Vasoactive biomarkers and oxidative stress in healthy recently postmenopausal women treated with hormone replacement therapy

The Silent Threat to Women's Fertility: Uncovering the Devastating Effects of Oxidative Stress

Oxidative stress (OS), which arises through an imbalance between the formation of reactive oxygen species (ROS) and antioxidant defenses, plays a key role in the pathophysiology of female infertility, with the latter constituting just one of a number of diseases linked to OS as a potential cause. The aim of the present article is to review the literature regarding the association between OS and female infertility. Among the reproductive diseases considered are endometriosis and polycystic ovary syndrome (PCOS), while environmental pollutants, lifestyle variables, and underlying medical conditions possibly resulting in OS are additionally examined. Current evidence points to OS likely contributing to the pathophysiology of the above reproductive disorders, with the amount of damage done by OS being influenced by such variables as duration and severity of exposure and the individual's age and genetic predisposition. Also discussed are the processes via which OS may affect female fertility, these including DNA damage and mitochondrial dysfunction. Finally, the last section of the manuscript contains an evaluation of treatment options, including antioxidants and lifestyle modification, capable of minimizing OS in infertile women. The prime message underlined by this review is the importance of considering OS in the diagnosis and treatment of female infertility. Further studies are, nevertheless required to identify the best treatment regimen and its ideal duration.

Strategies to decrease oxidative stress biomarker levels in human medical conditions: A meta-analysis on 8-iso-prostaglandin F2α

The widespread detection of elevated oxidative stress levels in many medical conditions has led to numerous efforts to design interventions to reduce its effects. Efforts have been wide-ranging, from dietary changes to administration of antioxidants, supplements, e.g., omega-3-fatty acids, and many medications. However, there is still no systemic assessment of the efficacy of treatments for oxidative stress reduction across a variety of medical conditions. The goal of this meta-analysis is, by combining multiple studies, to quantitate the change in the levels of the popular oxidative stress biomarker 8-iso-prostaglandin F2α (8-iso-PGF2α) after a variety of treatment strategies in human populations. Nearly 350 unique publications with 180 distinct strategies were included in the analysis. For each strategy, the difference between pre- or placebo and post-treatment levels calculated using Hedges' g value of effect. In general, administration of antibiotics, antihyperlipidemic agents, or changes in lifestyle (g = - 0.63, - 0.54, and 0.56) had the largest effect. Administration of supplements, antioxidants, or changes in diet (g = - 0.09, - 0.28, - 0.12) had small quantitative effects. To fully interpret the effectiveness of these treatments, comparisons to the increase in g value for each medical condition is required. For example, antioxidants in populations with coronary artery disease (CAD) reduce the 8-iso-PGF2α levels by g = - 0.34 ± 0.1, which is quantitatively considered a small effect. However, CAD populations, in comparison to healthy populations, have an increase in 8-iso-PGF2α levels by g = 0.38 ± 0.04; therefore, the overall reduction of 8-iso-PGF2α levels is ≈ 90% by this treatment in this specific medical condition. In conclusion, 8-iso-PGF2α levels can be reduced not only by antioxidants but by many other strategies. Not all strategies are equally effective at reducing 8-iso-PGF2α levels. In addition, the effectiveness of any strategy can be assessed only in relation to the medical condition investigated.

The effects of progesterones on blood lipids in hormone replacement therapy

The safety of progestogens as a class has drawn much attention after the publication of data from the Women’s Health Initiative (WHI) trial, particularly with respect to cardiovascular disease. Depending on the chemical structure, pharmacokinetics, receptor affinity and potency of action, progestogens have a divergent range of properties that may translate to very different clinical effects. The purpose of this review is to describe the role of varied progestogens in hormone replacement therapy (HRT), especially focusing on blood lipids, which are the most important parameters for assessing cardiovascular disease risk.

Oxidative Stress and Low-Grade Inflammatory Status as Cardiometabolic Risk Factors in Italian Occupational Overweight/Obese Subjects

