Nebivolol decreases oxidative stress in essential hypertensive patients and increases nitric oxide by reducing its oxidative inactivation

The Dual Role of Oxidative Stress in Atherosclerosis and Coronary Artery Disease: Pathological Mechanisms and Diagnostic Potential

Oxidative stress plays a pivotal role in the pathogenesis of atherosclerosis and coronary artery disease (CAD), with both beneficial and detrimental effects on cardiovascular health. On one hand, the excessive production of reactive oxygen species (ROS) contributes to endothelial dysfunction, inflammation, and vascular remodeling, which are central to the development and progression of CAD. These pathological effects drive key processes such as atherosclerosis, plaque formation, and thrombosis. On the other hand, moderate levels of oxidative stress can have beneficial effects on cardiovascular health. These include regulating vascular tone by promoting blood vessel dilation, supporting endothelial function through nitric oxide production, and enhancing the immune response to prevent infections. Additionally, oxidative stress can stimulate cellular adaptation to stress, promote cell survival, and encourage angiogenesis, which helps form new blood vessels to improve blood flow. Oxidative stress also holds promise as a source of biomarkers that could aid in the diagnosis, prognosis, and monitoring of CAD. Specific oxidative markers, such as malondialdehyde (MDA), isoprostanes (isoP), ischemia-modified albumin, and antioxidant enzyme activity, have been identified as potential indicators of disease severity and therapeutic response. This review explores the dual nature of oxidative stress in atherosclerosis and CAD, examining its mechanisms in disease pathogenesis as well as its emerging role in clinical diagnostics and targeted therapies. The future directions for research aimed at harnessing the diagnostic and therapeutic potential of oxidative stress biomarkers are also discussed. Understanding the balance between the detrimental and beneficial effects of oxidative stress could lead to innovative approaches in the prevention and management of CAD.

Effect of nebivolol monotherapy or combination therapy on blood pressure levels in patients with hypertension: an updated systematic review and multilevel meta-analysis of 91 randomized controlled trials

AIMS

To systematically appraise and summarize the available evidence from published randomized controlled trials considering the effect of nebivolol on blood pressure in patients with hypertension.

METHODS

Literature search was performed through Medline (via PubMed), Cochrane Library and Scopus until December 15, 2023. Double-independent study selection, data extraction and quality assessment were performed. Evidence was pooled with three-level mixed-effects meta-analysis.

RESULTS

In total, 7,737 participants with hypertension, who were treated with nebivolol, were analyzed across 91 RCTs. Nebivolol was associated with significantly greater reduction in office systolic and diastolic BP compared to placebo (MD = - 6.01 mmHg; 95% CI = [- 7.46, - 4.55] and MD = - 5.01 mmHg; 95% CI = [- 5.91, - 4.11], respectively). Moreover, resulted a similar reduction in systolic BP (MD = - 0.22 mmHg; 95% CI = [- 0.91, 0.46]) and a significantly greater reduction in diastolic BP compared to the active comparator (MD = - 0.71 mmHg; 95% CI = [- 1.27, - 0.16]). When considering the effect of nebivolol on 24-hour ambulatory BP, notable reductions were observed compared to placebo. In contrast, compared to the active comparators, there was no significant difference in systolic BP reduction, but a significant reduction in diastolic BP favoring nebivolol. Based on moderator analyses, the impact of nebivolol on the pooled estimates remained independent of the dose of nebivolol, age, male sex, trial duration, body mass index (BMI), baseline diabetes, heart failure, and baseline systolic and diastolic BP.

CONCLUSION

Nebivolol, compared to placebo, showed a significant BP reduction and was non-inferior to other active comparators in terms of BP reduction.

The effects of antihypertensive drugs on glucose metabolism

Abnormal glucose metabolism is a common disease of the endocrine system. The effects of drugs on glucose metabolism have been reported frequently in recent years, and since abnormal glucose metabolism increases the risk of microvascular and macrovascular complications, metabolic disorders, and infection, clinicians need to pay close attention to these effects. A variety of common drugs can affect glucose metabolism and have different mechanisms of action. Hypertension is a common chronic cardiovascular disease that requires long-term medication. Studies have shown that various antihypertensive drugs also have an impact on glucose metabolism. Among them, α-receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and calcium channel blockers can improve insulin resistance, while β-receptor blockers, thiazides and loop diuretics can impair glucose metabolism. The aim of this review was to discuss the mechanisms underlying the effects of various antihypertensive drugs on glucose metabolism in order to provide reference information for rational clinical drug use.

Nanotechnology Approaches for Prevention and Treatment of Chemotherapy-Induced Neurotoxicity, Neuropathy, and Cardiomyopathy in Breast and Ovarian Cancer Survivors

Nanotechnology has emerged as a promising approach for the targeted delivery of therapeutic agents while improving their efficacy and safety. As a result, nanomaterial development for the selective targeting of cancers, with the possibility of treating off-target, detrimental sequelae caused by chemotherapy, is an important area of research. Breast and ovarian cancer are among the most common cancer types in women, and chemotherapy is an essential treatment modality for these diseases. However, chemotherapy-induced neurotoxicity, neuropathy, and cardiomyopathy are common side effects that can affect breast and ovarian cancer survivors quality of life. Therefore, there is an urgent need to develop effective prevention and treatment strategies for these adverse effects. Nanoparticles (NPs) have extreme potential for enhancing therapeutic efficacy but require continued research to elucidate beneficial interventions for women cancer survivors. In short, nanotechnology-based approaches have emerged as promising strategies for preventing and treating chemotherapy-induced neurotoxicity, neuropathy, and cardiomyopathy. NP-based drug delivery systems and therapeutics have shown potential for reducing the side effects of chemotherapeutics while improving drug efficacy. In this article, the latest nanotechnology approaches and their potential for the prevention and treatment of chemotherapy-induced neurotoxicity, neuropathy, and cardiomyopathy in breast and ovarian cancer survivors are discussed.

Protective effect of nebivolol on rat ovary exposed to deltamethrin toxicity

PURPOSE

We aimed to investigate the antioxidant activity of nebivolol against possible damage to the ovarian tissue due to the application of deltamethrin as a toxic agent, by evaluating histopathological proliferating cell nuclear antigen (PCNA) and tumor necrosis factor-alpha (TNF-α) signal molecules immunohistochemically.

METHODS

The animals were divided into three groups as control, deltamethrin and deltamethrin + nebivolol groups. Vaginal smears were taken after the animals were mated and detected on the first day of pregnancy. After the sixth day, deltamethrin (0.5 mL of 30 mg/kg BW undiluted ULV), and 2 mL of sterile nebivolol solution were administered intraperitoneally every day for 6-21 periods. After routine histopathological follow-up, the ovarian tissue was stained with hematoxylin and eosin stain.

RESULTS

Control group showed normal histology of ovarium. In deltamethrin group, hyperplasic cells, degenerative follicles, pyknotic nuclei, inflammation and hemorrhagic areas were observed. Nebivolol treatment restored these pathologies. Deltamethrin treatment increased TNF-α and PCNA reaction. However, nebivolol decreased the expression.

CONCLUSIONS

It was thought that deltamethrin toxicity adversely affected follicle development by inducing degeneration and apoptotic process in preantral and antra follicle cells, and nebivolol administration might reduce inflammation and slow down the apoptotic signal in the nuclear phase and regulate reorganization.

Endothelial dysfunction, platelet hyperactivity, hypertension, and the metabolic syndrome: molecular insights and combating strategies

Metabolic syndrome (MetS) is a multifaceted condition that increases the possibility of developing atherosclerotic cardiovascular disease. MetS includes obesity, hypertension, dyslipidemia, hyperglycemia, endothelial dysfunction, and platelet hyperactivity. There is a concerning rise in the occurrence and frequency of MetS globally. The rising incidence and severity of MetS need a proactive, multipronged strategy for identifying and treating those affected. For many MetS patients, achieving recommended goals for healthy fat intake, blood pressure control, and blood glucose management may require a combination of medicine therapy, lifestyles, nutraceuticals, and others. However, it is essential to note that lifestyle modification should be the first-line therapy for MetS. In addition, MetS requires pharmacological, nutraceutical, or other interventions. This review aimed to bring together the etiology, molecular mechanisms, and dietary strategies to combat hypertension, endothelial dysfunction, and platelet dysfunction in individuals with MetS.

