Impact of diabetes and hypertension on the heart

Association of Chronic Kidney Disease with Cardiovascular Disease in Cancer Patients: A Cross-Sectional Study

INTRODUCTION

Due to the cardiotoxicity of cancer treatment and traditional risk factors for cardiovascular disease (CVD) such as obesity, diabetes, dyslipidemia, and hypertension, cancer patients are at higher risk of developing CVD. However, limited research exists on the correlation between chronic kidney disease (CKD) and CVD risk in cancer patients.

METHODS

This cross-sectional study selected cancer patients aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES) conducted from 2015 to 2020. Multivariable logistic regression was used to assess the association between CKD and CVD in cancer patients. Additionally, subgroup analyses were conducted to investigate the association among different groups of cancer patients.

RESULTS

We included 1,700 adult cancer patients (52.53% were females). After multivariable adjustment for covariates including traditional CVD factors, CKD was significantly associated with CVD, with an odds ratio (95% confidence interval) and p value of 1.61 (1.18, 2.19) and 0.004. Subgroup analyses after multivariable adjustment showed a significant correlation between CKD and increased CVD risk in the following cancer patients: age ≥60 years, males, white ethnicity, and individuals with or without traditional CVD factors (obesity, diabetes, dyslipidemia, and hypertension).

CONCLUSIONS

CKD remains a significant factor in the higher risk of CVD among adult cancer patients in the United States, even after adjustment for traditional CVD risk factors. Therefore, to reduce the risk of CVD in cancer patients, it is important to treat CKD as a non-traditional risk factor for CVD and actively manage it.

Anti-Hyperglycemic Effects of Bioactive Compounds in the Context of the Prevention of Diet-Related Diseases

Diet-related diseases are health conditions primary caused by poor nutrition. These diseases encompass obesity, type 2 diabetes, cardiovascular diseases, osteoporosis, and certain types of cancer. Functional foods and nutraceuticals offer a promising dietary approach to addressing diet-related diseases across various clinical contexts. The bioactive compounds found in these foods are the subject of intensive studies aimed at discovering their anti-hyperglycemic effects, which are beneficial in alleviating chronic diseases and protecting human health. Hyperglycemia is a common risk factor for metabolic disease and mortality worldwide. Chronic hyperglycemic states can lead to many long-term complications, such as retinopathy, neuropathy, kidney disease, heart disease, cancer, and diabetes. This review explores the potential anti-hyperglycemic effects of bioactive compounds, specifically flavonoids and phenolic acids, and their proposed roles in mitigating chronic diseases and promoting human health. By thoroughly examining the existing literature, we investigated the potential anti-hyperglycemic effects of these bioactive compounds and their proposed roles in managing chronic diseases. The goal of this paper was to enhance our comprehension of how these compounds modulate glucose transporters, with the ultimate aim of identifying effective strategies for the prevention and treatment of diet-related diseases. Overall, this review investigated the use of bioactive compounds from functional foods as potential inhibitors of glucose transporters in the context of prevention/treatment of diet-related diseases.

Future perspective in diabetic patients with pre- and post-capillary pulmonary hypertension

Pulmonary hypertension is a clinical syndrome that may include multiple clinical conditions and can complicate the majority of cardiovascular and respiratory diseases. Pulmonary hypertension secondary to left heart disease is the prevalent clinical condition and accounts for two-thirds of all cases. Type 2 diabetes mellitus, which affects about 422 million adults worldwide, has emerged as an independent risk factor for the development of pulmonary hypertension in patients with left heart failure. While a correct diagnosis of pulmonary hypertension secondary to left heart disease requires invasive hemodynamic evaluation through right heart catheterization, several scores integrating clinical and echocardiographic parameters have been proposed to discriminate pre- and post-capillary types of pulmonary hypertension. Despite new emerging evidence on the pathophysiological mechanisms behind the effects of diabetes in patients with pre- and/or post-capillary pulmonary hypertension, no specific drug has been yet approved for this group of patients. In the last few years, the attention has been focused on the role of antidiabetic drugs in patients with pulmonary hypertension secondary to left heart failure, both in animal models and in clinical trials. The aim of the present review is to highlight the links emerged in the recent years between diabetes and pre- and/or post-capillary pulmonary hypertension and new perspectives for antidiabetic drugs in this setting.

