Lipids and clotting factors during low dose transdermal estradiol/norethisterone use

OBJECTIVE: To demonstrate the effects of 2-year transdermal continuous combined low-dose estradiol (0.025 mg/day) and norethisterone acetate (0.125 mg/day) on lipid/lipoprotein profile and coagulation/fibrinolysis. METHODS: A double-blind, randomized, multicenter, parallel, 1-year trial enrolled 266 healthy women at least 2 years post menopause. Patients received either 0.025 mg estradiol and 0.125 mg norethisterone acetate daily or placebo transdermally. One hundred and thirty five women completed a second year open follow-up (96 had used Estragest TTS, 39 placebo during the first year), where all women had the estradiol/norethisterone patch. Lipid/lipoprotein profile and coagulation/fibrinolysis parameters were studied at 0, 24, 48, 72 and 96 weeks. RESULTS: In women on estradiol/norethisterone total cholesterol, Lp(a) and VLDL cholesterol decreased significantly more than in the placebo group after 24 weeks and LDL cholesterol after 48 weeks. Women on estradiol/norethisterone had no change in HDL, triglycerides or Lp(a), an increased HDL/total cholesterol ratio and decreased LDL, VLDL and total cholesterol at 48 weeks compared to placebo. Women with active treatment also showed a significant reduction compared with the placebo group of Factor VII and antithrombin III at 24 and 48 weeks and a reduction of fibrinogen at 24 weeks. These changes persisted over the second year. CONCLUSIONS: A continuous combined low-dose transdermal patch daily delivering 0.025 mg estradiol and 0.125 mg norethisterone acetate provided beneficial effects on lipid/lipoprotein profile and coagulation/fibrinolysis. The changes were similar to those previously described after higher dose oral and transdermal estrogen/progestogen regimens.     

National differences in lipid response to postmenopausal hormone replacement therapy

Objective: To compare the response of serum lipids and lipoproteins to the transdermal hormone replacement therapy (HRT) in five European countries. Methods: Five-hundred and sixty-seven healthy postmenopausal women from Belgium, Finland, the Netherlands, Sweden, and the UK received transdermal estradiol 50 μg daily for 12 months. In addition, two groups received transdermally norethisterone acetate (NETA) continuously, two groups sequentially (170 or 350 μg/day); one group received sequentially oral NETA (1 mg/day), and one group dydrogestrone (20 mg/day). Serum total cholesterol, HDL-, HDL2-, LDL-cholesterol, lipoprotein(a) (Lp(a)), and triglycerides were assessed before and at the end of treatment. Results: No significant national differences existed in the pretreatment levels of lipids and lipoproteins. Mean cholesterol, LDL, Lp(a), and triglycerides decreased during HRT, and HDL and HDL2 increased. Individual changes in responses to HRT were strongly dependent on pretreatment values. In this regard, British women differed from the others: their cholesterol, HDL, HDL2, and Lp(a) responses, when related to the pretreatment levels, were smaller than those of the others. Conclusion: A national difference discovered in response of serum lipids to HRT calls for caution in generalization of lipid data from one nation to another during HRT.     

Effects of postmenopausal estrogen replacement on the concentrations and metabolism of plasma lipoproteins