Cardioprotective Strategies from Cardiotoxicity in Cancer Patients: A Comprehensive Review

Cardiotoxicity is a significant complication of chemotherapeutic agents in cancer patients. Cardiovascular incidents including LV dysfunction, heart failure (HF), severe arrhythmias, arterial hypertension, and death are associated with high morbidity and mortality. Risk stratification of cancer patients prior to initiation of chemotherapy is crucial, especially in high-risk patients for cardiotoxicity. The early identification and management of potential risk factors for cardiovascular side effects seems to contribute to the prevention or minimization of cardiotoxicity. Screening of cancer patients includes biomarkers such as cTnI and natriuretic peptide and imaging measurements such as LV function, global longitudinal strain, and cardiac MRI. Cardioprotective strategies have been investigated over the last two decades. These strategies for either primary or secondary prevention include medical therapy such as ACE inhibitors, ARBs, b-blockers, aldosterone antagonists, statins and dexrazoxane, physical therapy, and reduction of chemotherapeutic dosages. However, data regarding dosages, duration of medical therapy, and potential interactions with chemotherapeutic agents are still limited. Collaboration among oncologists, cardiologists, and cardio-oncologists could establish management cardioprotective strategies and approved follow-up protocols in patients with cancer receiving chemotherapy.

Nebivolol for the Treatment of Essential Systemic Arterial Hypertension: A Systematic Review and Meta-Analysis

INTRODUCTION

Cardiovascular diseases are the main cause of mortality worldwide, and systemic arterial hypertension is associated with a large number of these cases. The objective of health professionals and health policies should be searching for the best therapeutics to control this disease. A recent consensus indicated that β-blockers have recently lost their place in initial indications for the treatment of systemic arterial hypertension and are now more indicated for the treatment of hypertension in association with other clinical situations such as angina, heart failure and arrhythmia; however, it is known that this approach was based on studies that evaluated older β-blockers such as atenolol.

OBJECTIVE

The main objective of this study was to perform a systematic review with subsequent meta-analysis on the use of nebivolol for hypertensive disease treatment, comparing it with drugs of the main antihypertensive classes.

METHODS

This systematic review was based on a search of the MEDLINE (via Pubmed), Scopus, Cochrane, International Pharmaceuticals Abstracts (IPA), and Lilacs databases for randomized and double-blind clinical trials. In addition, we also searched for gray literature studies, to 31 July 2015. Next, a cumulative meta-analysis was performed, with studies being added in a sequential manner, evaluating their impact on the combined effect. For this project, we only meta-analyzed direct comparisons of random effect.

RESULTS

Overall, 981 clinical trials were included in this systematic review. After careful analysis, 34 randomized and double-blind clinical trials were included to investigate the efficacy of nebivolol on systolic (SBP) and diastolic blood pressure (DBP) control and adverse effects. The study population comprised 12,465 patients with systemic arterial hypertension (SAH) aged between 18 and 85 years; 17% of subjects were of Black ethnicity, approximately 55% were men, and almost 10% had diabetes. In SBP management, nebivolol was superior to other β-blockers and diuretics and showed no difference in efficacy when compared with angiotensin receptor blockers or calcium channel blockers. There were insufficient studies on angiotensin-converting enzyme inhibitors for adequate comparison of both SBP and DBP control. For DBP control, nebivolol was more efficient than other β-blockers, angiotensin receptor blockers, diuretics, and calcium channel blockers.

DISCUSSION

Nebivolol is a third-generation β-blocker with additional capabilities to improve blood pressure levels in patients with arterial hypertension, because it acts by additional mechanisms such as endothelium-dependent vasodilation associated with L-arginine and oxide nitric acid, nitric oxide activity on smooth muscle cells, decreasing platelet aggregation, and leukocyte adhesion in the endothelium, decreasing oxidative stress. Although nebivolol has shown good results in controlling hypertension in this study (with few adverse events when compared with placebo treatment) and has an unquestionable benefit in individuals with heart failure (mainly with reduced ejection fraction), there is a lack of studies proving the benefit of this drug for controlling hypertension and reducing clinical outcomes such as cardiovascular (or general) mortality, acute myocardial infarction, or stroke.

CONCLUSIONS

Nebivolol demonstrated at least similar control of blood pressure levels in hypertensive individuals when compared with drugs of the most used classes. In addition, in relation to the control of arterial hypertension, studies with clinical outcomes should be performed to ensure the use of this drug in detriment to others with these well-established results.

Molecules and Mechanisms to Overcome Oxidative Stress Inducing Cardiovascular Disease in Cancer Patients

Reactive oxygen species (ROS) are molecules involved in signal transduction pathways with both beneficial and detrimental effects on human cells. ROS are generated by many cellular processes including mitochondrial respiration, metabolism and enzymatic activities. In physiological conditions, ROS levels are well-balanced by antioxidative detoxification systems. In contrast, in pathological conditions such as cardiovascular, neurological and cancer diseases, ROS production exceeds the antioxidative detoxification capacity of cells, leading to cellular damages and death. In this review, we will first describe the biology and mechanisms of ROS mediated oxidative stress in cardiovascular disease. Second, we will review the role of oxidative stress mediated by oncological treatments in inducing cardiovascular disease. Lastly, we will discuss the strategies that potentially counteract the oxidative stress in order to fight the onset and progression of cardiovascular disease, including that induced by oncological treatments.

Effects of nebivolol versus other antihypertensive drugs on the endothelial dysfunction in patients with essential hypertension

We aim to determine whether nebivolol has a better effect on endothelial dysfunction compared with other β-blockers or other classes of antihypertensive drugs. Searches of the PubMed, Embase etc. were performed to analyze all the randomized controlled trials using nebivolol to treat essential hypertension. The primary end points included a measurement of peripheral endothelial function by brachial flow mediated vasodilatation (FMD) or forearm blood flow (FBF). A random-effect model was used to perform the meta-analysis when the studies showed significant heterogeneity, otherwise a descriptive analysis was conducted. Ten studies (689 patients) were included in qualitative analysis, four of which were included in quantitative synthesis. Meta-analysis showed that the changed FMD value before and after treatment with nebivolol was not statistically different from those treated with other β-blockers [mean difference = 1.12, 95% confidence interval (CI): −0.56, 2.81, P=0.19]. Descriptive analysis indicated that nebivolol did not have a better endothelium-protective effect than other classes of antihypertensive drugs including olmesartan and perindopril. Nebivolol is not a unique endothelial function-protective agent distinguished from other β-blockers or other classes of antihypertensive drugs. Reversal of endothelial dysfunction is a key point in the prevention and therapy of essential hypertension.

Strategies to Prevent Cardiotoxicity

OPINION STATEMENT

Cardiovascular disease is a leading cause of death among cancer survivors. While the field of cardiology as a whole is driven by evidence generated through robust clinical trials, data in cardio-oncology is limited to a relatively small number of prospective clinical trials with heterogeneous groups of cancer patients. In addition, many pharmaceutical trials in oncology are flawed from a cardiovascular perspective because they exclude patients with significant cardiovascular (CV) history and have wide variation in the definitions of CV events and cardiotoxicity. Ultimately, oncology trials often underrepresent the possibility of cardiovascular events in a "real world" population. Thus, the signal for CV toxicity from a cancer treatment is often not manifested until phase IV studies; where we are often caught trying to mitigate the CV effects rather than preventing them. Most of the data about cardiotoxicity from cancer therapy and cardioprotective strategies has been developed from our experience in using anthracyclines for over 50 years with dramatic improvement in cancer survivorship. However, as we are in an era where cancer drug discovery is moving at lightning pace with increasing survival rates, it is imperative to move beyond anthracyclines and commit to research on the cardiovascular side effects of all aspects of cancer therapy with a focus on prevention. We emphasize the role of pre-cancer treatment CV assessment to anticipate cardiac issues and ultimately optimizing CV risk prior to cancer therapy as an opportunity to mitigate cardiovascular risk from cancer therapy.

