Biology: risk factor modification by OCs and HRT lipids and lipoproteins

Smoking and combined oral contraceptives should be considered as an independent variable in sex and gender-oriented studies

The influence of sex combined with smoking and combined oral contraceptives (COC) use on atherogenic indexes is scarcely studied. Thus, traditional lipid parameters were measured, and non-traditional atherogenic indexes were calculated in a young and healthy population of men, COC-free women, and COC users. Total cholesterol (TChol), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and HDL/LDL ratio were lower in men, while triglycerides (TG)/HDL ratio, atherogenic index of plasma (AIP), Castelli's Risk Index I (CRII) and CRI-II, atherogenic coefficient (AC), creatinine, creatinine clearance, and estimated glomerular filtration rate (eGFR) were higher in men. The use of COC modified TChol, HDL, TG, TG/HDL, and AIP which had significantly higher values in COC users. In addition, TG were also increased in COC users in comparison with men. Smoking reduced sexually divergent parameters: BMI, TG, HDL/LDL, TG/HDL, AIP, CRII, CRI-II, and AC became similar among the three cohorts, losing the reported sex differences. Smoking also reduced differences in TChol, HDL, TG, and AIP between COC-free women and COC users, but it does not affect CRII, CRI-II, creatinine, creatinine clearance, and eGFR, underlining that COC users and COC-free women have to be considered two different populations. Our results represent a complex landscape suggesting that for both sexes smoking should be an independent variable in medical studies. Moreover, in women, the use of COC evidenced two different cohorts. Thus, more variables should be considered during a single study indicating that sex, smoking, and COC should be studied together to get a picture of the real-life context.

Comparison of Global Metabolite for Growing Pigs Fed at Metabolizable Energy Requirement for Maintenance

Though the energy requirement for maintenance is an important part of net energy system, little is known of the metabolic characteristics of maintenance energy expenditure. This study was investigated the effect of feeding level at metabolizable energy requirement for maintenance (FLM) on plasma metabolites in growing pigs. Ten barrows (22.5 ± 0.5 kg BW) were kept in metabolism crates and catheterized in the precaval vein during adaptation period. Pigs were fed a corn-soybean meal diet at 782 kJ ME/kg BW^0.6·d⁻¹ during d 1 to 8 and then were refeeding at 2,400 kJ ME/kg BW^0.6·d⁻¹ on d 9. Plasma samples of each pig were collected by catheter on the morning of d 1, 3, 5, 7, 9, and 10, respectively, for metabolomics testing. Results showed that the concentration of plasma urea nitrogen decreased under FLM (p < 0.01) and increased significantly after refeeding (p < 0.01). The concentration of total cholesterol, high-density lipoprotein, low-density lipoprotein, and albumin in plasma were decreased significantly after refeeding (p < 0.01). Eleven identified compounds were up-regulated and six ones were down-regulated under FLM. In conclusion, the energy metabolism of growing pigs was relatively stable after 4 days of feeding at FLM.

Atherogenic and cardiovascular risks of women on combined oral contraceptives: A comparative study

Background

Although combined oral contraceptive (COC) is commonly used in sub-Saharan Africa, data on its cardiovascular disease risk remains scanty. The study aimed to determine serial serum lipid profiles and cardiovascular disease risks among COC-users.

Methods

This is a prospective, comparative multicentered study conducted at four health facilities in Nigeria. Participants were new users of contraceptives; 120 each of women initiating COCs (group I) and those initiating other forms of nonhormonal contraceptives (group II) were recruited and monitored over a 6-month period. Serial lipid profile, blood pressure, and atherogenic risk for cardiovascular diseases were measured at recruitment (start) and scheduled follow-up clinic visits at 3 months and 6 months for all participants. Statistical analysis was performed with SPSS (version 21.0) and P value < 0.05 was considered significant.

Results

In all, 225 participants (111 COC-users, 114 nonCOC-users) that completed the study were aged 18 to 49 years. There was a statistically significant increase in the diastolic blood pressure (P = 0.001), Low Density Lipoprotein- Cholesterol (P = 0.038) and higher atherogenic risk (P = 0.001) among COC-users compared to nonCOC-users. The serial total serum cholesterol, triglyceride, High Density Lipoprotein, systolic blood pressure, and body mass index were higher among COC-users but were not statistically significant compared to nonCOC-users.

Conclusion

Alterations in lipid profile and increased short-term atherogenic risk for cardiovascular disease were reported among the COC-users in this study. Serial lipid profile and atherogenic risk assessment for cardiovascular diseases are recommended for monitoring of COC-users.

