Does First Nations ancestry modify the association between gestational diabetes and subsequent diabetes: a historical prospective cohort study among women in Manitoba, Canada

• Published in: Diabetic Medicine
• Main Authors: Shen, Garry X., Shafer, Leign Anne, Martens, Patricia J., Sellers, Elizabeth, Torshizi, Ali A., Ludwig, Sora, Phillips-Beck, Wanda, Heaman, Maureen, Prior, Heather J., McGavock, Jonathan, Morris, Margaret, Dart, Alison, Campbell, Rhonda, Dean, Heather J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2015
• Subjects: Gestational diabetes; Type 2 diabetes; Pregnancy; Offspring; First Nations; Manitoba; Canada; Meier
• Online Access: http://hdl.handle.net/1993/30933; https://doi.org/10.1111/dme.12962

Background: Over the past 30 years, the prevalence of diabetes has steadily increased among Canadians, which is particularly evident among First Nations (FN) women. The interplay between FN ancestry, gestational diabetes mellitus (GDM) and the development of subsequent diabetes among mothers remains unclear. Methods: After excluding known pre-existing diabetes, we explored whether FN ancestry may modify the association between GDM and postpartum diabetes among women in Manitoba (1981-2011) via a historical prospective cohort database study. We analyzed administrative data in the Population Health Research Data Repository with Kaplan-Meier survival analysis and Cox proportional hazards regression. Results: GDM was diagnosed in 11,906/404,736 deliveries (2.9%), 6.7% of FN and 2.2% of non-FN pregnant women (p<0.0001). Postpartum diabetes during ≤30 years follow-up was >3 times higher among FN women than among non-FN women (p<0.0001). Diabetes developed in 76.0% of FN and 56.2% of non-FN women with GDM within the follow-up period. The hazard ratio of GDM for postpartum diabetes was 10.6 among non-FN women and 5.4 among FN women. Other factors associated with a higher risk of diabetes included lower family income among FN and non-FN women and rural/remote residences among FN women. Among non-FN women, urban residence was associated with a higher risk of diabetes. Interpretation: GDM increases postpartum diabetes in FN and non-FN women. FN women had substantially more GDM or postpartum diabetes than non-FN women, partially due to socioeconomic and environmental barriers. Reduction in GDM and socioeconomic inequalities are required to prevent diabetes in women, particularly in FN population. Canadian Institutes of Health Research (SEC117115)