Pregnant women who develop gestational diabetes may be more at risk of developing heart disease later in life, according to new research.
Researchers at Kaiser Permanente Northern California in Oakland have published the results of their 20-year study in the Journal of the American Heart Association.
Gestational diabetes only occurs during pregnancy. It happens when hormones activated during pregnancy weaken the effect of insulin, the hormone that normally allows cells to absorb glucose from the blood.
Factors that can make pregnant women at greater risk of getting gestational diabetes include having a family history of diabetes, having previously had an unexplained miscarriage, being older than 25 when they became pregnant or being overweight before becoming pregnant.
Women who develop gestational diabetes are usually able to control their blood sugar without harming their baby's health. But having gestational diabetes does make women more likely to develop diabetes 5-10 years after giving birth.
The new study finds that women who get gestational diabetes while pregnant also have an associated risk of atherosclerosis - where the arteries around the heart become clogged by fatty substances. Because atherosclerosis disrupts the flow of blood to and from the heart, this can eventually cause heart attacks and other cardiovascular diseases.
Study tracked women's metabolic and heart health over 20 years
In the study, 898 women aged between 18 and 30, who later had children, were assessed for heart disease risk factors. Over a period of 20 years, the women were periodically tested for diabetes and other metabolic conditions. An average of 12 years after giving birth, the thickness of the walls of their carotid arteries was also measured using ultrasound.
Overall, 13% of the women in the study developed gestational diabetes. On average, the carotid artery walls of these women was 0.023 mm thicker than those of women who did not have gestational diabetes while they were pregnant.
Fast facts about gestational diabetes
- Although some women with gestational diabetes will need to take medicine, most women will not have to take insulin.
- Diet and exercise are the best way to manage gestational diabetes.
- Women with gestational diabetes tend to give birth to larger babies, so in some cases a C-section may be needed.
The thickness of carotid arteries is used by doctors to measure atherosclerosis and predict heart attack and stroke.
The researchers also took into account other factors that might have influenced the thickness of the women in the study's arteries, such as whether the women were obese, or if they had high glucose levels before pregnancy.
"This finding indicates that a history of gestational diabetes may influence development of early atherosclerosis before the onset of diabetes and metabolic diseases that previously have been linked to heart disease," says study lead author Erica P. Gunderson, PhD. "Gestational diabetes may be an early risk factor for heart disease in women."
"It's a shift in thinking about how to identify a subgroup at risk for atherosclerosis early," she added. "The concept that reproductive complications unmask future disease risk is a more recent focus."
In November 2013, Medical News Today reported on new screening guidelines to help medical professionals better detect gestational diabetes.