Pharmacogenetic Implications of eNOS Polymorphisms (Glu298Asp, T786C, 4b/4a) in Cardiovascular Drug Therapy

Endothelial nitric oxide synthase (NOS3 or eNOS) is the enzyme responsible for the highest production of nitric oxide, with the greatest impact on the cardiovascular system, encoded by the eNOS gene, which presents various polymorphisms. ENOS gene polymorphisms play an important role in the response to drugs affecting nitric oxide (NO) signaling. This review discusses the pharmacogenetic impact of eNOS polymorphisms on the response to drugs affecting NO activity: angiotensin converting enzyme inhibitors, angiotensin II receptor antagonists, calcium blockers, beta-blockers, diuretics, phosphodiesterase inhibitors, and statins. The identification of biomarkers that accurately predict particular phenotypes is a challenge that needs additional large studies, in different populations. Efforts should be oriented towards a more accurate evaluation of the effects of eNOS genetic variants on biochemical parameters reflecting eNOS gene expression and enzymatic activity, in different diseases, as well as following drug treatment. This approach will allow for a better understanding of the role of eNOS genetic variants in cardiovascular disease progression and for cardiovascular drug therapy optimization.

NFkappaB is a Key Player in the Crosstalk between Inflammation and Cardiovascular Diseases

Inflammation is a key mechanism of cardiovascular diseases. It is an essential component of atherosclerosis and a significant risk factor for the development of cardiovascular events. In the crosstalk between inflammation and cardiovascular diseases, the transcription factor NFκB seems to be a key player since it is involved in the development and progression of both inflammation and cardiac and vascular damage. In this review, we deal with the recent findings of the role of inflammation in cardiac diseases, focusing, in particular, on NFκB as a functional link. We describe strategies for the therapeutic targeting of NFκB as a potential strategy for the failing heart.

The Antioxidant Therapy: New Insights in the Treatment of Hypertension

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a key role in the regulation of the physiological and pathological signaling within the vasculature. In physiological conditions, a delicate balance between oxidants and antioxidants protects cells from the detrimental effects of ROS/RNS. Indeed, the imbalance between ROS/RNS production and antioxidant defense mechanisms leads to oxidative and nitrosative stress within the cell. These processes promote the vascular damage observed in chronic conditions, such as hypertension. The strong implication of ROS/RNS in the etiology of hypertension suggest that antioxidants could be effective in the treatment of this pathology. Indeed, in animal models of hypertension, the overexpression of antioxidants and the genetic modulation of oxidant systems have provided an encouraging proof of concept. Nevertheless, the translation of these strategies to human disease did not reach the expected success. This could be due to the complexity of this condition, whose etiology depends on multiple factors (smoking, diet, life styles, genetics, family history, comorbidities). Indeed, 95% of reported high blood pressure cases are deemed "essential hypertension," and at the molecular level, oxidative stress seems to be a common feature of hypertensive states. In this scenario, new therapies are emerging that could be useful to reduce oxidative stress in hypertension. It is now ascertained the role of Vitamin D deficiency in the development of essential hypertension and it has been shown that an appropriate high dose of Vitamin D significantly reduces blood pressure in hypertensive cohorts with vitamin D deficiency. Moreover, new drugs are emerging which have both antihypertensive action and antioxidant properties, such as celiprolol, carvedilol, nebivolol. Indeed, besides adrenergic desensitization, these kind of drugs are able to interfere with ROS/RNS generation and/or signaling, and are therefore considered promising therapeutics in the management of hypertension. In the present review we have dealt with the effectiveness of the antioxidant therapy in the management of hypertension. In particular, we discuss about Vitamin D and anti-hypertensive drugs with antioxidant properties.

Protective effects of nebivolol from oxidative stress to prevent hypertension-related target organ damage

Hypertension is one of the leading risk factors for morbidity and mortality in patients with cardiovascular and cerebrovascular diseases and renal impairment. It also leads to target organ damage (TOD), which worsens organ function and the patient's clinical status. Reactive oxygen species (ROS)-mediated oxidative stress may contribute significantly to TOD in patients with hypertension. NO (nitric oxide) is a paracrine factor derived from endothelial cells that has been shown to alleviate ROS-mediated oxidative damage. Nebivolol is a third-generation β-blocker with vasodilator activity, both actions contributing to decreased blood pressure in hypertensive patients. Its vasodilatory function is mediated by the endothelial l-arginine NO pathway. Nebivolol increases the bioavailability of NO in the vasculature. Its efficacy and safety profile is comparable to other commonly used antihypertensive agents. In this article, we review the current literature to understand TOD secondary to oxidative stress in patients with hypertension and the role of nebivolol in its prevention. A better understanding of the underlying mechanisms by which nebivolol reduces ROS-mediated TOD will not only help in the development of targeted therapies but may also improve health outcomes in hypertensive patients.

Heart Rate reduction by IVabradine for improvement of ENDothELial function in patients with coronary artery disease: the RIVENDEL study

AIMS

Data from experimental studies suggest that the _f current-inhibitor ivabradine may reduce oxidative stress and improve endothelial function. We aimed to evaluate the effect of ivabradine on endothelial function in patients with coronary artery disease (CAD) after complete revascularization with percutaneous coronary angioplasty (PCI).

METHODS AND RESULTS

At least 30 days after PCI, 70 patients were randomized (T0) to receive ivabradine 5 mg twice daily (ivabradine group, n = 36) or to continue with standard medical therapy (control group, n = 34). After 4 weeks (T1), ivabradine dose was adjusted up to 7.5 mg twice daily in patients with heart rate (HR) at rest >60 bpm, and thereafter continued for additional 4 weeks (T2). At all timings, brachial artery reactivity was assessed by flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD). No significant differences were observed at T0 between ivabradine and control groups in terms of HR (68.0 ± 6.4 vs. 67.6 ± 6.4 bpm; p = 0.803), FMD (8.7 ± 4.9 vs. 8.0 ± 5.5 %; p = 0.577) and NMD (12.7 ± 6.7 vs. 13.3 ± 6.2 %; p = 0.715). Over the study period, a significant reduction of HR (65.2 ± 5.9 bpm at T1, 62.2 ± 5.7 bpm at T2; p < 0.001), and improvement of FMD (12.2 ± 6.2 % at T1, 15.0 ± 7.7 % at T2; p < 0.001) and NMD (16.6 ± 10.4 % at T1, 17.7 ± 10.8 at T2; p < 0.001) were observed in the ivabradine group, while no significant changes were observed in the control group. In the ivabradine group, a moderate negative correlation was observed between the HR variation and FMD variation from T1 to T3 (r = -0.448; p = 0.006).

CONCLUSIONS

In patients with CAD undergoing complete revascularization with PCI, addition of ivabradine to the standard medical therapy produces a significant improvement in endothelial function. This effect seems to be related to HR reduction. ClinicalTrials.gov number, NCT02681978.

