The latest issue of the Journal of the American Heart Association carries the results of a 20-year study of gestational diabetes and heart disease. It seems gestational diabetes causes the carotid artery wall to thicken, a condition that may trigger heart disease in the future.

Gestational diabetes occurs only during pregnancy and, in most cases, goes away once the baby's born. Pregnancy hormones affect the way insulin works by weakening its ability to transport glucose, the body's main source of energy, from the bloodstream into individual cells.

A woman is more prone to gestational diabetes when her medical history includes:

  • Family history of diabetes
  • Previous miscarriage due to unexplained cause
  • Becoming pregnant after age 25
  • Being overweight when conception occurs

Even though the diabetic state resolves itself after pregnancy, the lingering effects of gestational diabetes continue to be a concern many years after the baby is born, according to the study in the heart association journal.

The study began with 2,787 women between ages 18 and 30. All women tested negative for diabetes and heart disease and each had the thickness of their carotid arteries measured using ultrasound technology. Over time, the study narrowed to long-term follow-up of just the 898 women who gave birth at least once after the study began. Of this smaller study group, 119 (13%) developed gestational diabetes.

During the course of the study, all the women were routinely assessed for type 2 diabetes and heart disease. Their artery walls were measured again about 12 years after their child was born. The artery walls of the women who experienced gestational diabetes were thicker than those not diagnosed with the the disorder.

Artery wall thickness is used to assess a person's risk or severity of atherosclerosis. When atherosclerosis develops, the arteries become clogged with fatty substances that limit or block the flow of blood to and from the heart. Diminished blood flow to and from the heart leads to cardiovascular disease, including heart attacks and strokes.

The research team, led by Dr. Erica P. Gunderson, concludes "Gestational diabetes may be an early risk factor for heart disease in women." By identifying the link between gestational diabetes and atherosclerosis, a woman's risk for cardiovascular disease can be assessed before diabetes or metabolic diseases set in.

Gunderson, affiliated with the Kaiser Permanente Northern California Division of Research / Cardiovascular and Metabolic Conditions Section, says her team's findings represent "a shift in thinking" about identifying subgroups at increased risk before symptoms begin. "The concept that reproductive complications unmask future disease risk is a more recent focus," she says.

Source: Gunderson, Erica P, PhD, et al. "History of Gestational Diabetes Mellitus and Future Risk of Atherosclerosis in Mid-life: The Coronary Artery Risk Development in Young Adults Study." Journal of the American Heart Association. American Heart Association / American Stroke Association. Mar 12, 2014. Web. Mar 20, 2014.