BACKGROUND. Postmenopausal estrogen-replacement therapy may reduce the risk of cardiovascular disease, and this beneficial effect may be mediated in part by favorable changes in plasma lipid levels. However, the effects on plasma lipoprotein levels of postmenopausal estrogens in the low doses currently used have not been precisely quantified, and the mechanism of these effects is unknown. METHODS. We conducted two randomized, double-blind crossover studies in healthy postmenopausal women who had normal lipid values at base line. In study 1, 31 women received placebo and conjugated estrogens at two doses (0.625 mg and 1.25 mg per day), each treatment for three months. In study 2, nine women received placebo, oral micronized estradiol (2 mg per day), and transdermal estradiol (0.1 mg twice a week), each treatment for six weeks. The metabolism of very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) was measured by endogenously labeling their protein component, apolipoprotein B. RESULTS. In study 1, the conjugated estrogens at doses of 0.625 mg per day and 1.25 mg per day decreased the mean LDL cholesterol level by 15 percent (95 percent confidence interval, 11 to 19 percent; P less than 0.0001) and 19 percent (95 percent confidence interval, 15 to 23 percent; P less than 0.0001), respectively; increased the HDL cholesterol level by 16 percent (95 percent confidence interval, 12 to 20 percent; P less than 0.0001) and 18 percent (95 percent confidence interval, 14 to 22 percent; P less than 0.0001), respectively; and increased VLDL triglyceride levels by 24 percent (95 percent confidence interval, 8 to 40 percent; P less than 0.003) and 42 percent (95 percent confidence interval, 26 to 58 percent; P less than 0.0001), respectively. In study 2, oral estradiol increased the mean concentration of large VLDL apolipoprotein B by 30 +/- 10 percent (P = 0.05) by increasing its production rate by 82 +/- 18 percent (P less than 0.01). Most of this additional large VLDL was cleared directly from the circulation and was not converted to small VLDL or LDL. Oral estradiol reduced LDL cholesterol concentrations by 14 +/- 3 percent (P less than 0.005), because LDL catabolism increased by 36 +/- 7 percent (P less than 0.005). The oral estradiol increased the HDL cholesterol level by 15 +/- 2 percent (P less than 0.0001). Transdermal estradiol had no effect. CONCLUSIONS. The postmenopausal use of oral estrogens in low doses favorably alters LDL and HDL levels that may protect women against atherosclerosis, while minimizing potentially adverse effects on triglyceride levels. The decrease in LDL levels results from accelerated LDL catabolism; the increase in triglyceride levels results from increased production of large, triglyceride-rich VLDL.     

Substitution of transdermal estradiol during oral estrogen-progestin therapy in postmenopausal women: effects on hypertriglyceridemia

OBJECTIVE: We investigated effects of changing from oral estrogen to transdermal estradiol on the lipid and lipoprotein profile of postmenopausal women who developed hypertriglyceridemia (serum concentrations exceeding 150 mg/dL) during estrogen-progestin therapy. DESIGN: Sixty-one postmenopausal Japanese women receiving 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate daily for 12 months had developed serum triglyceride concentrations exceeding 150 mg/dL after 12 months of treatment. Thirty-six of them, chosen randomly for study, were assigned at random to either a group that continued this oral regimen or another that changed to transdermal estradiol while continuing 2.5 mg of oral medroxyprogesterone acetate for the next 3 months (n = 18 for each). Blood lipids were compared between groups. RESULTS: Serum concentrations of triglyceride and very-low-density lipoprotein triglyceride decreased significantly after changing to transdermal estradiol (triglyceride, from 226.0 +/- 43.9 to 110.5 +/- 44.1 mg/dL, P < 0.01). No changes were seen in concentrations of low-density lipoprotein cholesterol or high-density lipoprotein cholesterol. CONCLUSION: Changing to transdermal estradiol may improve triglyceride metabolism in women who developed hypertriglyceridemia during oral estrogen-progestin therapy, with minimal effect on cholesterol profiles.     

Comparison of two HRT regimens with bimonthly and monthly progestin administration in postmenopause

OBJECTIVES: Here we report the results of a study in which natural estrogens were given transdermally cyclically and continuously for 1 year, and a progestin of the latest generation, namely nomegestrol acetate, was given for 10 days every month and for 15 days every 2 months. METHODS: The patients were a group of 34 post-menopausal women (51-56 years), 18 of whom (group A) were treated with continuous transdermal estradiol (50 micrograms/day) and cyclic oral nomegestrol at a dose of 5 mg/day for 15 days every 2 months for 1 year. The other 16 women (group B) were treated with cyclic transdermal estradiol for 3 weeks with oral nomegestrol for 10 days (12-21)/month. Endometrial thickness was evaluated by transvaginal ultrasonography before and after treatment. At the end of treatment, an endometrial biopsy was performed. Serum total cholesterol, HDL, LDL and triglycerides were assessed at baseline and every 4 months. The characteristics of the cycle were deduced from the diary cards recorded by the women. RESULTS: No significant differences were found in the mean interval between the last dose of nomegestrol and the start of bleeding or in the duration of bleeding. The total number of days of bleeding per year was significantly lower in group A than group B (27 +/- 12 vs. 52 +/- 18; P < 0.01). Total serum cholesterol and LDL significantly decreased after 1 year of treatment in both groups, HDL-cholesterol and triglycerides were found increased at most of the time points studied. CONCLUSIONS: The present protocol involving continuous transdermal administration of estrogen combined with oral progestin every 2 months gave good control of the menstrual cycle, did not increase the risk of endometrial pathology and met with good patient compliance.     

