Table 4.

Heritability estimates (h2) for breast density measures (n = 1,140) and serum sex-hormone levels (n = 810)

TraitAge and menopausal status adjustedMultivariate adjusted
h2 ± SEh2 ± SE
Density measures
 Percentage density0.70 ± 0.080.63 ± 0.08
 Absolute dense area0.68 ± 0.080.66 ± 0.08
 Nondense area0.77 ± 0.060.65 ± 0.07
Hormone levels
 Estradiol0.52 ± 0.100.40 ± 0.10
 Testosterone0.27 ± 0.100.25 ± 0.10
 SHBG0.59 ± 0.090.58 ± 0.10