Response of plasma low density lipoprotein subfractions to oestrogen replacement therapy following surgical menopause

Abstract

In view of a similar and characteristic response of LDL subfractions to hypolipidaemic drugs that enhance the clearance of LDL via the LDL receptor, the present findings suggest that oestrogen promotes the preferential removal of LDL-I and II by activating LDL receptors. As this effect is normally associated with a reduction in the circulating level of LDL, it should not be regarded as an unfavourable response to oestrogen replacement therapy.

Alterations in hepatic lipase and lipoprotein subfractions with transdermal testosterone replacement therapy

“…In females, oestrogen replacement therapy after surgical menopause is associated with a decrease in the concentration of the less dense LDL‐I and LDL‐II subfractions with a resultant shift in the distribution of LDL subfractions towards small dense LDL‐III. These changes are thought to be mediated through the activation of LDL receptors by oestrogen leading to the preferential removal of LDL‐I and II (Griffin et al ., 1993). We have also found changes in LDL subfraction profile in our patients after testosterone replacement.…”

Hormone Replacement Therapy in Postmenopausal Women and Its Effects on Plasma Lipid Levels

“…According to Campos et al (20), estrogen therapy reduces the number of large LDL particles, while increasing these of smaller size, but this adverse effect can be minimized by the beneficial effect of estrogens on the levels of TC, LDL-C and HDL-C. Other studies have suggested that estrogens decrease the size of the LDL particles in conjunction with a significant increase in plasma TG (19)(20)(21)(22)(23)(24). Several investigators have reported that hypertriglyceridemia increases the exchange of cholesterol esters with TG in LDL particles by way of the transfer of lipids among the VLDL, LDL and HDL fractions (25)(26)(27).…”

Impact of menopause and diabetes on atherogenic lipid profile: is it worth to analyse lipoprotein subfractions to assess cardiovascular risk in women?

“…Several clinical trials were conducted to investigate the effects of different schemes of HRT on the lipid profile after menopause [117–120], but those using accurate methods for the determination of subfractions of lipoproteins are less numerous [121, 122]. In one study, 38 postmenopausal Brazilian women with formal indication for HRT were treated with continuous doses of 0.625 mg of conjugated equine estrogen (CEE) with (if they had uterus) or without 2.5 mg of medroxyprogesterone for 12 weeks.…”

“…Combined therapy resulted in a significant increase in the proportion of bigger HDL particles in circulation, also diminishing the absolute amount of smaller HDL particles. Other trials with estrogen alone in surgically induced menopause have shown a tendency for an increase in HDL and HDL 2 , but a variety of results were found for LDL particles [118–121]. Different HRT regimens, such as natural vs synthetic, transdermal vs oral, cyclic vs continuous, different progestogens or estrogens and doses have also been tested, but modifications in both lipid and lipoprotein subclasses are inconsistent across trials.…”