Table 2.

Distributions of demographic characteristics and potential predictors of breast density by acculturation category and age-adjusted ORs and corresponding 95% CIs for higher breast density (n = 212)

CharacteristicsDistribution by acculturation category*
Age-adjusted OR for higher vs lower breast density
6-8 (n = 84)>8-10 (n = 69)>10 (n = 59)P
Age (y)51.7 ± 9.256.2 ± 11.551.7 ± 10.10.010.6 (0.5-0.6)
Postmenopausal5061530.390.5 (0.2-1.1)
Length of U.S. residence (y)9.6 ± 7.510.9 ± 8.515.9 ± 9.0<0.00011.0 (0.8-1.1)
Age at migration (y)42.1 ± 12.444.9 ± 13.335.9 ± 12.60.00051.0 (0.9-1.2)
Level of education
    Less than high school68365<0.00011.0
    High school graduate to less than college2645371.6 (0.9-2.9)
    College graduate or more619581.7 (0.9-3.4)
Place of birth
    China9380660.00031.0
    Southeast Asia514141.4 (0.6-3.4)
    Taiwan26201.8 (0.7-4.8)
BMI (kg/m2)24.3 ± 3.623.9 ± 3.324.1 ± 3.40.780.8 (0.8-0.9)
First-degree relative with breast cancer53100.194.7 (1.4-16.4)
Age at menarche (y)15.0 ± 2.014.3 ± 1.713.8 ± 1.4<0.00011.0 (0.5-2.1)
Nulliparity49120.171.7 (0.6-4.8)
No. live births§2.4 ± 1.32.5 ± 1.31.9 ± 0.80.0080.6 (0.5-0.8)
Age at first birth (y)§25.6 ± 5.126.2 ± 5.128.9 ± 4.40.00081.5 (1.1-2.0)
No. months breast-fed§15.9 ± 24.09.8 ± 15.15.7 ± 7.80.0060.9 (0.9-1.0)
Ever used hormonal contraceptives109200.121.5 (0.7-3.5)
Ever used hormone therapy1021320.061.6 (0.7-3.8)
Tertile 2 vs tertile 1Tertile 3 vs tertile 1
Dietary intake (servings/wk)
    Red meat6.8 ± 5.77.3 ± 4.67.0 ± 6.00.850.6 (0.3-1.2)0.6 (0.3-1.2)
Ptrend = 0.19
    Dairy4.6 ± 4.46.3 ± 4.96.4 ± 5.50.031.3 (0.7-2.5)2.3 (1.1-4.8)
Ptrend = 0.05
    Vegetables22.5 ± 9.928.0 ± 12.726.9 ± 14.60.021.0 (0.5-2.0)0.5 (0.2-1.0)
Ptrend = 0.05
    Greens7.6 ± 5.05.8 ± 3.75.2 ± 3.70.0020.5 (0.3-0.9)0.7 (0.3-1.5)
Ptrend = 0.35
    Tofu1.4 ± 1.52.2 ± 2.02.2 ± 2.00.0071.0 (0.5-2.0)0.7 (0.3-1.3)
Ptrend = 0.18
  • * Categorical variables are expressed as percent distribution within each acculturation category. Continuous variables are expressed as mean (SD). Ps were determined by Cochran-Mantel-Haenszel test statistic for categorical variables or by ANOVA for continuous variables.

  • OR for 5-year increment.

  • Due to missing data, n differed for the following variables: length of U.S. residence and age at migration (n = 209), BMI (n = 208) and hormonal contraceptive use (n = 208).

  • § Conducted among 196 parous women; for age at first live birth, n = 194 due to missing data.

  • Conducted among 115 postmenopausal women.