Table 2.

Associations between breast density and other risk factors

Breast density category

Entirely fat
Scattered
Heterogeneous
Extremely
Mean (SD)Mean (SD)Mean (SD)Mean (SD)P Value
Age60.2 (11.6)56.0 (12.0)51.0 (11.0)47.7 (9.6)<0.001
BMI (kg/m2)31.2 (7.0)27.4 (5.8)25.0 (4.8)22.8 (3.8)<0.001
n%n%N%n%P Value
Family history of breast cancer
    No3,61982.127,04281.015,50881.64,05980.80.140
    Yes79017.96,35519.03,50718.496419.2
Age at first childbirth
    <211,36531.29,03927.24,09821.679315.8<0.001
    21–302,23351.117,46852.59,42849.82,26745.3
    >302595.92,6187.92,10111.169013.8
    No children51411.84,12912.43,32017.51,25625.1
Menopausal status
    Premenopausal78417.810,54431.69,65150.83,25964.9<0.001
    Postmenopausal3,62582.222,85368.49,36849.21,76435.1
Postmenopausal hormone use
    Currently using1,30736.110,47045.84,97353.11,00056.7<0.001
    Formerly used3599.92,1159.37878.41247.0
    Never used1,95954.010,26844.93,60438.564036.3