Several factors associated with the insulin resistance syndrome are predictors of left ventricular systolic dysfunction in a male population after 20 years of follow-up

A review of air pollution as a driver of cardiovascular disease risk across the diabetes spectrum

The prevalence of diabetes is estimated to reach almost 630 million cases worldwide by the year 2045; of current and projected cases, over 90% are type 2 diabetes. Air pollution exposure has been implicated in the onset and progression of diabetes. Increased exposure to fine particulate matter air pollution (PM2.5) is associated with increases in blood glucose and glycated hemoglobin (HbA1c) across the glycemic spectrum, including normoglycemia, prediabetes, and all forms of diabetes. Air pollution exposure is a driver of cardiovascular disease onset and exacerbation and can increase cardiovascular risk among those with diabetes. In this review, we summarize the literature describing the relationships between air pollution exposure, diabetes and cardiovascular disease, highlighting how airborne pollutants can disrupt glucose homeostasis. We discuss how air pollution and diabetes, via shared mechanisms leading to endothelial dysfunction, drive increased cardiovascular disease risk. We identify portable air cleaners as potentially useful tools to prevent adverse cardiovascular outcomes due to air pollution exposure across the diabetes spectrum, while emphasizing the need for further study in this particular population. Given the enormity of the health and financial impacts of air pollution exposure on patients with diabetes, a greater understanding of the interventions to reduce cardiovascular risk in this population is needed.

Triglyceride-Glucose Index and Homeostasis Model Assessment-Insulin Resistance in Young Adulthood and Risk of Incident Congestive Heart Failure in Midlife: The Coronary Artery Risk Development in Young Adults Study

Objective

This study aimed to assess the association between triglyceride-glucose (TyG) index/homeostasis model assessment-insulin resistance (HOMA-IR) within young adults and congestive heart failure (CHF), and to explore whether TyG index can replace HOMA-IR as a surrogate marker for IR in predicting the risk of CHF.

Methods

A total of 4,992 participants between the ages of 18 and 30 years were enrolled from the Coronary Artery Risk Development in Young Adults (CARDIA) investigation [from 1985 to 1986 (year 0)]. A Cox proportional hazard regression analysis was conducted for assessing correlations between baseline TyG index/HOMA-IR and CHF events, together with the receiver operating characteristic (ROC) curve employed for scrutinizing TyG index/HOMA-IR and the risk of CHF.

Results

During the 31-year follow-up period, 64 (1.3%) of the 4,992 participants developed CHF. In multivariable Cox proportional hazards models, adjusted for confounding factors for CHF, an increased risk of CHF was associated with a per-unit increase in the TyG index [hazard ratio (HR) 2.8; 95% confidence interval (CI), 1.7–4.7] and HOMA-IR (HR 1.2; 95% CI, 1.1–1.3). A Kaplan–Meier curve analysis showed that participants in the TyG index and HOMA-IR index Q4 group had a higher risk of CHF than those in the Q1 group. The area under curve (AUC) for the TyG index and HOMA-IR consisted of 0.67 (95% CI, 0.6–0.742) and 0.675 (95% CI, 0.604–0.746), respectively. There were no significant differences between the TyG index and HOMA-IR for AUC (p = 0.986).

Conclusion

The higher TyG index and HOMA-IR are independent risk factors for CHF. The TyG index can replace HOMA-IR in young adulthood as a surrogate marker for IR to predict the risk of CHF.

Lipids: a Potential Molecular Pathway Towards Diastolic Dysfunction in Youth-Onset Type 2 Diabetes

PURPOSE OF THE REVIEW

Obesity and type 2 diabetes (T2D) with onset in youth are emerging public health concerns. Youth with obesity and T2D are at risk for the development of heart failure with preserved ejection fraction (HFpEF) due to diabetes-related cardiomyopathy with evidence of precursor stages, namely diastolic dysfunction, present in youth. We review the literature regarding diastolic dysfunction in youth with obesity and T2D; discuss the potential mechanisms including the role of lipids, contractile proteins and their post-translational modifications, and conclude with studies to guide future treatments.