Obesity is associated with increased risk of cardiometabolic diseases. Adipocytokines (e.g. leptin), produced by the endocrine function of adipose tissue, can contribute to cardiometabolic risk in overweight and obese people. Oxidative stress, imbalance between oxidants and antioxidants, is considered a cardiovascular risk factor. High serum oxidized LDL (oxLDL) levels, marker of lipid peroxidation, a primary cause of atherosclerosis, can contribute to its progression. The aims of this study are to assess markers of oxidative status and cytokine profile and evaluate their role as cardiometabolic risk factors and possible correlations. In this cross-sectional study, we enrolled 76 occupational overweight-obese adults (46 females, 30 males; aged 46.8±9.5; BMI 33.7±4.8 kg/m2) without any previous cardiovascular disease. Oxidative status was measured by evaluating serum Reactive Oxygen Species (ROS) levels, Total Antioxidant Capacity (TAC) and oxLDL concentrations. All subjects' soluble cytokine and adhesion molecule levels were evaluated by cytofluorimetric method and compared with 35 controls matched for sex and age. ROS and oxLDL levels were high in 84% and 92% of the study population, respectively, despite adequate TAC (68%). Female ROS levels were significantly higher than those of males (414±99.3 vs 318±48.2 UCarr, p<0.0001), while their oxLDL levels were lower (95.3±22 vs 105.2±19.4 U/L, p=0.1). Leptin and sICAM-1 (intracellular adhesion molecule involved in leukocyte migration to inflamed area) levels of the study population were significantly higher than those of controls (93.8±89.1 vs 25.3±23 ng/mL, p=0.0002 and 505.8±236.7 vs 339.2±119.6 ng/mL, p=0.0009, respectively). Overweight/obese occupational subjects showed oxidative stress conditions accompanied by low chronic inflammatory status, possibly contributing to increased cardiometabolic risk.

The role of oxidative stress in menopause

This review will discuss the concept of reproductive aging, which includes the definition of menopause, its symptoms, and predisposing conditions. It will elaborate upon the contributory factors implicated in the pathogenesis of menopause, focusing most prominently on oxidative stress. Specifically, this paper will explain how oxidative stress, in the form of free radicals and antioxidant deficiencies, has been directly linked to the decline of estrogen during reproductive aging. Additionally, this paper will elaborate upon the treatment options aimed at mitigating the menopausal symptoms and hormonal deficiencies that can lead to various disease processes. Treatment options such as hormonal therapy, antioxidant supplementation, and lifestyle modification have been explored for their effectiveness in treating and preventing the symptoms and sequelae of menopause. The majority of information in this review was obtained through PubMed and the National Library of Medicine. While most references in this paper are original research articles, a limited number of references are comprehensive reviews on the topic.

Determinants of oxidative stress related to gender: relevance of age and smoking habit

BACKGROUND

Magnitude and major causes of oxidative stress may be different between sexes, although limitedly addressed in clinical studies with controversial results. The present study aimed to determine whether any gender-related difference exists concerning oxidative stress in a population of 332 subjects of both sexes, in a wide age range, with and without cigarette smoking habit.

METHODS

The Oxidative-INDEX was calculated after evaluation of serum hydroperoxides (ROMs) and total antioxidant capacity (OXY) by means of commercial kits (d-ROMs and Oxy-adsorbent Tests, Diacron, Italy) subtracting the OXY standardized variable from the ROMs standardized variable.

RESULTS

The Oxidative-INDEX resulted higher in women with respect to men (p<0.001), in smokers (p<0.01) than in non-smokers, and correlated with cigarette number (p<0.01), age (p<0.001), and post-menopausal status (p<0.001). The multivariate analysis identified age, high blood pressure, and smoking habit as factors independently associated with the Oxidative-INDEX in men, whereas cigarette smoking and age represented the independent risk factors for an elevated oxidative stress status in women.

CONCLUSIONS

Gender-based differences in oxidative stress levels may provide a biochemical basis for the epidemiologic differences in the disease susceptibility between sexes, and suggest different strategies for risk assessment, diagnosis, and treatment specifically targeted to men and women.

Gender differences in cardiovascular disease: hormonal and biochemical influences

OBJECTIVE

Atherosclerosis is a complex process characterized by an increase in vascular wall thickness owing to the accumulation of cells and extracellular matrix between the endothelium and the smooth muscle cell wall. There is evidence that females are at lower risk of developing cardiovascular disease (CVD) as compared to males. This has led to an interest in examining the contribution of genetic background and sex hormones to the development of CVD. The objective of this review is to provide an overview of factors, including those related to gender, that influence CVD.

METHODS

Evidence analysis from PubMed and individual searches concerning biochemical and endocrine influences and gender differences, which affect the origin and development of CVD.

RESULTS

Although still controversial, evidence suggests that hormones including estradiol and androgens are responsible for subtle cardiovascular changes long before the development of overt atherosclerosis.

CONCLUSION

Exposure to sex hormones throughout an individual's lifespan modulates many endocrine factors involved in atherosclerosis.

Oxidative status and cardiovascular risk in women: Keeping pink at heart

Although cardiovascular disease (CVD) has always been perceived as a pathology regarding essentially males, incidence and death from cardiovascular events dramatically increase after menopause in women. Obviously, while many aspects of CVD are similar in both sexes, it is now clear that there are significant differences as well. Exploration of these gender-related differences in CVD might provide a basis for the development of new strategies in the management of patients with CVD from a gender point of view. In particular, a growing amount of data suggested the possible major role of oxidative stress in female patients and the possibility to integrate this new biomarker in future study evaluating CVD risk in women.