Hyperalphalipoproteinemia and Beyond: The Role of HDL in Cardiovascular Diseases

Hyperalphalipoproteinemia (HALP) is a lipid disorder characterized by elevated plasma high-density lipoprotein cholesterol (HDL-C) levels above the 90th percentile of the distribution of HDL-C values in the general population. Secondary non-genetic factors such as drugs, pregnancy, alcohol intake, and liver diseases might induce HDL increases. Primary forms of HALP are caused by mutations in the genes coding for cholesteryl ester transfer protein (CETP), hepatic lipase (HL), apolipoprotein C-III (apo C-III), scavenger receptor class B type I (SR-BI) and endothelial lipase (EL). However, in the last decades, genome-wide association studies (GWAS) have also suggested a polygenic inheritance of hyperalphalipoproteinemia. Epidemiological studies have suggested that HDL-C is inversely correlated with cardiovascular (CV) risk, but recent Mendelian randomization data have shown a lack of atheroprotective causal effects of HDL-C. This review will focus on primary forms of HALP, the role of polygenic inheritance on HDL-C, associated risk for cardiovascular diseases and possible treatment options.

Vasomotor symptoms and lipids/lipoprotein subclass metrics in midlife women: Does level of endogenous estradiol matter? The SWAN HDL Ancillary Study

BACKGROUND

A greater frequency of vasomotor symptoms (VMSs) has been associated with higher low-density lipoprotein cholesterol (LDL-C), but the association with high-density lipoprotein cholesterol (HDL-C) remains unclear. Endogenous estradiol (E2) levels are associated with both VMS and lipid levels and thus may confound such associations.

OBJECTIVES

To assess the relationship of VMS frequency with HDL-C, LDL-C, and lipoprotein concentrations (HDL and LDL particles [HDL-P; LDL-P]) and lipoprotein sizes in midlife women and to evaluate whether these associations are explained by E2.

METHODS

Participants were from the Study of Women's Health Across the Nation (SWAN) HDL ancillary study who had both nuclear magnetic resonance (NMR) spectroscopy lipoprotein subclass metrics and self-reported frequency of VMS measured 2-5 times over the menopause transition. VMS frequency was categorized into none, 1-5 days (infrequent), or ≥6 days (frequent) within the past 2 weeks.

RESULTS

We evaluated 522 women [at baseline: mean age 50.3 (SD: 2.8) years; infrequent VMS: 29.8%, frequent VMS: 16.5%]. Adjusting for potential confounders except E2, frequent VMS was associated with smaller HDL size [β(SE): -0.06 (0.03); P = .04] and higher concentrations of LDL-C [β(SE): 3.58 (1.77); P = .04] and intermediate LDL-P [β(SE): 0.09 (0.05); P = .04] than no VMS. These associations were largely explained by E2, all P's > .05.

CONCLUSIONS

Frequent VMSs were associated with smaller HDL size and higher concentrations of LDL-C and intermediate LDL-P. These associations were explained by endogenous E2. Whether treating frequent VMS with exogenous E2 could simultaneously improve lipids/lipoproteins profile should be assessed in future studies.

Combined Oral Contraceptives Increase High-Sensitivity C-Reactive Protein but Not Haptoglobin in Female Athletes

BACKGROUND

No studies have examined the effects of oral hormonal contraception on chronic low-grade inflammation as assessed by stratified levels of high-sensitivity C-reactive protein (hsCRP) in athletes. We explored the impact of combined oral contraceptives (OCs) on serum hsCRP, haptoglobin, triglycerides and cholesterol in white female athletes.

METHODS

Italian sportswomen (n = 205; mean age 24 ± 5.3 years; body mass index 21 ± 2.2 kg m^-2; sport activity 8.7 ± 3.65 h week^-1) were analyzed according to OC use.

RESULTS

Progressive hsCRP levels were evaluated in OC users (n = 53) compared to non-OC users (n = 152). Levels of hsCRP from 3.0 to <10.0 mg L^-1 (at high risk of future cardiovascular events) were found in 26.4 % (14/53) of OC users and only in 2.6 % (4/153) of non-OC users (OR = 13.3, 95 % CI 4.14-42.6, P < 0.001). Risky hsCRP levels ≥1.0 mg L^-1 were found in 62.3 % of OC users versus 13.2 % non-OC users (OR = 10.9, 95 % CI 5.26-22.5, P < 0.001). Protective hsCRP levels (<0.5 mg L^-1) were found in 17.0 % of OC users and in 64.5 % of non-OC users (OR = 0.11, 95 % CI 0.05-0.25, P < 0.001). OC use increased serum triglycerides (P < 0.001), total cholesterol (P = 0.027) and HDL cholesterol (P = 0.018), whereas haptoglobin was unaffected. Hours of exercise week^-1 had a mild inverse association with hsCRP (P = 0.048) in non-OC users only.