Chronic Nebivolol Treatment Suppresses Endothelin-1-Mediated Vasoconstrictor Tone in Adults With Elevated Blood Pressure

Endothelin-1 (ET-1) plays a major role in the pathophysiology of hypertension and its associated cardiovascular risk. We tested the hypothesis that chronic nebivolol treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure (BP). Furthermore, reducing ET-1 vasoconstrictor activity contributes to the improvement in endothelial vasodilator function associated with nebivolol treatment. Forty-two middle-aged adults with elevated BP (systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg) completed a 3-month, double-blind, randomized, placebo controlled trial: 14 received nebivolol (8 men/6 women; 5 mg per day); 14 received metoprolol succinate (9 men/5 women; 100 mg per day); and 14 received placebo (9 men/5 women). Forearm blood flow (plethysmography) responses to selective (BQ-123: 100 nmol/min; 60 minutes) and nonselective (BQ-123+BQ-788 [50 nmol/min]; 60 minutes) ET-1 receptor blockade, as well as acetylcholine (4.0, 8.0, and 16.0 μg per 100 mL of tissue per minute) in the absence and presence of nonselective ET-1 receptor blockade were determined before and after each treatment intervention. Forearm blood flow responses to BQ-123 and BQ-123+BQ-788 were similarly and significantly elevated (≈30% and 60%, respectively) from baseline in all 3 groups. Nebivolol, but not metoprolol or placebo, therapy resulted in a marked (≈25% and 45%; P<0.05) reduction in forearm blood flow response to BQ-123 and BQ-123+BQ-788. Moreover, after nebivolol therapy only, vasodilator response to acetylcholine was not significantly increased by ET-1 receptor blockade. These results demonstrate that nebivolol, but not metoprolol, treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated BP. In addition, nebivolol-induced reduction in ET-1-mediated vasoconstrictor tone underlies the favorable effects of this β-blocker on endothelial vasodilation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01395329.

Nitric Oxide Contributes to Vasomotor Tone in Hypertensive African Americans Treated With Nebivolol and Metoprolol

Endothelial dysfunction is more prevalent in African Americans (AAs) compared with whites. The authors hypothesized that nebivolol, a selective β1 -antagonist that stimulates nitric oxide (NO), will improve endothelial function in AAs with hypertension when compared with metoprolol. In a double-blind, randomized, crossover study, 19 AA hypertensive patients were randomized to a 12-week treatment period with either nebivolol 10 mg or metoprolol succinate 100 mg daily. Forearm blood flow (FBF) was measured using plethysmography at rest and after intra-arterial infusion of acetylcholine and sodium nitroprusside to estimate endothelium-dependent and independent vasodilation, respectively. Physiologic vasodilation was assessed during hand-grip exercise. Measurements were repeated after NO blockade with L-N(G) -monomethylarginine (L-NMMA) and after inhibition of endothelium-derived hyperpolarizing factor (EDHF) with tetraethylammonium chloride (TEA). NO blockade with L-NMMA produced a trend toward greater vasoconstriction during nebivolol compared with metoprolol treatment (21% vs 12% reduction in FBF, P=.06, respectively). This difference was more significant after combined administration of L-NMMA and TEA (P<.001). Similarly, there was a contribution of NO to exercise-induced vasodilation during nebivolol but not during metoprolol treatment. There were significantly greater contributions of NO and EDHF to resting vasodilator tone and of NO to exercise-induced vasodilation with nebivolol compared with metoprolol in AAs with hypertension.

Exploiting the Pleiotropic Antioxidant Effects of Established Drugs in Cardiovascular Disease

Cardiovascular disease is a leading cause of death and reduced quality of life worldwide. Arterial vessels are a primary target for endothelial dysfunction and atherosclerosis, which is accompanied or even driven by increased oxidative stress. Recent research in this field identified different sources of reactive oxygen and nitrogen species contributing to the pathogenesis of endothelial dysfunction. According to lessons from the past, improvement of endothelial function and prevention of cardiovascular disease by systemic, unspecific, oral antioxidant therapy are obviously too simplistic an approach. Source- and cell organelle-specific antioxidants as well as activators of intrinsic antioxidant defense systems might be more promising. Since basic research demonstrated the contribution of different inflammatory cells to vascular oxidative stress and clinical trials identified chronic inflammatory disorders as risk factors for cardiovascular events, atherosclerosis and cardiovascular disease are closely associated with inflammation. Therefore, modulation of the inflammatory response is a new and promising approach in the therapy of cardiovascular disease. Classical anti-inflammatory therapeutic compounds, but also established drugs with pleiotropic immunomodulatory abilities, demonstrated protective effects in various models of cardiovascular disease. However, results from ongoing clinical trials are needed to further evaluate the value of immunomodulation for the treatment of cardiovascular disease.

A Review of Nebivolol Pharmacology and Clinical Evidence

Nebivolol is a highly selective β1-adrenergic receptor antagonist with a pharmacologic profile that differs from those of other drugs in its class. In addition to cardioselectivity mediated via β1 receptor blockade, nebivolol induces nitric oxide-mediated vasodilation by stimulating endothelial nitric oxide synthase via β3 agonism. This vasodilatory mechanism is distinct from those of other vasodilatory β-blockers (carvedilol, labetalol), which are mediated via α-adrenergic receptor blockade. Nebivolol is approved for the treatment of hypertension in the US, and for hypertension and heart failure in Europe. While β-blockers are not recommended within the current US guidelines as first-line therapy for treatment of essential hypertension, nebivolol has shown comparable efficacy to currently recommended therapies in lowering peripheral blood pressure in adults with hypertension with a very low rate of side effects. Nebivolol also has beneficial effects on central blood pressure compared with other β-blockers. Clinical data also suggest that nebivolol may be useful in patients who have experienced erectile dysfunction while on other β-blockers. Here we review the pharmacological profile of nebivolol, the clinical evidence supporting its use in hypertension as monotherapy, add-on, and combination therapy, and the data demonstrating its positive effects on heart failure and endothelial dysfunction.

Influence of Different β-Blockers on Platelet Aggregation in Patients With Coronary Artery Disease on Dual Antiplatelet Therapy

INTRODUCTION

The use of β-blockers in the treatment of patients with coronary heart disease is associated with a decrease in the frequency of angina pectoris and mortality of patients. Due to the severity of the disease and previous cardiovascular interventions, many patients with coronary artery disease (CAD) use dual antiplatelet therapy to achieve greater inhibition of platelet aggregation. The influence of β-blockers on platelet aggregation in patients using antiplatelet therapy is not well understood.

OBJECTIVE

To examine the effect of different β-blockers on platelet aggregation in patients on dual antiplatelet therapy.

METHODOLOGY

The study included 331 patients who were treated at the Department of Cardiology, Clinical Center Kragujevac during 2011. Patients were divided into 4 groups depending on the type of β-blockers that were used (bisoprolol, nebivolol, metoprolol, and carvedilol). Platelet aggregation was measured using the multiplate analyzer and expressed through the value of adenosine diphosphate (ADP) test (to assess the effect of clopidogrel), ASPI test (to assess the effect of acetyl salicylic acid), TRAP test (to assess baseline platelet aggregation), and the ratio of ADP/TRAP and ASPI/TRAP ASPI/TRAP (ASPI - aranchidonic acid induced aggregation, TRAP - thrombin receptor activating peptide) representing the degree of inhibition of platelet aggregation compared to the basal value. In consideration were taken the representation of demographic, clinical characteristics, laboratory parameters, and cardiovascular medications between the groups.

RESULTS

Patients who used nebivolol had a significantly lower value of the ratio of ADP/TRAP (0.39 ± 0.30) compared to patients who used bisoprolol (0.48 ± 0.26; P = .038), and trend toward the lower values of ADP test (328.0 ± 197.3 vs 403.7 ± 213.2; P = .059), while there was no statistically significant difference in values of other laboratory parameters of platelet function between other groups.

CONCLUSION

Patients with CAD on dual antiplatelet therapy who used nebivolol had significantly lower levels of residual ADP-induced platelet aggregation compared to baseline than patients who used bisoprolol.

Differential effects of nebivolol and metoprolol on arterial stiffness, circulating progenitor cells, and oxidative stress

Unlike traditional beta receptor antagonists, nebivolol activates nitric oxide. We hypothesized that therapy with nebivolol compared with metoprolol would improve arterial stiffness, increase levels of circulating progenitor cells (PC), and decrease oxidative stress (OS). In a randomized, double-blind, cross-over study, 30 hypertensive subjects received either once daily nebivolol or metoprolol succinate for 3 months each. Pulse wave velocity and augmentation index were measured using tonometry. Flow cytometry was used to measure circulating PC. OS was measured as plasma aminothiols. Measurements were performed at baseline, and repeated at 3 and 6 months. No significant differences were present between the levels of OS, arterial stiffness, and PC numbers during treatment with metoprolol compared with nebivolol. In subgroup analyses of beta-blocker naïve subjects (n = 19), nebivolol reduced pulse wave velocity significantly compared with metoprolol (-1.4 ± 1.9 vs. -0.1 ± 2.2; P = .005). Both nebivolol and metoprolol increased circulating levels of CD34+/CD133 + PC similarly (P = .05), suggesting improved regenerative capacity.