Oxidative imbalance in HIV-1 infected patients treated with antiretroviral therapy

It is generally accepted that oxidative stress is involved in HIV infection. However, the role in oxidative balance of Highly Active Antiretroviral Therapy (HAART) is still debated. In our study we assessed serum oxidant and antioxidant levels in an HIV-1-infected population treated with HAART, and compared them with those of untreated HIV-1 patients and HIV-1-negative subjects. The study included 116 HIV-1-infected patients (86 HAART-treated and 30 untreated), and 46 HIV-negative controls. Serum oxidant levels were significantly higher in the HIV-1 treated group as compared to untreated and control groups. In addition, a decrease of serum total antioxidant status was observed in the HIV-1 treated group. To be noted is that patients who rigorously follow antiretroviral therapy (optimal HAART adherence) have significantly higher oxidative status than those who do not closely follow the therapy (poor HAART adherence). Analysis of variance revealed no significant further increase in oxidative status in HIV-1-infected patients taking antiretroviral and other drugs with the exception of psychiatric drugs (e.g. anxiolytics or antidepressants). Taken together, our results indicate that HAART may affect oxidative stress in HIV-1-infected patients and suggest that antiretroviral therapy plays an important role in the synergy of HIV infection and oxidative stress.

Transdermal estradiol reduces F2alpha-isoprostane levels in postmenopausal women

OBJECTIVE

F2alpha-isoprostanes are considered the most reliable index of in vivo oxidative stress. Given the implication of oxidative stress in the pathogenesis of atherosclerosis, we investigated the effects of hormone therapy on the plasma levels of F2alpha-isoprostanes.

DESIGN

Sixty-one healthy postmenopausal women were treated in a randomized trial with estradiol either orally (2 mg/day, 28 women) or transdermally (50 mug/day, 33 women) for 4 weeks. Then women in each group were randomly assigned to oral progestogen, either micronized progesterone (300 mg/day) or medroxyprogesterone acetate (5 mg/day) for 2 additional weeks. Plasma samples were collected before and at the end of each treatment period, either estradiol alone or estradiol plus progestogen. F2alpha-isoprostanes were measured by a commercial enzyme immunoassay.

RESULTS

A significant reduction in the levels of F2alpha-isoprostanes was detected only in women receiving transdermal estradiol, alone or in combination with medroxyprogesterone acetate.

CONCLUSIONS

Transdermal estradiol alone or associated with medroxyprogesterone acetate decreased plasma levels of F2alpha-isoprostanes. These data elucidate additional details of the beneficial effect of estradiol on oxidative stress, a relevant mechanism in atherogenesis.

Sex differences in control of blood pressure: role of oxidative stress in hypertension in females

In general, blood pressure is higher in normotensive men than in age-matched women, and the prevalence of hypertension in men is also higher until after menopause, when the prevalence of hypertension increases for women. It is likely then that the mechanisms by which blood pressure increases in men and women with aging may be different. Although clinical trials to reduce blood pressure with antioxidants have typically not been successful in human cohorts, studies in male rats suggest that oxidative stress plays an important role in mediating hypertension. The exact mechanisms by which oxidative stress increases blood pressure have not been completely elucidated. There may be several reasons for the discrepancies between clinical and animal studies. In this review, the data obtained in selected clinical and animal studies are discussed, and the hypothesis is put forward that oxidative stress may not be as important in mediating hypertension in females as has been shown previously in male rats. Furthermore, it is likely that differences in genetics, age, length of time with hypertension, endothelial dysfunction, and sex are all factored in to modulate the responses to antioxidants in humans. As such, future clinical trials should be designed and powered to evaluate the effects of oxidative stress on blood pressure separately in men and women.

Gender-related differences in oxidative stress levels among elderly patients with coronary artery disease

OBJECTIVE

To evaluate whether gender-related differences exist concerning oxidative stress levels in aged patients with coronary artery disease (CAD).

DESIGN

Case-control.

SETTING

Clinical and research center.

PATIENT(S)

Elderly subjects of both genders with or without CAD.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serum hydroperoxides (HP) as index of oxidative stress levels.

RESULT(S)

The HP levels were comparable in aged control subjects of both genders (376 +/- 20 arbitrary units [AU] in women, 333 +/- 19 AU in men) but significantly increased in CAD (456 +/- 15 AU) compared with all control subjects (357 +/- 14 AU). Moreover, among CAD patients, the HP levels were higher in women than in men (536 +/- 33 AU and 428 +/- 15 AU, respectively). Multivariate analysis, in which CAD represented the dependent variable, indicated that dyslipidemia was independently associated with CAD in men (odds ratio [OR] 5.8), whereas HP >50th percentile represented the only strong independent risk factor for CAD in elderly women (OR 8.4).

CONCLUSION(S)

Differences in oxidative stress levels between elderly males and females might provide a biochemical basis for the epidemiologic differences in CAD, which might help to open new opportunities in the management of patients with cardiovascular disease from a gender point of view.