Diabetes mellitus and heart failure: basic mechanisms, clinical features, and therapeutic considerations

Predicting depression in patients with heart failure based on a stacking model

BACKGROUND

There is a lack of literature discussing the utilization of the stacking ensemble algorithm for predicting depression in patients with heart failure (HF).

AIM

To create a stacking model for predicting depression in patients with HF.

METHODS

This study analyzed data on 1084 HF patients from the National Health and Nutrition Examination Survey database spanning from 2005 to 2018. Through univariate analysis and the use of an artificial neural network algorithm, predictors significantly linked to depression were identified. These predictors were utilized to create a stacking model employing tree-based learners. The performances of both the individual models and the stacking model were assessed by using the test dataset. Furthermore, the SHapley additive exPlanations (SHAP) model was applied to interpret the stacking model.

RESULTS

The models included five predictors. Among these models, the stacking model demonstrated the highest performance, achieving an area under the curve of 0.77 (95%CI: 0.71-0.84), a sensitivity of 0.71, and a specificity of 0.68. The calibration curve supported the reliability of the models, and decision curve analysis confirmed their clinical value. The SHAP plot demonstrated that age had the most significant impact on the stacking model's output.

CONCLUSION

The stacking model demonstrated strong predictive performance. Clinicians can utilize this model to identify high-risk depression patients with HF, thus enabling early provision of psychological interventions.

Mini-invasive methods of treatment of diabetic foot pain

Neuropathic pain occurs with diabetic polyneuropathy more often than with all polyneuropathies of another etiology. Because the cause of pain can rarely be cured, treatment is usually symptomatic. Neuropathic pain is usually poorly controlled by analgesics. Management of neuropathic pain is started with conservative pharmacotherapy before invasive pain management is applied. Although there are many drugs that can be used in patients with diabetic pain syndrome, pain syndrome can not be surely stoped with monotherapy. In addition, the patient may not tolerate the full therapeutic dose of the drug. All this dictates the need for combination therapy. It is believed that regional anesthesia as an independent type of analgesia or a component of combined anesthesia is the method of choice for the elderly and senile patients. The main reasons for this choice, when comparing regional anesthesia with narcosis, are less stressful response of the organism, absence of depression of the central nervous system, stable reliable analgesia with complete blockade of nociceptive reflexes with the provision of adequate muscle relaxation, prevention of neurovegetative reactions, which ultimately helps to reduce the incidence of postoperative complications and mortality. Clinicians have accumulated considerable experience demonstrating the need for regional analgesia in the management of diabetic foot pain.

The Role of Neuropeptide Y in Cardiovascular Health and Disease

Neuropeptide Y (NPY) is an abundant sympathetic co-transmitter, widely found in the central and peripheral nervous systems and with diverse roles in multiple physiological processes. In the cardiovascular system it is found in neurons supplying the vasculature, cardiomyocytes and endocardium, and is involved in physiological processes including vasoconstriction, cardiac remodeling, and angiogenesis. It is increasingly also implicated in cardiovascular disease pathogenesis, including hypertension, atherosclerosis, ischemia/infarction, arrhythmia, and heart failure. This review will focus on the physiological and pathogenic role of NPY in the cardiovascular system. After summarizing the NPY receptors which predominantly mediate cardiovascular actions, along with their signaling pathways, individual disease processes will be considered. A thorough understanding of these roles may allow therapeutic targeting of NPY and its receptors.

Sorcin ablation plus β-adrenergic stimulation generate an arrhythmogenic substrate in mouse ventricular myocytes

Sorcin, a penta-EF hand Ca²⁺-binding protein expressed in cardiomyocytes, is known to interact with ryanodine receptors and other Ca²⁺ regulatory proteins. To investigate sorcin's influence on cardiac excitation-contraction coupling and its role in the development of cardiac malfunctions, we generated a sorcin knockout (KO) mouse model. Sorcin KO mice presented ventricular arrhythmia and sudden death when challenged by acute stress induced by isoproterenol plus caffeine. Chronic stress, which was induced by transverse aortic constriction, significantly decreased the survival rate of sorcin KO mice. Under isoproterenol stimulation, spontaneous Ca²⁺ release events were frequently observed in sorcin KO cardiomyocytes. Sorcin KO hearts of adult, but not young mice developed overexpression of L-type Ca²⁺ channel and Na⁺-Ca²⁺ exchanger, which enhanced I_Ca and I_NCX. Consequently, spontaneous Ca²⁺ release events in sorcin KO cardiomyocytes were more likely to induce arrhythmogenic delayed afterdepolarizations. Our study demonstrates sorcin deficiency may trigger cardiac ventricular arrhythmias due to Ca²⁺ disturbances, and evidences the critical role of sorcin in maintaining Ca²⁺ homeostasis, especially during the adrenergic response of the heart.

