The researchers found that as estrogen levels rise, HDL, or "good" cholesterol also rises, peaking at ovulation.
At the same time, as estrogen levels increased, total and LDL, or "bad" cholesterol, as well as levels of triglycerides, fell, Schisterman's team found. This decline began a couple of days after estrogen levels peaked at ovulation.
In addition, levels of total cholesterol, LDL cholesterol and triglycerides were lowest just before the start of menstruation, the researchers noted.
"This is more recognition that hormones play a very important role in women's lives on all levels, including basic tests, like the test for cholesterol," Schisterman said. "The menstrual cycle plays a very important role in women's overall health."
Dr. Jennifer Glueck, an assistant professor of clinical medicine in the division of endocrinology, diabetes and metabolism at the University of Miami Miller School of Medicine, said that "I really wasn't aware that the levels of the lipids could fluctuate like that over the course of the menstrual cycle."
However, the finding may not be particularly clinically relevant to this group of young women, Glueck said.
"These are young healthy women that you wouldn't be considering to start cholesterol-lowering medications on," she said. "It doesn't seem like it pushed them into categories where you would initiate treatment."
So while the finding is interesting, it probably won't change clinical practice, she noted.
For more information on cholesterol, visit the American Heart Association.
SOURCES: Enrique F. Schisterman, Ph.D., chief, Epidemiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development; Jennifer Glueck, an
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