Table 1.

Characteristics of subjectsa at study entry

CharacteristicAll (n = 312)Premenopausal (n = 142)Postmenopausal (n = 170)
Age [yrs; mean (range)]55.4 (30–85)46.5 (30–54)62.8 (46–85)
Height [inches; mean (range)]64.4 (55–71)64.7 (59–71)64.1 (55–71)
Weight [pounds; mean (range)]156.2 (105–280)154.0 (108–280)158.0 (105–250)
BMI [kg/m2; mean (range)]26.3 (18.2–47.7)25.6 (18.2–47.7)26.9 (19.0–41.3)
IGF-1 [ng/ml; mean (range)]160.7 (74.5–414.0)175.4 (96.5–414.0)148.4 (74.5–256.5)
IGFBP-3 [ng/ml; mean (range)]2734.7 (511.4–4329.9)2775.8 (1791.1–3845.1)2700.3 (511.4–4329.9)
Percentage of breast density [mean (range)]25.8 (0.3–76.4)33.7 (1.0–76.4)19.1 (0.3–69.2)
Age at menopauseb [yrs; mean (range)]50.1 (35–58)
Age at menarche [yrs; mean (range)]12.8 (9–18)12.8 (9–18)12.8 (9–17)
Age at first birthc [yrs; mean (range)]25.3 (16–41)25.6 (16–41)25.1 (16–40)
Parity [mean (range)]2.1 (0–7)2.0 (0–6)2.2 (0–7)
Family history of breast cancer (%)d16.316.915.9
Previous OC use (%)49.063.437.1
Smoking history (%)
    Never53.857.051.2
    Past38.138.737.6
    Current8.04.211.2
Alcohol consumption (# drinks/wk; %)
    Do not drink24.012.034.1
    0–3 drinks per week45.252.538.2
    4–9 drinks per week24.426.822.4
    10 or more drinks per week6.47.75.3
Coffee consumption [# cups/day; mean (range)]1.8 (0–12)1.7 (0–10)1.8 (0–12)
  • a Subjects included in the mammogram-serum analysis.

  • b Age at menopause only includes women who had natural menopause or bilateral oophorectomy.

  • c Age at first birth of parous women.

  • d Percentage of women with at least one first degree relative (mother/sister/daughter) who had breast cancer.