Effect of estrogen/progestin potency on lipid/lipoprotein cholesterol

Influence of Oral Contraceptives on Lipid Profile and Trajectories in Healthy Adolescents-Data From the EVA-Tyrol Study

PURPOSE

Oral contraception is one of the most popular contraceptive methods both in adults and adolescents. However, the effects of oral contraception on lipids in adolescents are not well studied.

METHODS

Lipid profiles were measured and contraceptive use was assessed in 14- to 19-year-old female participants of the prospective population-based Early Vascular Ageing-Tyrol Study between 2015 and 2018, twice on average 22 months apart.

RESULTS

For this analysis, data from 828 young women with a median age of 17.0 years were available. Of them, 317 (38%) used oral contraceptives (OCs). OC users had a slightly higher systolic and diastolic blood pressure and larger changes over time and were more likely to use cigarettes than nonusers. Total cholesterol (179.6 vs. 162.4 mg/dL), low-density lipoprotein-cholesterol (106.4 vs. 94.6 mg/dL), and triglycerides (104.0 vs. 67.0 mg/dL) were significantly higher in OC users after multivariable adjustment in linear regression models. No difference in high-density lipoprotein-cholesterol between the two groups was found. In 558 females, follow-up data were available. Those who initiated OC use had on average 15.4 mg/dL higher low-density lipoprotein-cholesterol and 36.2 mg/dL higher triglyceride level changes between baseline and follow-up than never users. Duration of OC use did not show a significant association with lipid levels and changes.

DISCUSSION

We showed an independent association between OC use and blood lipids as well as lipid trajectories over time in a large cohort of healthy adolescents. These changes are especially relevant to consider in adolescents with other risk factors for dyslipidemia or other cardiovascular risk factors.

Bidirectional causality between the levels of blood lipids and endometriosis: a two-sample mendelian randomization study

BACKGROUND

Observational studies have found a correlation between the levels of blood lipids and the development and progression of endometriosis (EM). However, the causality and direction of this correlation is unclear. This study aimed to examine the bidirectional connection between lipid profiles and the risk of EM using publicly available genome-wide association study (GWAS) summary statistics.

METHODS

Eligible exposure variables such as levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were selected using a two-sample Mendelian randomization (MR) analysis method following a series of quality control procedures. Data on EM were obtained from the publicly available Finnish database of European patients. Inverse variance weighted (IVW), MR Egger, weighted median, and weighted mode methods were used to analyze the causal relationship between lipid exposure and EM, exclude confounders, perform sensitivity analyses, and assess the stability of the results. Reverse MR analyses were performed with EM as exposure and lipid results as study outcomes.

RESULTS

IVW analysis results identified HDL as a protective factor for EM, while TG was shown to be a risk factor for EM. Subgroup analyses based on the site of the EM lesion identified HDL as a protective factor for EM of the uterus, while TG was identified a risk factor for the EM of the fallopian tube, ovary, and pelvic peritoneum. Reverse analysis did not reveal any effect of EM on the levels of lipids.

CONCLUSION

Blood lipids, such as HDL and TG, may play an important role in the development and progression of EM. However, EM does not lead to dyslipidemia.

The associations between dietary flavonoid intake and hyperlipidemia: data from the national health and nutrition examination survey 2007-2010 and 2017-2018

Background

Hyperlipidemia is a worldwide health problem and a significant risk factor for cardiovascular diseases; therefore, it imposes a heavy burden on society and healthcare. It has been reported that flavonoids can increase energy expenditure and fat oxidation, be anti-inflammatory, and reduce lipid factor levels, which may reduce the risk of hyperlipidemia. However, the relationship between the prevalence of hyperlipidemia and dietary flavonoid intake in the population remains unclear.

Methods

This study included 8,940 adults from the 2007-2010 and 2017-2018 National Health and Nutrition Examination Surveys (NHANES). The relationship between dietary flavonoid intake and the prevalence of hyperlipidemia was analyzed using weighted logistic regression and weighted restricted cubic spline.

Results

We found an inverse relationship between subtotal catechins intake and hyperlipidemia prevalence in the third quartile [0.74 (0.56, 0.98), p = 0.04] compared with the first quartile. The prevalence of hyperlipidemia and total flavan-3-ol intake in the third quartile were inversely correlated [0.76 (0.59, 0.98), p = 0.03]. Total anthocyanin intake was inversely related to the prevalence of hyperlipidemia in the third quartile [0.77 (0.62, 0.95), p = 0.02] and the fourth quartile [0.77 (0.60, 0.98), p = 0.04]. The prevalence of hyperlipidemia was negatively correlated with total flavonols intake in the fourth quartile [0.75 (0.60, 0.94), p = 0.02]. Using restricted cubic splines analysis, we found that subtotal catechins intake and total flavan-3-ol intake had a nonlinear relationship with the prevalence of hyperlipidemia.

Conclusion

Our study may provide preliminary research evidence for personalizing improved dietary habits to reduce the prevalence of hyperlipidemia.

Trajectories of Blood Lipids Profile in Midlife Women: Does Menopause Matter?

Background It remains controversial whether changes of lipids over menopause transition (MT) are more age-related or more menopause-related. We aimed to classify women into different trajectory groups based on pattern and level of total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B (ApoB), high-density lipoprotein cholesterol (HDL-C), triglyceride, and apolipoprotein A-I over the MT, as well as examine the effect of MT-related factors on lipid trajectory groups and levels. Methods and Results The cohort included 2582 subjects from the Study of Women's Health Across the Nation. Different trajectory patterns of lipids during the MT were determined using the latent class growth mixture model. The predictors of distinct blood lipids trajectory groups were determined by multiple linear regression models and multinomial logistic regression models. Women were categorized into either inverse U-shape or progressing trajectory group in each blood lipids measurement. The inverse U-shape total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, high-density lipoprotein cholesterol, log(TG), and apolipoprotein A-I trajectories showed an increasing trend before menopause but a decreasing trend after menopause. The U-shape total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B trajectories started to rise 5 years before menopause. Age at menopause, follicle-stimulating hormone, vasomotor symptoms, and estradiol predicted the shape and level of the women's lipids over the MT. Conclusions Distinct lipid trajectories were identified during the MT, and the existence of at least 1 trajectory in each lipid parameters suggested a contribution of menopause. Our study highlights the need for earlier and continuous surveillance of lipids during the MT.

Is cholesterol a risk factor for breast cancer incidence and outcome?

Cholesterol plays important roles in many physiological processes, including cell membrane structure and function, hormone synthesis, and the regulation of cellular homeostasis. The role of cholesterol in breast cancer is complex, and some studies have suggested that elevated cholesterol levels may be associated with an increased risk of developing breast cancer, while others have found no significant association. On the other hand, other studies have shown that, for total cholesterol and plasma HDL-associated cholesterol levels, there was inverse association with breast cancer risk. One possible mechanism by which cholesterol may contribute to breast cancer risk is as a key precursor of estrogen. Other potential mechanisms by which cholesterol may contribute to breast cancer risk include its role in inflammation and oxidative stress, which have been linked to cancer progression. Cholesterol has also been shown to play a role in signaling pathways regulating the growth and proliferation of cancer cells. In addition, recent studies have shown that cholesterol metabolism can generate tumor promoters such as cholesteryl esters, oncosterone, 27-hydroxycholesterol but also tumor suppressor metabolites such as dendrogenin A. This review summarizes some of the most important clinical studies that have evaluated the role of cholesterol or its derivatives in breast cancer. It also addresses the role of cholesterol and its derivatives at the cellular level.