RECENT FINDINGS

The diabetes milieu namely hyperglycemia, hyperinsulinemia, and lipotoxicity favor development of diastolic dysfunction and HFpEF. Recent studies show HFpEF is associated with slow left ventricular relaxation and sarcomere stiffness induced by reduced calcium (Ca²⁺) and β-adrenergic responses. There are currently no effective therapies available for treating HFpEF. Targeting the sarcomere is an area of ongoing research.

Concurrent diabetes and heart failure: interplay and novel therapeutic approaches

Diabetes mellitus increases the risk of developing heart failure, and the co-existence of both diseases worsens cardiovascular outcomes, hospitalization and the progression of heart failure. Despite current advancements on therapeutic strategies to manage hyperglycemia, the likelihood of developing diabetes-induced heart failure is still significant, especially with the accelerating global prevalence of diabetes and an ageing population. This raises the likelihood of other contributing mechanisms beyond hyperglycemia in predisposing diabetic patients to cardiovascular disease risk. There has been considerable interest in understanding the alterations in cardiac structure and function in the diabetic patients, collectively termed as "diabetic cardiomyopathy". However, the factors that contribute to the development of diabetic cardiomyopathies is not fully understood. This review summarizes the main characteristics of diabetic cardiomyopathies, and the basic mechanisms that contribute to its occurrence. This includes perturbations in insulin resistance, fuel preference, reactive oxygen species generation, inflammation, cell death pathways, neurohormonal mechanisms, advanced glycated end-products accumulation, lipotoxicity, glucotoxicity, and posttranslational modifications in the heart of the diabetic. This review also discusses the impact of antihyperglycemic therapies on the development of heart failure, as well as how current heart failure therapies influence glycemic control in diabetic patients. We also highlight the current knowledge gaps in understanding how diabetes induces heart failure.

Association of fasting glucose with lifetime risk of incident heart failure: the Lifetime Risk Pooling Project

BACKGROUND

Given the rising prevalence of dysglycemia and disparities in heart failure (HF) burden, we determined race- and sex-specific lifetime risk of HF across the spectrum of fasting plasma glucose (FPG).

METHODS

Individual-level data from adults without baseline HF was pooled from 6 population-based cohorts. Modified Kaplan-Meier analysis, Cox models adjusted for the competing risk of death, and Irwin's restricted mean were used to estimate the lifetime risk, adjusted hazard ratio (aHR), and years lived free from HF in middle-aged (40-59 years) and older (60-79 years) adults with FPG < 100 mg/dL, prediabetes (FPG 100-125 mg/dL) and diabetes (FPG ≥ 126 mg/dL or on antihyperglycemic agents) across race-sex groups.

RESULTS

In 40,117 participants with 638,910 person-years of follow-up, 4846 cases of incident HF occurred. The lifetime risk of HF was significantly higher among middle-aged White adults and Black women with prediabetes (range: 6.1% [95% CI 4.8%, 7.4%] to 10.8% [95% CI 8.3%, 13.4%]) compared with normoglycemic adults (range: 3.5% [95% CI 3.0%, 4.1%] to 6.5% [95% CI 4.9%, 8.1%]). Middle-aged Black women with diabetes had the highest lifetime risk (32.4% [95% CI 26.0%, 38.7%]) and aHR (4.0 [95% CI 3.0, 5.4]) for HF across race-sex groups. Middle-aged adults with prediabetes and diabetes lived on average 0.9-1.6 and 4.1-6.0 fewer years free from HF, respectively. Findings were similar in older adults except older Black women with prediabetes did not have a higher lifetime risk of HF.

CONCLUSIONS

Prediabetes was associated with higher lifetime risk of HF in middle-aged White adults and Black women, with the association attenuating in older Black women. Black women with diabetes had the highest lifetime risk of HF compared with other race-sex groups.

