857.0 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 58/20212.9 | 1.29 (0.87‐1.91) | 1.41 (0.95‐2.09) | 1.38 (0.93‐2.07) | 1.37 (0.92‐2.05) | 1.39 (0.94‐2.06) |
| 3 | 52/19535.3 | 1.20 (0.81‐1.80) | 1.35 (0.90‐2.02) | 1.31 (0.85‐2.01) | 1.28 (0.84‐1.95) | 1.31 (0.87‐1.96) |
| 4 | 62/19950.1 | 1.39 (0.95‐2.05) | 1.62 (1.10‐2.40) | 1.56 (1.01‐2.41) | 1.52 (1.00‐2.31) | 1.56 (1.05‐2.32) |
| 5 | 72/19672.5 | 1.65 (1.13‐2.40) | 1.97 (1.35‐2.89) | 1.87 (1.19‐2.95) | 1.81 (1.18‐2.77) | 1.87 (1.27‐2.75) |
| 6 | 65/19124.9 | 1.54 (1.05‐2.25) | 1.83 (1.24‐2.70) | 1.71 1.03‐2.84) | 1.62 (1.03‐2.56) | 1.70 (1.14‐2.54) |
| 7 | 65/19092.4 | 1.55 (1.06‐2.27) | 1.93 (1.30‐2.85) | 1.77 (1.01‐3.12) | 1.68 (1.03‐2.75) | 1.80 (1.20‐2.69) |
| 8 | 65/18366.8 | 1.64 (1.12‐2.40) | 2.05 (1.38‐3.05) | 1.81 (0.87‐3.79) | 1.71 (0.97‐3.02) | 1.92 (1.28‐2.89) |
| P for trend | <.001 | <.001 | .064 | .110 | <.001 | |
| Trunk fat mass index (kg/m2) | ||||||
| Continuous per SD increase | 1.12 (1.03‐1.22) | 1.19 (1.09‐1.30) | 1.16 (0.95‐1.43) | 1.09 (0.92‐1.29) | 1.15 (1.05‐1.27) | |
| Octilesf | ||||||
| 1 | 41/20108.9 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 68/20311.7 | 1.63 (1.11‐2.40) | 1.74 (1.18‐2.57) | 1.73 (1.17‐2.57) | 1.71 (1.15‐2.54) | 1.72 (1.16‐2.54) |
| 3 | 50/19761.5 | 1.24 (0.82‐1.87) | 1.41 (0.93‐2.13) | 1.39 (0.90‐2.15) | 1.37 (0.88‐2.11) | 1.37 (0.90‐2.08) |
| 4 | 59/19662.3 | 1.46 (0.98‐2.18) | 1.70 (1.14‐2.55) | 1.68 (1.08‐2.60) | 1.63 (1.05‐2.53) | 1.64 (1.08‐2.47) |
| 5 | 65/19761.0 | 1.60 (1.08‐2.36) | 1.90 (1.28‐2.83) | 1.87 (1.19‐2.95) | 1.81 (1.15‐2.84) | 1.82 (1.21‐2.74) |
| 6 | 64/19142.1 | 1.64 (1.11‐2.43) | 2.00 (1.34‐2.98) | 1.95 (1.20‐3.18) | 1.86 (1.15‐3.02) | 1.88 (1.24‐2.85) |
| 7 | 72/18744.9 | 1.90 (1.29‐2.78) | 2.36 (1.59‐3.50) | 2.30 (1.35‐3.91) | 2.13 (1.27‐3.59) | 2.18 (1.44‐3.29) |
| 8 | 64/18319.4 | 1.75 (1.18‐2.60) | 2.21 (1.47‐3.32) | 2.13 (1.08‐4.19) | 1.97 (1.06‐3.68) | 2.07 (1.35‐3.18) |
| P for trend | <.001 | <.001 | .030 | .054 | .001 | |
a
Adjusted for age at enrollment
b
Adjusted for age at enrollment, education, race/ethnicity, family history of breast cancer, age at menarche, age at first full‐term birth, parity, age at menopause, oral contraceptive use, hormone therapy use, physical activity, alcohol intake, smoking, and study component
c
Also adjusted for BMI
d
Also adjusted for waist circumference
e
Also adjusted for waist to hip ratio
f
Cut‐points‐ whole body fat mass (kg):‐ ≤20.39, 27.40‐24.32, 24.33‐27.72, 27.73‐30.90, 30.91‐34.53, 34.54‐38.90,38.91‐45.93, >45.93; whole body percent fat (kg): ≤35.5, 35.6‐39.3, 39.4‐42.0, 42.1‐44.4, 44.5‐46.6, 46.7‐49.0, 49.1‐52.0, >52, trunk fat mass (kg): ≤8.23, 8.24‐10.65, 10.66‐12.62, 12.63‐14.43, 14.44‐16.44, 16.45‐18.85, 18.86‐22.33,>22.33; fat mass of right leg (kg): <3.98, 3.99‐4.66, 4.67‐5.23, 5.24‐5.81, 5.82‐6.46, 6.47‐7.24, 7.25‐8.57, >8.57; fat mass of left leg (kg): <3.87, 3.88‐4.54, 4.55‐5.09, 5.10‐5.67, 5.68‐6.31, 6.32‐7.08, 7.08‐8.39, >8.39, ratio of trunk fat mass to average of R and L leg fat mass: ≤1.66, 1.66‐1.98, 1.99‐2.21, 2.22 ‐2.43, 2.43‐2.68, 2.68‐2.96,2.97‐3.39, >3.39, body fat index:‐ ≤7.85, 7.85‐9.34, 9.35‐10.64, 10.65‐11.87, 11.88‐13.29, 13.30‐14.91, 14.92‐17.54, >17.54; trunk fat mass index: ≤3.14, 3.15‐4.09, 4.10‐4.85, 4.86‐ 5.57, 5.58‐6.31, 6.32‐7.20, 7.20‐8.58, >8.58 for octiles 1, 2, 3, 4, 5, 6, 7 and 8, respectively. One case had a missing value for the body fat index and the trunk fat mass index.