Association of High-Density Lipoprotein Subclasses Levels with Sleep Duration and Other Lifestyles in Middle-Aged and Elderly Women: Cross-Sectional Study

Objective: We aimed at investigating the association of high-density lipoprotein subclasses (HDL2-C and HDL3-C) levels with sleep duration, in comparison to other lifestyles in middle-aged and elderly women. Materials and Methods: A total of 69 women aged older than 40 who underwent "Anti-aging Health Checkups" were enrolled in the study. The analyses were conducted for all the subjects using personal data regarding clinical characteristics and lifestyle. Sleep duration was categorized into two groups of less than or more than 6 hrs. First, an analysis was performed to assess the correlation of two major HDL subclasses with various factors. Next, a multiple regression analysis was conducted to identify the association for each HDL2-C and HDL3-C with lifestyles such as sleep duration, daily breakfast, dinner time, habitual exercise, and drinking. Moreover, we examined the associations between HDL2-C and sleep duration combined with other lifestyle factors such as dinner time, daily breakfast, habitual exercise, and drinking. Results: In comparison to lifestyles, sleep duration had a strong association with only HDL2-C after adjustment for confounders. The "less 6 hrs sleep" group in combination with the "no exercise habit" or the "routine drinking habit" significantly decreased HDL2-C levels more than the assumed reference group. Regarding breakfast, there is a significant association between the "less than 6 hrs sleep with no daily breakfast" and the "more than 6 hrs sleep with daily breakfast." Conclusion: The results of this study may suggest that sufficient sleep might be significant for maintaining appropriate HDL2-C levels in middle-aged and elderly women under the condition that lifestyle might change during the ongoing COVID-19 pandemic.

Metabolic effects of estradiol versus testosterone in complete androgen insensitivity syndrome

PURPOSE

To study differences in metabolic outcomes between testosterone and estradiol replacement in probands with complete androgen insensitivity syndrome (CAIS).

METHODS

In this multicentre, double-blind, randomized crossover trial, 26 women with CAIS were included of whom 17 completed the study. After a two-months run in phase with estradiol, probands either received transdermal estradiol followed by crossover to transdermal testosterone or vice versa. After six months, differences in lipids, fasting glucose, insulin, hematocrit, liver parameters and blood pressure between the treatment phases were investigated.

RESULTS

Linear mixed models adjusted for period and sequence did not reveal major group differences according to treatment for the investigated outcomes. In each treatment group, there were however significant uniform changes in BMI and cholesterol. BMI increased significantly, following six months of estradiol ( + 2.7%; p = 0.036) as well as testosterone treatment ( + 2.8%; p = 0.036). There was also a significant increase in total ( + 10.4%; p = 0.001) and LDL-cholesterol ( + 29.2%; p = 0.049) and a decrease in HDL-cholesterol (-15.8%; p < 0.001) following six months of estradiol as well as six months of testosterone treatment (total cholesterol: + 14.6%; p = 0.008; LDL-cholesterol: + 39.1%; p = 0.005, HDL-cholesterol: -15.8%; p = 0.004). Other parameters remained unchanged.

CONCLUSION

Transdermal estradiol as well as testosterone treatment in women with CAIS results in worsening in lipid profiles. Given the relatively small sample size, subtle group differences in other metabolic parameters may have remained undetected.

Cardiometabolic traits mediated the relationship from early life famine exposure to adulthood nonalcoholic fatty liver disease risk

Early life exposure to famine was associated with adulthood metabolic syndrome and nonalcoholic fatty liver disease (NAFLD), and NAFLD was also affected by cardiometabolic traits. However, the role of cardiometabolic traits in the associations from famine exposure to NAFLD was largely unknown. This study aimed to investigate whether the relationship between early life famine exposure and adulthood NAFLD risk was mediated by cardiometabolic traits. Overall, 7578 subjects aged 56·0 (sd 3·7) years in the Dongfeng-Tongji cohort were included and classified into late-exposed (1952-1954), middle-exposed (1954-1956), early-childhood-exposed (1956-1958), fetal-exposed (1959-1961) and non-exposed (1962-1966, reference) group according to the birth year. NAFLD was diagnosed by experienced physicians via abdominal B-type ultrasound inspection. Mediation analysis was used to evaluate the mediating effects of cardiometabolic traits. Compared with those non-exposed, after multivariable adjustment, participants in fetal-exposed group (OR: 1·37; 95 % CI 1·08, 1·73) had 37 % higher risk to develop NAFLD, and the overall childhood-exposed group had marginally significant association with NAFLD (OR: 1·39; 95 % CI 0·99, 1·94). Stratification analysis found the famine-NAFLD associations more evident in women and those born in areas severely affected by famine. Mediation analysis showed that cardiometabolic traits such as total cholesterol, TAG glucose index, γ-glutamyl transpeptidase, alkaline phosphatase and alanine aminotransferase mediated 6·7-22·2 % of the relation from famine exposure to higher NAFLD risk. Early life exposure to famine was related to increased adulthood NAFLD risk, and this relationship was partly mediated by cardiometabolic traits.

Effects of hormonal contraceptive phase and progestin generation on stress-induced cortisol and progesterone release

The stress response differs between women using hormonal contraception and naturally cycling women. Yet, despite ample evidence showing that the stress response differs across the menstrual cycle in naturally cycling women, limited work has investigated whether the stress response differs across the hormonal contraceptive cycle, during which synthetic hormones are taken most of the month but not all of it. To induce a stress response, women using hormonal contraception completed the cold pressor test during either the active phase, when hormones are present, or during the inactive phase, when hormones are not present. Saliva was collected and assayed for free cortisol and progesterone levels prior to stress onset, immediately after stress termination, and 15-min post stress onset. Free cortisol and progesterone increased to a similar degree across both hormonal contraceptive phases in response to the cold pressor test. Post-hoc investigation indicates that the progestin “generation” (classification of synthetic progestins based on the compounds they are derived from) can differentially affect the free steroid response to cold pressor test stress, with the largest effects observed in women using formulations containing second-generation progestins. These findings indicate that progestin generation, particularly second-generation progestins, may have a more impactful influence on the stress response than hormonal contraceptive cycle phase. Potential mechanisms driving this effect and need for additional research are discussed.

Modification of body composition and metabolism during oral contraceptives containing non-androgenic progestins in association with estradiol or ethinyl estradiol

AIM

To observe the influence on metabolism and body composition of two oral contraceptives containing non-androgenic progestins in association with estradiol or ethinyl estradiol (EE).

STUDY DESIGN

Women on hormonal contraception with estradiol valerate (E2V)/dienogest (DNG) in a quadriphasic regimen (n = 16) or 30 μg EE/2 mg chlormadinone acetate (CMA) (n = 16) in a monophasic regimen were evaluated at the third cycle for modifications in lipoproteins, apoproteins and homeostatic model assessment for insulin resistance (HOMA-IR), and at the sixth cycle for body composition and the markers of bone turnover osteocalcin and C-telopeptide X.

RESULTS

During E2V/DNG lipoprotein, apoproteins and HOMA-IR remained stable. During EE/CMA, total-cholesterol (p = 0.003), high-density lipoprotein (HDL)-cholesterol (p = 0.001), triglycerides (p = 0.003) Apoprotein-A1 (Apo-A1; p = 0.001) and Apo B (p = 0.04) increased, low-density lipoprotein/HDL (p = 0.039) decreased and total-cholesterol/HDL and Apoprotein-B/Apo-A1 ratio did not vary. HOMA-IR slightly increased from 1.33 ± 0.87 to 1.95 ± 0.88 (p = 0.005). There was a reduction of markers of bone metabolism in both groups with no modification of body composition.

CONCLUSIONS

Administration of E2V/DNG does not influence lipid and glucose metabolism, while mixed effect are exerted by EE/CMA. Both preparations reduce bone metabolism without influencing short-term effect on body composition.