CONCLUSIONS

OC use markedly elevated chronic low-grade inflammation in athletes, which could predispose to a higher inflammatory response to physical stress and elevate cardiovascular risk. Physical activity without OC use seemed to favor low hsCRP. Further research is needed to extend our results and to elucidate the potential effects on athletic performance of chronically elevated hsCRP. Our findings would be useful for sport physicians interpreting blood tests in athletes.

Integrative analysis of indirect calorimetry and metabolomics profiling reveals alterations in energy metabolism between fed and fasted pigs

Background

Fasting is a simple metabolic strategy that is used to estimate the maintenance energy requirement where the energy supply for basic physiological functions is provided by the mobilization of body reserves. However, the underlying metabolic components of maintenance energy expenditure are not clear. This study investigated the differences in heat production (HP), respiratory quotient (RQ) and plasma metabolites in pigs in the fed and fasted state, using the techniques of indirect calorimetry and metabolomics.

Methods

Nine barrows (45.2 ± 1.7 kg BW) were fed corn-soybean based meal diets and were kept in metabolism crates for a period of 14 d. After 7 d adaptation, pigs were transferred to respiratory chambers to determine HP and RQ based on indirect calorimetry. Pigs were fed the diet at 2,400 kJ ME/(kg BW^0.6·d) during d 8 to 12. The last 2 d were divided into 24 h fasting and 48 h fasting treatment, respectively. Plasma samples of each pig were collected from the anterior vena cava during the last 3 d (1 d while pigs were fed and 2 d during which they were fasted). The metabolites of plasma were determined by high-resolution mass spectrometry using a metabolomics approach.

Results

Indirect calorimetry analysis revealed that HP and RQ were no significant difference between 24 h fasting and 48 h fasting, which were lower than those of fed state (P <  0.01). The nitrogen concentration of urine tended to decrease with fasting (P = 0.054). Metabolomics analysis between the fed and fasted state revealed differences in 15 compounds, most of which were not significantly different between 24 h fasting and 48 h fasting. Identified compounds were enriched in metabolic pathways related to linoleic acid metabolism, amino acid metabolism, sphingolipid metabolism, and pantothenate and CoA biosynthesis.

Conclusion

These results suggest that the decreases in HP and RQ of growing pigs under fasting conditions were associated with the alterations of linoleic acid metabolism and amino acid metabolism. The integrative analysis also revealed that growing pigs under a 24-h fasting were more appropriate than a 48-h fasting to investigate the metabolic components of maintenance energy expenditure.

Metabolic characterization of menopause: cross-sectional and longitudinal evidence

BACKGROUND

Women who experience menopause are at higher cardiometabolic risk and often display adverse changes in metabolic biomarkers compared with pre-menopausal women. It remains elusive whether the changes in cardiometabolic biomarkers during the menopausal transition are due to ovarian aging or chronological aging. Well-conducted longitudinal studies are required to determine this. The aim of this study was to explore the cross-sectional and longitudinal associations of reproductive status, defined according to the 2012 Stages of Reproductive Aging Workshop criteria, with 74 metabolic biomarkers, and establish whether any associations are independent of age-related changes.

METHODS

We determined cross-sectional associations of reproductive status with metabolic profiling in 3,312 UK midlife women. In a subgroup of 1,492 women who had repeat assessments after 2.5 years, we assessed how the change in reproductive status was associated with the changes in metabolic biomarkers. Metabolic profiles were measured by high-throughput quantitative nuclear magnetic resonance metabolomics. In longitudinal analyses, we compared the change in metabolic biomarkers for each reproductive-status category change to that of the reference of being pre-menopausal at both time points. As all women aged by a similar amount during follow-up, these analyses contribute to distinguishing age-related changes from those related to change in reproductive status.

RESULTS

Consistent cross-sectional and longitudinal associations of menopause with a wide range of metabolic biomarkers were observed, suggesting the transition to menopause induces multiple metabolic changes independent of chronological aging. The metabolic changes included increased concentrations of very small very low-density lipoproteins, intermediate-density lipoproteins, low-density lipoproteins (LDLs), remnant, and LDL cholesterol, and reduced LDL particle size, all toward an atherogenic lipoprotein profile. Increased inflammation was suggested via an inflammatory biomarker, glycoprotein acetyls, but not via C-reactive protein. Also, levels of glutamine and albumin increased during the transition. Most of these metabolic changes seen at the time of becoming post-menopausal remained or became slightly stronger during the post-menopausal years.

