Angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and diabetes: a meta-analysis of placebo-controlled clinical trials

MARRIAGE: A Randomized Trial of Moxonidine Versus Ramipril or in Combination With Ramipril in Overweight Patients With Hypertension and Impaired Fasting Glucose or Diabetes Mellitus. Impact on Blood Pressure, Heart Rate and Metabolic Parameters

BACKGROUND

Moxonidine, an imidazoline I1 receptor agonist, is an effective antihypertensive drug that was shown to improve insulin sensitivity. RAAS-blockers are recommended as first-line therapy in patients with diabetes, alone or in combination with a calcium-channel antagonist or a diuretic.

AIMS

This study compared the effects of moxonidine and ramipril on blood pressure (BP) and glucose metabolism in overweight patients with mild-to-moderate hypertension and impaired fasting glucose or type 2 diabetes.

METHODS

Treatment-naïve patients for hypertension and dysglycemia were randomized to 12 weeks of double-blind moxonidine 0.4 mg or ramipril 5 mg once-daily treatment. At 12 weeks, for a further 12 weeks non-responders received combination of mox/ram, while responders continued blinded treatment.

RESULTS

Moxonidine and ramipril were equivalent in lowering SiDBP and SiSBP at the end of the first 12 weeks. The responder rate was approximately 50% in both groups, with a mean SiDBP and SiSBP decrease of 10 and 15 mm Hg in the responders, respectively. The normalization rate (SiDBP < 85 mm Hg) was non significantly different between treatments groups. Moxonidine reduced heart rate (HR) (average -3.5 bpm, p = 0.017) during monotherapy, and when added to ramipril. HbA1c decreased significantly at Week 12 in both groups. Neither drug affected glucose or insulin response to the oral glucose tolerance test. In non-responders, moxonidine/ramipril combination further reduced BP without compromising metabolic parameters.

CONCLUSION

Moxonidine 0.4 mg and ramipril 5 mg were equally effective on BP lowering and were well tolerated and mostly metabolically neutral either as monotherapies or in combination. HR was lowered on moxonidine treatment.

Kidney Angiotensin in Cardiovascular Disease: Formation and Drug Targeting

The concept of local formation of angiotensin II in the kidney has changed over the last 10-15 years. Local synthesis of angiotensinogen in the proximal tubule has been proposed, combined with prorenin synthesis in the collecting duct. Binding of prorenin via the so-called (pro)renin receptor has been introduced, as well as megalin-mediated uptake of filtered plasma-derived renin-angiotensin system (RAS) components. Moreover, angiotensin metabolites other than angiotensin II [notably angiotensin-(1-7)] exist, and angiotensins exert their effects via three different receptors, of which angiotensin II type 2 and Mas receptors are considered renoprotective, possibly in a sex-specific manner, whereas angiotensin II type 1 (AT1) receptors are believed to be deleterious. Additionally, internalized angiotensin II may stimulate intracellular receptors. Angiotensin-converting enzyme 2 (ACE2) not only generates angiotensin-(1-7) but also acts as coronavirus receptor. Multiple, if not all, cardiovascular diseases involve the kidney RAS, with renal AT1 receptors often being claimed to exert a crucial role. Urinary RAS component levels, depending on filtration, reabsorption, and local release, are believed to reflect renal RAS activity. Finally, both existing drugs (RAS inhibitors, cyclooxygenase inhibitors) and novel drugs (angiotensin receptor/neprilysin inhibitors, sodium-glucose cotransporter-2 inhibitors, soluble ACE2) affect renal angiotensin formation, thereby displaying cardiovascular efficacy. Particular in the case of the latter three, an important question is to what degree they induce renoprotection (e.g., in a renal RAS-dependent manner). This review provides a unifying view, explaining not only how kidney angiotensin formation occurs and how it is affected by drugs but also why drugs are renoprotective when altering the renal RAS. SIGNIFICANCE STATEMENT: Angiotensin formation in the kidney is widely accepted but little understood, and multiple, often contrasting concepts have been put forward over the last two decades. This paper offers a unifying view, simultaneously explaining how existing and novel drugs exert renoprotection by interfering with kidney angiotensin formation.

Geroscience-guided repurposing of FDA-approved drugs to target aging: A proposed process and prioritization

Common chronic diseases represent the greatest driver of rising healthcare costs, as well as declining function, independence, and quality of life. Geroscience-guided approaches seek to delay the onset and progression of multiple chronic conditions by targeting fundamental biological pathways of aging. This approach is more likely to improve overall health and function in old age than treating individual diseases, by addressing aging the largest and mostly ignored risk factor for the leading causes of morbidity in older adults. Nevertheless, challenges in repurposing existing and moving newly discovered interventions from the bench to clinical care have impeded the progress of this potentially transformational paradigm shift. In this article, we propose the creation of a standardized process for evaluating FDA-approved medications for their geroscience potential. Criteria for systematically evaluating the existing literature that spans from animal models to human studies will permit the prioritization of efforts and financial investments for translating geroscience and allow immediate progress on the design of the next Targeting Aging with MEtformin (TAME)-like study involving such candidate gerotherapeutics.

Ramipril Reduces Acylcarnitines and Distinctly Increases Angiotensin-Converting Enzyme 2 Expression in Lungs of Rats

The angiotensin-converting enzyme 2 (ACE2) receptor has been identified as the entry receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is abundantly expressed in many organs. With respect to the role of circulating ACE2 and its receptor expression in the pathogenesis of the SARS-CoV-2 infection, it is still debated whether diseases such as hypertension or pharmacotherapies, including ACE inhibitors and angiotensin receptor blockers that affect ACE2 receptor expression, may modulate the severity and outcome of the coronavirus disease 2019 (COVID-19). We therefore tested the hypothesis that treatment with the ACE inhibitor Ramipril affects organ-specific ACE2 receptor mRNA and protein expression as well as the serum metabolome in BioBreeding (BB) rats. Twelve male BioBreeding rats were randomly divided into a Ramipril (10 mg/kg body weight) treatment group or a control group (N = 12; n = 6 per group) over a period of seven days. Ramipril treatment resulted in the reduction of acylcarnitines (C3–C6) out of 64 metabolites. Among the different organs studied, only in the lungs did Ramipril treatment significantly increase both Ace2 mRNA and ACE2 receptor membrane protein levels. Increased ACE2 receptor lung expression after Ramipril treatment was not associated with differences in ACE2 serum concentrations between experimental groups. Our data provide experimental in vivo evidence that the ACE inhibitor Ramipril selectively increases pulmonary ACE2 receptor mRNA and protein levels and reduces acylcarnitines.

