Gestational Diabetes and Risk of Stroke Among US Black Women

BACKGROUND: There is a paucity of evidence on whether gestational diabetes (GDM) is a risk factor for cerebral vascular disease for Black women and lack of data on incident stroke as end point. METHODS: We conducted a large prospective cohort study of Black women across the United States and assessed the association between self-reported history of GDM and incident stroke. The study began when participants became parous or enrolled in 1995. We followed up 41-143 parous Black women who were free of cerebral vascular disease or cancer and followed up until incident stroke, death, or the end of 2021. Our exposure was self-reported history of GDM, and outcome was incident stroke. Multivariable Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% CIs, adjusting for major known risk factors for stroke. RESULTS: A total of 1495 incident stroke cases were identified among 41-143 Black women from 1995 until 2021 (881-505 person-years of follow-up). Black women with a history of GDM had a consistent 1.4-fold increased risk of stroke compared with those with a healthy pregnancy (age-adjusted HR, 1.44 [95% CI, 1.14-1.82]; multivariable HR, 1.41 [95% CI, 1.11-1.79]). Compared with healthy parous women with neither GDM nor type 2 diabetes, women with a history of both had a 2.6-fold increased stroke risk (multivariable HR, 2.59 [95% CI, 1.88-3.57]); women with only type 2 diabetes have 2-fold increased stroke risk (multivariable HR, 2.04 [95% CI, 1.79-2.32]); women with a history of GDM but no progression to type 2 diabetes do not have an increased risk of stroke (multivariable HR, 1.22 [95% CI, 0.86-1.73]). CONCLUSIONS: In this large prospective study of Black women, a vulnerable population at high risk for stroke, a history of GDM increased stroke incidence by 41%. There was no elevated risk of stroke for Black women with a history of GDM and no progression to type 2 diabetes, while the stroke risk increased by 2.6-fold for Black women with GDM and progression to type 2 diabetes. Our results highlight the importance of consideration of history of GDM for stroke early prevention, especially Black women with progression to T2DM after GDM.