Pregnancy-related diabetes does not go away after childbirth

Gestational diabetes (GDM) occurs during pregnancy and affects approximately 14% of pregnant women worldwide, 10% in Switzerland. It is characterized by an increase in blood sugar levels (glycemia).

“Contrary to popular belief that GDM disappears after childbirth, we now know that it can increase the long-term risk of type 2 diabetes by up to ten times, as well as the onset of other cardiovascular diseases. -metabolic”, indicates TinhHai Collet, assistant professor at the Faculty of Medicine of the University of Geneva (UNIGE), assistant physician in the Department of Endocrinology, Diabetology, Nutrition and Therapeutic Patient Education at HUG.

With a team made up of scientists from UNIGE, CHUV, HUG, UNIL and EPFL, the researcher wanted to better assess this risk by monitoring the physiological markers and behavioral habits of women during the post-partum period. -partum.

The study, published in Diabetologia, shows that women who have had gestational diabetes have a higher weight. Furthermore, even when consuming fewer carbohydrates (foods like bread, pasta, rice or added sugars all result in glucose) their blood sugar takes longer to return to normal after meals. Their daily blood sugar rhythm is also disrupted, suggesting a malfunction of their internal clocks, or circadian rhythms.

“The physiological dynamics of blood sugar have two aspects. After meals, in particular, a transient increase is generally observed. There is also a 24-hour blood sugar cycle, influenced by circadian rhythms. These two dynamics are disrupted in women who have had gestational diabetes,” reveals Jardena Puder, associate professor at the Faculty of Biology and Medicine at UNIL, assistant physician at the Gestational Diabetes Consultation of the Obstetrics Service of the Women’s Department. mother of a child at CHUV, and co-author of the study.

Scientists followed CHUV patients, with or without a diagnosis of gestational diabetes, using cutting-edge wearable devices capable of measuring blood sugar, eating habits, physical activity, sleep and heart rate in real time for 24 hours. “For example, we were able to integrate blood glucose data with a food diary-style smartphone app to analyze glucose dynamics after meals. It is really these new technologies that made the difference for this study,” indicates Charna Dibner, associate professor in the Department of Surgery at HUG, in the Department of Cellular Physiology and Metabolism as well as at the Faculty Diabetes Center of the Faculty of Medicine of UNIGE, and co-author of the study.

These measurements were taken over a period of two weeks, between one and two months after delivery, then repeated six months later. The study included 22 women with gestational diabetes and compared them to 15 women with normal glucose metabolism during the preceding pregnancy.

Women who have had GDM therefore continue to present alterations in the regulation of their blood sugar, including those who had normal blood sugar values ​​in their usual blood test. “The conventional techniques used today for clinical monitoring are adequate. However, our approach shows that gestational diabetes does not completely disappear after delivery. A glucose regulation disorder persists. This could have long-term consequences, even when the glycemic values ​​in the blood are normal,” insists Tinh-Hai Collet.

This work suggests that monitoring blood glucose variability during the postpartum period would make it possible to identify women at risk. The measurements taken by the research team could serve as markers of potential complications, even if the latter will have to be defined in the long term, in particular their link with the development of type 2 diabetes.