Supraphysiological concentrations of estradiol in menopausal women given repeated implant therapy do not adversely affect lipid profiles

BACKGROUND: The effects of oral estrogen therapy (ERT) on lipids and metabolic parameters are well known, in contrast to the effects of subcutaneously administered estrogen, particularly high concentrations of estrogen. We examined metabolic parameters in cohorts of women with and without subcutaneous estrogen therapy with concomitant supra-normal concentrations of estradiol (SE). METHODS: Lipids and lipoprotein concentrations, low density lipid (LDL) subfractions, and activity of hepatic lipase (HL) were assessed in 30 menopausal women with SE and 19 control subjects not using ERT, matched for body mass index and age. RESULTS: Waist-hip ratio (WHR) and fasting insulin (FI) concentrations were lower in the SE group compared with the women not on ERT (P < 0.05). The concentrations of triglyceride and high density lipid (HDL) cholesterol were similar (P > 0.1), whereas total cholesterol (P < 0.05), LDL cholesterol (P < 0.05), and HL activity (P < 0.01) were lower in the SE group. Concentrations of the large, buoyant LDL I subfraction were significantly lower in the SE group (P < 0.05), but there was no difference in LDL III concentrations. CONCLUSIONS: Women with SE have similar triglyceride and HDL cholesterol levels but lower LDL cholesterol concentrations compared with post-menopausal women not taking ERT. The observations that the SE group showed reduced fasting insulin and WHR suggest that supra-normal circulating concentrations of estradiol, delivered subcutaneously, may beneficially influence insulin metabolism.     

Oral, more than transdermal, estrogen therapy improves lipids and lipoprotein(a) in postmenopausal women: a randomized, placebo-controlled study

OBJECTIVE: To assess the effects of low-dose oral and transdermal estrogen therapy on the lipid profile and lipoprotein(a) [Lp(a)] levels in healthy, postmenopausal women and to study the additional influence of gestodene administration. DESIGN: In a multicenter, randomized, double-blind, placebo-controlled study, 152 healthy, hysterectomized, postmenopausal women received daily either placebo (n = 49), 50 microg transdermal 17beta-estradiol (tE2, n = 33), 1 mg oral 17beta-estradiol (oE2, n = 37), or 1 mg oE2 combined with 25 microg gestodene (oE2 + G, n = 33) for 13 cycles of 28 days, followed by 4 cycles of placebo in each group. Fasting serum concentrations of total, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol, triglycerides, and Lp(a) were measured at baseline and in cycles 4, 13, and 17. RESULTS: In cycle 13, a significant mean percentage decrease from baseline was found in all treatment groups compared with placebo in total cholesterol (tE2, -4.7%; oE2, -6.9%; oE2 + G, -10.5%) and LDL cholesterol (tE2, -5.8%; oE2, -12.6%; oE2 + G, -13.6%). For both oral groups, the reductions were already significant in cycle 4. None of the treatment groups showed a significant change in HDL cholesterol or triglycerides. In cycle 13, Lp(a) was decreased compared with placebo in the oE2 group (-6.6%) and the oE2 + G group (-8.2%). After washout, all observed changes had returned to baseline level, except for the decreases in total and LDL cholesterol in the oE2 + G group. CONCLUSIONS: Oral E2 and E2 + G, and to a lesser extent transdermal E2, decreased total and LDL cholesterol. Lp(a) was lowered only by the oral treatments.     