CONCLUSIONS

The transition to post-menopause has effects on multiple circulating metabolic biomarkers, over and above the underlying age trajectory. The adverse changes in multiple apolipoprotein-B-containing lipoprotein subclasses and increased inflammation may underlie women's increased cardiometabolic risk in their post-menopausal years.

Hormonal contraception in women with polycystic ovary syndrome: choices, challenges, and noncontraceptive benefits

Polycystic ovary syndrome (PCOS) is an endocrine disorder among women of reproductive age characterized by chronic anovulation and polycystic ovary morphology and/or hyperandrogenism. Management of clinical manifestations of PCOS, such as menstrual irregularities and hyperandrogenism symptoms, includes lifestyle changes and combined hormonal contraceptives (CHCs). CHCs contain estrogen that exerts antiandrogenic properties by triggering the hepatic synthesis of sex hormone-binding globulin that reduces the free testosterone levels. Moreover, the progestogen present in CHCs and in progestogen-only contraceptives suppresses luteinizing hormone secretion. In addition, some types of progestogens directly antagonize the effects of androgens on their receptor and also reduce the activity of the 5α reductase enzyme. However, PCOS is related to clinical and metabolic comorbidities that may limit the prescription of CHCs. Clinicians should be aware of risk factors, such as age, smoking, obesity, diabetes, systemic arterial hypertension, dyslipidemia, and a personal or family history, of a venous thromboembolic event or thrombophilia. This article reports a narrative review of the available evidence of the safety of hormonal contraceptives in women with PCOS. Considerations are made for the possible impact of hormonal contraceptives on endocrine, metabolic, and cardiovascular health.

The impact of oral contraceptives on cardiometabolic parameters

PURPOSE

There is much controversy regarding the use of oral contraceptive pills (OCPs) on cardiometabolic parameters, which is why this longitudinal population-based study was conducted to assess the impact of OCP use and its duration on cardiometabolic factors.

METHODS

Of 5532 reproductive-aged participants of the Tehran lipid and glucose study, 3160 women who met our inclusion criteria were subdivided according to the duration of OCPs consumption into four sub-groups: (1) Non-users; (2) <11 month users; (3) 12-35 month users, and (4) ≥36 month users, and their cardiometabolic parameters were compared.

RESULTS

No statistical significant differences were observed between the cardiometabolic parameters of these sub-groups, after further adjustment for confounding factors including age, parity, and education, except for mean low-density lipoprotein-cholesterol which was significantly higher in women who used OCPs for >36 months in comparison to non-OCP users. The odds ratio of hypercholesterolemia was significantly higher in women who used OCPs for >36 months in comparison to non-OCP users; being 1.5 times higher than non-users (95 % CI 1.01-2.2).

CONCLUSION

Results showed that if used for less than 3 years, OCPs have no cardiometabolic effects.

The role of hormones and aromatase inhibitors on breast tumor growth and general health in a postmenopausal mouse model

BACKGROUND

Breast cancer is the most frequently diagnosed cancer in women in the United States. Approximately 70% of breast cancers are diagnosed in postmenopausal women. Major clinical trials and experimental studies showed that aromatase inhibitors are effective against postmenopausal breast cancer. Despite their effectiveness in reducing tumor recurrence, aromatase inhibitors have adverse effects on the cardiovascular system and increase osteoporosis and bone fractures. Our study is aimed at investigating the role of natural steroid hormones on serum cardiovascular and bone resorption markers in an established mouse model mimicking postmenopausal breast cancer.

METHODS

Ovariectomized nude mice were transplanted with MCF-7 breast cancer cells constitutively expressing aromatase. The mice were treated with different combinations and doses of steroids, [estrogen (25 pg, 40 pg, 100 pg), progesterone (6 ng) and testosterone (50 ng)] along with dehydroepiandrostenedione (100 ug). Serum levels of HDL, LDL/VLDL, free and total cholesterol, total and bone specific alkaline phosphatase and triglycerides were analyzed after 5, 10 and 15 months.

RESULTS

Free cholesterol and LDL/VLDL levels in serum were reduced in groups mimicking estrous cycle and menstrual cycle hormones treatment. HDL cholesterol was increased in all the hormone treated groups except the estrous cycle-mimicking group. Bone specific alkaline phosphatase was decreased in menstrual cycle levels of estrogen and progesterone treatment.