Metformin in Pulmonary Hypertension in Left Heart Disease

Metformin is ubiquitously used in the management of Type II Diabetes Mellitus (DMII). Over the years, our growing knowledge of its therapeutic potential has broadened its use to the treatment of infertility in polycystic ovarian syndrome, gestational diabetes, and even obesity. Recently, it has been suggested as a novel therapy in cardiovascular disease (CVD). Given that CVD is the leading cause of death in patients with DMII, with ~ 75% dying from a cardiovascular event, the intersection of DMII and CVD provides a unique therapeutic target. In particular, pulmonary hypertension (PH) related to CVD (Group II PH) may be an optimal target for metformin therapy. The objective of this review article is to provide an overview of the pathophysiology of PH related to left heart disease (PH-LHD), outline the proposed pathophysiologic mechanism of insulin resistance in heart failure and PH-LHD, and evaluate the role metformin may have in heart failure and PH-LHD.

Flavonoids and Their Metabolites: Prevention in Cardiovascular Diseases and Diabetes

The occurrence of atherosclerosis and diabetes is expanding rapidly worldwide. These two metabolic disorders often co-occur, and are part of what is often referred to as the metabolic syndrome. In order to determine future therapies, we propose that molecular mechanisms should be investigated. Once the aetiology of the metabolic syndrome is clear, a nutritional intervention should be assessed. Here we focus on the protective effects of some dietary flavonoids, and their metabolites. Further studies may also pave the way for development of novel drug candidates.

Effect of Nigella sativa supplementation over a one-year period on lipid levels, blood pressure and heart rate in type-2 diabetic patients receiving oral hypoglycemic agents: nonrandomized clinical trial

BACKGROUND

Diabetic patients with hypertension and dyslipidemia are at a high risk of cardiovascular complications.

OBJECTIVES

To determine the effect of Nigella sativa supplementation on the lipid profile, mean arterial pressure, and heart rate in persons with type 2 diabetes on oral hypoglycemic agents (OHA).

DESIGN

Single-blind, nonrandomized.

SETTING

Diabetes clinic of a university hospital in Saudi Arabia.

PATIENTS AND METHODS

Type-2 diabetic patients were recruited by purposive sampling and assigned to treatment or control at the discretion of the investigator with the patient blinded to treatment. Before the in.tervention and every 3 months thereafter until the end of the treatment period, the following parameters were measured: triglycerides (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and body mass index (BMI). Results at the baseline and each subsequent visit were compared between the two groups.

MAIN OUTCOME MEASURE(S)

Lipid and cardiovascular parameters, and BMI.

RESULTS

Fifty-seven patients were assigned to receive N sativa 2 g daily for one year and 57 were assigned to receive an identical regimen of placebo, along with OHA. A significant decrease in HDL-C and increase in the TC/HDL-C and LDL-C/HDL-C ratios were seen in the control group. The N sativa group had a signifi.cant decline in TC, LDL-C, TC/HDL-C and LDL-C/HDL-C ratios, compared with the respective baseline data and the control group. HDL-C was significantly elevated in the N sativa group. The control group showed a significant elevation in MAP. The N sativa group had a significant reduction in SBP, DBP, MAP and HR and a significant decrease in DBP, MAP and HR as compared with the control group.

CONCLUSION

N sativa supplementation improves total cholesterol, mean arterial pressure and heart rate in type 2 diabetes patients on oral hypoglycemic agents.

LIMITATIONS

There were 9 subjects in each group lost to follow up; thus the sample size could not be maintained as per the sample size calculation. The study was nonrandomized and thus there was a possibility of allocation bias. (Clinical trial registration number: CTRI/2013/06/003781, Clinical Trial Registry of India).