Pharmacology of conjugated equine estrogens: efficacy, safety and mechanism of action

Oral conjugated equine estrogens (CEE) are the most used estrogen formulation for postmenopausal hormone therapy either alone or in combination with a progestin. CEE is most commonly used for the management of early menopausal symptoms such as hot flashes, vaginitis, insomnia, and mood disturbances. Additionally, if used at the start of the menopausal phase (age 50-59 years), CEE prevents osteoporosis and may in some women reduce the risk of cardiovascular disease (CVD) and Alzheimer's disease (AD). There appears to be a common mechanism through which estrogens can protect against CVD and AD. CEE is a natural formulation of an extract prepared from pregnant mares' urine. The product monogram lists the presence of only 10 estrogens consisting of the classical estrogens, estrone and 17β-estradiol, and a group of unique ring B unsaturated estrogens such as equilin and equilenin. The ring B unsaturated estrogens are formed by an alternate steroidogenic pathway in which cholesterol is not an obligatory intermediate. Both the route of administration and structure of these estrogens play a role in the overall pharmacology of CEE. In contrast to 17β-estradiol, ring B unsaturated estrogens express their biological effects mainly mediated by the estrogen receptor β and not the estrogen receptor α. All estrogen components of CEE are antioxidants, and some ring B unsaturated estrogens have several fold greater antioxidant activity than estrone and 17β-estradiol. The cardioprotective and neuroprotective effects of CEE appear to be, to some extent, due to its ability to prevent the formation of oxidized LDL and HDL, and by inhibiting or modulating some of the key proteases involved in programmed cell death (apoptosis) induced by the excess neurotransmitter glutamate and other neurotoxins. Selective combinations of ring B unsaturated estrogens have the potential of being developed as novel therapeutic agents for the prevention of cardiovascular disease and Alzheimer's disease in both aging women and men. This article is part of a Special Issue entitled 'Menopause'.

Berberine and monacolin effects on the cardiovascular risk profile of women with oestroprogestin-induced hypercholesterolemia

INTRODUCTION

One of the most frequent side effect of oral contraceptives use is a stable alteration of the lipid profile. This could be even more relevant in women affected by polycystic ovary syndrome (PCOS).

AIM

Considering the importance of a balanced lipid profile in cardiovascular prevention and that the exposure to the drugs could be many years long, our aim was to investigate the possible beneficial effect of a largely tested low-dosed combined lipid-lowering nutraceutical on dyslipidemias induced by oestroprogestins prescribed to young women for different indications.

METHODS

We prospectively enrolled 84 patients in primary cardiovascular disease prevention, with low estimated cardiovascular disease risk (<5 % according to the ESC/EAS guidelines), and LDL-C increased above normal value (LDL-C >130 mg/dL) after the use of at least two different oral oestroprogestins treatments. Forty-four women were prescribed oral oestroprogestins for PCOS, while 40 for pure contraception. The tested nutraceutical contained berberine 500 mg/tab and monacolins 3 mg/tab was prescribed to all enrolled patients, associated the previously prescribed standard lipid-lowering diet.

RESULTS

After 3 months of nutraceutical treatment, we observed a significant improvement in BMI (-1.5 ± 0.8 %, p < 0.001), FPG (-6.9 ± 5.8 %, p < 0.001), HOMA index (-3.5 ± 5.6 %, p < 0.001), TC (-20.1 ± 6.6 %, p < 0.001), LDL-C (-25.3 ± 8.9 %, p < 0.001), HDL-C (+14.1 ± 2.2 %, p < 0.001), TG (-29.9 ± 25.2 %, p < 0.001) and hsCRP (-2.5 ± 2.4 %, p = 0.019). Similar results have been obtained even repeating the analysis by subgroups, beyond hsCRP that significantly improved in PCOS patients compared to both the baseline and the non-PCOS group.

CONCLUSION

It appears that the tested combined lipid-lowering nutraceutical is able to equally improve lipid metabolism in oral contraceptive induced hypercholesterolemia in women affected or not by PCOS.

Effect of oral contraceptive use on lipid profile in Korean women aged 35-55 years

BACKGROUND

Although oral contraceptives (OCs) are widely used, their effects on lipid profile need monitoring according to current usage in different populations.

STUDY DESIGN

A cross-sectional study was conducted using data from 1541 participants aged 35-55 years collected by the 2005-2009 Korea National Health and Nutrition Examination Surveys. OC use, demographic characteristics and dietary intake were obtained from the participants by questionnaire, and lipid levels were determined by analysis of blood samples.

RESULTS

Longer duration of OC use was positively associated with increasing levels of high-density lipoprotein cholesterol (HDL-C) and decreasing levels of low-density lipoprotein cholesterol (LDL-C). After adjusting for demographic and dietary factors, the odds ratio (OR) of low HDL-C (<50 mg/dL) was significantly decreased in the longer-term (>12 months) OC users (OR=0.36, 95% confidence interval 0.24-0.52) compared with those who never used OCs. However, use of OCs was not associated with a risk of high total cholesterol (≥ 240 mg/dL), high LDL-C (≥ 130 mg/dL), high triglycerides (≥ 150 mg/dL) or high ratio of triglycerides to HDL-C (>3.8).

CONCLUSIONS

These data suggest that the use of OCs may reduce the risk of dyslipidemia, mainly due to the decreased risk of low HDL-C, in Korean women.

Reciprocal coordination of a combination oral contraceptive containing desogestrel+ethinyl estradiol on the expression of LOX-1 and LDLR in placental trophoblast cells

BACKGROUND

The aim of this study was to assess the consistency of antiatherosclerotic potential of a combination oral contraceptive steroid (ethinyl estradiol+desogestrel) by rating its effect on the differential expression of the low-density lipoprotein receptor (LDLR) and lectin-like oxidized LDL (LOX-1) receptor.

STUDY DESIGN

Cells from placental trophoblast cell line (JAR) and differentiated primary placental trophoblast cells isolated from term human placentae were used for this study. Expressions of LOX-1 and LDLR were assessed by immunoblot and immunocytochemistry assays. Differential effects of the constituent steroids in the combination of ethinyl estradiol and desogestrel were verified on the expression profile of the receptors.

RESULTS

Desogestrel opposed the effect of ethinyl estradiol on LOX-1 expression, and when used in combination, the combination oral contraceptive reduced the expression of LOX-1 in contrast to LDLR. The characteristic change in the expressions of LOX-1 and LDLR showed an antiatherosclerotic improvisation at the unique combination of ethinyl estradiol (10 ng/mL) and desogestrel (20 ng/mL).

CONCLUSION

The aforesaid combination of ethinyl estradiol and desogestrel keeps LOX-1 and LDLR reciprocally expressed in antiatherosclerotic mode.

The effect of gonadectomy and estradiol on sensitivity to oxidative stress

The sexual dimorphism of life span and caloric restriction effects in numerous species suggest that estradiol (E2) is protective against oxidative damage. The only direct test of E2's protective effect in mice against in vivo oxidative stress to date may have been confounded by E2's direct chemical action as an antioxidant because it was administered at very high dosages. Therefore, we have identified a low yet physiologically effective dose of E2. We then administered this dose using subcutaneous time-release pellets to ovariectomized mice. Two weeks after E2 pellet implantation, sham-operated, ovariectomized, and ovariectomized E2-supplemented female mice were injected with a lethal dose of paraquat and their survival was followed. It was observed that ovariectomy exacerbates paraquat-induced mortality and is rescued by E2 supplementation. An equivalent experiment was performed on sham-operated, orchidectomized, and E2-supplemented orchidectomized male mice. The survival of male mice was improved by orchidectomy, and E2 gave no further benefit. We interpret the results to mean that E2 is protective against oxidative stress through its regulatory role and that testosterone diminishes protection against oxidative stress.

Insulin sensitivity and lipid metabolism with oral contraceptives containing chlormadinone acetate or desogestrel: a randomized trial

BACKGROUND

Second-generation and third-generation oral contraceptives containing 30 mcg or more of ethinylestradiol (EE) decrease insulin sensitivity (SI). In this study, we investigated whether SI is decreased by contraceptives containing lower doses EE or by progestins with antiandrogenic properties.