Cardiac Dysfunction and Heart Failure in Hematopoietic Cell Transplantation Survivors: Emerging Paradigms in Pathophysiology, Screening, and Prevention

Hematopoietic cell transplantation (HCT) has been used for curative intent in patients with hematologic and nonhematologic malignancies, resulting in an increasing number of HCT survivors. These survivors are at risk for serious and life-threatening complications, including cardiovascular disease (CVD). This article provides an overview of CVD in HCT survivors, describing the pathophysiology of disease, with a special emphasis on therapeutic exposures and comorbidities unique to this population. This article also discusses novel screening and prevention strategies that have shown promise in non-HCT cancer populations, emphasizing opportunities for collaboration between cardiologists and hematologists to improve the cardiovascular health of HCT survivors.

Management of heart failure with preserved ejection fraction in a local public hospital in Hong Kong

BACKGROUND

Heart failure (HF) is one of the most debilitating chronic illnesses. The prevalence is expected to increase due to aging population. The current study aimed to examine the management of heart failure with preserved ejection fraction (HFpEF) including drug use pattern, direct medical cost and humanistic outcome in a local public hospital in Hong Kong.

METHODS

The current study adopted the retrospective observational study design. Subjects were recruited from the Heart Failure Registry of the Prince of Wales Hospital in Hong Kong between 2006 and 2008 and completed the Minnesota Living with Heart Failure Questionnaire (MLHFQ) at 3 designated time-points conferred eligibility. Patients with significant valvular disorder were excluded. Each patient's medical record was reviewed for 12 months after the date of admission. Heart failure related admissions, clinic visits, cardiovascular drugs, laboratory tests and diagnostic tests were documented. Costs and MLHFQ scores in patients with or without hypertension, diabetes and renal impairment were compared.

RESULTS

A total of 73 HFpEF patients were included. It was found that loop diuretics (93.1%, 78.1%) was the most frequently used agent for HFpEF management in both in-patient and out-patient settings. The mean 1-year direct medical cost was USD$ 19969 (1 US $ = 7.8 HK$), with in-patient ward care contributing to the largest proportion (72.2%) of the total cost. Patients with diabetes or renal impairment were associated with a higher cost of HFpEF management. Significant difference was found in the renal impairment group (median cost: USD$ 24604.2 versus USD$ 12706.8 in no impairment group, p = 0.023). The MLHFQ scores of the subjects improved significantly during the study period (p < 0.0005).

CONCLUSIONS

The cost of management of HFpEF was enormous and further increased in the presence of comorbidities.

The association of comorbid diabetes mellitus and symptoms of depression with all-cause mortality and cardiac rehospitalization in patients with heart failure

BACKGROUND

More than 22% of individuals with diabetes mellitus have concomitant heart failure (HF), and the prevalence of diabetes in those with HF is nearly triple that of individuals without HF. Comorbid depressive symptoms are common in diabetes and HF. Depressive symptoms are an independent predictor of mortality in individuals with diabetes alone, as well as those with HF alone and are a predictor of rehospitalization in those with HF. However, the association of comorbid HF, diabetes and depressive symptoms with all-cause mortality and rehospitalization for cardiac causes has not been determined.

OBJECTIVE

The purpose of this study was to evaluate the association of comorbid HF, diabetes and depression with all-cause mortality and rehospitalization for cardiac cause.

METHOD

Patients provided data at baseline about demographic and clinical variables and depressive symptoms; patients were followed for at least 2 years. Participants were divided into four groups based on the presence and absence of diabetes and depressive symptoms. Cox regression analysis was used to determine whether comorbid diabetes and depressive symptoms independently predicted all-cause mortality and cardiac rehospitalization in these patients with HF.

RESULTS

Patients (n=663) were primarily male (69%), white (76%), and aged 61±13 years. All-cause mortality was independently predicted by the presence of concomitant diabetes and depressive symptoms (HR 3.71; 95% CI 1.49 to 9.25; p=0.005), and depressive symptoms alone (HR 2.29; 95% CI 0.94 to 5.40; p=0.05). The presence of comorbid diabetes and depressive symptoms was also an independent predictor of cardiac rehospitalization (HR 2.36; 95% CI 1.27 to 4.39; p=0.007).

CONCLUSIONS

Comorbid diabetes and depressive symptoms are associated with poorer survival and rehospitalization in patients with HF; effective strategies to regularly evaluate and effectively manage these comorbid conditions are necessary to improve survival and reduce rehospitalization rates.

