Hot flashes and night sweats are symptoms commonly associated with menopause but the hormonal changes that accompany this phase of life usher in another major shift — an increased risk of cardiovascular disease. The decline in the hormone estrogen can lead to changes in cholesterol, blood pressure and plaque buildup in blood vessels, which increase the risk of heart attack and stroke.
The research team was interested in understanding the long-term effect of hormone therapy on cardiovascular biomarkers, which hasn’t been evaluated over an extended period of time. Prior research in the field primarily looked at short-term effects.
Here, the team analyzed biomarkers associated with cardiovascular health over a six-year period from a subset of women who had participated in an oral hormone therapy clinical trial that was part of the WHI. Participants were randomly assigned to one of two groups — an estrogen-only group and an estrogen plus progesterone group — were between the ages of 50 and 79 when they were assigned to a group and were post-menopausal. They provided blood samples at baseline and at one-, three- and six-years. In total, they analyzed samples from 2,696 women, approximately 10% of the total trial participants.
The research team found that hormone therapy had a beneficial effect on most biomarkers in both the estrogen-only and the estrogen-plus-progesterone groups over time. Levels of LDL cholesterol, the so-called “bad” cholesterol, were reduced by approximately 11% while total cholesterol and insulin resistance decreased in both groups. HDL cholesterol, the so-called “good” cholesterol, increased by 13% and 7% for the estrogen-only and estrogen-and-progesterone groups, respectively.
However, triglycerides and coagulation factors, proteins in the blood that help form blood clots, increased.
More surprising to the research team, they said, levels of lipoprotein(a), a type of cholesterol molecule, decreased 15% and 20% in the estrogen-only and the estrogen-plus-progesterone groups, respectively. Unlike other types of cholesterol, which can be influenced by lifestyle and health factors such as diet and smoking, concentrations of lipoprotein(a) are thought to be determined primarily by genetics, Nudy explained. Patients with a high lipoprotein(a) concentration have an increased risk of heart attack and stroke, especially at a younger age. There’s also an increased risk of aortic stenosis, where calcium builds up on a heart valve.
“As a cardiologist, this finding is the most interesting aspect of this research,” Nudy said. “Currently, there are no medications approved by the Food and Drug Administration (FDA) to lower lipoprotein(a). Here, we essentially found that oral hormone therapy significantly reduced lipoprotein(a) concentrations over the long-term.”