Comparison of transdermal and oral estrogen-progestin replacement therapy: effects on cardiovascular risk factors

OBJECTIVE: To determine the effects of oral and transdermal hormone replacement therapy on lipid profile and hemostatic factors in postmenopausal women. DESIGN: Twenty subjects were treated with oral E2 valerate (2 mg) combined with cyproterone acetate (1 mg) (group I) and 21 with transdermal E2 (1.5 mg) plus oral medroxyprogesterone acetate (5 mg) (group II). The effects on lipid profile and hemostatic parameters were evaluated at baseline and after 3, 6, and 12 months of treatment. RESULTS: Group I showed a stronger increase of high-density lipoprotein (HDL) cholesterol levels (2-8%) and stronger reduction of atherogenic indices (total cholesterol/HDL cholesterol and low-density lipoprotein/HDL cholesterol) than group II. Group II showed a more pronounced reduction of triglyceride (21-31%) and factor VII (6-10%) levels than group I. Both groups showed reduced concentrations of total cholesterol, low-density lipoprotein cholesterol, tissue plasminogen activator, plasminogen activator inhibitor-1, antithrombin III, and protein S, whereas protein C was increased after 12 months of treatment. CONCLUSIONS: The cardioprotective effects of hormone replacement therapy are demonstrated by favorable effects on lipid profile and fibrinolytic activity. Oral hormone replacement therapy showed a more prominent effect on lipoprotein metabolism than did transdermal administration, but transdermal medication had a stronger effect on triglyceride and coagulation factors. However, it needs to be considered that there is an increased risk of venous thrombotic events in the first year of treatment.     

Effects of estrogen on susceptibility to oxidation of low-density and high-density lipoprotein in postmenopausal women

Objective: To investigate the effects of estrogen on the susceptibility to oxidation of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) in postmenopausal women. Methods: A total of 23 postmenopausal women were treated with 0.625 mg of conjugated equine estrogen daily for 3 months. Blood samples were obtained before and after therapy. Plasma levels of total cholesterol and triglyceride and the concentrations of cholesterol, triglyceride, phospholipid in LDL and HDL were determined enzymatically and the levels of apolipoprotein A-I, A-II in HDL and apolipoprotein B in LDL were measured by turbidimetric immunoassay. The isolated LDL and HDL were incubated at 37°C for 24 h with CuSO₄ 5 μmol/l and the lipid peroxide concentration of LDL and HDL was measured. Results: Estrogen significantly reduced the plasma level of total cholesterol and significantly increased the plasma level of triglyceride. The LDL concentrations of cholesterol, phospholipid and apolipoprotein B were significantly decreased following estrogen therapy. The triglyceride level of LDL did not change significantly. The HDL concentrations of cholesterol, triglyceride, phospholipid and apolipoprotein A-I and A-II were all significantly elevated after estrogen therapy. Estrogen significantly inhibited the peroxidation of LDL at 50–2000 μg of LDL protein (14.17±4.17–11.49±1.42 nmol/200 μg of LDL protein, P<0.001) and of HDL (4.49±1.74–3.37±1.24 nmol/200 μg of HDL protein, P<0.03) induced by their incubation in the presence of CuSO₄. Conclusions: Estrogen inhibited the susceptibility of LDL and HDL to oxidative modification and favorably affected lipid metabolism by reducing the number of LDL particles and increasing the number of HDL particles in plasma that were resistant to oxidation.     

Intrauterine administration of levonorgestrel in two low doses in HRT. A randomized clinical trial during one year: effects on lipid and lipoprotein metabolism

Objective: To investigate the effects on lipid and lipoprotein metabolism of two doses (5- or 10 μg/24 h) of levonorgestrel released from an intrauterine device (IUD) in combination with orally administered estradiol (2 mg estradiol valerate) in perimenopausal women. Design: A 1-year prospective randomized single blind clinical trial. setting: Department of Obstetrics and Gynaecology, Östra Hospital, Göteborg, Sweden. Subjects: Fifty-one perimenopausal women with climacteric symptoms. Outcome measures: Cholesterol in serum and in lipoprotein fractions; high-density lipoprotein 9HDL), low-density lipoprotein (LDL). Triglycerides in serum and in very low-density lipoprotein. Results: In both treatment groups significant elevations in HDL-cholesterol of similar magnitude were observed after 1 month and these changes were maintained during the 12 month observation period. In both treatment groups an initial significant decrease of LDL-cholesterol was observed and the decrement was maintained after 12 months. Serum levels of cholesterol decreased significantly in both groups after 1 month and were maintained after 12 months in the levonorgestrel-IUD (LNG-IUD) 5 μg group. However, the initial reduction of serum cholesterol in the LNG-IUD 10 μg group did not differ from baseline after 12 months. Serum triglyceride levels fluctuated during the observation period. No significant changes occurred. Conclusion: continuous combined HRT with intrauterine administration of levonorgestrel, 5- or 10 μg/24 h, in perimenopausal women was observed to increase HDL-cholesterol and to decrease LDL-cholesterol compared with pretreatment values. the low doses of levonorgestrel did not reverse the beneficial effects on lipid metabolism usually seen after estradiol administration.     