Correlation between Diastolic Function and Endothelial Function in Patients with Type 2 Diabetes and Hypertension

BACKGROUND

Endothelial dysfunction may be involved in the pathophysiology of cardiac abnormalities in patients with diabetes mellitus (DM). A correlation between endothelial dysfunction and diastolic dysfunction in patients with type 1 DM has been demonstrated, but this relationship has not been well investigated in type 2 DM.

OBJECTIVE

Compare groups of patients with type 2 DM and hypertension with and without diastolic dysfunction using endothelial function indexes, and to assess whether correlations exist between the diastolic function and the endothelial function indexes.

METHOD

This was a cross-sectional study of 34 men and women with type 2 DM and hypertension who were aged between 40 and 70 years and were categorized based on assessments of their Doppler echocardiographic parameters as having normal (14 patients) and abnormal (20 patients) diastolic function. Flow-mediated dilatation (FMD) assessments of the brachial artery evaluated the patients' endothelial function.

RESULTS

The mean maximum FMD was 7.15 ± 2.80% for the patients with diastolic dysfunction and it was 11.85 ± 4.77% for the patients with normal diastolic function (p = 0.004). Correlations existed between the maximum FMD and the E/e' ratio (p = 0.040, r = -0.354) and the early wave velocity (e') at the lateral mitral annulus (p = 0.002, r = 0.509).

CONCLUSION

The endothelial function assessed by FMD was worse in hypertensive diabetic patients with diastolic dysfunction. There were correlations between the diastolic function indexes and the endothelial function indexes in our sample.

A rational approach to fluid therapy in sepsis

Aggressive fluid resuscitation to achieve a central venous pressure (CVP) greater than 8 mm Hg has been promoted as the standard of care, in the management of patients with severe sepsis and septic shock. However recent clinical trials have demonstrated that this approach does not improve the outcome of patients with severe sepsis and septic shock. Pathophysiologically, sepsis is characterized by vasoplegia with loss of arterial tone, venodilation with sequestration of blood in the unstressed blood compartment and changes in ventricular function with reduced compliance and reduced preload responsiveness. These data suggest that sepsis is primarily not a volume-depleted state and recent evidence demonstrates that most septic patients are poorly responsive to fluids. Furthermore, almost all of the administered fluid is sequestered in the tissues, resulting in severe oedema in vital organs and, thereby, increasing the risk of organ dysfunction. These data suggest that a physiologic, haemodynamically guided conservative approach to fluid therapy in patients with sepsis would be prudent and would likely reduce the morbidity and improve the outcome of this disease.

Comparison of benazepril and losartan on endothelial function and vascular stiffness in patients with Type 2 diabetes mellitus and hypertension: A randomized controlled trial

INTRODUCTION

The purpose of this study was to compare the effects of benazepril and losartan on endothelial function and vascular stiffness, in patients with diabetes mellitus and hypertension.

MATERIALS AND METHODS

We included hypertensive diabetic patients with an office systolic blood pressure (BP) ⩾ 130 mmHg and/or diastolic BP ⩾ 80 mmHg. Patients were rolled over to amlodipine for 6 weeks, then we performed C-reactive protein assays, BP measurement and vascular tests; next, patients were randomized to benazepril or losartan. The tests were repeated after 12 weeks.

RESULTS

We randomized 14 patients to benazepril and 16 to losartan. There were no differences in systolic (139 versus 134 mmHg, p = 0.618) and diastolic (82 versus 80 mmHg, p = 0.950) BP at the end of the study. C-reactive protein values were lower in the benazepril group (0.38 versus 0.42 mg/dl, p = 0.020). There was a slightly higher flow-mediated vasodilation (FMD) response in the benazepril group (45% increase, p = 0.057) than in the losartan group (19% increase, p = 0.132). Both central systolic BP (129 versus 123 mmHg, p = 0.934) and carotid-femoral pulse wave velocity (cfPWV) (8.5 versus 8.5 m/s, p = 0.280) were the same between groups.

CONCLUSIONS

Hypertensive diabetic patients using benazepril had a greater reduction in C-reactive protein, and a slight improvement in FMD, than those taking losartan.