STUDY DESIGN

Twenty-eight young healthy women were randomly allocated to receive 20 mcg of EE and 150 mcg of desogestrel (DSG) (n=14) or 30 mcg of EE and 2 mg of chlormadinone acetate (CMA) (n=14) for 6 months. SI and glucose utilization independent of insulin (Sg) were investigated by the minimal model method. Lipid modifications were also analyzed.

RESULTS

SI decreased with EE/DSG (7.09+/-1.4 vs. 4.30+/-0.91; p=.04; n=12), but not with EE/CMA (5.79+/-0.93 vs. 6.79+/-1.1; p=.48; n=12). SI modifications observed in the two groups were significantly different (-2.79+/-1.15 vs. 1.0+/-1.38; p=.05). Sg did not vary with either treatment. The response of C-peptide to glucose increased, but significantly so only with EE/CMA (p=.01). The C-peptide/insulin response increased with both EE/DSG (p=.05) and EE/CMA (p=.04). High-density lipoprotein (HDL) cholesterol (p=.02) and triglycerides (p=.02 and p=.01) increased in both groups, but HDL/low-density lipoprotein cholesterol (p=.02), apoprotein A1 (Apo-A1) (p=.04) and Apo-A1/apoprotein B (p=.048) increased significantly only with EE/CMA.

CONCLUSIONS

The present study confirms that DSG, even when associated with low EE dose, decreases SI. By contrast, EE/CMA does not deteriorate SI and induces a favorable lipid profile.

Study of low-density lipoprotein receptor regulation by oral (steroid) contraceptives: desogestrel, levonorgestrel and ethinyl estradiol in JEG-3 cell line and placental tissue

BACKGROUND

The aim of this study was to compare in vitro the role of two oral contraceptives, desogestrel (a less androgenic derivative of levonorgestrel) and levonorgestrel--alone and in combination with ethinyl estradiol--on low-density lipoprotein (LDL) receptor regulation by assessing receptor protein expression and functional effectiveness.

STUDY DESIGN

Placental tissue and cultured placental cells (JEG-3) were used to study the expression and endocytotic activity of LDL receptor protein. The expression of the receptor was assessed by immunocytochemistry and immunoblot assays with and without contraceptive challenge. Functioning activity of LDL receptor was studied by measuring the rate of uptake of LDL by placental cells. Quantification of LDL was based on the total cholesterol content of the lipoprotein.

RESULTS

A combination of desogestrel (20 ng/mL of incubation medium) and ethinyl estradiol (10 ng/mL of incubation medium) maintained the LDL receptor at high level of expression and functioning mode. In contrast, the double-blind preparation of levonorgestrel (20 ng/mL) and ethinyl estradiol (10 ng/mL) had shown much lower expression as well as receptor-mediated LDL uptake. The concentration of contraceptives used in this study was similar to the prevailing concentration of oral contraceptives in clinical use.

CONCLUSION

Higher expression of LDL receptor and enhanced rate of LDL uptake by the receptor protein projects the possibility that there might be less atherosclerosis-related disorders from the combination of desogestrol and ethinyl estradiol.

The effect of hormone replacement therapy on the levels of serum lipids, apolipoprotein AI, apolipoprotein B and lipoprotein (a) in Turkish postmenopausal women

OBJECTIVES

Estrogen replacement therapy alters the lipid profiles favorably for delaying atherosclerosis in postmenopausal women. The effects of estrogen plus progesterone combination therapy on lipids are controversial. This study was designed to evaluate the effect of female sex hormones on lipids and lipoproteins and to clarify the influence of progesterone on the effect of estrogen in postmenopausal women.

METHODS

Of the 60 postmenopausal women admitted to our menopause clinic, 40 had intact uterus and received continuous 0.625 mg conjugated equine estrogen (CEE) plus 2.5 mg medroxyprogesterone acetate (MPA), whereas the remaining 20 were hysterectomized and received 0.625 mg CEE daily. To assess the alterations in lipids and lipoproteins during menopause, 45 healthy premenopausal women were investigated. Lipid and lipoprotein levels were assessed in each subject at baseline and at the 6th and 18th months of therapy.

RESULTS

In menopause, a shift towards more atherogenic lipid and lipoprotein profiles than those of the premenopausal state was found. Following 18 months of treatment, both regimens reduced total cholesterol (TC) levels as compared with the baseline (6.4 vs. 6.9% in the CEE/MPA and CEE groups, respectively). The CEE group had a more pronounced increase in high-density lipoprotein (HDL) cholesterol than the CEE/MPA group (10.3 vs. 8.8%, respectively). Both groups displayed reduced TC, low-density lipoprotein (LDL) cholesterol and apolipoprotein-B (ApoB) concentrations, whereas triglycerides increased, with a greater tendency to increase in the CEE/MPA group at the end of the trial. Also, the lipoprotein (a) [Lp(a)] levels decreased significantly (27.6 vs. 24.5% in the CEE/MPA and CEE groups, respectively). This decrease was more pronounced in subjects with a relatively higher basal Lp(a) concentration.

CONCLUSION

Both treatment regimens caused positive alterations in the lipid and lipoprotein profiles. This association might play a pivotal role in the postmenopausal increases in atherosclerotic diseases and cardioprotective effect of estrogen in postmenopausal women.

Medroxyprogesterone acetate inhibits the cardioprotective effect of estrogen in experimental ischemia-reperfusion injury

OBJECTIVE

Results from recent clinical trials of estrogen and progestogen therapy (EPT) suggest that some progestogens may interfere with the cardiovascular benefits of estrogen (E). The aim of this study was to investigate whether medroxyprogesterone acetate (MPA) modifies the protective effect of E in experimental ischemia-reperfusion (IR) injury in vivo and in vitro in the rat.

DESIGN

Ovariectomized female Wistar rats (250-280 g, n = 61) received E, MPA, E and MPA, or placebo subcutaneously. Fourteen days later, hearts were isolated and perfused with Krebs Henseleit for in vitro experiments or left in situ for in vivo experiments. In both cases, the left coronary artery was occluded for 45 minutes, followed by 2 hours of reperfusion.

RESULTS

In vivo E significantly reduced the necrotic zone of reperfused hearts (21.8% +/- 1.7% of area at risk) compared with placebo (42.8% +/- 4.8% area at risk; P < 0.05). This protection was reversed by co-administration of MPA with E (necrotic zone 38.2% +/- 6.1% area at risk). The influence of E on neutrophil infiltration was demonstrated by its ability to reduce myocardial myeloperoxidase activity (0.2 +/- 0.1 U/g tissue) relative to placebo (1.3 +/- 0.5 U/g tissue; P < 0.05). Myocardial myeloperoxidase activity was significantly increased to 1.1 +/- 0.3 U/g tissue in rats receiving E and MPA. However, MPA also reversed the protective effect of E in neutrophil-free buffer-perfused hearts, suggesting that additional mechanisms are involved.

CONCLUSION

In this study, we showed that the administration of MPA can inhibit the effects of E that lead to protection of the myocardium from reperfusion injury and that this involves both neutrophil-dependent and neutrophil-independent mechanisms.

Lipid profile in women over 35 years old using triphasic combined oral contraceptives

Twenty-nine women aged 35 years old or more, using triphasic combined oral contraceptive (COC) were evaluated during six cycles for the following parameters: total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and its subfraction HDL2, triglycerides, apoproteins A and B, Castelli risk index I and II (cholesterol/HDL-C and LDL-C/HDL-C) and apoprotein ratio (apoprotein B/apoprotein A). The same laboratory measurements were done in a control group of 49 non-COC-user women. The results showed that there were no differences on most of the studied parameters between user and nonuser women. There was a significant reduction of HDL-C and HDL2-C, although within the normal range. In addition, it was observed a significant increment of triglycerides and apoprotein B at 6 months of follow-up only in user group (p < 0.05), although within the normal range. It is concluded that the use of levonorgestrel triphasic COC appeared to have no additional adverse impact when used by women aged over 35 years. Further studies are needed to obtain conclusive data.

