Table 1.
Age-standardized characteristics of 54,337 participants of the Black Women’s Health Study according to diabetes status
| No diabetes | Type 2 diabetes | |
|---|---|---|
|
|
||
| Total person-years (n) | 815,252 | 55,106 |
| Mean age (years) | 47.0 ± 11.2 | 56.1 ± 10.6 |
| Mean body mass index (kg/m2) | 29.5 ± 6.8 | 34.9 ± 8.4 |
| Mean body mass index at age 18 (kg/m2) | 21.3 ± 3.9 | 23.7 ± 5.5 |
| Waist to hip ratio ≥ 0.85 (%) | 29 | 51 |
| ≥ 16 years of education (%) | 53 | 47 |
| Age at menarche ≤ 11 (%) | 11 | 18 |
| Nulliparous (%) | 27 | 28 |
| First birth before age 25 (%) | 73 | 74 |
| Never lactation among parous women (%) | 56 | 60 |
| Premenopausal (%) | 60 | 57 |
| Use of oral contraceptives for ≥ 5 years (%) | 37 | 35 |
| Ever use estrogen with progesterone supplements (%) | 10 | 10 |
| First degree family history of breast cancer (%) | 9 | 7 |
| Vigorous activity, ≥ 3 hrs/wk (%) | 20 | 13 |
| Current drinker, ≥ 7 drinks/wk (%) | 5 | 3 |
| Current smoker (%) | 13 | 13 |
| Recent mammography among women age 40–69 (%) | 81 | 81 |
| Tumor characteristics among breast cancer cases | ||
| Estrogen receptor status | ||
| Estrogen receptor positive (n) | 841 | 73 |
| Estrogen receptor negative (n) | 426 | 42 |
| Unknown estrogen receptor status (n) | 411 | 48 |
| Stage at diagnosis | ||
| Stage I (n) | 638 | 62 |
| Stage II (n) | 509 | 36 |
| Stage III (n) | 141 | 15 |
| Stage IV (n) | 49 | 4 |
| Unknown stage (n) | 351 | 46 |