Gestational diabetes, type II diabetes, and mammographic breast density in a U.S. racially diverse population screened for breast cancer.

Purpose: Type II diabetes mellitus (T2DM) has consistently been associated with an increased risk of breast cancer, but the association of gestational diabetes mellitus (GDM) with breast cancer is less clear. T2DM and GDM may influence breast cancer risk through mammographic breast density, a strong risk factor for breast cancer. We examined whether T2DM and GDM are associated with higher mammographic breast density in a largely racial/ethnic minority sample.