Adolescent endogenous sex hormones and breast density in early adulthood

Breast Cancer Research

Table 2 Multivariate^a-adjusted geometric mean and 95 % confidence interval (CI) for percent dense breast volume by quartiles of estrogens and progesterone at pre-^b and postmenarcheal^c period

Abbreviations: CI confidence interval, SHBG sex hormone-binding globulin
^aGeometric means and 95 % CI are estimated from linear mixed-effects models including clinic as a random effect and adjusted for treatment group (diet intervention group, usual-care control group), BMI (kg/m², continuous), parity (0 and >0), duration of hormone use (yrs, continuous), race (white and nonwhite), and education (bachelor's degree, graduate school and other) as fixed effects
^bThe premenarcheal estrogen levels were standardized by adjusting for age at visit, BMI z-score at visit, and visit number in years after randomization by residual method
^cThe postmenarcheal estrogens and progesterone levels were standardized by adjusting for age at visit, BMI z-score at visit, visit number in years after randomization and days from blood draw to start of next menses as a cubic spline by residual method
^d.Days 1 through 14 before next menses were defined as luteal, whereas days 0 and greater than 14 were defined as follicular
^e P-test for trend was conducted by modeling the quartile medians of standardized hormone concentrations as a continuous term in linear mixed-effects models and calculating the Wald test statistic

ISSN: 1465-542X