Table 1.

Baseline characteristics for patient cases and matched controls not currently using menopausal hormone replacement therapy.

Premenopausal womenPostmenopausal women
Cases (n = 222)Controls (n = 381)Cases (n = 407)Controls (n = 842)
CharacteristicNMean (SD), or %NMean (SD), or %P valueaNMean (SD), or %NMean (SD), or %P valuea
Age at blood draw, y22246.7 (4.4)38146.6 (4.2)0.88140763.9 (6.4)84264.1 (6.5)0.501
BMI at study entry, kg/m222224.8 (3.8)38024.8 (4.0)0.71340726.3 (4.4)83925.6 (4.0)0.009
Age at menarche, y22212.9 (1.5)38113.0 (1.4)0.25540713.1 (1.5)84213.3 (1.5)0.105
Alcohol consumption, g/d2206.7 (7.3)3806.4 (7.8)0.0704028.4 (10.0)8377.1 (8.5)0.031
Smoking status, %0.0840.031
 Never smoked11150.521456.215638.937945.2
 Past smoker7634.512722.318345.635442.2
 Current smoker3314.94010.56215.510612.6
Ever use of MHTb94.1164.20.93114435.428033.30.457
Ever use of oral contraceptives, %19990.135593.20.17729574.364478.10.145
Age at first birth and parity, %0.3040.317
Nulliparous3314.95514.54811.9819.6
 <25 years/1–2 children3013.5359.29122.619022.6
 <25 years/≥3 children156.8318.25413.413315.8
 25–29 years/1–2children5323.97920.810927.122126.3
 25–29 years/≥3children135.94411.6266.5758.9
 ≥30 years/≥1 children7734.713635.87418.414116.8
Total lifetime breastfeeding, %0.5030.505
 ≤6 months4923.79126.012833.625731.7
 7–12 months8340.114942.619450.942051.9
 ≥13 months7536.211031.45915.513316.4
History of benign breast disease, %5826.16918.40.01112331.119123.10.003
Family history of breast cancer, %5022.55414.60.00810125.314517.10.002
Mean 2-year breast cancer risk score
 CAD2Y1380.4 (0.5)3760.3 (0.3)<0.0022500.9 (0.0)8290.6 (0.4)<0.001
Mean 5-year breast cancer risk score
 Gail2201.1 (0.4)3811.0 (0.4)0.0364031.6 (0.6)8421.1 (0.4)0.002
 Tyrer–Cuzick2201.3 (1.0)3811.2 (0.6)0.1394032.4 (1.4)8421.9 (0.0)<0.001
Median (10th–90th percentile)Median (10th–90th percentile)Median (10th–90th percentile)Median (10th–90th percentile)
DHEA, ng/mL17119.6 (1.8–64.4)29419.4 (1.8–56.2)0.72028913.2 (1.1–44.4)6069.5 (1.1–42.8)0.038
DHEAS, μg/mL2082.0 (0.7–4.1)3501.9 (0.9–3.7)0.5753841.4 (0.6–3.1)7881.2 (0.5–2.8)0.002
Mammographic density, %21436.6 (9.5–67.1)37330.7 (4.2–60.8)<0.00140110.9 (1.3–36.3)8319.0 (0.8–32.7)0.004
  • aP value for test of means, or χ2 test of proportions between cases and controls.

  • bCurrent users not included.