Disturbed angiogenic activity of adipose-derived stromal cells obtained from patients with coronary artery disease and diabetes mellitus type 2

BACKGROUND

Multipotent mesenchymal stem/stromal cells (MSC) including adipose-derived stromal cells (ADSC) have been successfully applied for cardiovascular diseases treatment. Their regenerative potential is considered due to the multipotency, paracrine activity and immunologic privilege. However, therapeutic efficacy of autologous MSC for myocardial ischemia therapy is modest. We analyzed if ADSC properties are attenuated in patients with chronic diseases such as coronary artery disease (CAD) and diabetes mellitus type 2 (T2DM).

METHODS AND RESULTS

ADSC were isolated from subcutaneous fat tissue of patients without established cardiovascular diseases and metabolic disorders (control group, n = 19), patients with CAD only (n = 32) and patients with CAD and T2DM (n = 28). ADSC phenotype (flow cytometry) was CD90(+)/CD73(+)/CD105(+)/CD45(-)/CD31(-) and they were capable of adipogenic and osteogenic differentiation. ADSC morphology and immunophenotype were similar for all patients, but ADSC from patients with CAD and T2DM had higher proliferation activity and shorter telomeres compared to control patients. ADSC conditioned media stimulated capillary-like tubes formation by endothelial cells (EA.hy926), but this effect significantly decreased for patients with CAD (p = 0.03) and with CAD + T2DM (p = 0.017) compared to the control group. Surprisingly we revealed significantly higher secretion of some pro-angiogenic factors (ELISA) by ADSC: vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) for patients with CAD and HGF and placental growth factor (PlGF) for patients with CAD + T2DM. Among angiogenesis inhibitors such as thrombospondin-1, endostatin and plasminogen activator inhibitor-1 (PAI-1) level of PAI-1 in ADSC conditioned media was significantly higher for patients with CAD and CAD + T2DM compared to the control group (p < 0.01). Inhibition of PAI-1 in ADSC conditioned media by neutralizing antibodies partially restored ADSC angiogenic activity (p = 0.017).

CONCLUSIONS

ADSC angiogenic activity is significantly declined in patients with CAD and T2DM, which could restrict the effectiveness of autologous ADSC cell therapy in these cohorts of patients. This impairment might be due to the disturbance in coordinated network of pro- and anti-angiogenic growth factors secreted by ADSC. Changes in ADSC secretome differ between patients with CAD and T2DM and further investigation are necessary to reveal the MSC-involved mechanisms of cardiovascular and metabolic diseases and develop novel approaches to their correction using the methods of regenerative medicine.

Stem cell therapy to treat heart ischaemia: implications for diabetes cardiovascular complications

Diabetes mellitus is a well-known risk factor for coronary artery disease (CAD), which can lead to acute myocardial infarction, chronic myocardial ischaemia and heart failure. Despite the advantages in medical treatment, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), morbidity and mortality is still high in patients with CAD. Along with PCI and CABG or in patients without options for revascularization, stem cell regenerative therapy in controlled trials is a possibility. Stem cells are believed to exert their actions by angiogenesis and regeneration of cardiomyocytes. Recently published clinical trials and meta-analysis of stem cell studies have shown encouraging results with increased left ventricle ejection fraction and reduced symptoms in patients with CAD and heart failure. There is some evidence of mesenchymal stem cell being more effective compared to other cell types and cell therapy may be more effective in patients with known diabetes mellitus. However, further investigations are warranted.

Cardiac rehabilitation in chronic heart failure: data from the Italian SurveY on carDiac rEhabilitation (ISYDE-2008)

BACKGROUND

Using data from the Italian SurveY on carDiac rEhabilitation (ISYDE-2008), this study provides insight into the level of implementation of cardiac rehabilitation in patients with chronic heart failure (CHF).

METHODS

Data from 165 Italian cardiac rehabilitation units were collected online from 28 January to 10 February 2008.

RESULTS

The study cohort consisted of 2281 patients (66.9 ± 11.8 years): 285 (71.3 ± 12.2 years, 66% male) CHF patients and 1996 (66.3 ± 11.6 years, 74% male) non-CHF patients. Compared with non-CHF, CHF patients were older, showed more comorbidity, had lower left ventricular (LV) ejection fraction and reduced access to functional evaluation, underwent more complications during cardiac rehabilitation, and had longer length of in-hospital stay. CHF patients were also more likely to be transferred to ICU (9 versus 3%, P < 0.0001), and less likely to be discharged home (85 versus 92%, respectively, P < 0.0001). Also, discharge prescriptions were significantly different from those of non-CHF patients. Finally, CHF patients had higher mortality during cardiac rehabilitation (1.7 versus 0.5%, P = 0.01). After adjusting for age, ejection fraction, comorbidity, previous interventions and complications during cardiac rehabilitation, multivariate logistic analysis showed that not performing any of the physical performance tests [odds ratio (OR) = 7.0, 95% confidence interval (CI), 1.9-25.8, P = 0.003], acute respiratory failure (OR = 2.3, 95% CI, 1.3-4.1, P = 0.002), acute kidney insufficiency or worsening of chronic kidney disease (OR = 2.9, 95% CI, 1.5-5.6, P = 0.001) and worsening of cognitive impairment (OR = 3.7, 95% CI, 2.0-6.7, P < 0.001) were significant predictors of death in CHF patients.