Lipid metabolic changes during hormonal treatment of endometriosis

Three groups of patients with pelvic endometriosis were treated with medroxyprogesterone acetate (MPA) 50 mg/day (n = 10), lynestrenol (LYN) 10 mg/day (n = 25) and danazol (DAN) 600 mg/day (n = 25) respectively. Total cholesterol, triglycerides, alpha-lipoprotein, prebetalipoprotein, beta-lipoprotein cholesterol, high-density (HDL) and low-density (LDL) lipoprotein and apolipoprotein A1 and B concentrations were determined before treatment and after 3 and 6 mth of therapy. Whereas lipid, lipoprotein and apolipoprotein levels did not change in the MPA group, the patients on LYN and in particular those on DNA showed marked changes in lipoportein patterns. Alpha-lipoprotein, HDL and apolipoprotein A1 levels fell, while beta-lipoprotein, LDL and apolipoprotein concentrations rose, these changes being statistically significant. No alterations were seen in the serum levels of cholesterol, triglycerides or prebetalipoprotein cholesterol. In view of a possible relationship between high LDL and low HDL levels and a risk of accelerated coronary arteriosclerosis in women it was concluded that progestogen-induced alterations in lipoprotein patterns should be avoided as far as long-term treatment is concerned and where additional risk factors are present.     

Impact of hormone replacement therapy on postprandial lipoproteins and lipoprotein(a) in normolipidemic postmenopausal women

In 43 normolipidemic postmenopausal women we studied fasting and postprandial (oral fat load with 50 g fat per square meter; blood sampling for 5 h) lipoprotein components and lipoprotein(a) levels before and with the administration of conjugated equine estrogens opposed by medrogestone (on days 11–21). Data was compared intraindividually; the second testing was performed during the last 5 days of the combined estrogen/progestogen phase of the third cycle. Fasting low-density lipoprotein (LDL) and total cholesterol concentrations decreased significantly; high-density lipoprotein (HDL) cholesterol, including subfractions HDL₂ and HDL₃, was not changed. Fasting triglyceride concentrations increased. All lipoprotein fractions measured showed a postprandial elevation with the exception of chylomicron cholesterol concentrations. There was a significant effect of hormone replacement therapy on the postprandial course of total cholesterol (decrease; P < 0.001), VLDL cholesterol (increase; P = 0.025), and the triglyceride proportion in the LDL plus HDL fraction (increase; P < 0.001). With hormone replacement therapy the postprandial curve of total triglycerides was increased only 1 h after the fat load while chylomicron triglyceride concentrations were lowered after 5 h. VLDL triglycerides were not influenced. In all patients with lipoprotein(a) levels above 10 mg/dl, this parameter decreased (about 25%). Although increasing fasting triglyceride concentrations, hormone replacement therapy does not bring about an exaggerated postprandial increase in triglycerides. Postprandial chylomicron clearance is evidently promoted. Hormone replacement therapy leads to a small increase in triglycerides in the LDL plus HDL fraction by inhibiting hepatic lipase activity. Moreover, the decrease in lipoprotein(a) levels may contribute to the antiatherosclerotic effect.Abbreviations: CEE conjugated equine estrogens - HDL high-density lipoproteins - HRT hormone replacement therapy - LDL low-density lipoproteins - TG triglycerides - VLDL very low density lipoproteins Correspondence to: U. Julius     