Alterations in connexin 43 during diabetic cardiomyopathy: competition of tyrosine nitration versus phosphorylation

BACKGROUND

Cardiac conduction abnormalities are observed early in the progression of type 1 diabetes (T1D), but the mechanism(s) involved are undefined. Connexin 43, a critical component of ventricular gap junctions, depends on tyrosine phosphorylation status to modulate channel conductance; changes in connexin 43 content, distribution, and/or phosphorylation status may be involved in cardiac rhythm disturbances. We tested the hypothesis that cardiac content and/or distribution of connexin 43 is altered in a rat model of T1D cardiomyopathy, investigating a mechanistic role for tyrosine.

METHODS

Electrocardiographic analyses were conducted during the progression of diabetic cardiomyopathy in rats dosed with streptozotocin (STZ; 65 mg/kg) 3, 7, and 35 days after the induction of diabetes. Following functional analyses, we conducted immunohistochemical and immunoprecipitation studies to assess alterations in connexin 43.

RESULTS

There was significant evidence of ventricular conduction abnormalities (QRS complex, Q-T interval) as early as 7 days after STZ, persisting throughout the study. Connexin 43 levels were increased 7 days after STZ and remained elevated throughout the study. Connexin 40 content was unchanged relative to controls throughout the study. Changes in connexin 43 distribution were also observed: connexin 43 staining was dispersed from myocyte short axis junctions. Connexin 43 tyrosine phosphorylation declined during the progression of diabetes, with concurrent increases in tyrosine nitration.

CONCLUSIONS

The data suggest that changes in connexin 43 content and distribution occur during experimental diabetes and likely contribute to alterations in cardiac function, and that oxidative modification of tyrosine-mediated signaling may play a mechanistic role.

New strategies for heart failure with preserved ejection fraction: the importance of targeted therapies for heart failure phenotypes

The management of heart failure with reduced ejection fraction (HF-REF) has improved significantly over the last two decades. In contrast, little or no progress has been made in identifying evidence-based, effective treatments for heart failure with preserved ejection fraction (HF-PEF). Despite the high prevalence, mortality, and cost of HF-PEF, large phase III international clinical trials investigating interventions to improve outcomes in HF-PEF have yielded disappointing results. Therefore, treatment of HF-PEF remains largely empiric, and almost no acknowledged standards exist. There is no single explanation for the negative results of past HF-PEF trials. Potential contributors include an incomplete understanding of HF-PEF pathophysiology, the heterogeneity of the patient population, inadequate diagnostic criteria, recruitment of patients without true heart failure or at early stages of the syndrome, poor matching of therapeutic mechanisms and primary pathophysiological processes, suboptimal study designs, or inadequate statistical power. Many novel agents are in various stages of research and development for potential use in patients with HF-PEF. To maximize the likelihood of identifying effective therapeutics for HF-PEF, lessons learned from the past decade of research should be applied to the design, conduct, and interpretation of future trials. This paper represents a synthesis of a workshop held in Bergamo, Italy, and it examines new and emerging therapies in the context of specific, targeted HF-PEF phenotypes where positive clinical benefit may be detected in clinical trials. Specific considerations related to patient and endpoint selection for future clinical trials design are also discussed.