CONCLUSION

The ISYDE-2008 survey provided a detailed snapshot of cardiac rehabilitation in CHF patients, and confirmed the complexity and the more severe clinical course of these patients during cardiac rehabilitation.

Cardiovascular disease in survivors of hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) is increasingly offered as a curative option for many patients with hematologic malignancies. Improvements in HCT strategies and supportive care have resulted in a growing number of long-term survivors. However, these survivors are at an increased risk of developing long-term debilitating chronic health conditions, including premature cardiovascular disease. These complications are more common than in the general population, and there are well-described associations between therapeutic exposures, traditional cardiovascular risk factors, and subsequent cardiovascular disease risk. The authors present herein an overview of the current state of knowledge regarding pathogenesis and risk factors for some of the more commonly occurring cardiovascular complications after HCT, highlighting existing surveillance recommendations and future directions for research to minimize cardiovascular morbidity in these survivors.

Asymptomatic Left Ventricular Dysfunction and Metabolic Syndrome: Results from an Italian Multicenter Study

Context:

Metabolic syndrome (MS) is a cluster of interrelated common clinical disorders, including obesity, insulin resistance, glucose intolerance, hypertension and dyslipidemia, associated with a greater risk of atherosclerotic cardiovascular disease than any of its individual components. Although MS is associated with increased cardiovascular risk (CVR), its relationship with heart failure (HF) and left ventricular (LV) dysfunction is not fully understood.

Aims:

We sought to determine whether MS is associated to LV systolic and diastolic dysfunction in a sample of patients with MS and no symptoms for HF.

Subjects and Methods:

We enrolled 6422 consecutive asymptomatic patients admitted to echo-lab for a routine echocardiogram. We calculated LV systolic and diastolic function, by Simpson biplane method and validated Doppler parameters, respectively. MS was diagnosed if three or more CVR factors were found.

Results:

LV systolic function was evaluated in 6175 patients (96.2%). In the group of patients without MS (n = 5630), the prevalence of systolic dysfunction was 10.8% (n = 607) while in the group of patients with MS (n = 545) it was 12.5% (n = 87), (RR1.57; CI 95% 1.2-2.0; P < 0.001). Diastolic function was evaluated in 3936 patients (61.3%). In the group of patients without MS (n = 3566) the prevalence of diastolic dysfunction was 33.3% (n = 1187), while in patients with MS (n = 370) it was 45.7% (n = 169), (RR1.68; CI95% 1.3-2.0; P < 0.001). After adjustment for age and gender, MS proved to be an independent predictor of LV systolic and diastolic dysfunction.

Conclusions:

Our data show that asymptomatic LV systolic and diastolic dysfunction, is correlated with MS and demonstrate that echocardiography is a useful tool to detect patients at high risk for HF. Echocardiography in asymptomatic patients with MS may lead to a therapy initiation at early stages to prevent future cardiovascular events and HF.

Diabetic cardiomyopathy: pathophysiological mechanisms and cardiac dysfuntion

Several experimental, pathological, epidemiological, and clinical studies have clearly depicted that diabetes mellitus results in cardiac functional and structural changes. Diabetic cardiomyopathy results in both structural and functional alterations in the myocardium. Several mechanisms have been implicated in the pathophysiology of diabetic cardiomyopathy. Of these, metabolic disturbances, myocardial fibrosis, small vessel disease, and cardiac autonomic neuropathy are the major players in the pathophysiology of diabetic cardiomyopathy. This review is intended to discuss various such pathophysiological mechanisms of diabetic cardiomyopathy. We have also described the systolic and diastolic dysfunctioning and its corelation to structural changes in diabetes.

Strategies to prevent anthracycline-related congestive heart failure in survivors of childhood cancer

Cardiovascular complications are a leading cause of therapy-related morbidity and mortality in long-term survivors of childhood malignancy. In fact, childhood cancer survivors are at a 15-fold risk of developing CHF compared to age-matched controls. There is a strong dose-dependent association between anthracycline exposure and risk of CHF, and the incidence increases with longer followup. Outcome following diagnosis of CHF is generally poor, with overall survival less than 50% at 5 years. The growing number of childhood cancer survivors makes it imperative that strategies be developed to prevent symptomatic heart disease in this vulnerable population. We present here an overview of the current state of knowledge regarding primary, secondary, and tertiary prevention strategies for childhood cancer survivors at high risk for CHF, drawing on lessons learned from prevention studies in nononcology populations as well as from the more limited experience in cancer survivors.

