Table 5.

Genetic and environmental correlations (ρG and ρE, respectively) between breast density measures and endogenous sex-hormone levels, n = 1,268

Trait 2ρG = 0bρE = 0
Trait 1 (breast density)(sex hormones)ρPaρG ± SEP valueρE ± SEP value
Age and menopausal status adjusted
Percentage densityEstradiol−0.27−0.24 ± 0.130.09−0.33 ± 0.170.08
Testosterone−0.15−0.41 ± 0.180.030.07 ± 0.160.68
SHBG0.270.28 ± 0.120.030.26 ± 0.180.18
Dense areaEstradiol−0.14−0.05 ± 0.150.75−0.27 ± 0.180.15
Testosterone−0.10−0.16 ± 0.200.44−0.07 ± 0.150.66
SHBG0.080.04 ± 0.130.750.15 ± 0.190.43
Nondense areaEstradiol0.340.49 ± 0.110.00010.12 ± 0.180.52
Testosterone0.160.55 ± 0.160.001−0.24 ± 0.180.16
SHBG−0.38−0.42 ± 0.090.0002−0.31 ± 0.170.09
Multivariate adjusted
Percentage densitycEstradiold,e−0.06−0.06 ± 0.170.75−0.07 ± 0.170.66
Testosteronef−0.06−0.30 ± 0.210.150.11 ± 0.150.45
SHBGg0.050.01 ± 0.140.930.11 ± 0.200.57
Dense areacEstradiold,e−0.07−0.02 ± 0.170.91−0.12 ± 0.170.48
Testosteronef−0.06−0.14 ± 0.210.52−0.006 ± 0.150.97
SHBGg0.01−0.12 ± 0.140.410.22 ± 0.200.27
Nondense areacEstradiold,e0.020.17 ± 0.170.30−0.14 ± 0.160.38
Testosteronef0.050.40 ± 0.200.04−0.22 ± 0.150.12
SHBGg−0.06−0.11 ± 0.130.430.02 ± 0.190.90

NOTE: Values significant with a P value less than 0.05 have been highlighted in bold.

  • aPhenotypic correlation estimate.

  • bP value for test of null hypothesis that correlation due to additive genetic factors is 0 (ρG = 0).

  • cDensity measures were square root–transformed and adjusted for age, previous HRT use, BMI, WHR, age at first birth, menarche, and menopause.

  • dEstradiol levels were log-transformed and adjusted for age at blood draw, BMI, HRT use, and batch.

  • eThe sample size for estradiol levels and density measures correlation estimation was 1,284.

  • fTestosterone levels were log-transformed and adjusted for age at blood draw, BMI, HRT use, bilateral oopherectomy, age at menopause, and batch.

  • gSHBG levels were log-transformed and adjusted for age at blood draw, BMI, WHR, HRT use, and batch.