In the liver, estrogen stimulates the synthesis of apoprotein A1, which can be considered a precursor of HDL. At the same time, these hormones decrease the activity of an enzyme, hepatic lipase. These phenomena result in an increase in the HDL cholesterol in the circulation.
Furthermore, at the cell level, estrogen favors an increase in LDL receptors, thus promoting a greater use of circulating cholesterol.
The end result is a decrease in the ratio of total / LDL cholesterol to HDL, which equates to a low cardiovascular risk.
of female hormones on cholesterol and triglyceride levels has been known for some time.
Starting from the second trimester of pregnancy, the total cholesterol level rises considerably under the pressure of the estrogens produced by the placenta; even birth control pills with high estrogen concentrations, or replacement therapies during menopause, tend to significantly increase total cholesterol. In both cases, the increase in blood cholesterol values mainly affects the HDL fraction; this represents a positive and desirable factor in reducing cardiovascular risk.
Also for this important contribution, during the fertile age of every woman, estrogens confer a very important protection against cardiovascular diseases.
and progesterone. Consequently, it is also important to evaluate the phase of the menstrual cycle in which you undergo cholesterol and triglyceridemia tests.Generally speaking, cholesterol levels rise during the first half of the menstrual cycle and decrease in the luteal phase.
As anticipated, the increasing levels of estrogen that characterize the first half of the menstrual cycle bring with them a gradual increase in HDL lipoproteins (good cholesterol), which reach a peak at ovulation.
On the other hand, total cholesterol, LDL cholesterol and triglycerides appear to decrease as estrogen levels increase; this decline, however, is not immediate, but manifests itself with a few days of delay.
Therefore, it must be considered that the peak of total cholesterol levels during the menstrual phase is the consequence of the decline in estrogen in the late luteal phase, while the subsequent decline in total cholesterolemia follows the slight increase in estrogen during the menstrual phase; this decline becomes even more abrupt a few days after estrogen levels begin to increase significantly in view of ovulation.