Positive effects of conjugated equine estrogen on triglyceride metabolism in oophorectomized women based on a stratification analysis of pretreatment values

OBJECTIVE

To evaluate the effects of conjugated equine estrogen (CEE) on the triglyceride (TG) metabolism in oophorectomized women based on a stratified analysis.

DESIGN

Randomized, clinical study.

SETTING

Menopause Clinic of Kyushu University Hospital.

PATIENT(S)

Three hundred oophorectomized women.

INTERVENTION(S)

Three hundred oophorectomized women were randomly divided into two groups and treated by the following regimens for a year: group 1 received calcium alone, group 2 received 0.625 mg/day of CEE and calcium.

MAIN OUTCOME MEASURE(S)

The changes in serum lipid profile were analyzed according to the individual initial levels in each group. Apolipoprotein E was also measured.

RESULT(S)

A greater reduction in low-density lipoprotein cholesterol (LDL-C) levels was observed in group 2 women with higher initial levels. For high-density lipoprotein cholesterol (HDL-C) a greater increase was observed in group 2 women with lower initial levels. Although TG levels increased as a whole in group 2, a reduction was observed in the high-TG groups. The initial values of apolipoprotein E were higher in the high-TG groups and decreased to greater amounts in group 2 patients.

CONCLUSION(S)

Administration of CEE induced positive changes in the serum lipid profile according to the individual initial levels, including levels of TG. Therefore, changes in the TG levels shown by the stratification may be related to the apolipoprotein E changes that are observed following CEE replacement.

Estrogen therapies, lipids, and the heart disease prevention controversy

One of the most highly unexpected reports in recent medical literature was the lack of benefit of estrogen-progestin replacement therapy in cardiovascular disease prevention in postmenopausal women. The ensuing negative view of hormone replacement therapy has now extended to all forms of postmenopausal hormone treatment, including estrogen alone. Is this pessimism justified? A review of the effects of estrogens and progestins on the estrogen-sensitive systems of the body can help explain why combined oral estrogen and low-dose continuous medroxyprogesterone acetate administration may not be the paradigm for all other forms of postmenopausal hormone replacement. Some of these effects include the following: progestins are anti-estrogens, as evidenced in their divergent effects on plasma lipids; not all progestins are equal in their effect on lipids and other physiologic functions; administration of any hormone by mouth is not physiologic; giving estrogen 10 to 15 years postmenopausally may be too late to prevent atherosclerosis. On the other hand, high doses of oral estrogen/progestin in the presence of high cardiovascular risk appear to promote atherosclerosis risk. Given the current evidence the common sense answer to the question of the benefit of estrogen is "it depends." Until these and other points are formally addressed, the hypothesis that estrogen prevents heart disease remains open.

Effect of Implanon® and Norplant® subdermal contraceptive implants on serum lipids—a randomized comparative study

The objective of this study was to assess the possible differences in effects of Implanon (etonogestrel 68 mg, single-rod) and Norplant (levonorgestrel 36 mg, six capsules) implants on serum lipids over 2 years of use. In this 2-year open randomized study of 80 implant acceptors, selected serum lipids were tested before implant insertion and at 6, 12 and 24 months after implant insertion. The lipid parameters evaluated were: total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, apolipoprotein A-I and apolipoprotein B. During the 2 years, the serum lipid pattern in the Implanon users was not significantly different from that of the Norplant users. There was slight decrease in HDL-C levels in both the groups but there were no significant changes in the HDL/TC ratio and the HDL/LDL ratio. Although it was statistically significant, the magnitude of decrease in HDL-C from preinsertion levels in Implanon users was only 5.8% at the end of 2 years.

Oestrogen receptor alpha gene polymorphism is related to aortic valve sclerosis in postmenopausal women

OBJECTIVES

Aortic valvular sclerosis (AS) is an inflammatory process and not a result of normal ageing. The sclerotic process is accelerated by risk factors such as smoking and high cholesterol levels. The genetic factors for the development of AS are however unknown. Therefore the purpose of the present study was to investigate whether polymorphisms in the oestrogen receptor alpha (ORalpha) gene and in the transforming growth factor beta (TGF-beta1) gene were related to the presence of AS in postmenopausal women.

DESIGN

Case-control study.

SUBJECTS AND METHODS

Relationships were tested between polymorphisms in the ORalpha gene defined by the restriction enzymes PvuII and XbaI, and in the TGF-beta1 gene defined by AocI, and AS, lipid levels, and lipoprotein(a) [Lp(a)] in 41 postmenopausal female patients and 41 age- and sex-matched controls. These polymorphisms were also tested in relation to lipid levels and Lp(a), in 99 healthy Caucasian girls, aged 16.9 +/- 1.2 years.

RESULTS

In the postmenopausal patients and age-matched controls, the PvuII polymorphism was independently associated with an increased risk of AS [odds ratio (OR) = 3.38; 95% confidence interval (CI) 1.13-10.09). A genotype defined by at least one restriction site in the PvuII polymorphism and two restriction sites in the TGF-beta1 polymorphism was related to a highly significantly increased risk of AS (OR = 4.58; 95% CI 1.68-12.51). In the adolescent female cohort, presence of two restriction sites in the PvuII polymorphism was associated with higher levels of total cholesterol (TC) (P = 0.02), and low-density lipoprotein cholesterol (LDL) (P = 0.04).

CONCLUSIONS

We have demonstrated that the PvuII polymorphism in the ORalpha gene is related to both the presence of AS in postmenopausal women and to lipid levels in adolescent females, suggesting that this polymorphism may influence the risk of AS partly by affecting lipid levels.

The RATIO study: oral contraceptives and the risk of peripheral arterial disease in young women

With regard to oral contraceptives, much research has concentrated on venous thrombosis and on the coronary and cerebral forms of atherosclerotic disease, while peripheral arterial disease (PAD) has received little attention. In this case-control study, we assessed oral contraceptive use and the risk of PAD in young women using a population-based case-control study. The women were 18-49 years of age, and had been admitted to a collaborating hospital between January 1990 and October 1995, and had a diagnosis of PAD. Participants were patients with PAD (n = 152), and control women (n = 925), identified by random digit dialing. The diagnosis of PAD was based almost exclusively on intra-arterial angiography. Patients and control subjects filled out the same structured questionnaire, which included questions on medical history, cardiovascular risk factors, and contraceptive use. The adjusted odds ratio for PAD in women using any type of oral contraceptives vs. no use, was 3.8 (95% CI 2.4-5.8). When first generation oral contraceptive use was compared with no use, the odds ratio was 8.7 (95% CI 3.6-21.3). For second and third generation oral contraceptives, the adjusted odds ratios (compared with non-users) were 2.6 (95% CI 1.4-4.9) and 3.0 (95% CI 1.4-6.6), respectively. This is the first study on oral contraceptive use and PAD in humans. All types of oral contraceptives were associated with an increased risk of PAD.

The lipid and clinical effects of sequential transdermal estradiol and estradiol/norethisterone acetate in 674 women

OBJECTIVE

To measure lipid changes induced by patches delivering continuous estradiol (E(2)) and sequential norethisterone acetate (NETA) in a large population of symptomatic menopausal women, compared with a non-symptomatic control group.

PATIENTS AND METHODS

A total of 748 women recruited in 42 different hospital services and clinics in Spain were invited to participate in a prospective, open, controlled study for 48 weeks. Six hundred and seventy-four women were evaluated in the treatment group, and 74 in the control group. Treatment consisted of patches delivering 0.05 mg/day E(2) for the first 14 days of the cycle, and 0.05 mg/day E(2) plus 0.25 mg/day NETA for another 14 days.