Endothelial dysfunction in conduit arteries and in microcirculation. Novel therapeutic approaches

The vascular endothelium not only is a single monolayer of cells between the vessel lumen and the intimal wall, but also plays an important role by controlling vascular function and structure mainly via the production of nitric oxide (NO). The so called "cardiovascular risk factors" are associated with endothelial dysfunction, that reduces NO bioavailability, increases oxidative stress, and promotes inflammation contributing therefore to the development of atherosclerosis. The significant role of endothelial dysfunction in the development of atherosclerosis emphasizes the need for efficient therapeutic interventions. During the last years statins, angiotensin-converting enzyme inhibitors, angiotensin-receptor antagonists, antioxidants, beta-blockers and insulin sensitizers have been evaluated for their ability to restore endothelial function (Briasoulis et al., 2012). As there is not a straightforward relationship between therapeutic interventions and improvement of endothelial function but rather a complicated interrelationship between multiple cellular and sub-cellular targets, research has been focused on the understanding of the underlying mechanisms. Moreover, the development of novel diagnostic invasive and non-invasive methods has allowed the early detection of endothelial dysfunction expanding the role of therapeutic interventions and our knowledge. In the current review we present the available data concerning the contribution of endothelial dysfunction to atherogenesis and review the methods that assess endothelial function with a view to understand the multiple targets of therapeutic interventions. Finally we focus on the classic and novel therapeutic approaches aiming to improve endothelial dysfunction and the underlying mechanisms.

Adrenoreceptors and nitric oxide in the cardiovascular system

Nitric Oxide (NO) is a small molecule that continues to attract much attention from the scientific community. Since its discovery, it has been evident that NO has a crucial role in the modulation of vascular tone. Moreover, NO is involved in multiple signal transduction pathways thus contributing to the regulation of many cellular functions. NO effects can be either dependent or independent on cGMP, and rely also upon several mechanisms such as the amount of NO, the compartmentalization of the enzymes responsible for its biosynthesis (NOS), and the local redox conditions. Several evidences highlighted the correlation among adrenoreceptors activity, vascular redox status and NO bioavailability. It was suggested a possible crosstalk between NO and oxidative stress hallmarks in the endothelium function and adaptation, and in sympathetic vasoconstriction control. Adrenergic vasoconstriction is a balance between a direct vasoconstrictive effect on smooth muscle and an indirect vasorelaxant action caused by α₂- and β-adrenergic endothelial receptor-triggered NO release. An increased oxidative stress and a reduction of NO bioavailability shifts this equilibrium causing the enhanced vascular adrenergic responsiveness observed in hypertension. The activity of NOS contributes to manage the adrenergic pathway, thus supporting the idea that the endothelium might control or facilitate β-adrenergic effects on the vessels and the polymorphic variants in β₂-receptors and NOS isoforms could influence aging, some pathological conditions and individual responses to drugs. This seems to be dependent, almost in part, on differences in the control of vascular tone exerted by NO. Given its involvement in such important mechanisms, the NO pathway is implicated in aging process and in both cardiovascular and non-cardiovascular conditions. Thus, it is essential to pinpoint NO involvement in the regulation of vascular tone for the effective clinical/therapeutic management of cardiovascular diseases (CVD).

Nebivolol treatment increases splanchnic blood flow and portal pressure in cirrhotic rats via modulation of nitric oxide signalling

BACKGROUND

We evaluated the effects of nebivolol, a third generation beta-blocker capable of increasing NO-bioavailability on portal pressure, and on splachnic and systemic haemodynamics in a cirrhotic portal hypertensive rat model.

METHODS

Male Sprague-Dawley rats underwent sham operation (SO) or bile duct ligation (BDL). When cirrhosis was fully developed, the animals were orally treated with low-dose (5 mg/kg) or high-dose (10 mg/kg) nebivolol (NEBI) or vehicle (VEH) for 7 days. Heart rate (HR), mean arterial pressure (MAP), portal pressure (PP) and superior mesenteric artery blood flow (SMABF) were measured. Portosystemic collateral blood flow (PSCBF) was quantified using radioactive microspheres. Hepatic and splanchnic NOx levels and GSH/GSSG ratios (RedOx state) were determined using commercially available kits.

RESULTS

BDL-VEH rats showed increased HR, PP and PSCBF, whereas MAP was decreased compared to SO-VEH rats. Nebivolol significantly reduced HR both in SO (P < 0.001) and BDL (P < 0.001) rats. BDL-NEBI animals had significantly higher PP (15.5 vs. 12.6 mmHg; P = 0.006) and SMABF (5.3 vs. 3.7 ml/min/100g; P = 0.016) than BDL-VEH animals. The increase in PP and SMABF was noted both in low-dose and high-dose BDL-NEBI rats. While no beneficial effects on hepatic RedOx state were observed, splanchnic NOx levels were significantly increased by NEBI treatment in a dose-dependent manner. Nebivolol treatment did not affect PSCBF in SO and BDL animals.

CONCLUSION

Nebivolol increases portal pressure in cirrhotic animals by increasing splanchnic blood flow via modulation of NO signalling. Portosystemic collateral blood flow remained unchanged. These data do not support the use of nebivolol for treatment of cirrhotic patients with portal hypertension.

The evolving role of β-adrenergic receptor blockers in managing hypertension

β-Adrenergic blocking agents (or β-blockers) have been widely used for the treatment of hypertension for the past 50 years, and continue to be recommended as a mainstay of therapy in many national guidelines. They have also been used in a variety of cardiovascular conditions commonly complicating hypertension, including angina pectoris, myocardial infarction (MI), acute and chronic heart failure, as well as conditions like essential tremor and migraine. Moreover, they have played a primary role in controlling blood pressure in patients with these specific comorbidities and in reducing cardiovascular risk with regard to the composite outcome of death, stroke, and MI among patients younger than 60 years of age. However, in patients 60 years of age or older, β-blockers were not associated with significantly lower rates of MI, heart failure or death, and demonstrated higher rates of stroke compared with other first-line therapies. Consequently, the Canadian Hypertension Education Program recommends the use of β-blockers as first-line therapy in hypertensive patients younger than 60 years of age but not for those age 60 and older, with the exception of patients with concomitant β-blocker-requiring cardiac diseases. Several reports suggest that the lack of consistent outcome data may relate to the use of traditional β-blockers such as atenolol and their ability only to reduce cardiac output, without beneficial effect on peripheral vascular resistance. The present report will describe the clinically relevant mechanisms of action of β-blockers, their pharmacological differences, their metabolic effects, and their usefulness in patients with hypertension.

Nebivolol and metoprolol: long-term effects on inflammation and oxidative stress in essential hypertension

Arterial hypertension is characterised by increased oxidative stress and inflammation, which are associated with further cardiovascular risk. The aim of our study was to investigate the long-term effects of nebivolol and metoprolol succinate on oxidative stress, and on inflammatory and pro-inflammatory markers in patients with hypertension. Eighty patients with never-treated mild-to-moderate essential hypertension, aged 30-65 years, were randomised to a 5 mg daily dose of nebivolol or a 50-100 mg daily dose of metoprolol succinate. Brachial blood pressure, plasma oxidized LDL (oxLDL), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), fibrinogen, intercellular adhesion molecule-1 (ICAM-1), asymmetric dimethylarginine (ADMA), and urine 8-isoprostane levels were measured before and after 1 year of treatment. Nebivolol and metoprolol reduced equally significantly brachial blood pressure. The oxLDL was significantly reduced in both groups (p < 0.01 and for both drugs), but only nebivolol reduced 8-isoprostanes (p = 0.01). In the metoprolol group, change in oxLDL levels correlated with change in systolic blood pressure (r = 0.45; p < 0.01) and pulse pressure (r = 0.47; p < 0.01). Both metoprolol and nebivolol reduced ICAM-1 (p < 0.01). There was no change in IL-6, hsCRP, fibrinogen, or ADMA levels in either group. These data suggest that in long-term antihypertensive treatment both the cardioselective beta blocker metoprolol succinate and the vasodilating beta blocker nebivolol have inflammation-related effects but only nebivolol has a favourable blood pressure-independent effect on oxidative stress.

