Table 2 Characteristics of study subjects (N = 741)
From: Polymorphisms in genes involved in the estrogen pathway and mammographic density
Characteristic | Mean | SD |
|---|---|---|
Age at mammography (years) | 46.8 | 4.6 |
Body mass index (kg/m2) | 25.2 | 4.6 |
Waist-to-hip ratio | 0.8 | 0.1 |
Height (cm) | 160.5 | 5.8 |
Age at menarche (years) | 12.7 | 1.6 |
Age at first pregnancy (years) a (n = 563) | 26.0 | 3.7 |
Number of live births a (n = 563) | 2.1 | 0.8 |
Alcohol intake (drinks/wk) (n = 738) | 3.4 | 3.8 |
Total energy intake (Kcal/day) (n = 736) | 1906.0 | 514.9 |
Physical activity (MET-h/wk) (n = 740) | 27.1 | 22.2 |
Percent density (%) | 42.3 | 24.3 |
Absolute density (cm²) | 47.1 | 28.7 |
| Â | % | Â |
Parity (parous) | 76.0 | Â |
Lactation (yes) a (n = 563) | 62.0 | Â |
Personal history of breast biopsies (yes) | 14.2 | Â |
Past hormonal derivative use (yes) (n = 740) b | 92.4 | Â |
First degree relative with breast cancer (yes) | 36.8 | Â |
Education (college or university degree) | 62.0 | Â |
Smoking status (never) | 45.1 | Â |