Table 2.

Geometric mean plasma hormone levels by breast cancer risk factors and other lifestyle factors

No. women* (%)Androstenedione (pg/mL)Testosterone (ng/dL)Bio testosterone (ng/dL)E1 (pg/mL)E2 (pg/mL)Bio E2 (pg/mL)SHBG (nmol/L)
BMI (kg/m2)
    <25261 (36.6)49421.39.730.79.96.146.6
    25.0-29.9259 (36.3)50121.511.035.212.28.136.7
    ≥30.0194 (27.2)47322.211.741.515.310.434.2
    Ptrend0.420.44<0.001<0.001<0.001<0.001<0.001
Age at menarche (y)
    ≤12341 (47.9)49722.110.936.112.38.039.1
    13-14278 (39.0)48521.110.534.211.97.839.0
    ≥1593 (13.1)48420.910.032.911.17.142.7
    Ptrend0.540.250.160.0360.070.050.23
Age at first birth (y)
    ≤20252 (39.4)51122.710.936.312.27.841.4
    21-30346 (54.2)49620.910.534.011.77.737.9
    ≥3141 (6.4)49322.311.338.512.98.638.3
Ptrend0.490.210.850.550.790.570.06
Parity
    1 child71 (11.0)49421.811.034.412.48.238.1
    2-3 children272 (42.3)50021.810.735.912.17.839.9
    ≥4 children300 (46.7)49120.810.334.111.67.639.0
Ptrend0.810.370.320.450.150.200.95
Age (y) and type of menopause
    Natural
        <4469 (10.4)4872.010.934.011.97.839.3
        45-49142 (21.5)4821.210.533.411.27.340.1
        ≥50241 (36.5)5223.911.936.412.68.239.5
    Bilateral oophorectomy
        <4446 (7.0)47518.68.833.211.87.642.7
        ≥4526 (3.9)48416.17.938.312.58.138.7
    Hysterectomy
        <4476 (11.5)44519.79.831.511.57.539.2
        ≥4535 (5.3)43917.79.031.410.77.136.8
    Unknown26 (3.9)48719.59.236.111.77.341.8
Pheterogeneity0.30<0.001<0.0010.110.240.350.92
Alcohol drinking
    Nondrinkers455 (65.2)48321.410.534.611.87.739.7
    <1 drink/d194 (27.8)50221.210.635.212.17.938.8
    ≥1 drink/d49 (7.0)54125.312.536.012.78.240.2
Ptrend0.120.210.140.490.320.310.85
Smoking
    Never399 (57.2)47420.410.134.511.87.738.7
    Past191 (27.4)49422.511.235.312.17.938.9
    Current108 (15.5)54624.311.636.212.57.943.3
Pheterogeneity0.0340.0100.0300.560.380.720.08
Vigorous physical activity (h/wk)
    <3612 (89.3)49521.610.735.312.07.939.2
    ≥3 (90th)73 (10.7)45821.510.432.311.97.641.5
Pheterogeneity0.220.950.660.110.920.570.32
Calorie intake (kcal/d)
    <1,348174 (24.9)47520.610.236.212.28.038.8
    1,348-1,837175 (25.1)50823.511.535.612.48.040.2
    1,838-2,455174 (24.9)50423.011.234.812.17.841.2
    ≥2,456175 (25.1)48219.710.033.011.27.437.7
Ptrend§0.790.310.360.070.060.100.67
% Calories from fat
    <24.7174 (24.9)47321.210.434.712.07.840.4
    24.7-30.2175 (25.1)48722.511.436.012.28.137.4
    30.3-35.1174 (24.9)50120.910.634.511.97.937.2
    ≥35.2175 (25.1)51321.910.234.311.67.343.9
Ptrend§0.110.880.600.530.390.270.26
Total fiber intake, density (g/kcal/d)
    <9.9175 (25.1)52722.610.935.612.58.041.6
    9.9-12.6174 (24.9)50122.411.133.911.57.538.6
    12.7-16.2175 (25.1)45920.410.235.212.07.838.9
    ≥16.3174 (24.9)47820.910.534.811.77.738.6
Ptrend§0.070.120.400.350.510.900.21
Total soy intake, density (g/kcal/d)
    <2.7523 (74.9)49622.711.335.112.28.039.3
    ≥2.7 (75th)175 (25.1)48519.89.734.511.57.539.8
Ptrend§0.670.0430.0420.690.220.250.92
  • NOTE: Adjusted for age at blood draw (continuous), race/ethnicity (categorical), and assay batch (categorical); further adjusted for BMI (continuous) for bio testosterone, estrogens, and SHBG.

  • * Numbers may not add up to total due to missing values.

  • Among parous women only.

  • Women were premenopausal at baseline but were postmenopausal at blood draw (age ≥56 y) with unknown age and type of menopause.

  • § Continuous variables.