Pregnancy-Induced Hypertension May Signify Later Vessel Dysfunction
A hypertensive disorder experienced during pregnancy may subtly alter the way arteries respond to insulin in the blood -- increasing a mother's cardiovascular risk long after a child is born, according to research published in Hypertension: Journal of the American Heart Association.
In a small study, researchers found a significant positive association between vasodilatation --the ability of artery walls to expand -- and insulin sensitivity in women with preeclampsia (pregnancy-induced hypertension) or a history of the disorder.
"Although preeclampsia is mainly 'cured' after delivery, metabolic abnormalities have been shown to prevail for months to several years afterward, which could contribute to the increased risk of cardiovascular disease in these women," said Risto Kaaja, M.D., D.M.Sc., co-author of the study and a researcher at Helsinki University Hospital in Finland.
Researchers studied 28 non-obese women with previous severe preeclampsia and a similar group of 20 women who had normal pregnancies. Five to six years later, they found a correlation between insulin sensitivity and vascular dysfunction only among the women with a history of preeclampsia.
"To our knowledge, there are no previous studies on insulin sensitivity and its relationship to vascular dilatory function during preeclampsia or after preeclamptic pregnancy," Kaaja said. "These results indicate changes in the muscle wall of the artery might impair the vasodilatory capacity, as well as alterations in the lining of the artery."
Analysis showed that waist-hip ratio (WHR) and blood triglycerides had the greatest effect on insulin sensitivity.
"With increasing waist-hip ratio, these will become insulin resistant and their vasodilatation will be impaired," Kaaja said. "Both insulin resistance and impaired vasodilatation can lead to atherosclerosis."
The severity of preeclampsia and gestational weeks at the onset of the condition were associated with later insulin sensitivity, the researchers said.
Women should be informed about their increased risk for cardiovascular disease if they have had preeclamptic pregnancies, researchers said. Non-obese women (normal WHR) with history of preeclamptic pregnancy should avoid gaining weight and maintain normal WHR. Other risk factors, including blood pressure, blood lipids and glucose levels should also be checked regularly and treated if abnormal.
Preeclampsia occurs only during pregnancy and the postpartum period and, together with other hypertensive disorders of pregnancy, are leading global causes of maternal and infant illness and death, affecting an estimated 5 percent to 8 percent of all pregnancies worldwide.
Preeclampsia is a rapidly progressive condition characterized by high blood pressure and the presence of protein in the urine. Swelling, sudden weight gain, headaches and changes in vision are important symptoms; however, some women with rapidly advancing disease report few symptoms.