Chronic AT1 blockade improves hyperglycemia by decreasing adipocyte inflammation and decreasing hepatic PCK1 and G6PC1 expression in obese rats

Inappropriate activation of the renin-angiotensin system decreases glucose uptake in peripheral tissues. Chronic angiotensin receptor type 1 (AT1) blockade (ARB) increases glucose uptake in skeletal muscle and decreases the abundance of large adipocytes and macrophage infiltration in adipose. However, the contributions of each tissue to the improvement in hyperglycemia in response to AT1 blockade are not known. Therefore, we determined the static and dynamic responses of soleus muscle, liver, and adipose to an acute glucose challenge following the chronic blockade of AT1. We measured adipocyte morphology along with TNF-α expression, F4/80- and CD11c-positive cells in adipose and measured insulin receptor (IR) phosphorylation and AKT phosphorylation in soleus muscle, liver, and retroperitoneal fat before (T0), 60 (T60) and 120 (T120) min after an acute glucose challenge in the following groups of male rats: 1) Long-Evans Tokushima Otsuka (LETO; lean control; n = 5/time point), 2) obese Otsuka Long Evans Tokushima Fatty (OLETF; n = 7 or 8/time point), and 3) OLETF + ARB (ARB; 10 mg olmesartan/kg/day; n = 7 or 8/time point). AT1 blockade decreased adipocyte TNF-α expression and F4/80- and CD11c-positive cells. In retroperitoneal fat at T60, IR phosphorylation was 155% greater in ARB than in OLETF. Furthermore, in retroperitoneal fat AT1 blockade increased glucose transporter-4 (GLUT4) protein expression in ARB compared with OLETF. IR phosphorylation and AKT phosphorylation were not altered in the liver of OLETF, but AT1 blockade decreased hepatic Pck1 and G6pc1 mRNA expressions. Collectively, these results suggest that chronic AT1 blockade improves obesity-associated hyperglycemia in OLETF rats by improving adipocyte function and by decreasing hepatic glucose production via gluconeogenesis.NEW & NOTEWORTHY Inappropriate activation of the renin-angiotensin system increases adipocyte inflammation contributing to the impairment in adipocyte function and increases hepatic Pck1 and G6pc1 mRNA expression in response to a glucose challenge. Ultimately, these effects may contribute to the development of glucose intolerance.

Angiotensin-converting enzyme inhibitors from plants: A review of their diversity, modes of action, prospects, and concerns in the management of diabetes-centric complications

Angiotensin-converting enzyme (ACE) inhibitors are antihypertensive medications often used in the treatment of diabetes-related complications. Synthetic ACE inhibitors are known to cause serious side effects like hypotension, renal insufficiency, and hyperkalaemia. Therefore, there has been an intensifying search for natural ACE inhibitors. Many plants or plant-based extracts are known to possess ACE-inhibitory activity. In this review, articles focusing on the natural ACE inhibitors extracted from plants were retrieved from databases like Google Scholar, PubMed, Scopus, and Web of Science. We have found more than 50 plant species with ACE-inhibitory activity. Among them, Angelica keiskei, Momordica charantia, Muntingia calabura, Prunus domestica, and Peperomia pellucida were the most potent, showing comparatively lower half-maximal inhibitory concentration values. Among the bioactive metabolites, peptides (e.g., Tyr-Glu-Pro, Met-Arg-Trp, and Gln-Phe-Tyr-Ala-Val), phenolics (e.g., cyanidin-3-O-sambubioside and delphinidin-3-O-sambubioside), flavonoids ([-]-epicatechin, astilbin, and eupatorin), terpenoids (ursolic acid and oleanolic acid) and alkaloids (berberine and harmaline) isolated from several plant and fungus species were found to possess significant ACE-inhibitory activity. These were also known to possess promising antioxidant, antidiabetic, antihyperlipidemic and anti-inflammatory activities. Considering the minimal side effects and lower toxicity of herbal compounds, development of antihypertensive drugs from these plant extracts or phytocompounds for the treatment of diabetes-associated complications is an important endeavour. This review, therefore, focuses on the ACE inhibitors extracted from different plant sources, their possible mechanisms of action, present status, and any safety concerns.

ARB-Based Combination Therapy for the Clinical Management of Hypertension and Hypertension-Related Comorbidities: A Spotlight on Their Use in COVID-19 Patients

Essential hypertension is the most common cardiovascular (CV) risk factor, being primarily involved in the pathogenesis of CV disease and mortality worldwide. Given the high prevalence and growing incidence of this clinical condition in the general population in both high and low-income countries, antihypertensive drug therapies are frequently prescribed in different hypertension-related CV diseases and comorbidities. Among these conditions, evidence are available demonstrating the clinical benefits of lowering blood pressure (BP) levels, particularly in those hypertensive patients at high or very high CV risk profile. Preliminary studies, performed during the Sars-COVID-19 epidemic, raised some concerns on the potential implication of hypertension and antihypertensive medications in the susceptibility of having severe pneumonia, particularly with regard to the use of drugs inhibiting the renin-angiotensin system (RAS), including angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). These hypotheses were not confirmed by subsequent studies, which independently and systematically demonstrated no clinical harm of these drugs also in patients with Sars-COVID-19 infection. The aim of this narrative review is to critically discuss the available evidence supporting the use of antihypertensive therapies based RAS blocking agents in hypertensive patients with different CV risk profile and with additional clinical conditions or comorbidities, including Sars-COVID-19 infection, with a particular focus on single-pill combination therapies based on olmesartan medoxomil.

Latin American Expert Consensus for Comprehensive Management of Type 2 Diabetes from a Metabolic-Cardio-Renal Perspective for the Primary Care Physician

Growing scientific evidence from studies on type 2 diabetes (T2D) has recently led to a better understanding of the associated metabolic-cardio-renal risks. The large amount of available information makes it essential to have a practical guide that summarizes the recommendations for the initial management of patients with T2D, integrating different aspects of endocrinology, cardiology, and nephrology. The expert consensus presented here does not attempt to summarize all the evidence in this regard but rather attempts to define practical summary recommendations for the primary care physician to improve the clinical prognosis and management of patients with T2D, while ensuring economic sustainability of health systems, beyond glycemic control.

Comparison of Blood Pressure Variability Between Losartan and Amlodipine in Essential Hypertension (COMPAS-BPV)

BACKGROUND

Antihypertensive therapy using renin-angiotensin system blockers and calcium channel blockers to target blood pressure variability (BPV) has not yet been established. We aimed to compare the ability of losartan and amlodipine to lower BPV and systolic blood pressure (SBP) in essential hypertensive patients.

METHODS

Patients were randomly assigned either losartan 50 mg or amlodipine 5 mg. Medications were uptitrated and hydrochlorothiazide was added according to protocol for 6 months. The primary endpoint was the office visit-to-visit SD of SBP. The secondary endpoints included average real variability (ARV), office SBP, and home SBP.

RESULTS

The losartan group (n = 71) and amlodipine group (n = 73) finished the scheduled visits between April 2013 and May 2017. The office visit-to-visit SD of SBP was comparable between the losartan and amlodipine groups (11.0 ± 4.2 vs. 10.5 ± 3.8, P = 0.468). The office visit-to-visit ARV of SBP was significantly elevated in the losartan group (10.6 ± 4.3 vs. 9.1 ± 3.4, P = 0.02). The absolute SBP decrement from baseline to 6 months was similar between groups, although the office mean SBP at 6 months was higher in the losartan group (132.3 ± 12.9 vs. 127.5 ± 9.0 mm Hg, P = 0.011). In home blood pressure analysis, evening day-to-day BPV indexes (SD and ARV) were significantly higher in the losartan group at 6 months.

CONCLUSIONS

The lowering effect of the office visit-to-visit SD of SBP was similar between losartan and amlodipine. However, the losartan group showed a higher office visit-to-visit ARV of SBP and evening day-to-day home BPV indexes. Therefore, amlodipine may be better to lower BPV in essential hypertensive patients.

