Racial differences in the association between gestational diabetes mellitus and risk of type 2 diabetes.

Background: It is recognized that a history of gestational diabetes mellitus (GDM) predicts incident type 2 diabetes in women. However, it is unclear if there is a racial disparity between the association of GDM and type 2 diabetes.

Methods: We studied 1,142 women with a history of GDM and 18,856 women without a history of GDM aged 13-50 years with their first record of pregnancy in Louisiana State University Hospital-Based Longitudinal Study database between 1990 and 2009. History of GDM was used to predict incident type 2 diabetes.

Results: During a mean follow-up of 8.6 years, 1,394 women developed type 2 diabetes. The multivariable adjusted hazard ratio (HR) of type 2 diabetes was 6.52 (95% confidence interval [CI] 5.73-7.43) among women with GDM compared to women without GDM. Stratification by age, race, and body mass index (BMI) gave similar results. Compared with African American and white women without a history of GDM, the relative risk for type 2 diabetes was higher in African American women than in white women with a history of GDM. Compared with non-GDM women compartments, GDM women after delivery for <1, 1.0-3.9, 4.0-5.9, 6.0-7.9, 8-9.9, and ≥10.0 years had 4.00, 5.44, 4.26, 3.16, 4.49, and 4.17 times higher risk of having type 2 diabetes, respectively.

Conclusions: A history of GDM is a strong predictor of subsequent type 2 diabetes among Louisiana women, especially among African American women.