The effects of hormone replacement therapy on plasma lipids in type II diabetes

Objectives: The effects of hormone replacement therapy on cardiovascular risk factors in postmenopausal women with non-insulin dependent diabetes mellitus (type II diabetes) is uncertain. Methods: The effects of estrogen replacement therapy (ERT, conjugated equine estrogen 0.625 mg orally daily), combined estrogen and continuous progestogen therapy (HRT, 0.625 mg of conjugated equine estrogens plus medroxyprogesterone acetate 5 mg daily) or placebo was compared in 20 postmenopausal type II diabetic women and 20 normal postmenopausal women in a double blind, randomised, crossover study. Patients receiving insulin were excluded from the study and all lipid modifying drugs were ceased at least 4 weeks prior to randomisation. Other medication including oral hypoglycaemics was kept constant for the duration of the study. Results: Women with type II diabetes were a similar age (58.7±1.3 years) to the non-diabetic women (59.6±1.6 years) but they had a significantly greater body mass index, a higher incidence of treated hypertension, higher fasting plasma glucose levels, higher triglycerides and lower HDL cholesterol levels than non-diabetic women. ERT reduced total cholesterol and LDL cholesterol by a similar extent (8.9–12.3%) in normal and type II diabetic women and increased HDL cholesterol to a similar extent in both groups (11.0 and 8.9% respectively). ERT did not significantly alter fasting triglyceride levels in either group. The addition of medroxyprogesterone acetate 5 mg daily abolished the increase in HDL cholesterol associated with ERT in both groups but did not significantly affect any of the other lipid measurements. ERT and HRT did not significantly alter fasting insulin levels nor alter fasting glucose levels in either non-diabetic women or women with type II diabetes. Conclusions: ERT and HRT have similar effects on lipids in women with type II diabetes and non-diabetic women after 1 month of therapy.     

Effects of continuous medroxyprogesterone acetate on lipoprotein metabolism in postmenopausal women receiving estrogen

Objective: To investigate the effects of medroxyprogesterone acetate (MPA) on the beneficial effects of estrogen therapy on lipid metabolism in postmenopausal women. Methods: Postmenopausal women were administered either conjugated equine estrogen (CEE) 0.625 mg daily for 3 months (Group 1) or CEE 0.625 mg in conjunction with MPA 2.5 mg (Group 2) or MPA 5.0 mg (Group 3) daily for 3 months. Plasma levels of cholesterol, triglyceride, lipoprotein lipids, apolipoproteins, sex steroid hormones and lecithin cholesterol acyltransferase activity (LCAT) were determined. Lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) activities were measured in postheparin plasma. Changes in the lipid concentrations and enzymatic activities were evaluated in each group. Results: Total, low-density lipoprotein (LDL) cholesterol, apolipoprotein B concentrations and LCAT activity were all significantly reduced by treatment in the three groups. The levels of high-density lipoprotein (HDL), HDL2, and HDL3 cholesterol as well as the levels of apolipoprotein AI and AII were significantly elevated in groups 1 and 2. The mean decrease in these parameters was related to the dose of MPA. Levels of triglyceride in the HDL and HDL2 were significantly increased in group 1. The levels of triglyceride in plasma, very low density lipoprotein (VLDL), LDL, HDL3 and VLDL cholesterol and LPL activity were unaffected. H-TGL activity was significantly inhibited only in groups 1 and 2. MPA produced a dose-dependent increase in H-TGL activity. A significant negative correlation was observed between the HDL cholesterol concentration and H-TGL activity (r = 0.58 P < 0.001). Conclusions: The administration of MPA 2.5 mg and 5.0 mg did not adversely affect the changes in VLDL-LDL metabolism produced by estrogen. However, MPA has dose-dependent negative effects on HDL metabolism by increasing H-TGL activity and the 5.0 mg MPA interferes with the favorable effects on lipids of estrogen in postmenopausal women.     

Changes in lipoproteins and subfractions following oophorectomy and oestrogen replacement in peri-menopausal women

Serum cholesterol concentrations in lipoprotein fractions and subfractions were determined in 11 peri-menopausal women both before and after bilateral oophorectomy, as well as 60 days after commencement of oral oestradiol replacement therapy. Pre-operatively, all subjects were found to have normal lipid and lipoprotein concentrations. There was a post-operative increase in the total cholesterol level, which was attributed to a raised very-low-density lipoprotein (VLDL) cholesterol. Changes in high-density lipoprotein (HDL) subfractions HDL-2 and HDL-3 were noted but since these were compensatory little difference in total HDL cholesterol was observed. Following oral oestrogen replacement, the cholesterol level decreased as a result of a drop in both VLDL and low-density lipoprotein (LDL) cholesterol. The oestradiol-induced HDL cholesterol increment reflected an increase in the levels of both HDL subfractions.     