SARS-CoV-2 and diabetes: New challenges for the disease

A novel small enveloped RNA virus with the typical characteristic of the family to which it belongs, a crown, hence the name coronavirus, appeared in December 2019 in Wuhan, China, and subdued the world to its influence. The particular severity of the disease and higher mortality rates in patients with associated morbidities, including hypertension, obesity and diabetes, increases the concern over the consequences of this pandemic. In this review, the features of SARS-CoV-2 will be addressed, as well as the reasons why it poses a particular challenge to diabetic patients. We will also highlight the recent treatment strategies being explored to control this pandemic. Emerging evidence demonstrates that the correct management of diabetes in those patients infected with SARS-CoV-2 is of utmost importance for the viral disease progression, therefore, the importance of blood glucose control will also be addressed.

Management of arterial hypertension with angiotensin receptor blockers: Current evidence and the role of olmesartan

Elevated blood pressure (BP) is a major determinant of morbidity and mortality burden related to cardio‐metabolic risk. Current guidelines indicate that controlling and lowering BP promotes cardiovascular (CV) risk reduction. Among antihypertensive agents, angiotensin receptor blockers (ARBs) are characterized by an efficacy profile equivalent to other antihypertensive agents and are provided with excellent tolerability and low discontinuation rates during chronic treatments. Moreover, CV outcomes are reduced by ARBs. Olmesartan is a long‐lasting ARB which proved to achieve a comparable or more effective action in lowering BP when compared to other ARBs. Olmesartan, in fact, displayed a larger and more sustained antihypertensive effect over the 24 hours, with a buffering effect on short‐term BP variability. These are important features which differentiate olmesartan from the other principles of the same class and that may help to control the increased CV risk in the presence of high BP variability. Olmesartan shows similar benefits as other ARBs in terms of all‐cause and CV mortality, and a favorable tolerability profile. Combination of olmesartan with long‐lasting calcium‐channel blockers and thiazide diuretics represents a rational and effective therapy. Thus, ARBs, including olmesartan, represent one of the most effective and safe treatments for patients with arterial hypertension.

Simultaneous GLP-1 receptor activation and angiotensin receptor blockade increase natriuresis independent of altered arterial pressure in obese OLETF rats

Obesity is associated with an inappropriately activated renin-angiotensin-aldosterone system, suppressed glucagon-like peptide-1 (GLP-1), increased renal Na⁺ reabsorption, and hypertension. To assess the link between GLP-1 and angiotensin receptor type 1 (AT₁) signaling on obesity-associated impairment of urinary Na⁺ excretion (U_NaV) and elevated arterial pressure, we measured mean arterial pressure (MAP) and heart rate by radiotelemetry and metabolic parameters for 40 days. We tested the hypothesis that stimulation of GLP-1 signaling provides added benefit to blockade of AT₁ by increasing U_NaV and further reducing arterial pressure in the following groups: (1) untreated Long-Evans Tokushima Otsuka (LETO) rats (n = 7); (2) untreated Otsuka Long-Evans Tokushima Fatty (OLETF) rats (n = 9); (3) OLETF + ARB (ARB; 10 mg olmesartan/kg/day; n = 9); (4) OLETF + GLP-1 receptor agonist (EXE; 10 µg exenatide/kg/day; n = 7); and (5) OLETF + ARB + EXE (Combo; n = 6). On day 2, U_NaV was 60% and 62% reduced in the EXE and Combo groups, respectively, compared with that in the OLETF rats. On day 40, U_NaV was increased 69% in the Combo group compared with that in the OLETF group. On day 40, urinary angiotensinogen was 4.5-fold greater in the OLETF than in the LETO group and was 56%, 62%, and 58% lower in the ARB, EXE, and Combo groups, respectively, than in the OLETF group. From day 2 to the end of the study, MAP was lower in the ARB and Combo groups than in the OLETF rats. These results suggest that GLP-1 receptor activation may reduce intrarenal angiotensin II activity, and that simultaneous blockade of AT₁ increases U_NaV in obesity; however, these beneficial effects do not translate to a further reduction in MAP.

Fifteen years of LIFE (Losartan Intervention for Endpoint Reduction in Hypertension)-Lessons learned for losartan: An "old dog playing good tricks"

There is an unmet need to prevent cardiovascular disease and chronic kidney disease development and progression worldwide. Losartan, the first angiotensin receptor blocker, was shown to exert significant cardioprotective and renoprotective effects in the LIFE (Losartan Intervention for Endpoint Reduction in Hypertension) and RENAAL (Reduction of Endpoints in NIDDM With the Angiotensin II Antagonist Losartan) trials. Losartan significantly prevented stroke and decreased serum uric acid levels and the rates of new-onset diabetes mellitus and atrial fibrillation. The present review discusses the LIFE (and its subanalyses) and RENAAL trials and the translation of their results to clinical practice. The place of losartan in the current guidelines for hypertension management is also discussed. Losartan still represents an efficacious, safe, and cost-effective therapeutic option in patients with hypertension who have left ventricular hypertrophy. Losartan is a useful antihypertensive agent for stroke prevention and in the management of patients with chronic kidney disease, atrial fibrillation, diabetes mellitus, albuminuria, and hyperuricemia.

Chronic AT1 blockade improves glucose homeostasis in obese OLETF rats

Obesity is associated with the inappropriate activation of the renin-angiotensin system (RAS), which increases arterial pressure, impairs insulin secretion and decreases peripheral tissue insulin sensitivity. RAS blockade reverses these detriments; however, it is not clear whether the disease state of the organism and treatment duration determine the beneficial effects of RAS inhibition on insulin secretion and insulin sensitivity. Therefore, the objective of this study was to compare the benefits of acute vs chronic angiotensin receptor type 1 (AT₁) blockade started after the onset of obesity, hyperglycemia and hypertension on pancreatic function and peripheral insulin resistance. We assessed adipocyte morphology, glucose intolerance, pancreatic redox balance and insulin secretion after 2 and 11 weeks of AT₁ blockade in the following groups of rats: (1) untreated Long-Evans Tokushima Otsuka (lean control; n = 10), (2) untreated Otsuka Long-Evans Tokushima Fatty (OLETF; n = 12) and (3) OLETF + ARB (ARB; 10 mg olmesartan/kg/day by oral gavage; n = 12). Regardless of treatment duration, AT₁ blockade decreased systolic blood pressure and fasting plasma triglycerides, whereas chronic AT₁ blockade decreased fasting plasma glucose, glucose intolerance and the relative abundance of large adipocytes by 22, 36 and 70%, respectively. AT₁ blockade, however, did not improve pancreatic oxidative stress or reverse impaired insulin secretion. Collectively, these data show that AT₁ blockade after the onset of obesity, hyperglycemia and hypertension improves peripheral tissue insulin sensitivity, but cannot completely reverse the metabolic derangement characterized by impaired insulin secretion once it has been compromised.

Hyperkalemia in the Hypertensive Patient

PURPOSE OF REVIEW

Hyperkalemia develops in a patient with systemic arterial hypertension (HTN) if one or more risk factors are present, namely chronic kidney disease (CKD) (especially severe stage 4-5 CKD), diabetes mellitus (DM), heart failure (HF), or pharmacological therapies that interfere with potassium homeostasis, mainly through renin-angiotensin-aldosterone inhibition (RAASi). Hyperkalemia is a considerable reason of morbidity (emergency department (ED) visits and hospitalizations) and portends a higher mortality risk in patients at risk; for instance, hyperkalemia increases the risk of mortality within 1 day of a hyperkalemic event. This review aims to identify the risk factors for high-serum potassium, highlight the risk versus benefit of RAASi in certain patient populations, and outline preventive as well as therapeutic strategies for hyperkalemia.

