Co-Occuring Gestational Diabetes, Hypertension Linked with Doubling of Future Cardiovascular Risk

An analysis of data from nearly 900,000 women is providing clinicians with an overview of the cardiovascular risk associated with concomitant occurrence of a pair of conditions common among expectant mothers in the US and abroad.

Using data from the Ministry of Health and Long-Term Care of Ontario administrative databases, results of the analysis demonstrated concomitant occurrence gestational diabetes and gestational hypertensive disorder was associated with a 2.4-fold increase in risk of incident cardiovascular disease compared to their counterparts with neither condition, which investigators noted was significantly higher than the increase in risk observed for either condition individually.

“This cohort study found that over time, co-occurrence of [Gestational Diabetes] and [Gestational Hypertensive Disorder] was associated with a much greater postpartum CVD risk than the individual conditions. The systematic identification of both [Gestational Hypertensive Disorder] and [Gestational Diabetes] in obstetrical practice offers an opportunity for a more effective CVD prevention among young women of childbearing age.”

Despite advances across medicine, pitfalls in care and maternal morbidity remain persistent issues for health care systems in North America. With this in mind, a team from Johns Hopkins University School of Medicine, Mount Sinai Hospital, and the Institute for Clinical Evaluative Studies in Toronto, Canada sought to further explore the impact of gestational hypertensive disorders and gestational diabetes on subsequent cardiovascular risk. To do so, they designed a population-based cohort study using data from the Ministry of Health and Long-Term Care of Ontario health care administrative databases, which is that provide investigators with information related to 866,295 women in Ontario with a gestational hypertensive disorder and/or gestational diabetes diagnosis, and a live-birth singleton delivery from July 1, 2007-March 31, 2018 for inclusion in their analyses.

Study participants were identified using diagnostic coding. Investigators pointed out women with pregravid diabetes, hypertension, or cardiovascular disease were excluded from the study. The 866,295-person cohort included in final analyses had a mean age of 30 (SD, 5.6) years.

The primary outcome of interest for the investigators analyses was incident cardiovascular disease, which was a composite of myocardial infarction, acute coronary syndrome, stroke, coronary artery bypass grafting, percutaneous coronary intervention, or carotid endarterectomy. Associations were assessed using Cox regression models, with adjustment for relevant cardiometabolic risk factors.

Overall, 4.9% had an isolated gestational hypertensive disorder, 6.1% had isolated gestational diabetes, and 0.6% had both a gestational hypertensive disorder and gestational diabetes. During the follow-up period, which lasted a mean of 12.8 years and included 7.0 million person-years, a total of 1999 cardiovascular disease events were observed among the study cohort, with 867 occurring during the first 5 years postpartum and 1162 events occurring during the period subsequent to the first 5 years post index delivery.

Results of the investigators’ analysis indicated there was no association of co-occurrence of gestational hypertensive disorders and gestational diabetes (aHR, 1.42 [95% CI, 0.78-2.58]) or gestational diabetes alone (aHR, 0.80 [95% CI, 0.60-1.06]) with incident cardiovascular disease in the first 5 years postpartum. However, investigators noted there was an association observed between isolated gestational hypertensive disorders and incident CVD compared with no gestational hypertensive disorders and no gestational diabetes (aHR, 1.90 [95% CI, 1.51-2.35]) during this time period.

When assessing risk after the initial 5-year period, results suggested isolated gestational hypertensive disorder (aHR, 1.41 [95% CI, 1.12-1.76]) and co-occurrence of gestational hypertensive disorders and gestational diabetes (aHR, 2.43 [95% CI, 1.60-3.67]) were each associated with a higher risk of incident cardiovascular disease compared to no gestational diabetes and no gestational hypertensive disorder. Investigators pointed out no association was observed between isolated gestational diabetes and incident cardiovascular disease.

“In this large population-based cohort study, extended follow-up after delivery found that while [Gestational Hypertensive Disorder] and [Gestational Diabetes] would each be individually associated with a high risk of CVD, women who experienced both [Gestational Hypertensive Disorder] and [Gestational Diabetes] during a pregnancy were ultimately at significantly higher absolute and relative risk of CVD, as compared to those without either of these conditions,” investigators wrote. “Over time, this risk became more pronounced than that observed among women with each of these conditions separately.”

This study, “Association of Concomitant Gestational Hypertensive Disorders and Gestational Diabetes With Cardiovascular Disease,” was published in JAMA Network Open.