Effects of continuous combined conjugated estrogen/medroxyprogesterone acetate and 17beta-estadiol/norethisterone acetate on lipids and lipoproteins

OBJECTIVES: Various estrogen/progestogen combinations used in hormonal replacement therapy (HRT) have been reported to influence lipid and lipoprotein fractions differently. This motivated a comparative study where the two continuous combined regimens most commonly used in Sweden during the 1990s have been studied regarding effects on lipid profile. METHODS: In a 1-year prospective, double-blind study, 62 post-menopausal women were randomized to conjugated estrogen (CE), 0.625 mg, and medroxyprogesterone acetate (MPA), 5 mg, or 17beta-estradiol (E2), 2 mg, and norethisterone acetate (NETA), 1 mg. Serum concentrations of lipids and lipoproteins were measured at baseline and after 1 year of treatment. RESULTS: Both treatment groups significantly lowered the lipoprotein(a) (Lp(a)) levels. The CE/MPA group showed no significant changes in total cholesterol (TC), high-density (HDL) and low-density lipoprotein (LDL), but a significant increase of triglyceride (TG) levels. The E2/NETA group developed a significant lowering of total cholesterol, HDL, and LDL, but no significant changes of TG levels. The magnitude of change in serum concentrations of total cholesterol, HDL and TG differed significantly between the two treatment groups. CONCLUSIONS: Continuous combined treatment with CE/MPA and E2/NETA equally lowered Lp(a), an important risk factor for cardiovascular disease in women. Apart from this, the two treatments produced different effects on lipids and lipoproteins, findings that are more delicate to interpret.     

Effects of estradiol and norethisterone on lipids, insulin resistance and carotid flow

OBJECTIVES: To evaluate the lipid profile, insulin resistance and vasomotricity, and the interaction between these factors, in postmenopausal women receiving hormone therapy. METHODS: A prospective, randomized, double-blind study was carried out in which 77 postmenopausal women received one of the three treatment regimens: (A) 2mg oral micronized estradiol (E2) (n=25); (B) 2mg oral E2+1mg oral norethisterone acetate (NETA) (n=28); or C) placebo (n=24), daily for 6 months. Evaluations were carried out at baseline and at the end of treatment on lipid and lipoprotein profiles, homeostasis model assessment of insulin resistance (HOMA-IR) and pulsatility index (PI) of the internal carotid artery by Doppler ultrasonography. RESULTS: Mean increases of 15.6% and 2.4% and a reduction of 6.4% in high-density lipoprotein (HDL) levels were found for the E2, E2+NETA and placebo groups, respectively. Reductions of 9.5% and 3.7% and an increase of 12.1% in low-density lipoprotein (LDL), and reductions of 20.0% and 3.8% and an increase of 28.8% in the LDL:HDL ratio were found for the E2, E2+NETA and placebo groups, respectively (p<0.001 in all cases). Insulin levels and HOMA-IR decreased 12.8% and 12.3% in the E2 group and increased 12.9% and 16.0% in the E2+NETA group (p<0.05), respectively. Carotid PI following treatment was 1.18+/-0.23, 1.38+/-0.20 and 1.41+/-0.21 for the E2, E2+NETA and placebo groups, respectively (p=0.0006). CONCLUSIONS: Oral estrogen therapy led to an improvement in lipid profile, insulin resistance and carotid blood flow, which was cancelled when NETA was associated.     

Effects in post-menopausal women of transdermal estrogen associated with progestin upon the removal from the plasma of a microemulsion that resembles low-density lipoprotein (LDL)