RECENT FINDINGS

A growing body of evidence supports the safety and efficacy of cation-exchange resins, patiromer, or sodium zirconium cyclosilicate, in patients with a compelling indication for RAASi, yet in whom such therapy was complicated by hyperkalemia, allowing these patients to benefit from continued RAASi therapy. In summary, novel cation exchange polymers present the clinician with a new and safe strategy to address hyperkalemia in patients with a compelling indication for ongoing RAASi therapy instead of withdrawal of such therapy.

How to Improve Effectiveness and Adherence to Antihypertensive Drug Therapy: Central Role of Dihydropyridinic Calcium Channel Blockers in Hypertension

Essential hypertension is a complex clinical condition, characterized by multiple and concomitant abnormal activation of different regulatory and contra-regulatory pathophysiological mechanisms, leading to sustained increase of blood pressure (BP) levels. Asymptomatic rise of BP may, indeed, promote development and progression of hypertension-related organ damage, which in turn, increases the risk of major cardiovascular and cerebrovascular events. A progressive and independent relationship has been demonstrated between high BP levels and increased cardiovascular risk, even in the high-to-normal range. Conversely, evidence from randomized controlled clinical trials have independently shown that lowering BP to the recommended targets reduces individual cardiovascular risk, thus improving event-free survival and reducing the incidence of hypertension-related cardiovascular events. Despite these benefits, overall rates of BP control remain poor, worldwide. Currently available guidelines support a substantial equivalence amongst various antihypertensive drug classes. However, several studies have also reported clinically relevant differences among antihypertensive drugs, in terms of both BP lowering efficacy and tolerability/safety profile. These differences should be taken into account not only when adopting first-line antihypertensive therapy, but also when titrating or modulating combination therapies, with the aim of achieving effective and sustained BP control. This review will briefly describe evidence supporting the use of dihydropyridinic calcium channel blockers for the clinical management of hypertension, with a particular focus on barnidipine. Indeed, this drug has been demonstrated to be effective, safe and well tolerated in lowering BP levels and in reducing hypertension-related organ damage, thus showing a potential key role for improving the clinical management of hypertension.

Verapamil Use Is Associated With Reduction of Newly Diagnosed Diabetes Mellitus

OBJECTIVE

The mechanism of the beneficial effect of calcium-channel blockers (CCBs), especially verapamil, on the development of type 2 diabetes mellitus (T2DM) has been described. This study compared the incidence of T2DM in adults prescribed oral verapamil and propensity score-matched adults prescribed other oral CCBs.

METHODS

This retrospective population-based cohort study used Taiwan's National Health Insurance Research Database from 2000 to 2011. T2DM was defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification.

RESULTS

During follow-up periods of 41,958 and 42,118 person-years, 269 of 4930 patients in the verapamil cohort and 340 of 4930 patients in the matched cohort, respectively, developed T2DM. The incidence rates were 6.41 and 8.07 per 1000 population per year among verapamil and other CCB users, respectively. The adjusted hazard ratio (HR) for T2DM associated with use of verapamil (vs. other CCBs) was 0.80 [95% confidence interval (CI), 0.68 to 0.94; P = 0.006]. After exclusion of patients followed for <180 days or <365 days (to avoid bias derived from delayed diagnosis), adjusted HRs remained significant [0.79 (95% CI, 0.67 to 0.93; P = 0.005) and 0.77 (95% CI, 0.65 to 0.91; P = 0.002), respectively]. Only the interaction term for age was significant (P = 0.009). Verapamil had a more prominent effect on patients aged older than 65 years (P < 0.001).

CONCLUSIONS

In patients with no known history of diabetes mellitus, oral verapamil use was associated with a decreased incidence of T2DM compared with other CCBs.

Comparing six antihypertensive medication classes for preventing new-onset diabetes mellitus among hypertensive patients: a network meta-analysis

Hypertensive patients usually have a higher risk of new‐onset diabetes mellitus (NOD) which may trigger cardiovascular diseases. In this study, the effectiveness of six antihypertensive agents with respect to NOD prevention in hypertensive patients was assessed. A network meta‐analysis was conducted to compare the efficacy of specific drug classes. PubMed and Embase databases were searched for relevant articles. Results of the pairwised meta‐analysis were illustrated by odd ratios (OR) and a corresponding 95% confidence interval (CI). The probabilities and outcome of each treatment were ranked and summarized using the surface under the cumulative ranking curve (SUCRA).Twenty‐three trials were identified, including 224,832 patients with an average follow‐up period of 3.9 ± 1.0 years. The network meta‐analysis showed that patients treated by angiotensin II receptor blockers (ARBs) were associated with a lower risk of NOD compared to placebo (PCB), calcium channel blockers (CCBs) and β‐blockers, while diuretic appeared to be ineffective for NOD prevention. Network meta‐analysis results of specific drugs showed that enalapril exhibited distinct advantages and hydrochlorothiazide also exhibited a reliable performance. Our results suggested that both ARBs and angiotensin converse enzyme inhibitors (ACEIs), especially candesartan and enalapril, were preferable for NOD prevention in hypertensive patients. Hydrochlorothiazide also exhibited a reliable performance in comparison with other agents.

Phase 4 Studies in Heart Failure - What is Done and What is Needed?

Congestive heart failure (CHF) therapeutics is generated through a well-described evidence generating process. Phases 1 - 3 of this process are required prior to approval and widespread clinical use. Phase 3 in almost all cases is a methodologically sound randomized controlled trial (RCT). After this phase it is generally accepted that the treatment has a significant, independent and prognostically beneficial effect on the pathophysiological process. A major criticism of RCTs is the population to whom the result is applicable. When this population is significantly different from the trial cohort the external validity comes into question. Should the continuation of the evidence generating process continue these problems might be identified. Post marketing surveillance through phase 4 and comparative effectiveness studies through phase 5 trials are often underperformed in comparison to the RCT. These processes can help identify remote adverse events and define new hypotheses for community level benefits. This review is aimed at exploring the post-marketing scene for CHF therapeutics from an Australian health system perspective. We explore the phases of clinical trials, the level of evidence currently available and options for ensuring greater accountability for community level CHF clinical outcomes.

The Different Therapeutic Choices with ARBs. Which One to Give? When? Why?

The renin-angiotensin-aldosterone system plays an important role in the pathophysiology of hypertension and is closely related with cardio- and cerebrovascular events and chronic kidney diseases. Each angiotensin receptor blocker (ARB) is important in the treatment of hypertension, according to the results of recent years. This is a practical review of the available evidence on the different benefits of ARBs beyond their blood pressure-lowering effect, with an emphasis on the differences found between the particular compounds and the therapeutic implications of the findings, with specific reference to the co-morbidities.

Insulin Resistance and Endothelial Dysfunction Constitute a Common Therapeutic Target in Cardiometabolic Disorders

Insulin resistance and other risk factors for atherosclerosis, such as hypertension and hypercholesterolemia, promote endothelial dysfunction and lead to development of metabolic syndrome which constitutes an introduction to cardiovascular disease. The insulin resistance and endothelial dysfunction cross talk between each other by numerous metabolic pathways. Hence, targeting one of these pathologies with pleiotropic treatment exerts beneficial effect on another one. Combined and expletive treatment of hypertension, lipid disorders, and insulin resistance with nonpharmacological interventions and conventional pharmacotherapy may inhibit the transformation of metabolic disturbances to fully developed cardiovascular disease. This paper summarises the common therapeutic targets for insulin resistance, endothelial dysfunction, and vascular inflammatory reaction at molecular level and analyses the potential pleiotropic effects of drugs used currently in management of cardiovascular disease, metabolic syndrome, and diabetes.