High prevalence of previously unknown heart failure and left ventricular dysfunction in patients with type 2 diabetes

AIMS/HYPOTHESIS

The aim of this study was to assess the prevalence of (unknown) heart failure and left ventricular dysfunction in older patients with type 2 diabetes.

METHODS

In total, 605 patients aged 60 years or over with type 2 diabetes in the south west of the Netherlands participated in this cross-sectional study (response rate 48.7%), including 24 with a cardiologist-confirmed diagnosis of heart failure. Between February 2009 and March 2010, the patients without known heart failure underwent a standardised diagnostic work-up, including medical history, physical examination, ECG and echocardiography. An expert panel used the criteria of the European Society of Cardiology to diagnose heart failure.

RESULTS

Of the 581 patients studied, 161 (27.7%; 95% CI 24.1%, 31.4%) were found to have previously unknown heart failure: 28 (4.8%; 95% CI 3.1%, 6.6%) with reduced ejection fraction, and 133 (22.9%; 95% CI 19.5%, 26.3%) with preserved ejection fraction. The prevalence of heart failure increased steeply with age. Heart failure with preserved ejection fraction was more common in women. Left ventricular dysfunction was diagnosed in 150 patients (25.8%; 95% CI 22.3%, 29.4%); 146 (25.1%; 95% CI 21.6%, 28.7%) had diastolic dysfunction.

CONCLUSIONS/INTERPRETATION

This is the first epidemiological study that provides exact prevalence estimates of (previously unknown) heart failure and left ventricular dysfunction in a representative sample of patients with type 2 diabetes. Previously unknown heart failure and left ventricular dysfunction are highly prevalent. Physicians should pay special attention to 'unmasking' these patients.

Incidence and predictors of congestive heart failure after autologous hematopoietic cell transplantation

Advances in autologous hematopoietic cell transplantation (HCT) strategies have resulted in a growing number of long-term survivors. However, these survivors are at increased risk of developing cardiovascular complications due to pre-HCT therapeutic exposures and conditioning and post-HCT comorbidities. We examined the incidence and predictors of congestive heart failure (CHF) in 1244 patients undergoing autologous HCT for a hematologic malignancy between 1988 and 2002. The cumulative incidence of CHF was 4.8% at 5 years and increased to 9.1% at 15 years after transplantation; the CI for female lymphoma survivors was 14.5% at 15 years. The cohort was at a 4.5-fold increased risk of CHF (standardized incidence ratio = 4.5), compared with the general population. The risk of CHF increased substantially for patients receiving ≥ 250 mg/m(2) of cumulative anthracycline exposure (odds ratio [OR]: 9.9, P < .01), creating a new and lower threshold for cardiac surveillance after HCT. The presence of hypertension among recipients of high-dose anthracycline (≥ 250 mg/m(2)) resulted in a 35-fold risk (OR: 35.3, P < .01) of CHF; the risk was nearly 27-fold (OR: 26.8, P < .01) for high-dose anthracycline recipients with diabetes, providing evidence that hypertension and diabetes may be critical modifiers of anthracycline-related myocardial injury after HCT and creating targeted populations for aggressive intervention.

Diabetic neuropathy and heart failure: role of neuropeptides

Cardiovascular autonomic neuropathy (CAN), in which patients present with damage of autonomic nerve fibres, is one of the most common complications of diabetes. CAN leads to abnormalities in heart rate and vascular dynamics, which are features of diabetic heart failure. Dysregulated neurohormonal activation, an outcome of diabetic neuropathy, has a significant pathophysiological role in diabetes-associated cardiovascular disease. Key players in neurohormonal activation include cardioprotective neuropeptides and their receptors, such as substance P (SP), neuropeptide Y (NPY), calcitonin-gene-related peptide (CGRP), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP). These neuropeptides are released from the peripheral or autonomic nervous system and have vasoactive properties. They are further implicated in cardiomyocyte hypertrophy, calcium homeostasis, ischaemia-induced angiogenesis, protein kinase C signalling and the renin-angiotensin-aldosterone system. Therefore, dysregulation of the expression of neuropeptides or activation of the neuropeptide signalling pathways can negatively affect cardiac homeostasis. Targeting neuropeptides and their signalling pathways might thus serve as new therapeutic interventions in the treatment of heart failure associated with diabetes. This review discusses how neuropeptide dysregulation in diabetes might affect cardiac functions that contribute to the development of heart failure.