Diabetic cardiomyopathy: ongoing controversies in 2012

Diabetic cardiomyopathy is a controversial clinical entity that in its initial state is usually characterized by left ventricular diastolic dysfunction in patients with diabetes mellitus that cannot be explained by coronary artery disease, hypertension, or any other known cardiac disease. It was reported in up to 52-60% of well-controlled type-II diabetic subjects, but more recent studies, using standardized tissue Doppler criteria and more strict patient selection, revealed a much lower prevalence. The pathological substrate is myocardial damage, left ventricular hypertrophy, interstitial fibrosis, structural and functional changes of the small coronary vessels, metabolic disturbance, and autonomic cardiac neuropathy. Hyperglycemia causes myocardial necrosis and fibrosis, as well as the increase of myocardial free radicals and oxidants, which decrease nitric oxide levels, worsen the endothelial function, and induce myocardial inflammation. Insulin resistance with hyperinsulinemia and decreased insulin sensitivity may also contribute to the left ventricular hypertrophy. Clinical manifestations of diabetic cardiomyopathy may include dyspnea, arrhythmias, atypical chest pain, and dizziness. Currently, there is no specific treatment of diabetic cardiomyopathy that targets its pathophysiological substrate, but various therapeutic options are discussed that include improving diabetic control with both diet and drugs (metformin and thiazolidinediones), the use of ACE inhibitors, beta blockers, and calcium channel blockers. Daily physical activity and a reduction in body mass index may improve glucose homeostasis by reducing the glucose/insulin ratio and the increase of both insulin sensitivity and glucose oxidation by the skeletal and cardiac muscles.

A guide to the management of blood pressure in the diabetic hypertensive patient

Diabetes mellitus and hypertension frequently coexist in patients with the insulin resistance syndrome (IRS). Patients with both diabetes and hypertension typically have widespread endothelial dysfunction, increased oxidative stress, an activated sympathoadrenal system, and an elevated systemic burden of inflammatory mediators. Patients with diabetes and hypertension also have concomitant mixed dyslipidemia and obesity with significant frequency, and are at high risk for the development of macro- and microvascular disease, congestive heart failure, and nephropathy. Current data suggest that ACE inhibitors or angiotensin receptor blockers with or without a diuretic are important, if not preferred, initial therapies for the patient with diabetes and hypertension. Other drug classes such as combined alpha-/beta-adrenoceptor antagonists, dihydropyridine calcium channel antagonists (CCAs), and peripheral alpha-adrenoceptor antagonists are also useful therapeutic options in these patients. In order to optimally reduce the risk for cardiovascular events in the patient with diabetes and hypertension, optimal BP control should be coupled with comprehensive lifestyle modification and aggressive management of dyslipidemia and hyperglycemia.

Myocardial fatty acid metabolism and lipotoxicity in the setting of insulin resistance

Management of diabetes and insulin resistance in the setting of cardiovascular disease has become an important issue in an increasingly obese society. Besides the development of hypertension and buildup of atherosclerotic plaques, the derangement of fatty acid and lipid metabolism in the heart plays an important role in promoting cardiac dysfunction and oxidative stress. This review discusses the mechanisms by which metabolic inflexibility in the use of fatty acids as the preferred cardiac substrate in diabetes produces detrimental effects on mechanical efficiency, mitochondrial function, and recovery from ischemia. Lipid accumulation and the consequences of toxic lipid metabolites are also discussed.

The effect of sitagliptin versus glibenclamide on arterial stiffness, blood pressure, lipids, and inflammation in type 2 diabetes mellitus patients

AIM

This study evaluated the effect of sitagliptin versus glibenclamide on arterial stiffness, blood pressure, lipid profile, oxidative stress, and high-sensitivity C-reactive protein (hsCRP) in type 2 diabetes mellitus patients.

SUBJECTS AND METHODS

Forty diabetes patients, inadequately controlled on metformin, were randomly assigned to either sitagliptin (100 mg/day) or glibenclamide (5 mg/day) for 3 months. Following a 1-month washout period, a crossover switch from glibenclamide to sitagliptin and vice versa was performed for an additional 3 months. Arterial stiffness, 24-h ambulatory blood pressure monitoring, lipids, hsCRP, glycated hemoglobin, fasting glucose, STAT-8-isoprostane (a measure of oxidative stress), body mass index (BMI), and waist circumference were measured at baseline and at 3 months with each of the study drugs.