Novel renin inhibitors containing derivatives of N-alkylleucyl-β-hydroxy-γ-amino acids

In search for new drugs lowering arterial blood pressure, which could be applied in anti-hypertensive therapy, research concerning agents blocking of renin-angiotensin-aldosteron system has been conducted. Despite many years of research conducted at many research centers around the world, aliskiren is the only one renin inhibitor, which is used up to now. Four novel potential renin inhibitors, having structure based on the peptide fragment 8-13 of human angiotensinogen, a natural substrate for renin, were designed and synthesized. All these inhibitors contain unnatural moieties that are derivatives of N-methylleucyl-β-hydroxy-γ-amino acids at the P2-P1' position: 4-[N-(N-methylleucyl)-amino]-3-hydroxy-7-(3-nitroguanidino)-heptanoic acid (AHGHA), 4-[N-(N-methylleucyl)-amino]-3-hydroxy-5-phenyl-pentanoic acid (AHPPA) or 4-[N-(N-methylleucyl)-amino]-8-benzyloxycarbonylamino-3-hydroxyoctanoic acid (AAHOA). The previously listed synthetic β-hydroxy-γ-amino acids constitute pseudodipeptidic units that correspond to the P1-P1' position of the inhibitor molecule. An unnatural amino acid, 4-methoxyphenylalanin (Phe(4-OMe)), was introduced at the P3 position of the obtained compounds. Three of these compounds contain isoamylamide of 6-aminohexanoic acid (ε-Ahx-Iaa) at the P2'-P3' position. The proposed modifications of the selected human angiotensinogen fragment are intended to increase bioactivity, bioavailability, and stability of the inhibitor molecule in body fluids and tissues. The inhibitor Boc-Phe(4-OMe)-MeLeu-AHGHA-OEt was obtained in the form of an ethyl ester. The hydrophobicity coefficient, expressed as log P varied between 3.95 and 8.17. In vitro renin inhibitory activity of all obtained compounds was contained within the range 10(-6)-10(-9) M. The compound Boc-Phe(4-OMe)-MeLeu-AHPPA-Ahx-Iaa proved to be the most active (IC50 = 1.05 × 10(-9) M). The compounds Boc-Phe(4-OMe)-MeLeu-AHGHA-Ahx-Iaa and Boc-Phe(4-OMe)-MeLeu-AHPPA-Ahx-Iaa are resistant to chymotrypsin.

The role of dietary potassium in hypertension and diabetes

Potassium is an essential mineral which plays major roles for the resting membrane potential and the intracellular osmolarity. In addition, for several years, it has been known that potassium also affects endothelial and vascular smooth muscle functions and it has been repeatedly shown that an increase in potassium intake shifts blood pressure to a more preferable level. Meanwhile, the blood pressure lowering effects of potassium were presented in several intervention trials and summarized in a handful of meta-analyses. Furthermore, accumulating epidemiological evidence from, especially, the last decade relates low dietary potassium intake or serum potassium levels to an increased risk for insulin resistance or diabetes. However, intervention trials are required to confirm this association. So, in addition to reduction of sodium intake, increasing dietary potassium intake may positively affect blood pressure and possibly also glucose metabolism in many populations. This concise review not only summarizes the studies linking potassium to blood pressure and diabetes but also discusses potential mechanisms involved, like vascular smooth muscle relaxation and endothelium-dependent vasodilation or stimulation of insulin secretion in pancreatic β-cells, respectively.

Benefits and risks of antihypertensive medications in the elderly

Hypertension is highly prevalent in older age and accounts for a large proportion of cardiovascular (CV) morbidity and mortality worldwide. Isolated systolic hypertension is more common in the elderly than younger adults and associated with poor outcomes such as cerebrovascular disease and acute coronary events. International guidelines are inconsistent in providing recommendations on optimal blood pressure targets in hypertensive elderly patients as a result of the limited evidence in this population. Evidence from clinical trials supports the use of antihypertensive drugs in hypertensive elderly patients due to benefits in reducing CV disease and mortality. However, elderly participants in these trials may not be typical of elderly patients seen in routine clinical practice, and the potential risks associated with use of antihypertensive drugs in the elderly are not as well studied as younger participants. Therefore, the purpose of this review was to provide a comprehensive summary of the benefits and risks of the use of antihypertensive drugs in elderly patients (aged ≥65 years), highlighting landmark clinical trials and observational studies. We will focus on specific outcomes relating to the benefits and risks of these medications in hypertensive elderly patients, such as CV disease, cognitive decline, dementia, orthostatic hypotension, falls, fractures, cancer and diabetes, in order to provide an update of the most relevant and current evidence to help inform clinical decision-making.

ACE2 deficiency reduces β-cell mass and impairs β-cell proliferation in obese C57BL/6 mice

Drugs that inhibit the renin-angiotensin system (RAS) decrease the onset of type 2 diabetes (T2D). Pancreatic islets express RAS components, including angiotensin-converting enzyme 2 (ACE2), which cleaves angiotensin II (Ang II) to angiotensin-(1-7) [Ang-(1-7)]. Overexpression of ACE2 in pancreas of diabetic mice improved glucose homeostasis. The purpose of this study was to determine if deficiency of endogenous ACE2 contributes to islet dysfunction and T2D. We hypothesized that ACE2 deficiency potentiates the decline in β-cell function and augments the development of diet-induced T2D. Male Ace2(+/y) or Ace2(-/y) mice were fed a low-fat (LF) or high-fat (HF) diet for 1 or 4 mo. A subset of 1-mo HF-fed mice were infused with Sal (Sal), losartan (Los), or Ang-(1-7). At 4 mo, while both genotypes of HF-fed mice developed a similar level of insulin resistance, adaptive hyperinsulinemia was reduced in Ace2(-/y) vs. Ace2(+/y) mice. Similarly, in vivo glucose-stimulated insulin secretion (GSIS) was reduced in 1-mo HF-fed Ace2(-/y) compared with Ace2(+/y) mice, resulting in augmented hyperglycemia. The average islet area was significantly smaller in both LF- and HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Additionally, β-cell mass and proliferation were reduced significantly in HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Neither infusion of Los nor Ang-(1-7) was able to correct impaired in vivo GSIS of HF-fed ACE2-deficient mice. These results demonstrate a critical role for endogenous ACE2 in the adaptive β-cell hyperinsulinemic response to HF feeding through regulation of β-cell proliferation and growth.