Diabetic cardiomyopathy--to take a long story serious

Being independent of coronary artery disease and hypertension, diabetic cardiomyopathy is a distinct primary disease process, which precedes the development of congestive heart failure. Epidemiologic as well as clinical studies confirmed the close link between diabetes mellitus and heart failure. Altered cardiac structure and function are common diagnoses in patients with type 2 diabetes mellitus. Hyperglycemia leading to the formation of advanced glycation end products and hyperlipidemia resulting in lipotoxicity are of structural and functional impact on cardiac muscle and cardiomyocytes. New and more sensitive methods of diagnosis identify early diastolic dysfunction as a precursor of the development of congestive heart failure. This review focuses on the mechanistic approach to understand the molecular basis of diabetic cardiomyopathy in patients with type 2 diabetes mellitus.

The metabolic syndrome predicts incident congestive heart failure: a 20-year follow-up study of elderly Finns

OBJECTIVE

We investigated whether the metabolic syndrome (MetS) and its components defined by four different criteria including subjects with prevalent diabetes in their definitions were associated with congestive heart failure (CHF) independent of interim myocardial infarction (MI) and prevalent diabetes during a 20-year follow-up in an elderly population-based study.

METHODS AND RESULTS

The MetS was defined according to the World Health Organization (WHO), the National Cholesterol Education Program (NCEP), the International Diabetes Federation (IDF), and the American Heart Association and the National Heart, Lung, and Blood Institute (AHA) criteria. The association of the MetS with incident CHF (303 cases) was investigated with Cox regression analyses in a 20-year follow-up study of 1032 Finns, aged 65-74 years at baseline. Among all subjects the MetS by all four criteria was significantly associated with a 1.45-1.74-fold risk for incident CHF after the adjustment for confounding factors. When subjects with interim MI during the follow-up and with prevalent diabetes were excluded, the MetS was significantly associated with a 1.37-1.87-fold risk for incident CHF after the adjustment for confounding factors. Of the single components of the MetS, the following were associated with incident CHF: impaired fasting glucose (IFG) [fasting plasma glucose (FPG)> or = 6.1 mmol/l, Hazards ratio (HR) 1.46 or FPG > or = 5.6 mmol/l, HR 1.62)]; raised blood pressure (BP) [(BP > or = 140/90 mmHg or antihypertensive medications, HR 1.89); central obesity (waist circumference > or = 94 cm in men or > or = 80 cm in women, HR 1.49); (waist circumference > or = 102 cm in men or > or = 88 cm in women, HR 1.48); obesity (body mass index > or = 30 kg/m(2), HR 1.79); and low high-density lipoprotein cholesterol (<1.03 mmol/l in men or <1.29 mmol/l in women, HR 1.55).

CONCLUSIONS

The MetS defined by four different criteria predicted CHF independent of interim MI and prevalent diabetes in elderly Finns, but not above and beyond the risk associated with one component of the MetS, hypertension.

HbA 1c as a risk factor for heart failure in persons with diabetes: the Atherosclerosis Risk in Communities (ARIC) study

AIMS/HYPOTHESIS

Heart failure (HF) incidence in diabetes in both the presence and absence of CHD is rising. Prospective population-based studies can help describe the relationship between HbA(1c), a measure of glycaemia control, and HF risk.

METHODS

We studied the incidence of HF hospitalisation or death among 1,827 participants in the Atherosclerosis Risk in Communities (ARIC) study with diabetes and no evidence of HF at baseline. Cox proportional hazard models included age, sex, race, education, health insurance status, alcohol consumption, BMI and WHR, and major CHD risk factors (BP level and medications, LDL- and HDL-cholesterol levels, and smoking).

RESULTS

In this population of persons with diabetes, crude HF incidence rates per 1,000 person-years were lower in the absence of CHD (incidence rate 15.5 for CHD-negative vs 56.4 for CHD-positive, p<0.001). The adjusted HR of HF for each 1% higher HbA(1c) was 1.17 (95% CI 1.11-1.25) for the non-CHD group and 1.20 (95% CI 1.04-1.40) for the CHD group. When the analysis was limited to HF cases which occurred in the absence of prevalent or incident CHD (during follow-up) the adjusted HR remained 1.20 (95% CI 1.11-1.29).

CONCLUSIONS/INTERPRETATIONS

These data suggest HbA(1c) is an independent risk factor for incident HF in persons with diabetes with and without CHD. Long-term clinical trials of tight glycaemic control should quantify the impact of different treatment regimens on HF risk reduction.

Diabetes mellitus and heart failure: epidemiology, mechanisms, and pharmacotherapy

Diabetes mellitus and heart failure (HF), both of which are associated with high rates of adverse cardiovascular outcomes, commonly coexist. Given the marked increases in diabetes prevalence in developed countries, the proportion of the population with both conditions is likely to increase substantially. This article reviews the epidemiology of HF and diabetes, the mechanisms whereby diabetes causes HF, and the pharmacotherapy of both HF and diabetes. Specific challenges in treating patients with both HF and diabetes are also addressed.