RESULTS

Use of patches led to a slight, but significant decrease of 1.3% and 0.9% in concentrations of total cholesterol and low-density lipoprotein cholesterol (LDL-C), respectively. A substantial 37.0% decrease in triglycerides concentration was observed in treated women. The treatment effectively reduced climacteric symptoms (Kupperman index) for the duration of the study. Compliance was acceptable, with 489 (72.6%) women completing the study. Adverse events were reported by 137 (20.3%) women.

CONCLUSIONS

Transdermal administration of E(2) and sequential NETA for a period of 48 weeks (twelve 28-day cycles) was associated with beneficial changes, albeit of differing magnitudes, in the concentration of total cholesterol, LDL-C and triglycerides. This protective lipid profile, together with satisfactory clinical efficacy and acceptable safety and compliance, makes this system a good alternative in hormone replacement therapy.

Effects of estrogen, progesterone, and combination exposure on interleukin-1 beta-induced expression of VCAM-1, ICAM-1, PECAM, and E-selectin by human female iliac artery endothelial cells

The cardioprotective effect of hormone replacement therapy (HRT) in healthy, postmenopausal women is well documented. Little work has been performed on the effect of HRT in peripheral arteries. Recent work suggests that HRT may adversely affect the patency of peripheral grafts. This study investigates the in vitro effects of estrogen and/or progesterone exposure on adhesion molecule expression by normal human female iliac artery endothelial cells (HIAEC). Control and interleukin-1 beta (IL-1 beta)-stimulated HIAEC monolayers were labeled with fluorescent-tagged antibodies against the adhesion molecules VCAM-1, ICAM-1, PECAM, and E-selectin. FACS analysis was used to measure antibody-labeled adhesion molecule expression. ICAM-1 and PECAM were found to be constitutively expressed. VCAM-1 and ICAM-1 expression were significantly upregulated by IL-1 beta, while E-selectin was neither constitutively expressed nor upregulated by IL-1 beta. Pretreatment with estrogen or progesterone alone decreased IL-1 beta-stimulated VCAM-1 and ICAM-1 expression, but not to statistically significant levels. Combined hormone exposure significantly decreased, in an additive fashion, the expression of VCAM-1 and ICAM-1 in stimulated cells. This study supports extension of the beneficial effects ascribed to HRT to include the peripheral arterial endothelium of healthy women.

Estrogen/progesterone replacement versus pravastatin and their sequential association in hypercholesterolemic postmenopausal women

OBJECTIVES

The objectives of this study were to assess serum lipid changes in response to an oral estrogen combined with progesterone (Group A) as compared with pravastatin (Group B) and to evaluate the additive effects of the sequential addition of statin to hormonal replacement therapy (HRT) and of HRT to statin.

METHODS

Thirty-seven of 63 hypercholesterolemic menopausal women initially submitted to a 4-month diet were randomised to oral conjugated estrogens (0.625 mg)/micronised progesterone (200 mg) or to pravastatin (40 mg). After 6 months, each group received both medications for another 6 months.

RESULTS

Nineteen percent of women corrected their lipids below decision levels with diet alone. Low density lipoprotein-cholesterol (LDL-C) decreased by 8+/-5% with HRT and by 26+/-3% (P<0.001) with the statin. These single medications increased high density lipoprotein-cholesterol (HDL-C) by 13+/-5% (P<0.01) and 11+/-7%, respectively. Combined interventions produced cumulative LDL-C reductions of 40+/-2 and 42+/-3% (P<0.001) and additive HDL-C augmentations of 16+/-4 and 23+/-5% (P<0.01) with proportional changes in apolipoprotein (Apo)B-100 and ApoA-1. These combined effects brought the atherogenic index (C/HDL-C) for Groups A and B, respectively, from a moderate (5.18+/-0.25 and 5.87+/-0.18) to a reduced (3.35+/-0.20 and 3.52+/-0.19) risk category. Triglycerides (TG) which were increased by HRT and decreased by the statin returned to baseline during combined treatments. No changes in diet, physical activity or anthropomorphometric measurements explained the lipid modifications.

CONCLUSIONS

In menopausal patients with elevated C not responding to diet, pravastatin was most effective to decrease LDL-C, and oral estrogen-micronised progesterone most effective to increase HDL-C. Marked reduction of the atherogenic index is achieved by sequential combinations of medications resulting from beneficial cumulative effects on both C-LDL and C-HDL.

[Hormone replacement therapy in ischemic heart disease prevention in women. Arguments in favor]

Numerous evidence have suggested a physiologic action of sexual steroids upon the cardiovascular system and the coherence of epidemiological studies have raised the possibility of a positive action of estradiol in preventing cardiovascular disease, specially through atheroma inhibition and other vascular wall-related mechanisms. From an experimental point of view, some clinical trials have demonstrated an improvement in some intermediate clinical variables, such as hypercholesterolemia and hypertension, after the administration of estradiol. Nonetheless, the HERS study, the first secondary prevention trial of estrogen and cardiovascular disease, failed to demonstrate these positive actions suggested by epidemiological studies and the efficacy of estradiol in the treatment of postmenopausal women with cardiovascular disease has been questioned. In spite of this, the HERS study has also been questioned because of different pitfalls in its development and, for some authors, it is inconclusive. Therefore, at present, it is not possible to make an evidence based clinical decision regarding the key question about the real actions of estradiol in the prevention of cardiovascular disease in postmenopausal women.

Comparison of the lipoprotein, carbohydrate, and hemostatic effects of phasic oral contraceptives containing desogestrel or levonorgestrel

Desogestrel (DSG) is a less-androgenic progestogen than levonorgestrel (LNG). This difference in androgenicity may be responsible for observed differences in metabolic effects between oral contraceptive (OC) formulations containing almost equivalent estrogen doses but with either DSG or LNG as a progestogen. To test the hypothesis, a prospective 9-month randomized comparison of plasma lipids, glucose, insulin, hemostasis, and sex hormone binding globulin (SHBG) was conducted in 66 healthy women using phasic formulations of OCs containing either DSG (DSG-OC) or LNG (LNG-OC). The study results showed that SHBG increased 3-fold with DSG-OC and 2-fold with LNG-OC. DSG-OC increased HDL-C, HDL(2)-C and HDL(3)-C; LDL-C decreased transiently. LNG-OC decreased HDL(2)-C and increased HDL(3)-C; HDL-C was unchanged and LDL-C decreased transiently. Both formulations increased VLDL-C and triglycerides, more with DSG-OC, but apolipoprotein B levels increased equally. Apo A-I and A-II increased more with DSG-OC than with LNG-OC. Neither formulation altered Lp(a) or fasting glucose and insulin levels. Postprandially, both formulations decreased glucose and increased insulin responses, but to an equivalent degree. Both OCs slightly enhanced procoagulant and profibrinolytic parameters to the same extent except for internally compensating decreases in Factor V and protein S with DSG-OC. In summary, at almost equivalent estrogen doses, a phasic OC containing DSG compared with LNG has a less androgenic effect on lipoproteins and SHBG, similar effects on hemostatic parameters with lower protein S and factor V activity and equivalent effects on carbohydrate metabolism. The lipoprotein, SHBG, and protein S and factor V differences are likely due to the lesser androgenicity of DSG allowing for a greater expression of the dose of estrogen.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Impact of subdermal norgestrel on hepatic acyl-coenzyme A:cholesterol- acyltransferase (ACAT) activity: possible antiatherogenic effect