Calcium channel blockers and hypertension

Effective treatment of high blood pressure (BP) represents a key strategy for reducing the burden of hypertension-related cardiovascular and renal diseases. In spite of these well-established concepts, hypertension remains poorly controlled worldwide. In order to improve BP control in patients with hypertension, several interventions have been proposed, among which (1) preferred use of more effective, sustained, and well-tolerated antihypertensive drug aimed to ensure adherence to prescribed medications and (2) extensive use of rational, integrated, and synergistic combination therapies, even as first-line strategy, aimed to achieve the recommended BP targets. Within the possible antihypertensive drug classes currently available for the clinical management of hypertension, both in monotherapy and in combination therapy, drugs inhibiting the renin-angiotensin system and calcium channel blockers (CCBs) have demonstrated to be effective and safe in lowering BP levels and achieving the recommended BP targets with a good tolerability profile. In particular, CCBs have been one of the most widely used classes of antihypertensive agents in the last 20 years, based on their effectiveness in reducing BP levels, good tolerability, and abundant evidence on reducing cardiovascular and renal consequences of hypertension. This article provides an updated overview of the evidence supporting the use of CCBs-based antihypertensive regimen, both in monotherapy and in combination therapies with different classes of antihypertensive drugs.

A randomized controlled trial of the effects of aerobic dance training on blood lipids among individuals with hypertension on a thiazide

PURPOSE

Hypertension is associated with dyslipidemia. Thiazides adversely affect serum lipid levels in hypertensives. There is currently a dearth of information on benefits of aerobic exercise training on serum lipid levels in individuals on thiazides and this study aimed at bridging this gap in knowledge.

METHODS

This randomized-controlled trial involved 120 newly-diagnosed adults with essential hypertension (≥65 years). They were treated with 50 mg of hydrochlorothiazide + 5 mg of hydrochloride amiloride and 5 or 10 mg of amlodipine for 4-6 weeks before they were randomly assigned into exercise group (EG) and control croup (CG). Only EG underwent 12-week aerobic dance training at 50-70 % of heart rate reserve three times per week. Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglyceride and total cholesterol were measured and recorded at baseline and post-study.

RESULTS

Eighty-eight (45 in EG and 43 in CG) of 120 participants randomly assigned to groups completed the study. Systolic (p = 0.370) and diastolic (p = 0.771) blood pressures (BP) were similar between the two groups at baseline. Systolic (p < 0.001) and diastolic (p < 0.001) BPs reduced significantly in exercise and control groups. LDL-C (from 120.10 ± 33.41 to 110.50 ± 31.68 mg/dl; p = 0.037) and triglyceride (from 117.49 ± 45.12 to 100.63 ± 35.42 mg/dl; p = 0.002) decreased in EG post-study but no significant between-group differences were observed.

CONCLUSIONS

Although, LDL-C and triglyceride are reduced after aerobic dance training, they were not any more than without it. Aerobic dance training has favorable effects on LDL-C, triglyceride, and systolic and diastolic BP in individuals with hypertension on a thiazide.

Impaired glucose metabolism in hypertensive patients with/without the metabolic syndrome

BACKGROUND

In hypertension clinics, screening patients for the metabolic syndrome (MetS) is common practice, while performing the cumbersome oral glucose tolerance test (OGTT) is not. How large is the underestimation of diabetes and prediabetes that ensues is unknown.

METHODS

We recruited N=1397 patients with essential arterial hypertension who underwent a 75-g OGTT and were classified as normally glucotolerant (NGT) or having impaired glucose metabolism (IGM), and as affected or not by MetS (ATPIII criteria). The agreement between the OGTT and the ATPIII criteria in attributing a high cardiovascular risk was estimated by matching the categories of MetS and no-MetS with NGT and IGM.

RESULTS

n=677/1397 patients (48%) satisfied criteria for MetS, while n=757/1397 (54%) had an IGM. MetS and IGM were both present in n=512/1397 patients (36.6%), and both absent in n=475/1397 (34%). Further n=410/1397 patients (29%) were discordant for the two conditions: n=165/410 (40%) had the MetS but were NGT, and n=245/410 (60%) had IGM but no MetS. Among IGM patients, n=168/757 (22%; of which 45 had no MetS) received a new diagnosis of diabetes based on OGTT criteria. Among all discordant patients, those with IGM and no MetS were more commonly males (p<0.001), and had older age (p<0.001) and lower body mass index (p<0.05).

CONCLUSIONS

Among patients with hypertension, the estimate of the prevalence of diabetes and prediabetes, hence of the global cardiovascular risk, can be seriously flawed unless an OGTT is performed. Our results support a wider use of the OGTT in the management of hypertension.

ARB-based single-pill platform to guide a practical therapeutic approach to hypertensive patients

Hypertension is a major modifiable risk for the development of cardiovascular, cerebrovascular and renal diseases. Thus, effective treatment of high blood pressure is an important strategy for reducing disease burden; however, in spite of the availability of numerous effective therapies only 30-40 % of patients with hypertension achieve the recommended blood pressure goals of <140/90 mmHg. Lack of adherence to therapy and reluctance to intensify therapy are cited frequently to explain the discrepancy between potential and attained outcomes. Adherence is closely related to the tolerability, effectiveness and complexity of therapy. Therapeutic inertia may be influenced by concerns over tolerability, as well as the lack of clear preferences for therapies when managing patients with risk factors and comorbidities. Effective and well-tolerated single pill combination therapies are now available that improve adherence and simplify treatment. The combination of a renin-angiotensin system blocker with a calcium channel blocker and a diuretic improves adherence to therapy. We have devised a practical tool for orienting the application of well-tolerated single pill 2/3 drug fixed dose combination therapies in clinical situations commonly encountered when treating hypertensive patients. This approach employs the angiotensin receptor blocker olmesartan alone or in combinations with amlodipine and/or hydrochlorothiazide. This platform is based on clinical evidence, guidelines, best practice, and clinical experience where none of these is available. We believe it will increase the percentage of hypertensive patients who achieve blood pressure control when applied as part of an integrative approach that includes regular follow-up and instruction on lifestyle changes.

Asymmetric dimethylarginine predicts decline of glucose tolerance in men with stable coronary artery disease: a 4.5-year follow-up study

Background

Endothelial dysfunction, largely dependent on impaired nitric oxide bioavailability, has been reportedly associated with incident type 2 diabetes. Our aim was to test the hypothesis that asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide formation, might be linked to future deterioration in glucose tolerance in stable coronary artery disease (CAD).

Methods

We studied 80 non-diabetic men (mean age 55 ± 11 years) with stable angina who underwent successful elective complex coronary angioplasty and were receiving a standard medication according to practice guidelines. Plasma ADMA and its structural isomer symmetric dimethylarginine (SDMA) were measured prior to coronary angiography. An estimate of insulin resistance by homeostasis model assessment (HOMA-IR index) was calculated from fasting insulin and glucose. Deterioration in glucose tolerance was defined as development of type 2 diabetes or progression from a normal glucose tolerance to impaired fasting glucose.

Results

Over a median follow-up of 55 months 11 subjects developed type 2 diabetes and 13 progressed to impaired fasting glucose. Incident deterioration of glucose tolerance was associated with ADMA (hazard ratio [HR] per 1-SD increment 1.64 [95% CI: 1.14–2.35]; P = 0.007), log (HOMA-IR index) (HR = 1.60 [1.16–2.20]; P = 0.004) and body-mass index (HR = 1.44 [0.95–2.17]; P = 0.08) by univariate Cox regression. ADMA (HR = 1.65 [1.14–2.38]; p = 0.008) and log (HOMA-IR index) (HR = 1.55 [1.10–2.17]; P = 0.01) were multivariate predictors of a decline in glucose tolerance. ADMA and SDMA were unrelated to body-mass index, HOMA-IR index, insulin or glucose.

