Table 1.

Age-standardized characteristics of 54,337 participants of the Black Women's Health Study according to diabetes status

No diabetesType II diabetes
Total person-years (n)815,25255,106
Mean age (years)47.0 ± 11.256.1 ± 10.6
Mean body mass index (kg/m2)29.5 ± 6.834.9 ± 8.4
Mean body mass index at age 18 (kg/m2)21.3 ± 3.923.7 ± 5.5
Waist to hip ratio ≥ 0.85 (%)2951
≥16 years of education (%)5347
Age at menarche ≤ 11 (%)1118
Nulliparous (%)2728
First birth before age 25 (%)7374
Never lactation among parous women (%)5660
Premenopausal (%)6057
Use of oral contraceptives for ≥5 years (%)3735
Ever use estrogen with progesterone supplements (%)1010
First degree family history of breast cancer (%)97
Vigorous activity, ≥3 hours/week (%)2013
Current drinker, ≥7 drinks/week (%)53
Current smoker (%)1313
Recent mammography among women age 40–69 (%)8181
Tumor characteristics among breast cancer cases
Estrogen receptor status
 Estrogen receptor positive (n)84173
 Estrogen receptor negative (n)42642
 Unknown estrogen receptor status (n)41148
Stage at diagnosis
 Stage I (n)63862
 Stage II (n)50936
 Stage III (n)14115
 Stage IV (n)494
 Unknown stage (n)35146