Alterations in cardiac contractile performance and sarcoplasmic reticulum function in sucrose-fed rats is associated with insulin resistance

Diabetes mellitus (DM) causes the development of a specific cardiomyopathy that results from the metabolic derangements present in DM and manifests as cardiac contractile dysfunction. Although myocardial dysfunction in Type 1 DM has been associated with defects in the function and regulation of the sarcoplasmic reticulum (SR), very little is known about SR function in Type 2 DM. Accordingly, this study examined whether abnormalities in cardiac contractile performance and SR function occur in the prestage of Type 2 DM (i.e., during insulin resistance). Sucrose feeding was used to induce whole body insulin resistance, whereas cardiac contractile performance was assessed by echocardiography and SR function was measured by SR calcium (Ca2+) uptake. Sucrose-fed rats exhibited hyperinsulinemia, hyperglycemia, and hyperlipidemia relative to control rats. Serial echocardiographic assessments in the sucrose-fed rats revealed early abnormalities in diastolic function followed by late systolic dysfunction and concurrent alterations in myocardial structure. The hearts of the 10-wk sucrose-fed rats showed depressed SR function demonstrated by a significant reduction in SR Ca2+uptake. The decline in SR Ca2+uptake was associated with a significant decrease in the cAMP-dependent protein kinase and Ca2+/calmodulin-dependent protein kinase II-mediated phosphorylation of phospholamban. The results show that abnormalities in cardiac contractile performance and SR function occur at an insulin-resistant stage before the manifestation of overt Type 2 DM.

Diabetic cardiomyopathy

This article focuses on advances in the understanding of the pathogenesis and treatment of diabetic cardiomyopathy. Patients with diabetes are at an elevated risk for heart failure, and comorbid heart failure confers an increased risk of morbidity and mortality. Diabetic cardiomyopathy and to apply proven lifesaving therapies in all heart failure patients, including those with diabetes, in the absence of contraindications or intolerance.

Sex difference in cardiomyocyte function in normal and metallothionein transgenic mice: the effect of diabetes mellitus

Evidence suggests a sex difference in intrinsic physiological and diabetic myocardial contractile function related to antioxidant properties of female ovarian hormones. This study was designed to examine the effect of cardiac overexpression of antioxidant metallothionein on intrinsic and diabetic cardiomyocyte function. Weight-matched wild-type (FVB) and metallothionein transgenic mice of both sexes were made diabetic with streptozotocin (220 mg/kg). Contractile and intracellular Ca2+ properties were evaluated including peak shortening (PS), time to PS, time to 90% relengthening (TR90), maximal velocity of shortening or relengthening (±d L/d t), fura-2 fluorescence intensity change, and Ca2+ decay rate. Akt and transcription factor c-Jun levels were evaluated by Western blot. Myocytes from female FVB mice exhibited lower PS, ±d L/d t, and fura-2 fluorescence intensity change, prolonged time to PS, TR90, and Ca2+ decay compared with male FVB mice. Interestingly, this sex difference was not present in metallothionein mice. Diabetes depressed PS, ±d L/d t and caffeine-induced Ca2+ release, as well as prolonged TR90 and Ca2+ decay in male FVB mice, whereas it only reduced PS in female FVB mice. These diabetic dysfunctions were nullified by metallothionein in both sexes. Females displayed elevated Akt phosphorylation and reduced c-Jun phosphorylation. Diabetes dampened Akt phosphorylation in male FVB mice and enhanced c-Jun in both sexes. Diabetes-induced alterations in Akt phosphorylation and c-Jun were abolished by metallothionein. The sex difference in Akt phosphorylation but not c-Jun levels was reversed by metallothionein. These data indicate that antioxidant capacity plays an important role in sex differences in both intrinsic and diabetic cardiomyocyte contractile properties possibly related to phosphorylation of Akt and c-Jun.

Caffeic acid phenethyl ester ameliorates changes in IGFs secretion and gene expression in streptozotocin-induced diabetic rats

The protective effect of caffeic acid phenethyl ester (CAPE) against diabetes-induced alteration of IGFs protein and gene expression was investigated in serum, liver, heart, and kidney. In the present study, diabetic rats exhibited the decrease of IGF-I content in serum, liver and heart but the increase of that in kidney and CAPE blocked them. Diabetic rats also manifested the increase of IGF-II content in serum, liver, heart, and kidney and CAPE prevented them. CAPE prevented the diabetes-induced decrease of liver IGF-I mRNA and IGF-II mRNA, which is similar to pattern of IGFs mRNA in kidney. Moreover, diabetic rats exhibited the decrease of heart IGF-I mRNA but the increase of IGF-II mRNA and CAPE blocked them. In conclusion, CAPE, in part, prevented diabetes-induced alteration of IGF-I and IGF-II protein and gene expression in liver, heart, and kidney in rats.