Differential effects of nebivolol and metoprolol on insulin sensitivity and plasminogen activator inhibitor in the metabolic syndrome

Early-generation β-blockers lower blood pressure and reduce cardiovascular morality in coronary artery disease and congestive heart failure but worsen glucose homeostasis and fibrinolytic balance. Nebivolol is a third-generation β-blocker that increases the bioavailability of nitric oxide. We compared the effect of nebivolol (5 mg/d) and the β(1)-selective antagonist metoprolol (100 mg/d) on glucose homeostasis and markers of fibrinolysis in 46 subjects with metabolic syndrome. Subjects underwent a frequently sampled IV glucose tolerance test after 3-week washout and placebo treatment and after randomized treatment with study drug. After 12-week treatment, nebivolol and metoprolol equivalently decreased systolic blood pressure, diastolic blood pressure, and heart rate. Neither drug affected β-cell function, disposition index, or acute insulin response to glucose. Metoprolol significantly decreased the insulin sensitivity index. In contrast, nebivolol did not affect insulin sensitivity, and the decrease in sensitivity was significantly greater after metoprolol than after nebivolol (-1.5±2.5×10(-4)×min(-1) per milliunit per liter versus 0.04±2.19×10(-4)×min(-1) per milliunit per liter after nebivolol; P=0.03). Circulating plasminogen activator inhibitor also increased after treatment with metoprolol (from 9.8±6.8 to 12.3±7.8 ng/mL) but not nebivolol (from 10.8±7.8 to 10.5±6.2 ng/mL; P=0.05 versus metoprolol). Metoprolol, but not nebivolol, increased F(2)-isoprostane concentrations. In summary, treatment with metoprolol decreased insulin sensitivity and increased oxidative stress and the antifibrinolytic plasminogen activator inhibitor 1 in patients with metabolic syndrome, whereas nebivolol lacked detrimental metabolic effects. Large clinical trials are needed to compare effects of nebivolol and the β(1) receptor antagonist metoprolol on clinical outcomes in patients with hypertension and the metabolic syndrome.

Serum oxidative stress-induced repression of Nrf2 and GSH depletion: a mechanism potentially involved in endothelial dysfunction of young smokers

Background

Although oxidative stress plays a major role in endothelial dysfunction (ED), the role of glutathione (GSH), of nuclear erythroid-related factor 2 (Nrf2) and of related antioxidant genes (ARE) are yet unknown. In this study we combined an in vivo with an in vitro model to assess whether cigarette smoking affects flow-mediated vasodilation (FMD), GSH concentrations and the Nrf2/ARE pathway in human umbilical vein endothelial cells (HUVECs).

Methods and Results

52 healthy subjects (26 non-smokers and 26 heavy smokers) were enrolled in this study. In smokers we demonstrated increased oxidative stress, i.e., reduced concentrations of GSH and increased concentrations of oxidation products of the phospholipid 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (oxPAPC) in serum and in peripheral blood mononuclear cells (PBMC), used as in vivo surrogates of endothelial cells. Moreover we showed impairment of FMD in smokers and a positive correlation with the concentration of GSH in PBMC of all subjects. In HUVECs exposed to smokers' serum but not to non-smokers' serum we found that oxidative stress increased, whereas nitric oxide and GSH concentrations decreased; interestingly the expression of Nrf2, of heme oxygenase-1 (HO-1) and of glutamate-cysteine ligase catalytic (GCLC) subunit, the rate-limiting step of synthesis of GSH, was decreased. To test the hypothesis that the increased oxidative stress in smokers may have a causal role in the repression of Nrf2/ARE pathway, we exposed HUVECs to increasing concentrations of oxPAPC and found that at the highest concentration (similar to that found in smokers' serum) the expression of Nrf2/ARE pathway was reduced. The knockdown of Nrf2 was associated to a significant reduction of HO-1 and GCLC expression induced by oxPAPC in ECs.

Conclusions

In young smokers with ED a novel further consequence of increased oxidative stress is a repression of Nrf2/ARE pathway leading to GSH depletion.

Carvedilol-lisinopril combination therapy and endothelial function in obese individuals with hypertension

The authors hypothesized that carvedilol controlled-release plus lisinopril combination therapy (C+L) would increase endothelial function and decrease oxidative stress to a greater extent than hydrochlorothiazide plus lisinopril combination therapy (H+L) in obese patients with hypertension. Twenty-five abdominally obese patients (aged 54.4±7.3 years; 14 women) with hypertension/prehypertension were enrolled in a 7-month (two 3-month treatment periods separated by a 1-month washout), randomized, double-blind, controlled, crossover clinical trial comparing C+L vs H+L. Endothelial function, measured by digital reactive hyperemic index (RHI), circulating oxidized low-density lipoprotein (oxLDL), 8-isoprostane, and asymmetric dimethylarginine (ADMA) were obtained at baseline, post-period 1, post-washout, and post-period 2. Analyses were adjusted for baseline measurements by analysis of covariance, with robust variance estimation for confidence intervals and P values. C+L treatment compared to H+L treatment significantly improved RHI (0.74, 95% confidence interval, 0.31-1.19, P =.001). This difference persisted after adjustment for the change in systolic blood pressure. No significant treatment differences were observed for oxLDL, 8-isoprostane, or ADMA. These data provide evidence that independent of blood pressure-lowering, C+L therapy improves endothelial function to a greater extent than H+L therapy. Levels of oxidative stress were not significantly different between treatments, suggesting that other mechanisms may be responsible for the improvement in endothelial function.

Comparison of nebivolol and atenolol on blood pressure, blood sugar, and lipid profile in patients of essential hypertension

Background:

Nebivolol is a third-generation β-blocker, with highest β₁ selectivity and nitric-oxide-derived vasodilatation. It also exhibits antiproliferative and antioxidant property that has beneficial metabolic profile compared to second-generation β blockers like atenolol. This study was planned to study the comparative effects of nebivolol and atenolol on metabolic parameters in patients with essential hypertension.

Materials and Methods:

A prospective, randomized, parallel, open-label clinical study was carried out on patients with essential hypertension. The patients were randomly assigned to receive tablet atenolol (Group A) and nebivolol (Group B) for a period of 24 weeks. Investigations were carried out at baseline and at the end of study period, that is, 24 weeks. Out of 69 patients, 60 completed the study and the data was analyzed using student's t-test. P < 0.05 was considered statistically significant.

Results:

Atenolol and nebivolol both showed significant (P < 0.001) antihypertensive action after 24 weeks. Mean blood sugar and lipid profile were found to be significantly (P < 0.001) elevated after 24 weeks of treatment with atenolol but not with nebivolol. Heart rate was significantly (P < 0.001) decreased in both groups at 24 weeks.

Conclusion:

In view of metabolic adverse effects of atenolol, nebivolol is the better choice whenever β-blockers have to be used in essential hypertension.

The role of Beta-blockers as first-line therapy in hypertension

National and international guidelines still recommend β-blockers (BBs) as first-line agents in uncomplicated prevention of hypertension. However, it has been shown that BBs reduce blood pressure less than other drugs, specifically with regard to central aortic pressure. More importantly, recent meta-analyses have highlighted that in primary prevention BBs are associated with a relatively weak effect in reducing stroke compared to placebo or no treatment and, compared with other drugs, show evidence of a worse cardiovascular outcome. Several reasons might explain their mild cardioprotective effect, such as their unfavorable metabolic properties, a lack of efficacy on left ventricular hypertrophy regression and endothelial dysfunction, and reduced patient compliance. Thus, the available evidence does not support the use of BBs as first-line drugs in the treatment of uncomplicated hypertension. It remains to be determined whether newer BBs, such as nebivolol and carvedilol, will be more effective than older compounds in improving cardiovascular prognosis.