CONCLUSIONS

All together our results show that use of natural hormones in appropriate combinations have beneficial effects on cardiac and bone toxicity, along with better tumor reduction than current treatments.

Influence of oral contraceptives on anthropomorphometric, endocrine, and metabolic profiles of anovulatory polycystic ovary syndrome patients

OBJECTIVE

To evaluate the influence of oral contraceptive pills (OCPs) on anthromorphometric, endocrine, and metabolic parameters in women with polycystic ovary syndrome (PCOS).

DESIGN

Retrospective cross-sectional cohort study for the period 1993-2011.

SETTING

Tertiary university hospital.

PATIENT(S)

PCOS patients, who never, ever, or at time of screening were using OCPs were included. A total of 1,297 patients, of whom 827 were white, were included. All PCOS patients diagnosed according to the Rotterdam 2003 consensus criteria were divided into three groups: current users, (n = 76; 6% of total), ever users (n = 1,018; 78%), and never users (n = 203; 16%). Ever users were subdivided based on the OCP-free interval.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Anthromorphometric (blood pressure, cycle duration) and ultrasound (follicle count, mean ovarian volume) parameters, endocrine (SHBG, testosterone, free androgen index, antimüllerian hormone [AMH]) and lipid profiles.

RESULT(S)

Current users and ever users were compared with never users. In current users, SHBG was increased and androgen levels decreased. Patients with an OCP-free interval of <1 year had a higher mean follicle count, higher AMH level, and increased serum androgen level compared with never users. SHBG levels remained increased until 5-10 years after cessation of OCP use.

CONCLUSION(S)

OCP use causes a milder phenotypic presentation of PCOS regarding hyperandrogenism. However, it does not alter parameters associated with increased health risks.

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol compared with one containing levonorgestrel and ethinylestradiol on haemostasis, lipids and carbohydrate metabolism

OBJECTIVES

To compare the effects of a combined oral contraceptive (COC) containing nomegestrol acetate and 17β-oestradiol (NOMAC/E2) on haemostasis, lipids, carbohydrate metabolism, C-reactive protein (CRP) and sex hormone-binding globulin (SHBG) with those of a COC containing levonorgestrel and ethinylestradiol (LNG/EE).

METHODS

In a randomised, open-label study, 121 healthy women, 18-50 years of age, were randomly assigned to receive NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n=60) or LNG/EE (150 μg/30 μg) in a 21/7-day regimen (n=61) for six cycles. The primary outcome was the change from baseline to cycle 6 for all indices.

RESULTS

All parameters were similar at baseline between the two groups. Over six cycles, NOMAC/E2 had less effect on most haemostatic indices than LNG/EE. Lipids were essentially unchanged with NOMAC/E2, whereas with LNG/EE high-density lipoprotein cholesterol decreased and low-density lipoprotein cholesterol and triglycerides slightly increased. NOMAC/E2 induced negligible changes in glucose and insulin parameters, in contrast to LNG/EE. A much smaller increase in CRP was observed with NOMAC/E2 than with LNG/EE. NOMAC/E2 was associated with a greater increase in SHBG.

CONCLUSIONS

The monophasic COC NOMAC/E2 had less influence on haemostasis, lipids and carbohydrate metabolism than the COC LNG/EE.

Effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on lipid metabolism during 1 year of conventional or extended-cycle use

BACKGROUND

The effects of extended regimens of combined oral contraceptives (COC) on lipid parameters are largely unknown. The present study compared the effects of a COC containing 30 mcg ethinyl estradiol and 2 mg dienogest (EE/DNG) in conventional and extended-cycle regimen over 1 year.

STUDY DESIGN

Lipid parameters were measured in 59 women treated with EE/DNG either conventionally (21+7 days) or in extended-cycle regimen (84+7 days). Blood samples were taken in a control cycle and at 3 and 12 months of treatment.

RESULTS

The mean levels of total cholesterol, HDL cholesterol and HDL(2) cholesterol underwent modest to moderate significant increases over time, while the significant increase in triglycerides and VLDL cholesterol was more pronounced with both regimens. LDL cholesterol decreased slightly in both regimen groups, whereas lipoprotein(a) was transiently decreased at 3 months only in the extended-cycle group. The changes reached a steady-state at latest at 3 months, but did not exceed the given normal ranges for any of the parameters. Notably, except for lipoprotein(a), the changes in mean lipid levels were not significantly different in the conventional and the extended-cycle regimen at 3 or 12 months of treatment.

CONCLUSION

Use of EE/DNG in conventional or extended-cycle regimen resulted in comparable changes of lipid parameters.