RESULTS

Thirty-four patients completed the study. Glibenclamide had a better glucose-lowering effect than sitagliptin, but this was associated with more hypoglycemic events. BMI increased following glibenclamide treatment, whereas sitagliptin proved weight-neutral. Mean BMI gain was +0.5±1.0 kg/m(2) for glibenclamide versus -0.01±0.9 kg/m(2) for sitagliptin (P<0.001). Triglyceride levels significantly dropped following sitagliptin, although they remained unaltered after glibenclamide treatment. Mean triglyceride decrease was -18.4±45 mg/mL after sitagliptin but -0.2±57 mg/dL following glibenclamide treatment (P=0.018). There was no change in low-density lipoprotein, high-density lipoprotein, arterial stiffness, blood pressure monitoring, hsCRP, or STAT-8-isoprostane with each of the study drugs.

CONCLUSIONS

Sitagliptin, but not glibenclamide, demonstrated a significant beneficial effect on BMI and triglyceride levels. However, arterial stiffness, blood pressure, oxidative stress, and inflammatory status were not significantly affected by adding sitagliptin or glibenclamide to metformin-treated type 2 diabetes patients.

Therapies for type 2 diabetes: lowering HbA1c and associated cardiovascular risk factors

OBJECTIVES

To summarize data supporting the effects of antidiabetes agents on glucose control and cardiovascular risk factors in patients with type 2 diabetes.

METHODS

Studies reporting on the effects of antidiabetes agents on glycemic control, body weight, lipid levels, and blood pressure parameters are reviewed and summarized for the purpose of selecting optimal therapeutic regimens for patients with type 2 diabetes.

RESULTS

National guidelines recommend the aggressive management of cardiovascular risk factors in patients with type 2 diabetes, including weight loss and achieving lipid and blood pressure treatment goals. All antidiabetes pharmacotherapies lower glucose; however, effects on cardiovascular risk factors vary greatly among agents. While thiazolidinediones, sulfonylureas, and insulin are associated with weight gain, dipeptidyl peptidase-4 inhibitors are considered weight neutral and metformin can be weight neutral or associated with a small weight loss. Glucagon-like peptide-1 receptor agonists and amylinomimetics (e.g. pramlintide) result in weight loss. Additionally, metformin, thiazolidinediones, insulin, and glucagon-like peptide-1 receptor agonists have demonstrated beneficial effects on lipid and blood pressure parameters.

CONCLUSION

Management of the cardiovascular risk factors experienced by patients with type 2 diabetes requires a multidisciplinary approach with implementation of treatment strategies to achieve not only glycemic goals but to improve and/or correct the underlying cardiovascular risk factors.

Neurohormonal profile of patients with heart failure and diabetes

Background. Neurohormonal activation is generally recognised to play an important role in the pathophysiology, prognosis and treatment of chronic heart failure (HF). While the number of patients with diabetes increases, little if anything is known about neurohormonal activation in HF patients with diabetes. Methods. The study population consisted of 371 patients with advanced HF who were enrolled in a multicentre survival trial. Ten different plasma neurohormones were measured (noradrenaline, adrenaline, dopamine, aldosterone, renin, endothelin, atrial natriuretic peptide [ANP], N-terminal (pro)ANP, brain natriuretic peptide [BNP] and N-terminal (pro)BNP. Comparisons were made between patients with diabetes (n=81) and those without (n=290). Results. At baseline, the two groups were comparable regarding age (mean 68 years), left ventricular ejection fraction (23%), severity and aetiology of HF, while body weight was higher in those with diabetes (77.4 vs. 74.2 kg, p=0.04). Most plasma neurohormones were similar between groups, but patients with diabetes had higher values of BNP (94 vs. 47 pmol/l, p=0.03), while a similar trend was observed for N-terminal (pro)BNP (750 vs. 554 pmol/l, p=0.10). During almost five years of follow-up, 51/81 patients with diabetes died (63%), as compared with 144 of 290 non-diabetic patients (50%) who died (p=0.046). Natriuretic peptides and noradrenaline were the most powerful predictors of mortality in both diabetic and non-diabetic HF patients. Conclusion. HF patients with diabetes have higher (N-terminal (pro)) BNP levels than non-diabetic patients, while other neurohormones are generally similar. Natriuretic peptides are also good prognostic markers in diabetic HF patients. (Neth Heart J 2010;18:190-6.).