The impact of subdermally placed ethinyl estradiol, norgestrel, and the combination of the two on cholesterol metabolism as measured by hepatic acyl:cholesterol-acyltransferase (ACAT) activity was examined in the rat model. A total of 48 rats were assigned to one of 6 groups, receiving either 0.1 mg or 1.0 mg of ethinyl estradiol daily, 1.0 or 10 mg of norgestrel daily, and combinations of either 0.1 mg ethinyl estradiol/1.0 mg norgestrel or 1.0 mg ethinyl estradiol/10 mg norgestrel daily. All drugs were administered through subdermally placed time release capsules. The administration of norgestrel only in either 1.0 mg or 10 mg resulted in significantly lower rates of ACAT activity (0.77 +/- 0.566 and 0.91 +/- 0.239 pmol/mg/min, respectively). The combination of 1.0 ethinyl estradiol and 10 mg norgestrel resulted in a significant increase in ACAT activity to 2.17 +/- 0.873. This combination also resulted in significantly greater weight loss at the conclusion of treatment [247.83 +/- 6.2 g (pre) vs. 205.50 +/- 10.6 (post)]. There were no other differences in ACAT activity between groups and no other differences in weight, both between groups and pre- and post-treatment within groups. In summary, subdermally placed norgestrel resulted in a significant lowering of ACAT activity not seen with either administration of ethinyl estradiol alone or the combination of ethinyl estradiol and norgestrel in doses ranging from 0.1 to 1.0 mg of ethinyl estradiol and 1.0 to 10.0 mg of norgestrel. Significantly increased ACAT activity for the combination of 1.0 ethinyl estradiol and 10 mg norgestrel over either ethinyl estradiol or norgestrel alone or a lower dose combination suggests a dose-related threshold and drug-drug interaction for this effect. These results suggest that subdermally placed norgestrel may result in significantly lower ACAT activity and may have a potential role as an antiatherogenic treatment.

Vitamin D receptor and estrogen receptor gene polymorphisms in postmenopausal Danish women: no relation to bone markers or serum lipoproteins

OBJECTIVE

To investigate the polymorphisms of the vitamin D receptor (VDR) and estrogen receptor (ER) genes in relation to biochemical markers of bone turnover (serum osteocalcin and urinary collagen type I degradation products (CrossLaps), and to study ER genotypes in relation to serum lipoproteins, blood pressure, or changes in these parameters after 2 years of hormone replacement therapy (HRT) in 499 Danish postmenopausal women.

METHODS

The VDR gene polymorphisms were determined by means of the three restriction enzymes, i.e. BsmI, ApaI and TaqI, while the ER gene polymorphisms were determined by means of the PvuII and XbaI restriction enzymes. Serum osteocalcin, urinary CrossLaps and the lipoproteins were also assessed. Body mass index was recorded.

RESULTS

The VDR or ER genotypes did not differ significantly with respect to age, age at menopause or body mass index. No significant effect of VDR or ER genotype on bone turnover was found. Furthermore, we were unable to find any relationship between ER genotype and lipoproteins or blood pressure at baseline, or changes in these parameters during HRT.

CONCLUSION

A clinically significant relationship between VDR and ER genotypes and biochemical markers of bone turnover or serum lipoproteins could not be demonstrated in healthy Danish postmenopausal women.

Tibolone inhibits leukocyte adhesion molecule expression in human endothelial cells

Tibolone is a synthetic steroid with mixed estrogenic and progestogenic/androgenic activity used for post-menopausal hormone replacement therapy. Since its cardiovascular effects are still not clear, and no data have been published on possible direct actions on the vessel wall, we studied the effects of tibolone and its metabolites on lipopolysaccharide (LPS)-induced expression of leukocyte adhesion molecules on human endothelial cells. Tibolone and its two estrogenic 3alpha-OH and 3beta-OH metabolites, but not the progestogenic/androgenic Delta(4)-isomer, concentration-dependently decreased LPS-induced vascular cell adhesion molecule-1 protein expression. This effect was estrogen receptor dependent, since it was completely blocked by the pure estrogen receptor antagonist ICI 182780. Furthermore, only tibolone, the 3alpha-OH and the 3beta-OH metabolites decreased endothelial expression of E-selectin, while none of the compounds changed the levels of intercellular adhesion molecule-1. These findings were associated with parallel changes in mRNA levels for the three adhesion molecules. Our data show that tibolone and its estrogenic metabolites exert direct actions on the vascular wall, decreasing the expression of endothelial-leukocyte adhesion molecules, thus producing potentially important direct anti-atherogenic effects.

Long-term estrogen replacement therapy is associated with improved exercise capacity in postmenopausal women without known coronary artery disease

BACKGROUND

Short-term estrogen administration improves vasodilation and has been shown to improve exercise capacity. However, it is unknown whether long-term estrogen replacement therapy is associated with improved exercise capacity in postmenopausal women without known coronary artery disease.

METHODS AND RESULTS

We studied 248 postmenopausal women without known coronary artery disease (mean age 63.5 years); 158 (64%) were current or past hormone replacement therapy (HRT) users and 108 (44%) were current users of HRT. Attributes potentially affecting exercise capacity and cardiac risk factors were carefully measured. These included duration of estrogen replacement therapy, all variables in the Framingham risk index, physical activity level, body mass index, waist-to-hip ratio, presence of osteoporosis, and family history of heart disease. We measured maximal oxygen uptake (MVO (2)) and anaerobic threshold as objective markers of exercise capacity. The relation between exercise capacity and use of HRT was analyzed with the use of logistic regression, controlling for confounding variables. We found that fitness, as measured by MVO (2) and anaerobic threshold, was significantly greater in women who had used HRT currently or in the past compared with women who had never used HRT. This difference in fitness was not confounded by age or physical activity level.

CONCLUSIONS

Estrogen replacement therapy is associated with increased exercise capacity as measured by MVO (2) and anaerobic threshold in postmenopausal women without coronary artery disease. This finding is consistent with the beneficial effect of short-term estrogen administration on improved endothelium-dependent and endothelium-independent vasodilation.

Cardioprotection by the phytoestrogen genistein in experimental myocardial ischaemia-reperfusion injury

1. Soybean phytoestrogens have no oestrogen agonist effects on the reproductive system and therefore it is reasonable to explore the potential of these naturally occurring plant oestrogens in the cardiovascular pathology. We therefore investigated the effects of genistein in a rat model of myocardial ischaemia-reperfusion injury. 2. Anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham operated rats were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity (MPO), serum creatinine phosphokinase activity (CPK), serum and macrophage Tumour Necrosis Factor-alpha (TNF-alpha), cardiac intercellular adhesion molecule-1 (ICAM-1) immunostaining, cardiac mRNA for ICAM-1 evaluated by the means of reverse transcriptase polymerase chain reaction (RT - PCR), ventricular arrhythmias and myocardial contractility (left ventricle dP/dt(max)) were evaluated. 3. Myocardial ischaemia and reperfusion in untreated rats produced marked myocardial necrosis, increased serum CPK activity and MPO activity both in the area-at-risk and in the necrotic area, reduced myocardial contractility, caused ventricular arrhythmias and induced a marked increase in serum and macrophage TNF-alpha. Furthermore myocardial ischaemia-reperfusion injury increased ICAM-1 expression in the myocardium. 4. Administration of genistein (1 mg kg(-1), i.v., 5 min after coronary artery occlusion) lowered myocardial necrosis and MPO activity in the area-at-risk and in the necrotic area, decreased serum CPK activity, increased myocardial contractility, decreased the occurrence of ventricular arrhythmias, reduced serum and macrophages levels of TNF-alpha and blunted ICAM-1 expression in the injured myocardium. Finally genistein added in vitro to peritoneal macrophages collected from untreated rats subjected to myocardial ischaemia-reperfusion injury significantly reduced TNF-alpha production. 5. Our data suggest that genistein limits the inflammatory response and protects against myocardial ischaemia-reperfusion injury.

Beneficial effect of hormone replacement therapy on weight loss in obese menopausal women

OBJECTIVE

At the onset of menopause, weight-gain and the aggravation of certain cardiovascular risk factors are frequently observed. The aim of this study was to examine the metabolic effects of combined hormone replacement therapy (17beta-oestradiol transdermic 50 microg for 21 days and oral medroxyprogesterone acetate 5 mg from day 10 to 21) using, in particular, indirect calorimetry.