Long-term oral contraceptive treatment, metabolic syndrome and measures of cardiovascular risk in pre-menopausal women: National Health and Nutrition Examination Survey 1999-2004

AIM

Differences in subclinical cardiometabolic measures were examined as a function of oral contraceptive pills (OCP) treatment duration to compare never-treated women with four OCP-treatment groups (<1, 1-5, 5-10 and >10 years).

METHODS

The NHANES (1999-2004) database was used to evaluate 2089 healthy, pre-menopausal women, aged 18-55 years, with or without OCP history, no other hormonal treatment or history of systemic conditions. Outcome measures included body mass, central obesity, blood pressure, glycemia, insulinemia, lipid profile and inflammation. Analyses evaluated differences in prevalence of Metabolic Syndrome (MetS), constituent MetS and other clinical risk criteria, as well as outcome magnitudes. Analyses controlled for demographic and health-related variables, and study-eligible conditions.

RESULTS

Relative to other groups, women with >10 years OCP-use, and to some extent those with 5-10 years treatment, displayed no differences in prevalence of MetS and most risk criteria. Further analysis showed that, relative to women treated for <5 years, those with more prolonged OCP treatment displayed lower body mass and fasting glycemia with higher HDL-c levels, but more elevated LDL-c and total cholesterol.

CONCLUSIONS

The findings of both beneficial and detrimental subclinical cardiometabolic differences with more long-term OCP-treatment reinforces the need to monitor changes in these factors within the context of the treated patient's risk-benefit profile. However, because the magnitude of these differences was small, relative to normative ranges, it may be concluded that OCPs, as used in recent decades, are unlikely to markedly affect cardiometabolic risk.

Metabolic and cardiovascular impact of oral contraceptives in polycystic ovary syndrome

Chronic anovulation, polycystic ovarian morphology and hyperandrogenism are the diagnostic criteria for polycystic ovary syndrome (PCOS). Metabolic disturbances are more common in PCOS women who are prone to develop metabolic syndrome and to present higher levels of some cardiovascular disease risk marker. Oral contraceptives are widely used in PCOS, but conflicting data have been reported regarding their impact on carbohydrate and lipid metabolism on PCOS women. This paper presents a critical evaluation of combined oral contraceptives (COCs) metabolic effect - carbohydrate metabolism and insulin sensitivity, lipid metabolism, haemostasis, body weight, arterial pressure and cardiovascular impact - on PCOS women. Because of the paucity of data on the impact of COCs on cardiovascular and metabolic parameters in PCOS patients, most of there commendations are based on studies involving ovulatory women. The use of low-dose COCs is preferable in PCOS, especially among patients with glucose intolerance, insulin resistance and uncomplicated diabetes mellitus. Although reported as a side effect of COCs, marked weight gain has not been confirmed among users. However, when arterial hypertension or elevated risk for thromboembolism is present, progestogen-only hormonal contraceptives should be used instead of COCs. Regarding dyslipidaemia, COCs reduce low-density lipoprotein and total cholesterol and elevate high-density lipoprotein and triglycerides, and therefore are not recommended for women with high triglycerides levels. The choice of a COC, which alleviates the PCOS-induced hyperandrogenism without significant negative impact on cardiovascular risk, is one of the greatest challenges faced by gynaecologists nowadays.

In vivo effects of oral contraceptives on paraoxonase, catalase and carbonic anhydrase enzyme activities on mouse

Many effects that oestrogens and progestrogens used in oral contraceptive (OC) have on enzyme physiology are of importance on homeostasis. This study was carried out in order to determine the in vivo effect of three oral contraceptives containing ethinyl estradiol in combination with desogestrel and levonorgestrel on the paraoxonase (PON), catalase (CAT) and carbonic anhydrase (CA) activities in mice, which are model organisms for humans. Serum and liver paraoxonase activities were determined spectrophotometrically by using paraoxan as a substrate according to the methods of Gan et al. and Gil et al., respectively. Catalase and carbonic anhydrase activities were determined from erythrocytes used Aebi and Maren methods, respectively. For these studies, a group of ten mice (25+/-2 g) was selected for oral administration for 21 d of each drug (0.15 mg desogestrel+0.03 mg ethinylestradiol (A); 0.15 mg levanogestrel+0.03 mg ethinylestradiol (B) and 0.15 mg desogestrel+0.02 mg ethinylestradiol (C)). A group of ten mice was included in the study for a control group, which were not subject to drug administration. For each drug, a mean of the serum and liver paraoxonase activity and erythrocytes catalase and carbonic anhydrase activities were determined and compared to the control groups. While mouse liver PON activity showed a statistically significant decrease for all three drugs, serum PON activity increased. Erythrocytes catalase activity was significantly decreased by all contraceptives used. On the other hand, these contraceptives did not change the erythrocytes carbonic anhydrase activity.