Gut microbiome - A potential mediator of pathogenesis in heart failure and its comorbidities: State-of-the-art review

Gut microbiome (GMB) has been increasingly recognized as a contributor to development and progression of heart failure (HF), immune-mediated subtypes of cardiomyopathy (myocarditis and anthracycline-induced cardiotoxicity), response to certain cardiovascular drugs, and HF-related comorbidities, such as chronic kidney disease, cardiorenal syndrome, insulin resistance, malnutrition, and cardiac cachexia. Gut microbiome is also responsible for the "gut hypothesis" of HF, which explains the adverse effects of gut barrier dysfunction and translocation of GMB on the progression of HF. Furthermore, accumulating evidence has suggested that gut microbial metabolites, including short chain fatty acids, trimethylamine N-oxide (TMAO), amino acid metabolites, and bile acids, are mechanistically linked to pathogenesis of HF, and could, therefore, serve as potential therapeutic targets for HF. Even though there are a variety of proposed therapeutic approaches, such as dietary modifications, prebiotics, probiotics, TMAO synthesis inhibitors, and fecal microbial transplant, targeting GMB in HF is still in its infancy and, indeed, requires further preclinical and clinical evidence. In this review, we aim to highlight the role gut microbiome plays in HF pathophysiology and its potential as a novel therapeutic target in HF.

Multilayer global longitudinal strain assessment of subclinical myocardial dysfunction related to insulin resistance

Myocardial tissue is sensitive to insulin resistance (IR) due to its interactions with insulin levels. Previous studies demonstrated that heart failure prevalence was higher in IR patients. Evaluation of myocardial deformation by multilayer global longitudinal strain (MGLS) might provide more information about IR related left ventricular dysfunction. In this study, we aimed to investigate subclinical LV dysfunction with MGLS in patients with IR. The study was designed as a prospective cross-sectional study. The present study included 64 patients with IR (+), and 54 subjects without IR (-) prospectively. The homeostasis model of insulin resistance (HOMA-IR) was used to quantify insulin resistance. Specific analysis for endocardial, mid-myocardial and epicardial layers were performed by two-dimensional (2D) speckle tracking echocardiography (STE) for multilayer global longitudinal strain. MGLS (Endocard-Mid-myocard-Epicard) values were significantly lower in the IR (+) group compared to IR (-) group ((GLS-endocard; - 15.1 ± 1.5 vs. - 18.7 ± 1.3, p < 0.001), (GLS-mid-myocard; - 16.0 ± 2.0 vs. - 18.0 ± 2.0, p < 0.001), (GLS-epicard; - 17.0 ± 1.7 vs. - 18.01 ± 1.94, p = 0.004)). GLS-endocard levels were significantly and positively correlated with HOMA-IR levels (r = 0.643, p < 0.001). HOMA-IR and age were found to be independent factors in detecting a decrease in GLS-endocard level in regression analysis. In conclusion, our data reveal that IR (+) patients had significantly lower strain values compared to IR (-) group. Besides, we presented that the HOMA-IR value was an independent predictor of subclinical left ventricular dysfunction.

Type 2 Diabetes Mellitus and Heart Failure: A Scientific Statement From the American Heart Association and the Heart Failure Society of America: This statement does not represent an update of the 2017 ACC/AHA/HFSA heart failure guideline update

Type 2 diabetes mellitus is a risk factor for incident heart failure and increases the risk of morbidity and mortality in patients with established disease. Secular trends in the prevalence of diabetes mellitus and heart failure forecast a growing burden of disease and underscore the need for effective therapeutic strategies. Recent clinical trials have demonstrated the shared pathophysiology between diabetes mellitus and heart failure, the synergistic effect of managing both conditions, and the potential for diabetes mellitus therapies to modulate the risk of heart failure outcomes. This scientific statement on diabetes mellitus and heart failure summarizes the epidemiology, pathophysiology, and impact of diabetes mellitus and its control on outcomes in heart failure; reviews the approach to pharmacological therapy and lifestyle modification in patients with diabetes mellitus and heart failure; highlights the value of multidisciplinary interventions to improve clinical outcomes in this population; and outlines priorities for future research.