Nebivolol attenuates redox-sensitive glomerular and tubular mediated proteinuria in obese rats

Obesity and insulin resistance-related proteinuria is associated with oxidative stress and impaired tissue bioavailable nitric oxide. Recent data suggest that nicotinamide adenine dinucleotide phosphate oxidase-mediated oxidative injury to the proximal tubule, like that seen in the glomerulus, contributes to proteinuria in insulin-resistant states. The vasodilator β-blocker nebivolol reduces nicotinamide adenine dinucleotide phosphate oxidase activity, increases bioavailable nitric oxide, and improves insulin sensitivity. To test the hypothesis that a treatment strategy that reduces oxidative stress and attenuates obesity-associated increases in glomerular and proximal tubule derived protein, we treated young Zucker obese (ZO) and age-matched Zucker lean male rats with nebivolol (10 mg · kg(-1) · d(-1)) for 21 d. Compared with Zucker lean, ZO controls exhibited increased proteinuria and γ-glutamyl transpeptidase, reductions in systemic insulin sensitivity in association with increased renal renin, (pro)renin receptor, angiotensin II type 1 receptor, and mineralocorticoid receptor immunostaining, oxidative stress, and glomerular tubular structural abnormalities that were substantially improved with in vivo nebivolol treatment. Nebivolol treatment also led to improvements in glomerular podocyte foot-process effacement and improvement in podocyte-specific proteins (nephrin and synaptopodin) as well as proximal tubule-specific proteins (megalin and lysosomal-associated membrane protein-2) and proximal tubule ultrastructural remodeling in the ZO kidney. Our findings support the notion that obesity and insulin resistance lead to increased glomerulotubular oxidative stress and resultant glomerular and tubular sources of excess urine protein. Furthermore, the results of this study suggest the beneficial effect of nebivolol on proteinuria was derived from improvements in weight and insulin sensitivity and reductions in renal oxidative stress in a state of obesity and insulin resistance.

A comparative study of nebivolol and (S) atenolol on blood pressure and heart rate on essential hypertensive patients

Objectives:

To study the effect of nebivolol 5 mg once daily versus (S)-atenolol 25 mg once daily in patients with essential hypertension.

Materials and Methods:

A prospective study was conducted at RLJH and Research Centre which included 30 patients in each group with essential hypertension. The sex, age, presenting illness, and family history of the patients were recorded. Investigations such as blood sugar, urine analysis, kidney function test, lipid profile, and ECG were performed before starting the treatment. Any adverse effects during the treatment were noted. Blood pressure and heart rate were recorded at baseline and during follow-up. One group received nebivolol 5 mg once daily and other group (S)atenolol 25 mg once daily. Patients were followed-up every 15 days for 3 months.

Results:

Nebivolol group had 18 males and 12 females with mean age 50.6 ± 9.5 years, (S)-atenolol had 16 males and 14 females with mean age 54.4 ± 9 years. Patients receiving nebivolol and (S)-atenolol showed a significant fall (P <·0001) in systolic (SBP), diastolic blood pressure (DBP), and heart rate at the end of first, second, and third month when compared to baseline. The difference in fall in SBP and DBP was insignificant between the groups, but fall in heart rate was significant (P <·0001). Adverse effects such as headache, dizziness, and fatigue were reported with both drugs.

Conclusion:

Reduction of blood pressure with nebivolol and (S)atenolol was similar, but fall in blood pressure from baseline was highly significant in both groups.

Hypertension, dyslipidemia, and insulin resistance in patients with diabetes mellitus or the cardiometabolic syndrome: benefits of vasodilating β-blockers

Hypertension frequently coexists with diabetes and the cardiometabolic syndrome. β-Blockers have been a mainstay for controlling blood pressure for nearly 4 decades. However, β-blockers are perceived to cause glucose and lipid metabolism dysregulation, including hypoglycemia masking, reduced glycemic control, insulin resistance, and dyslipidemia. It should be noted, however, that β-blockers are diverse in their effects on glucose and lipid metabolism. Potential mechanisms that contribute to these metabolic effects include hemodynamic differences, anti-inflammatory and anti-oxidative pathways, and/or weight changes. Traditional β-blockers decrease cardiac output while peripheral vascular resistance increases or remains unchanged, which may result in glucose and lipid abnormalities. In contrast, vasodilating β-blockers reduce peripheral vascular resistance but have little effect on cardiac output. Vasodilating β-blockers may therefore result in less impact on insulin sensitivity and glycemic control, a reduced new-onset diabetes risk, and improved dyslipidemia compared with traditional β-blockers. Because of these effects, vasodilating β-blockers may represent a favorable option in the treatment of high-risk patients with hypertension.

Why beta-blockers should not be used as first choice in uncomplicated hypertension

In the past 4 decades, beta blockers (BBs) have been widely used in the treatment of uncomplicated hypertension and are still recommended as first-line agents in national and international guidelines. Their putative cardioprotective properties, however, derive from the extrapolation into primary prevention of data relative to the reduction of mortality observed in the 1970s in patients with previous myocardial infarctions. In the past 5 years, a critical reanalysis of older trials, together with several meta-analyses, has shown that in patients with uncomplicated hypertension BBs exert a relatively weak effect in reducing stroke compared to placebo or no treatment, do not have any protective effect with regard to coronary artery disease and, compared to other drugs, such as calcium channel blockers, renin-angiotensin-aldosterone system inhibitors or thiazide diuretics, show evidence of worse outcomes, particularly with regard to stroke. Several reasons can explain their reduced cardioprotection: their suboptimal effect in lowering blood pressure compared to other drugs; their "pseudoantihypertensive" efficacy (failure to lower central aortic pressure); their undesirable adverse effects, which reduce patients' compliance; their unfavorable metabolic effects; their lack of an effect on regression of left ventricular hypertrophy and endothelial dysfunction. In conclusion, the available evidence does not support the use of BBs as first-line drugs in the treatment of hypertension. Whether newer BBs, such as nebivolol and carvedilol, which show vasodilatory properties and a more favorable hemodynamic and metabolic profile, will be more efficacious in reducing morbidity and mortality remains to be determined.

Effects of beta-blockers on glucose and lipid metabolism

BACKGROUND

Activation of the sympathetic nervous system (SNS) has been linked to hypertension. Beta-blockers, which decrease SNS activation via beta-adrenergic receptor antagonism, are effective in lowering blood pressure and reducing cardiovascular morbidity and mortality in several conditions, including post-myocardial infarction and heart failure. Despite these clinical benefits, many physicians are reluctant to prescribe beta-blockers because of perceived negative metabolic effects, including reduced glycemic control, masking of hypoglycemia, insulin resistance, and dyslipidemia.

OBJECTIVE

This article reviews the pathophysiology of hypertension and either insulin resistance or dyslipidemia as well as treatment effects from glucose- and lipid-lowering regimens on cardiovascular morbidity and mortality. Based on a PubMed literature search from January 1980 to December 2008, the effects of nonvasodilating (atenolol, metoprolol, and propranolol) and vasodilating beta-blockers (carvedilol, labetalol, and nebivolol) on parameters of glucose and lipid metabolism in hypertension are presented. Preference for clinical trial inclusion was given to randomized, controlled trials with at least 100 patients. Limitations of a drug class literature review may include trial inclusion bias with associated result skewing and underrepresentation of an individual agent, which may give different results.

RESULTS

Beta-blockers differ in terms of their mechanism of action and their effects on glucose and lipid metabolism. Nonvasodilating beta-blockers reduce blood pressure in association with a cardiac output reduction and may increase or have no appreciable effect on peripheral vascular resistance. As a result, nonvasodilating beta-blockers are associated with a worsening of glycemic and lipidic control. In contrast, vasodilating beta-blockers reduce peripheral vascular resistance but have little or no effect on cardiac output. Numerous studies have established that vasodilating beta-blockers are associated with more favorable effects on glucose and lipid profiles than nonvasodilating beta-blockers.

