Table 2.
Geometric mean (95% confidence interval (CI)) from mixed-effect regression models for each pubertal factor in relation to percent dense breast volume (%DBV)
| Pubertal characteristic | Model 1 | Model 2 | Model 3 |
|---|---|---|---|
| Age at thelarche, years | |||
| 8.7 to < 9.9 | 19.56 (15.62–24.48) | 18.74 (16.93–20.76) | 20.83 (18.42–23.57) |
| 9.9 to < 10.4 | 19.36 (14.15–26.48) | 19.06 (16.24–22.36) | 19.50 (16.36–23.24) |
| 10.4 to < 11.1 | 16.27 (12.01–22.05) | 18.36 (14.54–23.19) | 17.79 (14.15–22.38) |
| 11.1+ | 19.90 (12.41–31.91) | 18.72 (13.55–25.86) | 17.04 (13.28–21.86) |
| p trend | 0.56 | 0.94 | 0.04 |
| Age at pubarche, years | |||
| 8.6 to < 10.3 | 22.08 (18.18–26.81) | 19.04 (16.9–21.45) | 20.84 (18.2–23.86) |
| 10.3 to < 10.9 | 17.31 (12.27–24.42) | 16.88 (11.9–23.94) | 16.97 (12.21–23.57) |
| 10.9 to < 11.5 | 16.20 (13.84–18.98) | 17.51 (14.91–20.56) | 17.73 (14.81–21.23) |
| 11.5+ | 19.72 (13.74–28.32) | 21.66 (18.25–25.71) | 19.47 (17.38–21.83) |
| p trend | 0.87 | 0.39 | 0.64 |
| Age at menarche, years | |||
| 10 to < 12.2 | 16.89 (13.04–21.87) | 15.96 (13.28–19.19) | 17.10 (14.15–20.66) |
| 12.2 to < 12.8 | 14.38 (12.03–17.19) | 15.39 (11.53–20.54) | 16.38 (12.4–21.65) |
| 12.8 to < 13.4 | 19.98 (15.19–26.27) | 22.90 (20.37–25.75) | 21.65 (19.36–24.21) |
| 13.4+ | 25.96 (17.03–39.56) | 21.76 (16.41–28.86) | 20.18 (15.66–25.99) |
| p trend | 0.03 | 0.01 | 0.13 |
| Thelarche-to-menarche tempo, years | |||
| < 1.6 | 13.90 (10.23–18.88) | 15.45 (14.08–16.95) | 15.55 (13.85–17.47) |
| 1.6 to < 2.3 | 19.91 (16.02–24.76) | 18.88 (16.17–22.04) | 19.49 (16.89–22.5) |
| 2.3 to < 2.9 | 18.90 (13.14–27.18) | 18.47 (15.77–21.62) | 18.38 (15.7–21.51) |
| 2.9+ | 24.85 (16.51–37.40) | 22.55 (17.8–28.56) | 21.84 (18.18–26.24) |
| p trend | 0.01 | 0.004 | 0.007 |
| Pubarche-to-menarche tempo, years | |||
| < 1.1 | 14.40 (10.03–20.66) | 15.9 (12.23–20.68) | 16.23 (12.3–21.41) |
| 1.1 to < 1.7 | 17.16 (13.85–21.26) | 18.69 (16.16–21.61) | 18.40 (16.82–20.14) |
| 1.7 to < 2.6 | 16.68 (11.20–24.85) | 17.85 (13.7–23.25) | 17.87 (13.88–23.02) |
| 2.6+ | 29.09 (25.22–33.56) | 22.80 (20.25–25.68) | 22.66 (20.79–24.7) |
| p trend | < 0.001 | 0.06 | 0.06 |
Model 1 is unadjusted
Model 2 adjusts for the following variables as fixed effects: adult covariates, including parity (nulliparous vs parous), duration of hormone use (years, continuous), education (some college or less (reference), bachelor degree, graduate degree), race (white vs. non-white), smoking status (never vs ever), whole-body percent fat measured by DXA (%, continuous), and height (continuous). Clinic included as a random effect
Model 3 adjusts for the same factors in model 2, and in addition, BMI at 8–10 years of age expressed as a z-score relative to CDC 2000 Growth Charts (continuous)