METHODS

Patients (21; 12 substituted and nine controls) were studied twice (3 months apart) during an oral glucose load (75 g).

RESULTS

Total body weight was unaltered after 3 months in the control group, whereas a fat-loss of 2.1+/-0.2 kg and a decrease of the waist:hip ratio were observed in the substituted group. In the latter group, a significant increase in lipid oxidation was observed (0.58+/-0.06 mg/kg/min before and 0.75+/-0.04 mg/kg/min after substitution P<0.05), whilst total energy expenditure and thermogenesis were also increased. Glucose, lipid and protein oxidation remained stable during three months in the control group. The insulin response to an oral glucose load diminished by 30% with hormone replacement therapy (102.3+/-32.8 mmicro/l versus 71.4+/-20.0 mmicro/l). Total and LDL-cholesterol improved after hormone replacement therapy whereas plasma triglycerides were not altered.

CONCLUSIONS

Combined hormone replacement therapy not only prevented weight-gain, but favored weight-loss by significantly increasing lipid oxidation after 3 months of treatment. It also favourably influenced the insulin response, plasma lipids and energy expenditure.

Cardiovascular disease: pathogenesis, epidemiology, and risk among users of oral contraceptives who smoke

Smoking increases the risk of lung cancer and cardiovascular disease among persons of both sexes. The risk of cardiovascular disease is further increased among users of oral contraceptives who smoke, particularly those who are >/=35 years old or carry the coagulation factor V Leiden mutation. Other important cardiovascular disease risk factors in women include waist/hip girth ratio >0.8, high concentration of low-density lipoprotein cholesterol (>115 mg/dL), high triglyceride level (>/=150 mg/dL) with low concentration of high-density lipoprotein cholesterol (</=45 mg/dL), high ratio of total cholesterol/high-density lipoprotein (4.0), high ratio of low-density lipoprotein/high-density lipoprotein (3.0), glucose values >/=100 mg/dL, hypertension, lack of physical activity, and high-fat diet. Most excess cardiovascular disease among users of oral contraceptives is due to thrombosis (not atherosclerosis); studies indicate that the lower the oral contraceptive estrogen dose is, the lower is this risk. Oral contraceptives containing the third-generation progestins desogestrel and gestodene have been associated with greater risks of venous thromboembolism than are associated with older progestins, although there is some controversy surrounding these findings.

Effect of 14 weeks of resistance training on lipid profile and body fat percentage in premenopausal women

OBJECTIVES

To study the effects of a supervised, intensive (85% of one repetition maximum (1-RM)) 14 week resistance training programme on lipid profile and body fat percentage in healthy, sedentary, premenopausal women.

SUBJECTS

Twenty four women (mean (SD) age 27 (7) years) took part in the study. Subjects were randomly assigned to either a non-exercising control group or a resistance exercise training group. The resistance exercise training group took part in supervised 45-50 minute resistance training sessions (85% of 1-RM), three days a week on non-consecutive days for 14 weeks. The control group did not take part in any structured physical activity.

RESULTS

Two way analysis of variance with repeated measures showed significant (p < 0.05) increases in strength (1-RM) in the exercising group. There were significant (p < 0.05) decreases in total cholesterol (mean (SE) 4.68 (0.31) v 4.26 (0.23) mmol/1 (180 (12) v 164 (9) mg/dl)), low density lipoprotein (LDL) cholesterol (2.99 (0.29) v 2.57 (0.21) mmol/l (115 (11) v 99 (8) mg/dl), the total to high density lipoprotein (HDL) cholesterol ratio (4.2 (0.42) v 3.6 (0.42)), and body fat percentage (27.9 (2.09) v 26.5 (2.15)), as well as a strong trend towards a significant decrease in the LDL to HDL cholesterol ratio (p = 0.057) in the resistance exercise training group compared with their baseline values. No differences were seen in triglycerides and HDL cholesterol. No changes were found in any of the measured variables in the control group.

CONCLUSIONS

These findings suggest that resistance training has a favourable effect on lipid profile and body fat percentage in healthy, sedentary, premenopausal women.

Estrogen improves abnormal norepinephrine-induced vasoconstriction in postmenopausal women

OBJECTIVE

An exaggerated blood pressure response to mental stress in postmenopausal women has been reported but the underlying mechanism is not clear. In the present study, we examined the role of estrogen in the blood pressure response to mental stress.

SUBJECTS AND METHODS

Hemodynamic responses to mental stress and constrictor responses to norepinephrine were compared in 18 premenopausal (mean +/- SD age 33 +/- 5 years), 22 postmenopausal women (62 +/- 7 years) and 13 postmenopausal women with estrogen replacement therapy (58 +/- 8 years). Premarin was infused in 10 postmenopausal women to determine whether estrogen attenuates norepinephrine-induced vasoconstriction. The hemodynamic responses to a standard mental arithmetic test were measured. Norepinephrine (12.5, 25, 50, 100 ng/min) was infused at 0.5 ml/min for 5 min via the dorsal hand vein. Norepinephrine (100 ng/min) combined with premarin (200 microg/min) was infused into the dorsal hand vein of postmenopausal women. Changes in venous diameter were measured by ultrasonography using a 7.5 MHz transducer.

RESULTS

All study subjects were healthy, normotensive and had normal lipid profiles. The postmenopausal women showed a significantly greater blood pressure response to the mental arithmetic test than the premenopausal women or those taking estrogen replacement therapy (P < 0.01). Norepinephrine induced significant dose-dependent vasoconstriction in all three groups (P < 0.001). The postmenopausal women showed significantly greater constriction in response to norepinephrine than the premenopausal women and those taking estrogen replacement therapy (P = 0.02). Premarin significantly attenuated the norepinephrine-induced vasoconstriction in the postmenopausal women (P< 0.001).

CONCLUSION

Healthy, normotensive postmenopausal women showed an exaggerated blood pressure response to mental stress. An increased vasoconstriction in response to norepinephrine and loss of estrogen-mediated vasodilation may contribute to the increased blood pressure response to stress in postmenopausal women without estrogen replacement therapy.

Decreased plasma tissue factor pathway inhibitor in women taking combined oral contraceptives

Use of combined oral contraceptives (OC) is associated with a significant risk of thrombosis. The mechanisms of this effect are not clearly defined. Tissue factor pathway inhibitor (TFPI) is a circulating anti-coagulant that inhibits the earliest steps in activation of the extrinsic coagulation pathway. It plays a central role in control of coagulation but its contribution to the thrombotic risk associated with OC has not been assessed. Plasma TFPI antigen and activity, factor VIIa, prothrombin fragments 1&2, von Willebrand antigen, fibrinogen, and low density lipoprotein cholesterol were measured by standard assays in women taking OC (aged 16 to 45 years, n = 40) and age-matched women not taking OC (controls, n = 40). Plasma TFPI antigen did not vary significantly across the menstrual cycle in controls. Women on OC had a 25% reduction in plasma TFPI antigen (median 51.0 ng/ml; 95% confidence intervals [CI] 37.5 to 85.5; control 68.0 ng/ml, CI 61.0 to 95.0; P < 0.001) and a 29% reduction in TFPI activity (78.5 U/ml, CI 57.5 to 107.5; control 111.0 U/ml, CI 79.5 to 171.0; P < 0.001) compared to controls. Plasma factor VIIa activity and prothrombin fragments 1&2 were also significantly increased in women using OC (both P < 0.001), indicating activation of the extrinsic coagulation pathway. These results demonstrate that normal cyclic variations in estrogen and/or progesterone do not significantly alter plasma TFPI levels. However, estrogens and/or progestogens in OC result in activation of the extrinsic coagulation pathway and significantly reduce plasma TFPI, its major circulating inhibitor. Reduced plasma TFPI levels may underlie the thrombotic effects of OC.