CONCLUSIONS

Improvements in glucose and lipid metabolism mediated by vasodilating beta-blockers may help reduce coronary artery disease risk among high-risk patients with hypertension.

Nebivolol attenuates maladaptive proximal tubule remodeling in transgenic rats

BACKGROUND/AIMS

The impact of nebivolol therapy on the renal proximal tubular cell (PTC) structure and function was investigated in a transgenic (TG) rodent model of hypertension and the cardiometabolic syndrome. The TG Ren2 rat develops nephropathy with proteinuria, increased renal angiotensin II levels and oxidative stress, and PTC remodeling. Nebivolol, a beta(1)-antagonist, has recently been shown to reduce albuminuria, in part, through reductions in renal oxidative stress. Accordingly, we hypothesized that nebivolol therapy would attenuate PTC damage and tubulointerstitial fibrosis.

METHODS

Young Ren2 (R2-N) and SD (SD-N) rats were treated with nebivolol (10 mg/kg/day) or vehicle (R2-C; SD-C) for 3 weeks. PTC structure and function were tested using transmission electron microscopy and functional measurements.

RESULTS

Nebivolol treatment decreased urinary N-acetyl-beta-D-glucosaminidase, tubulointerstitial ultrastructural remodeling and fibrosis, NADPH oxidase activity, 3-nitrotyrosine levels, and increased megalin and lysosomal-associated membrane protein-2 immunostaining in PTCs. Ultrastructural abnormalities that were improved with therapy included altered canalicular structure, reduced endosomes/lysosomes and PTC vacuoles, basement membrane thickening, and mitochondrial remodeling/fragmentation.

CONCLUSION

These observations support the notion that nebivolol may improve PTC reabsorption of albumin and other glomerular filtered small molecular weight proteins in association with the attenuation of oxidative stress, tubulointerstitial injury and fibrosis in this rat model of metabolic kidney disease.

Nebivolol reduces proteinuria and renal NADPH oxidase-generated reactive oxygen species in the transgenic Ren2 rat

BACKGROUND/AIMS

Renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system activation are crucial in the pathogenesis of hypertension, cardiovascular and renal disease. NADPH oxidase-mediated increases in reactive oxygen species (ROS) are an important mediator for RAAS-induced cardiovascular and renal injury. Increased levels of ROS can diminish the bioactivity of nitric oxide (NO), a critical modulator of RAAS effects on the kidney. Thereby, we hypothesized that in vivo nebivolol therapy in a rodent model of activated RAAS would attenuate glomerular damage and proteinuria through its actions to reduce NADPH oxidase activity/ROS and increase bioavailable NO.

METHODS

We utilized the transgenic Ren2 rat which displays heightened tissue RAAS, hypertension, and proteinuria. Ren2 rats (6-9 weeks of age) and age-matched Sprague-Dawley littermates were treated with nebivolol 10 mg/kg/day (osmotic mini-pump) for 21 days.

RESULTS

Ren2 rats exhibited increases in systolic blood pressure, proteinuria, kidney cortical tissue total NADPH oxidase activity and subunits (Rac1, p67(phox), and p47(phox)), ROS and 3-nitrotyrosine, as well as reductions in podocyte protein markers; each of these parameters improved with nebivolol treatment along with increases in renal endothelial NO synthase expression.

CONCLUSIONS

Our data suggest that nebivolol improves proteinuria through reductions in renal RAAS-mediated increases in NADPH oxidase/ROS and increases in bioavailable NO.

Genetic and pharmacogenetic associations between NOS3 polymorphisms, blood pressure, and cardiovascular events in hypertension

BACKGROUND

Polymorphisms in the endothelial nitric oxide synthase (NOS3) gene increase susceptibility to hypertension and cardiovascular disease. We examined genetic and pharmacogenetic associations between NOS3 polymorphisms, blood pressure (BP) control, and cardiovascular events in elderly, hypertensive coronary artery disease (CAD) patients.

METHODS

Patients with CAD were randomly assigned to either verapamil SR- or atenolol-based antihypertensive treatment and followed for cardiovascular events. Cases (all-cause death, nonfatal myocardial infarction (MI), or nonfatal stroke) and an age-, sex-, race/ethnicity-matched control population were genotyped for the -786T>C and Glu298>Asp polymorphisms in NOS3. On-treatment BP and BP control were compared across genotype groups. Logistic regression was performed to estimate odds ratios (ORs) for the -786T>C and Glu298>Asp polymorphisms in the combined population and in randomized treatment groups.

RESULTS

Genotype data were available for 256 cases and 769 controls. Among controls, mean on-treatment BP differed according to -786T>C genotype (T/T 137/78 mm Hg, T/C 133/76 mm Hg, C/C 133/75 mm Hg; P = 0.0007 for systolic, P = 0.09 for diastolic) which corresponded to differing rates of BP control (T/T 63%, T/C 72%, C/C 88%; P = 0.002). Neither polymorphisms was associated with case status, with or without regard to assigned treatment.

CONCLUSIONS

The -786T>C, but not the Glu298>Asp variant of NOS3, may correlate with BP but do not appear to be associated with incident cardiovascular events in patients with established cardiovascular disease. The antihypertensive treatment approach did not appear to alter the genetic contribution to either BP control or cardiovascular events.

Arterial stiffness, hypertension, and rational use of nebivolol

Arterial stiffness plays a key role in the pathophysiology of the cardiovascular system. Some indices of arterial stiffness (pulse wave velocity, augmentation index, characteristics of central blood pressure waveform) may be presently calculated and evaluated in the clinical setting. Age and blood pressure are the two major clinical determinants of increased arterial stiffness, while molecular determinants of arterial stiffness are related to fibrotic components of the extracellular matrix, mainly elastin, collagen and fibronectin. Increased arterial stiffness has been consistently observed in conditions such as hypertension, dyslipidemia and diabetes. Arterial stiffness evaluated by means of carotid-femoral pulse wave velocity yielded prognostic significance beyond and above traditional risk factors. A more favorable effect of calcium channel blockers, diuretics and ACE inhibitors compared with β-blockers on indices of arterial stiffness was observed in several studies. It is conceivable that newer β-blockers with additional vasodilating properties, such as nebivolol, which has favorable effects on carbohydrate and lipid metabolism, as well as on endothelial function and on oxidative stress, may have favorable effects on arterial stiffness, compared with atenolol. In fact, in recent studies, nebivolol was demonstrated to improve artery stiffness to a greater extent than older β-blockers. Because endothelial dysfunction and increased arterial stiffness play an important role in the early atherosclerotic processes and are associated with poor outcomes and increased mortality, independently of blood pressure, the ability of nebivolol to enhance release of endothelium-derived nitric oxide, and consequently improve endothelial function and arterial stiffness, may have significant clinical implications for the use of this agent in the treatment of hypertension and cardiovascular diseases.

Nitric oxide mechanisms of nebivolol

β-blockers are among the most widely used drugs in the prevention and treatment of cardiovascular disease, although they are associated with increased peripheral resistance. Third-generation β-blockers avoid this adverse effect by inducing vasodilation through different mechanisms. In particular, nebivolol, a highly selective blocker of β1-adrenergic receptors, is the only β-blocker known to induce vascular production of nitric oxide, the main endothelial vasodilator. The specific mechanism of nebivolol is particularly relevant in hypertension, where nitric oxide dysfunction occurs. Indeed, nebivolol is able to reverse endothelial dysfunction. Nebivolol induces nitric oxide production via activation of β3-adrenergic receptors, which can explain the good metabolic profile observed after treatment with this drug. Moreover, nebivolol can also stimulate the β3-adrenergic receptor-mediated production of nitric oxide in the heart, and this stimulation can result in a greater protection against heart failure. In conclusion, nebivolol has a unique profile among antihypertensive drugs, adding to a very high selectivity against β1 adrenergic receptors, and an agonist action on β3 receptors and nitric oxide (NO), which has led to clinically significant improvements in hypertensive patients.