Metabolic and clinical effects of progestogens

Synthetic progestogens differ not only in their hormonal potency, but also in their spectrum of hormonal activities. Beside their progestogenic and anti-oestrogenic effects, they may exert oestrogenic, androgenic, antiandrogenic, glucocorticoid and/or anti-mineralocorticoid activities. Consequently, progestogens may influence various metabolic parameters and modulate oestrogen-induced alterations in lipid metabolism, haemostasis, and various other factors. Progestogens with androgenic properties may counteract ethinyloestradiol (EE)-induced changes in lipoprotein metabolism, but do not cause atherosclerosis in the presence of EE. Oral contraceptives (OCs) containing androgenic progestogens which attenuate the EE-dependent changes in haemostasis, may be associated with a lower risk of venous thromboembolic disease than OCs whose progestogens have a less androgenic profile. Progestogens with androgenic activity may also antagonize oestrogen-induced alterations in various other hepatic proteins and modulate the effect of EE on growth factors. Progestogens with antiandrogenic activity may enhance the beneficial effect of EE in women with hyperandrogenic manifestations. Progestogens with glucocorticoid effects may increase procoagulatory activity in the vessel wall, while progestogens with anti-mineralocorticoid activity may reduce the aldosterone-induced water-retention in some women. For most women the differences in the hormonal pattern of progestogens used in OCs are without clinical relevance, but may be useful for women predisposed for the development of certain disorders.

The Cardiovascular Effects of Selective Estrogen Receptor Modulators

Coronary artery disease (CAD) is the main contributor of mortality among postmenopausal women. Menopause-associated estrogen deficiency has both metabolic and vascular consequences that increase the risk for CAD. Hormone therapy (HT) has been reported to have a beneficial effect on metabolic and vascular factors influencing the incidence of CAD. Although observational studies have reported that HT reduces significantly the risk for CAD, randomized clinical trials (WHI, HERS, ERA) have questioned the efficacy of HT in primary and secondary CAD prevention despite confirming the lipid-lowering effect of HT. In the aftermath of the WHI, increased interest has been given to the action of selective estrogen receptor modulators (SERMs) and their effect on the cardiovascular system. The chemical structure of SERMs, either triphenylethilyn (tamoxifen) or benzothiophene (raloxifene) derivatives, differs from that of estrogens. SERMs are nonsteroidal molecules that bind, with high affinity, to the ER. SERMs induce conformational changes to the ligand-binding domain of the ER that modulate the ability of the ER to interact with coregulator proteins. The relative balance of coregulators within a cell determines the transcriptional activity of the receptor-ligand complex. SERMs therefore may express an estrogen-agonist or estrogen-antagonist effect depending on the tissue targeted. SERMs express variable effects on the metabolic and vascular factors influencing the incidence of CAD. SERMs have been reported to modulate favorably the lipid-lipoprotein profile. Toremifene expresses the most beneficial effect followed by tamoxifene and raloxifene, while ospexifene and HMR-3339 have the least effect and may even increase triglycerides. Raloxifene and tamoxifene decrease serum homocysteine levels and C-reactive proteins (CRP), which are both markers of CAD risk. Raloxifene has been reported to increase the nitric oxide (NO)-endothelin (ET)-1 ratio and, thus, contribute to proper endothelial function and vasodilation. Toremifene has no effect on the NO-ET-1 ratio. Finally, raloxifene decreases the vascular cell adhesion molecules and the inflammatory cytokines TNF-alpha and IL-6. Of the SERMs, raloxifene has had the most extensive evaluation regarding the effect on the vascular wall of endothelium. Although not confirmed by large clinical trials, raloxifene has been reported to have an effect on the cohesion of the intercellular junction (VE-cadherin) and the synthesis-degradation of extracellular matrix (MMP-2). The Multiple Outcomes Raloxifene Evaluation (MORE) study has reported that raloxifene may have a cardioprotective effect when administered to postmenopausal women at high risk for CAD disease.

