From: Pubertal timing and breast density in young women: a prospective cohort study
Number | Mean | SD | Percentage | |
---|---|---|---|---|
Child characteristics | ||||
Race/ethnicity | ||||
White | 164 | 90 | ||
Other | 18 | 10 | ||
Age at baseline, years | 182 | 9.13 | 0.59 | |
BMI z-score at baseline | 182 | 0.23 | 0.90 | |
Age at thelarche, years | 170 | 10.59 | 1.09 | |
Age at pubarche, years | 173 | 10.97 | 1.19 | |
Age at menarche, years | 182 | 12.90 | 1.26 | |
Adult characteristics | ||||
Age at follow-up, years | 182 | 27.17 | 1.02 | |
BMI, kg/m2 | 182 | 25.39 | 5.36 | |
DXA % body fat, % | 176 | 35.41 | 8.82 | |
Exogenous hormone use | ||||
Never | 11 | 6 | ||
Former | 66 | 36 | ||
Current | 105 | 58 | ||
Duration of hormone use, years | 171 | 5.6 | 3.5 | |
Parous (vs nulliparous) | 53/182 | 29 | ||
Education | ||||
Graduate degree | 25 | 14 | ||
Bachelor’s degree | 95 | 52 | ||
Some college or less | 62 | 34 | ||
Ever smokers (vs never-smokers) | 82/182 | 45 | ||
Breast density measures | ||||
Percent dense breast volume (%) | 182 | 27.6 | 20.5 | |
Absolute dense breast volume (cm3) | 182 | 104.2 | 70.6 | |
Absolute non-dense breast volume (cm3) | 182 | 413.3 | 364.3 |