Conclusions

ADMA predicts future deterioration of glucose tolerance independently of baseline insulin resistance in men with stable CAD. Whether this association reflects a contribution of endothelial dysfunction to accelerated decline of insulin sensitivity, or represents only an epiphenomenon accompanying pre-diabetes, remains to be elucidated. The observed relationship might contribute to the well-recognized ability of ADMA to predict cardiovascular outcome.

The transcription factor HNF1α induces expression of angiotensin-converting enzyme 2 (ACE2) in pancreatic islets from evolutionarily conserved promoter motifs

Pancreatic angiotensin-converting enzyme 2 (ACE2) has previously been shown to be critical for maintaining glycemia and β-cell function. Efforts to maintain or increase ACE2 expression in pancreatic β-cells might therefore have therapeutic potential for treating diabetes. In our study, we investigated the transcriptional role of hepatocyte nuclear factor 1α (HNF1α) and hepatocyte nuclear factor 1β (HNF1β) in induction of ACE2 expression in insulin-secreting cells. A deficient allele of HNF1α or HNF1β causes maturity-onset diabetes of the young (MODY) types 3 and 5, respectively, in humans. We found that ACE2 is primarily transcribed from the proximal part of the ACE2 promoter in the pancreas. In the proximal part of the human ACE2 promoter, we further identified three functional HNF1 binding sites, as they have binding affinity for HNF1α and HNF1β and are required for induction of promoter activity by HNF1β in insulinoma cells. These three sites are well-conserved among mammalian species. Both HNF1α and HNF1β induce expression of ACE2 mRNA and lead to elevated levels of ACE2 protein and ACE2 enzymatic activity in insulinoma cells. Furthermore, HNF1α dose-dependently increases ACE2 expression in primary pancreatic islet cells. We conclude that HNF1α can induce the expression of ACE2 in pancreatic islet cells via evolutionarily conserved HNF1 binding sites in the ACE2 promoter. Potential therapeutics aimed at counteracting functional HNF1α depletion in diabetes and MODY3 will thus have ACE2 induction in pancreatic islets as a likely beneficial effect.

Metabolic actions of angiotensin II and insulin: a microvascular endothelial balancing act

Metabolic actions of insulin to promote glucose disposal are augmented by nitric oxide (NO)-dependent increases in microvascular blood flow to skeletal muscle. The balance between NO-dependent vasodilator actions and endothelin-1-dependent vasoconstrictor actions of insulin is regulated by phosphatidylinositol 3-kinase-dependent (PI3K)--and mitogen-activated protein kinase (MAPK)-dependent signaling in vascular endothelium, respectively. Angiotensin II acting on AT₂ receptor increases capillary blood flow to increase insulin-mediated glucose disposal. In contrast, AT₁ receptor activation leads to reduced NO bioavailability, impaired insulin signaling, vasoconstriction, and insulin resistance. Insulin-resistant states are characterized by dysregulated local renin-angiotensin-aldosterone system (RAAS). Under insulin-resistant conditions, pathway-specific impairment in PI3K-dependent signaling may cause imbalance between production of NO and secretion of endothelin-1, leading to decreased blood flow, which worsens insulin resistance. Similarly, excess AT₁ receptor activity in the microvasculature may selectively impair vasodilation while simultaneously potentiating the vasoconstrictor actions of insulin. Therapeutic interventions that target pathway-selective impairment in insulin signaling and the imbalance in AT₁ and AT₂ receptor signaling in microvascular endothelium may simultaneously ameliorate endothelial dysfunction and insulin resistance. In the present review, we discuss molecular mechanisms in the endothelium underlying microvascular and metabolic actions of insulin and Angiotensin II, the mechanistic basis for microvascular endothelial dysfunction and insulin resistance in RAAS dysregulated clinical states, and the rationale for therapeutic strategies that restore the balance in vasodilator and constrictor actions of insulin and Angiotensin II in the microvasculature.

Adipose tissue renin-angiotensin-aldosterone system (RAAS) and progression of insulin resistance

This review focuses on the expression of the key components of the renin-angiotensin-aldosterone axis in fat tissue. At the center of this report is the role of RAAS in normal and excessive fat mass enlargement, the leading etiology of insulin resistance. Understanding the expression and regulation of RAAS components in various fat depots allows insight not only into the processes by which these complex patterns are modified by the enlargement of adipose tissue, but also into their impact on local and systemic response to insulin.

Renin-angiotensin system blocking drugs

The two major classes of drugs that target the RAS are the angiotensin-converting enzyme (ACE) inhibitors and the selective AT1 receptor blockers (ARBs). Although both of these drug classes target angiotensin II, the differences in their mechanisms of action have implications for their effects on other pathways and receptors that may have therapeutic implications. Both ACEIs and ARBs are effective antihypertensive agents that have been shown to reduce the risk of cardiovascular and renal events. Direct inhibition of renin -the most proximal aspect of the RAS -became clinically feasible from 2007 with the introduction of aliskiren. This latter drug has been shown to be efficacious for the management of hypertension. Combined therapy of direct renin-inhibitors with ACEIs or ARBs has been tested in some clinical situations as congestive HF and proteinuria with diverse results. This article tries to offer an updated review of current knowledge on the use of RAS blocking drugs in clinical settings.

Angiotensin converting enzyme 2: a new important player in the regulation of glycemia

In spite of the novel antidiabetic drugs available on the market, type 2 diabetes mellitus (T2DM) affects nearly 25 million people in the USA and causes about 5% of all deaths globally each year. Given the rate and proportion by which T2DM is affecting human beings, it is indispensable to identify new therapeutic targets that can control the disease. Recent preclinical and clinical studies suggest that attenuating the activity of the renin-angiotensin system (RAS) could improve glycemia in diabetic patients. Angiotensin-converting enzyme 2 (ACE2) counteracts RAS overactivity by degrading angiotensin-II (Ang-II), a vasoconstrictor, to Ang-(1-7) which is a vasodilator. A decrease in ACE2 and an increase in A disintegrin and metalloproteinase (ADAM17)-mediated shedding activity have been observed with the progression of T2DM, suggesting the importance of this mechanism in the disease. Indeed, restoration of ACE2 improves glycemia in db/db and Ang-II-infused mice. The beneficial effects of ACE2 can be attributed to reduced oxidative stress and ADAM17 expression in the islets of Langerhans in addition to the improvement of blood flow to the β-cells. The advantage of ACE2 over other RAS blockers is that ACE2 not only counteracts the negative effects of Ang-II but also increases Ang-(1-7)/Mas receptor (MasR) [a receptor through which Ang-(1-7) produces its actions] signaling in the cells. Increased Ang-(1-7)/MasR signaling has been reported to improve insulin sensitivity and glycemia in diabetic animals. Altogether, ACE2/Ang-(1-7)/MasR axis of the RAS appears to be protective in T2DM and strategies to restore ACE2 levels in the disease seem to be a promising therapy for Ang-II-mediated T2DM.