Surgical Ventricular Remodeling for Patients with Clinically Advanced Congestive Heart Failure and Severe Left Ventricular Dysfunction

BACKGROUND

Surgical ventricular remodeling (SVR) is an accepted therapy for post-infarction ventricular remodeling. Current literature on SVR outcomes has focused on heterogeneous populations with regard to left ventricular function and New York Heart Association (NYHA) class. We assessed outcomes after SVR in patients with advanced congestive heart failure (CHF) (NYHA Class III/IV) and a pre-operative ejection fraction (EF) < or =20%.

METHODS

Data were analyzed for 51 consecutive SVR patients from January 2002 to June 2004. Cardiac catheterization, echocardiography and magnetic resonance imaging (MRI) identified 62.7% (32 of 51) of patients with an EF < or =20%, with the majority having an EF < or =15% (65.6%; 21 of 32). Cox regression analysis was performed to determine predictors of mortality in patients with an EF < or =20%. Follow-up was 100% (32 of 32) complete.

RESULTS

Mean age was 61.9 +/- 10.3 (range 40 to 80) years with a male:female ratio of 27:5. Operative mortality was 6.3% (2 of 32). Twenty-two percent (7 of 32) had concomitant mitral valve procedures. Follow-up demonstrated a statistically significant improvement in left ventricular volumes and EF in survivors. Cox regression analysis identified the following to be significant predictors of mortality: pre-operative left ventricular end-systolic volume index >130 ml/m2; pre-operative diabetes; and intra-aortic balloon pump usage. Pre-operatively, all patients (32 of 32) were categorized as NYHA Class III/IV, with 69% (22 of 32) improving to NYHA Class I/II at follow-up (p < 0.01). Survival did not differ statistically between patients with an EF < or =20% and an EF >20% (n = 19).

CONCLUSIONS

Our results indicate that SVR improves left ventricular function and functional status for patients with advanced CHF and a pre-operative EF < or =20%. Therefore, SVR is a viable surgical alternative for patients with severe left ventricular dysfunction.

Calreticulin Destabilizes Glucose Transporter-1 mRNA in Vascular Endothelial and Smooth Muscle Cells Under High-Glucose Conditions

Substrate autoregulation of glucose transporter-1 (GLUT-1) mRNA and protein expression provides vascular endothelial and smooth muscle cells a sensitive mechanism to adapt their rate of glucose transport in response to changing glycemic conditions. Hyperglycemia-induced downregulation of glucose transport is particularly important in protecting these cells against an excessive influx of glucose and consequently increased intracellular protein glycation and generation of free radicals; both are detrimental in the development of vascular disease in diabetes. We aimed to investigate the molecular mechanism of high glucose–induced downregulation of GLUT-1 mRNA expression in primary bovine aortic vascular endothelial (VEC) and smooth muscle (VSMC) cell cultures. Using RNA mobility shift, UV cross-linking, and in vitro degradation assays, followed by mass-spectrometric analysis, we identified calreticulin as a specific destabilizing trans -acting factor that binds to a 10-nucleotide cis -acting element (CAE 2181-2190 ) in the 3′-untranslated region of GLUT-1 mRNA. Pure calreticulin accelerated the rate of GLUT-1 mRNA-probe degradation in vitro, whereas overexpression of calreticulin in vascular cells decreased significantly the total cell content of GLUT-1 mRNA and protein. The expression of calreticulin was augmented in vascular cells exposed to high glucose in comparison with low-glucose conditions. Similarly, increased expression of calreticulin was observed in aortae of diabetic Psammomys obesus in comparison with normoglycemic controls. These data suggest that CAE 2181-2190 –calreticulin complex, which is formed in VSMC and VEC exposed to hyperglycemic conditions, renders GLUT-1 mRNA susceptible to degradation. This interaction underlies the process of downregulation of glucose transport in vascular cells under high-glucose conditions.

The ABC transporter structure and mechanism: perspectives on recent research

ATP-binding cassette (ABC) transporters are multidomain integral membrane proteins that utilise the energy of ATP hydrolysis to translocate solutes across cellular membranes in all phyla. ABC transporters form one of the largest of all protein families and are central to many important biomedical phenomena, including resistance of cancers and pathogenic microbes to drugs. Elucidation of the structure and mechanism of ABC transporters is essential to the rational design of agents to control their function. While a wealth of high-resolution structures of ABC proteins have been produced in recent years, many fundamental questions regarding the protein's mechanism remain unanswered. In this review, we examine the recent structural data concerning ABC transporters and related proteins in the light of other experimental and theoretical data, and discuss these data in relation to current ideas concerning the transporters' molecular mechanism.