Table 1.
Descriptive characteristics of study population (n=365)
| Characteristic | Mean ± SD Median (25th, 75th) |
N (%) | |
|---|---|---|---|
| Age (years) | 61.9 ± 8.4 | ||
| < 60 | 172 (47.1) | ||
| 60–69 | 119 (32.6) | ||
| ≥ 70 | 74 (20.3) | ||
| Race | |||
| White | 340 (93.2) | ||
| Other | 25 (6.8) | ||
| Education | |||
| ≤ High school | 93 (25.5) | ||
| Post-secondary education | 264 (72.3) | ||
| BMI (kg/m2) | 28.7 ± 6.1 | ||
| < 25 | 109 (29.9) | ||
| 25 to < 30 | 127 (34.8) | ||
| ≥ 30 | 129 (35.3) | ||
| Age at menopause (years) | 48.3 ± 5.3 | ||
| Age at menarche (years) | |||
| < 12 | 71 (19.5) | ||
| 12 | 103 (28.2) | ||
| 13 | 110 (30.1) | ||
| ≥ 14 | 80 (21.9) | ||
| Pregnancy | |||
| No | 65 (17.8) | ||
| Yes | 300 (82.2) | ||
| Number of live births | |||
| None | 82 (22.4) | ||
| 1 | 41 (11.2) | ||
| 2 | 102 (28.0) | ||
| 3 | 81 (22.2) | ||
| ≥ 4 | 59 (16.2) | ||
| History of Breast Biopsy | |||
| No | 298 (81.6) | ||
| Yes | 66 (18.1) | ||
| Oopherectomy | |||
| No | 289 (79.2) | ||
| Yes | 74 (20.3) | ||
| Family history of cancer | |||
| No | 131 (35.9) | ||
| Yes | 232 (63.6) | ||
| Smoking status | |||
| Never | 215 (58.9) | ||
| Ever | 150 (41.1) | ||
| Leptin Q223R* | |||
| Wild type | 110 (30.1) | ||
| Heterozygous | 190 (52.1) | ||
| Homozygous variant | 65 (17.8) | ||
| Leptin levels (ng/ml) | 43.0 ± 34.5 | ||
| 34.3 (18.9, 57.9) | |||
| Mammographic Density Measures | |||
| Dense area (cm2) | 35.6 (22.3, 55.8) | ||
| Non-dense area (cm2) | 104.6 (63.2, 168.0) | ||
| Total area (cm2) | 149.6 (106.2, 214.7) | ||
| Percent Breast Density | 27.0 (13.8, 40.6) | ||
Note: Percentages may not sum to 100% due to missing data;
*
p-value for HW equilibrium=0.27