Pancreatic angiotensin-converting enzyme 2 improves glycemia in angiotensin II-infused mice

An overactive renin-angiotensin system (RAS) is known to contribute to type 2 diabetes mellitus (T2DM). Although ACE2 overexpression has been shown to be protective against the overactive RAS, a role for pancreatic ACE2, particularly in the islets of Langerhans, in regulating glycemia in response to elevated angiotensin II (Ang II) levels remains to be elucidated. This study examined the role of endogenous pancreatic ACE2 and the impact of elevated Ang II levels on the enzyme's ability to alleviate hyperglycemia in an Ang II infusion mouse model. Male C57bl/6J mice were infused with Ang II or saline for a period of 14 days. On the 7th day of infusion, either an adenovirus encoding human ACE2 (Ad-hACE2) or a control adenovirus (Ad-eGFP) was injected into the mouse pancreas. After an additional 7-8 days, glycemia and plasma insulin levels as well as RAS components expression and oxidative stress were assessed. Ang II-infused mice exhibited hyperglycemia, hyperinsulinemia, and impaired glucose-stimulated insulin secretion from pancreatic islets compared with control mice. This phenotype was associated with decreased ACE2 expression and activity, increased Ang II type 1 receptor (AT1R) expression, and increased oxidative stress in the mouse pancreas. Ad-hACE2 treatment restored pancreatic ACE2 expression and compensatory activity against Ang II-mediated impaired glycemia, thus improving β-cell function. Our data suggest that decreased pancreatic ACE2 is a link between overactive RAS and impaired glycemia in T2DM. Moreover, maintenance of a normal endogenous ACE2 compensatory activity in the pancreas appears critical to avoid β-cell dysfunction, supporting a therapeutic potential for ACE2 in controlling diabetes resulting from an overactive RAS.

The endothelium in diabetes: its role in insulin access and diabetic complications

The vascular endothelium has been identified as an important component in diabetes-associated complications, which include many cardiovascular disorders such as atherosclerosis, hypertension and peripheral neuropathy. Additionally, insulin's actions on the endothelium are now seen as a major factor in the metabolic effects of the hormone by increasing access to insulin sensitive tissues. Endothelial function is impaired in diabetes, obesity, and the metabolic syndrome, which could reduce insulin access to the tissue, and thus reduce insulin sensitivity independently of direct effects at the muscle cell. As such, the endothelium is a valid target for treatment of both the impaired glucose metabolism in diabetes, as well as the vascular based complications of diabetes. Here we review the basics of the endothelium in insulin action, with a focus on the skeletal muscle as insulin's major metabolic organ, and how this is affected by diabetes. We will focus on the most recent developments in the field, including current treatment possibilities.

Redox-inflammatory synergy in the metabolic syndrome

Metabolic syndrome (MetS) comprises interrelated disease states including obesity, insulin resistance and type 2 diabetes (T2DM), dyslipidemia, and hypertension. Essential to normal physiological function, and yet massively damaging in excess, oxidative stress and inflammation are pivotal common threads among the pathologies of MetS. Increasing evidence indicates that redox and inflammatory dysregulation parallels the syndrome's physiological, biochemical, and anthropometric features, leading many to consider the pro-oxidative, pro-inflammatory milieu an unofficial criterion in itself. Left unchecked, cross-promotion of oxidative stress and inflammation creates a feed-forward cycle that can initiate and advance disease progression. Such redox-inflammatory integration is evident in the pathogenesis of obesity, insulin resistance and T2DM, atherogenic dyslipidemia, and hypertension, and is thus hypothesized to be the "common soil" from which they develop. The present review highlights the synergistic contributions of redox-inflammatory processes to each of the components of the MetS.

Associations of kidney disease measures with mortality and end-stage renal disease in individuals with and without hypertension: a meta-analysis

BACKGROUND

Hypertension is the most prevalent comorbidity in individuals with chronic kidney disease. However, whether the association of the kidney disease measures, estimated glomerular filtration rate (eGFR) and albuminuria, with mortality or end-stage renal disease (ESRD) differs by hypertensive status is unknown.

METHODS

We did a meta-analysis of studies selected according to Chronic Kidney Disease Prognosis Consortium criteria. Data transfer and analyses were done between March, 2011, and June, 2012. We used Cox proportional hazards models to estimate the hazard ratios (HR) of mortality and ESRD associated with eGFR and albuminuria in individuals with and without hypertension.

FINDINGS

We analysed data for 45 cohorts (25 general population, seven high-risk, and 13 chronic kidney disease) with 1,127,656 participants, 364,344 of whom had hypertension. Low eGFR and high albuminuria were associated with mortality irrespective of hypertensive status in the general population and high-risk cohorts. All-cause mortality risk was 1·1-1·2 times higher in individuals with hypertension than in those without hypertension at preserved eGFR. A steeper relative risk gradient in individuals without hypertension than in those with hypertension at eGFR range 45-75 mL/min per 1·73 m(2) led to much the same mortality risk at lower eGFR. With a reference eGFR of 95 mL/min per 1·73 m(2) in each group to explicitly assess interaction, adjusted HR for all-cause mortality at eGFR 45 mL/min per 1·73 m(2) was 1·77 (95% CI 1·57-1·99) in individuals without hypertension versus 1·24 (1·11-1·39) in those with hypertension (p for overall interaction=0·0003). Similarly, for albumin-creatinine ratio of 300 mg/g (vs 5 mg/g), HR was 2·30 (1·98-2·68) in individuals without hypertension versus 2·08 (1·84-2·35) in those with hypertension (p for overall interaction=0·019). We recorded much the same results for cardiovascular mortality. The associations of eGFR and albuminuria with ESRD, however, did not differ by hypertensive status. Results for chronic kidney disease cohorts were similar to those for general and high-risk population cohorts.

INTERPRETATION

Chronic kidney disease should be regarded as at least an equally relevant risk factor for mortality and ESRD in individuals without hypertension as it is in those with hypertension.

FUNDING

US National Kidney Foundation.

Angiotensin-converting enzyme inhibitors reduce mortality in hypertension: a meta-analysis of randomized clinical trials of renin-angiotensin-aldosterone system inhibitors involving 158,998 patients

Aims

Renin–angiotensin–aldosterone system (RAAS) inhibitors are well established for the reduction in cardiovascular morbidity, but their impact on all-cause mortality in hypertensive patients is uncertain. Our objective was to analyse the effects of RAAS inhibitors as a class of drugs, as well as of angiotensin-converting enzyme (ACE) inhibitors and AT1 receptor blockers (ARBs) separately, on all-cause mortality.

Methods and results

We performed a pooled analysis of 20 cardiovascular morbidity–mortality trials. In each trial at least two-thirds of the patients had to be diagnosed with hypertension, according to the trial-specific definition, and randomized to treatment with an RAAS inhibitor or control treatment. The cohort included 158 998 patients (71 401 RAAS inhibitor; 87 597 control). The incidence of all-cause death was 20.9 and 23.3 per 1000 patient-years in patients randomized to RAAS inhibition and controls, respectively. Overall, RAAS inhibition was associated with a 5% reduction in all-cause mortality (HR: 0.95, 95% CI: 0.91–1.00, P= 0.032), and a 7% reduction in cardiovascular mortality (HR: 0.93, 95% CI: 0.88–0.99, P= 0.018). The observed treatment effect resulted entirely from the class of ACE inhibitors, which were associated with a significant 10% reduction in all-cause mortality (HR: 0.90, 95% CI: 0.84–0.97, P= 0.004), whereas no mortality reduction could be demonstrated with ARB treatment (HR: 0.99, 95% CI: 0.94–1.04, P= 0.683). This difference in treatment effect between ACE inhibitors and ARBs on all-cause mortality was statistically significant (P-value for heterogeneity 0.036).

Conclusion

In patients with hypertension, treatment with an ACE inhibitor results in a significant further reduction in all-cause mortality. Because of the high prevalence of hypertension, the widespread use of ACE inhibitors may result in an important gain in lives saved.