Diabetes in Pregnancy Differs from One Woman to Another
Diabetes occurs when the body does not make enough insulin to keep up with demands. But not all diabetes is the same. We talk a lot about the most common forms of diabetes—type 1 diabetes and type 2 diabetes. Yet, we are just beginning to understand that there are many different things that can go wrong to damage or destroy the cells that make insulin. While type 1 diabetes is linked to autoimmunity, there may be many different triggers for the immune attack. And there seem to be many genetic and environmental factors that lead to risk for type 2 diabetes.
It is important to understand all of the factors that cause diabetes. By doing so, it may become possible to pinpoint an individual's exact cause or set of causes of their diabetes and to prescribe a particular treatment that selectively treats what went wrong in that person.
The diabetes that occurs during pregnancy is called gestational diabetes and it usually goes away after the baby is born. Gestational diabetes is known to increase the risks for large birth weight, birth complications, and later development of type 2 diabetes in both the mother and the child.
While gestational diabetes has historically been considered a uniform disease, Marie-France Hivert, MD, thought that, like other types of diabetes, it could have different causes. If we can begin to understand the various causes, we may be able to link them to differences in outcomes and determine which women are at high risk of complications.
Dr. Hivert's group recently reported finding that women with gestational diabetes had either primary insulin sensitivity defects (their bodies could not properly use insulin) or primary insulin secretion defects (their bodies could not make enough insulin). The women who were primarily affected by insulin sensitivity defects had higher body mass index, higher fasting glucose and larger birth weight infants than women who were primarily affected by insulin secretion defects, despite all women receiving the same care and treatments for their gestational diabetes. The women with insulin secretion defects had similar outcomes to women who did not have gestational diabetes at all. These findings support the idea that there are indeed different subtypes of gestational diabetes, and that different types of gestational diabetes may result in different complications requiring individualized treatment.
In her continuing studies with the Pathway to Stop Diabetes grant funding from the American Diabetes Association, Dr. Hivert will be studying how genes influence blood glucose regulation in pregnancy and determining how genetics are linked the subtypes of gestational diabetes. With this information, health care providers may begin to target more intensive treatments to the women and children who are at high risk for complications during or after pregnancy.
Dr. Hivert and her colleagues published these findings in the American Diabetes Association's journal Diabetes Care.
Powe CE, Allard C, Battista MC, Doyon M, Bouchard L, Ecker JL, Perron P, Florez JC, Thadhani R, Hivert MF. Heterogeneous Contribution of Insulin Sensitivity and Secretion Defects to Gestational Diabetes Mellitus. Diabetes Care. 2016 Jun;39(6):1052-5.