Objective: To evaluate the effects of transdermal estradiol and medroxyprogesterone acetate (MPA) treatment on the removal from the plasma of a cholesterol-rich microemulsion (LDE) that roughly resembles low-density lipoprotein (LDL) structure and that binds to LDL receptors. Methods: Ten healthy post-menopausal women were studied before and after 3-month treatment with transdermal estradiol in the following dosages administered every 3.5 days: 25, 50, 50, 100, 100, 50, 50 and 25 μg. From the 15th to the 21st day and from the 22nd to the 28th day of estrogen treatment, respectively, 10 and 5 mg q.d. MPA per oral were associated to the transdermal estrogen. The emulsion labeled with ¹⁴C-cholesteryl oleate was injected after 12 h fasting and its fractional catabolic rate (FCR) was calculated from the plasma decaying curves of the isotope. Results: Treatment reduced LDL-cholesterol levels by 8% only (149.0 ± 36.0 mg/dl, 138.0 ± 27.0 mg/dl; P = 0.046), but the FCR of LDE expressed in medians (25%; 75%) increased from 0.0054 (0.003; 0.052) h⁻¹ to 0.021 (0.009; 0.10) h⁻¹, P = 0.002. Conclusion: The association used in this study so as to mimic the increasing–decreasing pattern of the hormonal ovarian production reduced modestly LDL-cholesterol levels but pronouncedly increased the lipoprotein removal as tested by LDE FCR.     

Differential effects of oral conjugated equine estrogen and transdermal estrogen on atherosclerotic vascular disease risk markers and endothelial function in healthy postmenopausal women

BACKGROUND: Recent studies have revealed that HRT may increase the risk for atherosclerotic vascular disease (ASVD). METHODS: We investigated the effects of HRT via different administration routes on the markers for ASVD and endothelial function in healthy postmenopausal women. The oral HRT group (n=18) received conjugated equine estrogen 0.625 mg/day; the transdermal HRT group (n=18) received 17beta-estradiol (E2) gel 0.6 mg/day for 6 months. The control group (n=30) had no treatment for 6 months. RESULTS: The C-reactive protein (CRP) rose from 0.129+/-0.116 to 0.752+/-0.794 mg/dl (P<0.01) in the oral HRT group but remained unchanged in the transdermal HRT and control groups. The flow-mediated vasodilation (FMD) in the brachial artery was increased significantly by HRT from 6.0% before oral HRT to 14.7% after oral HRT (P<0.001) and from 5.9% before transdermal HRT to 13.9% after transdermal HRT (P=0.001). CONCLUSIONS: These data suggest that oral estrogen induces ASVD risk by increasing acute inflammation; however, transdermal estrogen avoids this untoward effect. Additionally, transdermal estrogen exerts a positive effect on endothelial function similar to that of oral estrogen. Therefore, the transdermal route might be favourable in terms of ASVD risks.     

Comparative effects of estrogens plus androgens and tibolone on bone, lipid pattern and sexuality in postmenopausal women

BACKGROUND: The main goals of estrogen replacement therapy (ERT) are the prevention of osteoporosis and cardioprotection and the improvement of quality of life (QL). Androgens and tibolone therapy may increase bone mineral density (BMD) to a greater extent than ERT and offer an increase in QL. Lipid and cardiovascular effects, however, are still a major concern. AIM: To evaluate whether the addition of a weak androgen to ERT may improve postmenopausal bone loss and sexual activity without adverse effects on lipid pattern and to compare these effects with those observed after tibolone therapy. SUBJECTS AND METHODS: This prospective study enrolled 120 surgical postmenopausal women; of these, 96 completed the 1-year follow-up. Patients were allocated to one of four groups. The first group (A; n = 23) received 4 mg of estradiol valerate plus 200 mg of enanthate of dihydroandrosterone im monthly. The second group (E; n = 26) received 50 microg/day of transdermal 17-b-estradiol continuously; the third (T; n = 23) received 2.5 mg of tibolone every day; and finally, the fourth group (C; n = 24) constituted a treatment-free control group. Bone mass (dual X-ray absorptiometry), serum total cholesterol, HDL, LDL, triglycerides, apolipoproteins A1 and B and sexual activity were evaluated before starting therapy and at the end of follow-up. RESULTS: All active treatment groups showed an increase in BMD. This increase was higher in the A treatment group (4.08% P < 0.01). Sexuality improved significantly with therapy; however, tibolone and androgens increased scores to a greater extent than ERT. Androgen therapy was associated with significant increases in total cholesterol, LDL and triglycerides. Cholesterol and LDL fall into groups E and T, HDL into groups A and T and triglycerides in group T only. CONCLUSION: The combined regimen of androgens and ERT increased vertebral bone mass and enhance sexual activity in postmenopausal women equal to that of tibolone and to a greater extent than ERT alone; its effects on lipids, however, are clearly adverse.