Differential effect of hormone therapy and tibolone on lipids, lipoproteins, and the atherogenic index of plasma

The aim of our study was to assess the effect of various regimens and doses of hormone therapy and tibolone on the Atherogenic Index of Plasma (AIP). A total of 519 postmenopausal women attending our menopause clinic were studied in a prospective design. Women with climacteric symptoms were randomly assigned to receive 1 of the following regimens: tibolone 2.5 mg, conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA), 17beta-estradiol 2 mg plus norethisterone acetate 1 mg (E2/NETA), or 17beta-estradiol 1 mg plus norethisterone acetate 0.5 mg (low E2/NETA). Serum parameters were assessed at baseline and after 6 months and included total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoprotein A1 and apolipoprotein B. The AIP was assessed as the log (triglycerides [mmol/L]/HDL-C [mmol/L]). CEE/MPA treatment associated with lower mean LDL-C but higher mean triglyceride levels (-15.5 mg/dL +/- 3.6, P = 0.0001; 12.6 mg/dL +/- 4.8, P = 0.01). Furthermore, CEE/MPA treatment resulted in higher AIP levels (0.073 +/- 0.021, P = 0.001). On the contrary, both E2/NETA regimens and tibolone associated with lower mean triglyceride and HDL-C levels (E2/NETA, triglycerides: -9.8 mg/dL +/- 5.0, P = 0.049; HDL-C: -4.9 mg/dL +/- 1.8, P = 0.01, low E2/NETA triglycerides: -12.5 mg/dL +/- 4.1, P = 0.003; HDL-C: -4.7 mg/dL +/- 1.3, P = 0.001; tibolone, triglycerides: -21.9 mg/dL +/- 2.7, P = 0.0001; HDL-C: -12.7 mg/dL +/- 1.1, P = 0.0001). None of the 3 regimens had any effect on AIP. The effect of a particular regimen of hormone therapy on the lipid-lipoprotein profile differs depending on the parameter assessed. The use of unified markers such as AIP will be helpful in evaluating the overall effect of lipid-lipoprotein modulation on the cardiovascular system. In fact, the concurrent assessment of the therapy effect on both LDL-C and AIP may be more dependable in evaluating the cardiovascular impact of a given regimen.

Chronic Treatment with Physiological Doses of Estradiol Affects the GH-IGF-1 Axis and Fat Metabolism in Young and Middle-aged Ovariectomized Rats

Estrogen deficiency may be partly responsible for the metabolic syndrome and the condition may be reversible with hormone replacement therapy. However, after the heart and estrogen/progestin replacement study and the women's health initiative study the prospect of HRT on CVD has changed dramatically. As the pituitary and the liver are targets for estrogen action we assessed the effect of ovariectomy (OVX) and long-term (3 months) estradiol (E2) treatment by means of subcutaneously (s.c.) implanted silastic capsules on pituitary and liver function in young and middle-aged female rats. Our results demonstrate that triglyceride serum levels increased, whereas insulin-like growth factor-1 (IGF-1), high density lipoprotein cholesterol (HDL), and glucose levels decreased during the transition from young to middle-age. E2 treatment increased dose-independently growth hormone (GH) secretion. IGF-1 levels were increased upon OVX in middle-aged rats and the high dose of E2 decreased IGF-1 concentrations in both age groups. Cholesterol concentrations increased after OVX and were attenuated by E2 administration in middle-aged rats. Both, low density lipoprotein cholesterol (LDL) and HDL levels raised after castration and both parameters decreased in response to E2 in young and middle-aged rats. Glucose serum concentrations decreased after E2 treatment in all animals. Taken together, our results clearly demonstrate that the pituitary and the liver metabolism of middle-aged rats remain susceptible to the influence of OVX and E2 treatment.

Transdermal Drug Delivery: Clinical Considerations for the Obstetrician–Gynecologist

INTRODUCTION

The first transdermal drug delivery system was introduced in the United States over 20 years ago. Created as an alternative route of administration to improve patient compliance as well as to reduce side effects, the transdermal delivery of drugs now represents a $1.5 to $2 billion market and is growing rapidly.

DATA SOURCES

The medical literature from 1980 to 2005 was searched using the PubMed search engine. The search term was "transdermal," limited to human clinical trials. Abstracts were used to identify clinical trials that compared transdermal preparations and their oral counterparts in the same study.

TABULATION, INTEGRATION, AND RESULTS

In this article, we review the rationale for the transdermal administration of drugs; discuss aspects of the anatomy and physiology of the skin relevant to drug transport; examine the qualities required for a drug to be a good candidate for transdermal delivery; and consider key principles for the evaluation of the relative benefits of transdermal delivery, using studies of hormone replacement therapy and oral contraceptive as examples.

CONCLUSION

The data reviewed here suggest that certain clinical situations support the use of the transdermal administration of drugs over their oral counterparts.