Current controversies in heart failure with a preserved ejection fraction

Heart failure with a preserved ejection fraction is a fascinating and multifaceted condition that has provoked enormous debate and a wealth of mechanistic studies. Controversies exist with regard to its nomenclature. If its nomenclature is questioned, one can be certain the pathogenesis is ill understood. If the pathogenesis is disputed, the diagnosis becomes difficult and inconsistent. These diagnostic challenges result in inappropriate recruitment to clinical trials. Therefore, the trials may be underpowered and difficult to interpret. This paper examines contemporary theories of heart failure with a preserved ejection fraction, clarifies the controversies and attempts to resolve the divergences of opinion.

Diabetic cardiomyopathy--a distinct disease?

Diabetic individuals have a significantly increased likelihood of developing cardiovascular disease. Whilst part of this association is explained by the presence of concomitant risk factors, large epidemiological studies have consistently reported diabetes as a strong risk factor for the development of heart failure after adjusting for such covariates. This has resulted in the notion that there is a distinct cardiomyopathy specific to diabetes, termed 'diabetic cardiomyopathy'. The natural history is characterized by a latent subclinical period, during which there is evidence of diastolic dysfunction and left ventricular hypertrophy, before overt clinical deterioration and systolic failure ensue. These clinical findings have been supported by a growing body of experimental data which support the notion that diabetes inflicts a direct insult to the myocardium, with cellular, structural and functional changes manifest as the diabetic myocardial phenotype. Several of these mechanisms appear to work in unison, forming complicated reciprocal pathways of disease. Reactive oxygen species and alterations in intracellular calcium homeostasis appear to play significant roles in many of these mechanisms. Determining the hierarchy of this cascade of disease will allow identification of the pathological trigger most responsible for disease. Translational research in this field is currently hindered by a lack of clinical studies and intervention trials specifically in patients with diabetic cardiomyopathy. Future clinical and experimental studies of accurate models of diabetic cardiomyopathy should help to define the true aetiology and lead to the development of specific pharmacotherapies for this condition, ultimately reducing the increased cardiovascular morbidity and mortality in diabetic patients.

Improving microvascular outcomes in patients with diabetes through management of hypertension

Diabetes mellitus is an independent risk factor for cardiovascular disease (CVD) and current opinion holds that hyperglycemia directly damages smaller blood vessels, resulting in microvascular complications of nephropathy, retinopathy, and neuropathy. In a patient with diabetes, hypertension compounds and greatly increases the risk of microvascular complications, and thus the risk of end-stage kidney disease, vision loss, and nontraumatic limb amputations. Hypertension and hyperglycemia directly damage the microvasculature, leading to small vessel dysfunction that manifests as the clinical disease states of diabetic retinopathy and nephropathy. Early recognition and treatment of both hyperglycemia and hypertension may prevent vision loss and chronic kidney disease, the devastating outcomes of these microvascular complications. One of the pathogenic mechanisms for microvascular dysfunction is upregulation of the angiotensin II type 1 receptor, the most physiologically common receptor for the vasoconstrictor properties of angiotensin II. In patients with diabetic retinopathy and nephropathy, tight control of blood pressure (BP) (< 130/80 mm Hg) delays the progression of retinopathy and nephropathy in addition to reducing cardiovascular morbidity and mortality. Aggressive treatment with 2 or more antihypertensive agents, selected from different drug classes, is often needed to reach the optimal BP target level. A PubMed search was conducted to identify randomized controlled trials that evaluated hypertension control and microvascular outcomes in patients with diabetes. Several clinical trials have yielded promising data with renin-angiotensin-aldosterone system (RAAS) inhibitors (the direct renin inhibitor aliskiren, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers). Attainment of BP control with RAAS inhibitors reduces the risk for CVD, nephropathy, and retinopathy. In addition, RAAS inhibitors have demonstrated renoprotective effectiveness independent of the BP reduction achieved. This review will examine the results of clinical trials in the context of BP control, diabetes, and the microvascular complications of retinopathy and nephropathy.