Women who have gestational diabetes during their pregnancy may be at higher risk of developing coronary artery calcification. That was the conclusion of a recent American multicenter community-based study.
Gestational diabetes, impaired glucose tolerance
Some pregnant women develop gestational diabetes during their pregnancy. This involves glucose intolerance, generally developing towards the end of the second trimester, resulting in chronically elevated blood glucose levels. The WHO defines gestational diabetes as impaired glucose tolerance resulting in chronic hyperglycemia of variable severity, depending on the individual.
The causes of this type of diabetes are not always known or obvious but it may sometimes be due to pancreatic beta-cell malfunction or to insulin resistance following placental hormone release. Human placental lactogen is the main hormone responsible for increased insulin resistance. But other hormones may also be implicated in the stimulation of insulin resistance, such as growth hormone, prolactin, corticotropin-releasing hormone and progesterone.1
A two-fold higher risk of coronary artery calcification following gestational diabetes
Fortunately, for the majority of women, the diabetes disappears after the end of their pregnancy. However, a recent study demonstrated that gestational diabetes is a not insignificant risk factor for the development of cardiovascular diseases. According to the researchers, women with a history of gestational diabetes were at higher risk of developing coronary artery calcification (CAC) in midlife. Indeed, a data analysis published recently in the Circulation journal revealed that a history of gestational diabetes at least doubled the lifetime risk of CAC in some women.
The data analyzed were obtained from the CARDIA study (Coronary Artery Risk Development in Young Adults) including a US multicenter prospective cohort of 1,133 women, with an average age of 47.6 years. All of the women followed up underwent glucose tolerance testing at the start of their pregnancy (age between 18 and 30 years) and up to five times over around 25 years after the pregnancy. The study takes into account the measurements obtained from one or more follow-up examinations 15, 20 and 25 years after the pregnancy. CAC was measured by non-contrast cardiac computed tomography. Among the sample of women, 139 of them reported gestational diabetes during the follow-up. According to the results of the study, a quarter of the women having had gestational diabetes had CAC, compared to 15% of the women never having had gestational diabetes.
This study suggests that it may be useful to more routinely conduct cardiovascular follow-up in women having developed gestational diabetes during a pregnancy.
Gunderson EP, Sun B, Catov JM, Carnethon M, Lewis CE, Allen NB, Sidney S, Wellons M, Rana JS, Hou L, Carr JJ. Gestational Diabetes History and Glucose Tolerance After Pregnancy Associated With Coronary Artery Calcium in Women During Midlife: The CARDIA Study. Circulation. 2021 Mar 9;143(10):974-987. doi: 10.1161/CIRCULATIONAHA.120.047320. Epub 2021 Feb 1. PMID: 33517667; PMCID: PMC7940578.