Vitamin D Deficiency in Rats Causes Cardiac Dysfunction by Inducing Myocardial Insulin Resistance

SCOPE

Cause-effect relationship between vitamin D deficiency and cardiometabolic abnormalities remains undefined. The aim is to investigate the role of vitamin D deficiency in cardiac failure, through possible involvement in myocardial insulin signaling.

METHODS AND RESULTS

Male SD rats (n = 6) are fed a normal diet (Con), vitamin D-deficient diet [Con(-)], or high-fat, high fructose diet (HFHFrD) for 20 weeks. Cardiac hypertrophy and fetal gene program are confirmed in Con(-) group. Cardiac dysfunction is assessed by echocardiography. Elevated renin, TGF-β and collagen-1α mRNAs, p-ERK1/2, and perivascular fibrosis indicate cardiac remodeling in Con(-) group. Increased serum insulin, triglycerides, and blood pressure, and decreased glucose tolerance and HDL cholesterol are observed in Con(-) rats. Decreased p-Akt/Akt, GLUT4, SOD2, and catalase, and increased NF-κB, TNF-α, and IL-6 are observed in Con(-) hearts. In H9c2 cells, calcitriol attenuates palmitate-induced insulin resistance. VDR-silenced H9c2 cells show reduced Akt phosphorylation, GLUT4 translocation, and 2-NBDG uptake. Findings in Con(-) and HFHFrD groups are comparable.

CONCLUSION

Vitamin D deficiency in rats mimic high-fat-, high-fructose-induced metabolic syndrome and cardiac dysfunction. This study demonstrates that vitamin D deficiency is an independent risk factor for heart failure, at least in part, through induction of myocardial insulin resistance.

Type 2 Diabetes Mellitus and Heart Failure, A Scientific Statement From the American Heart Association and Heart Failure Society of America

Type 2 diabetes mellitus is a risk factor for incident heart failure and increases the risk of morbidity and mortality in patients with established disease. Secular trends in the prevalence of diabetes mellitus and heart failure forecast a growing burden of disease and underscore the need for effective therapeutic strategies. Recent clinical trials have demonstrated the shared pathophysiology between diabetes mellitus and heart failure, the synergistic effect of managing both conditions, and the potential for diabetes mellitus therapies to modulate the risk of heart failure outcomes. This scientific statement on diabetes mellitus and heart failure summarizes the epidemiology, pathophysiology, and impact of diabetes mellitus and its control on outcomes in heart failure; reviews the approach to pharmacological therapy and lifestyle modification in patients with diabetes mellitus and heart failure; highlights the value of multidisciplinary interventions to improve clinical outcomes in this population; and outlines priorities for future research.

Cross-Talk Between Insulin Signaling and G Protein-Coupled Receptors

Diabetes is a major risk factor for the development of heart failure. One of the hallmarks of diabetes is insulin resistance associated with hyperinsulinemia. The literature shows that insulin and adrenergic signaling is intimately linked to each other; however, whether and how insulin may modulate cardiac adrenergic signaling and cardiac function remains unknown. Notably, recent studies have revealed that insulin receptor and β2 adrenergic receptor (β2AR) forms a membrane complex in animal hearts, bringing together the direct contact between 2 receptor signaling systems, and forming an integrated and dynamic network. Moreover, insulin can drive cardiac adrenergic desensitization via protein kinase A and G protein-receptor kinases phosphorylation of the β2AR, which compromises adrenergic regulation of cardiac contractile function. In this review, we will explore the current state of knowledge linking insulin and G protein-coupled receptor signaling, especially β-adrenergic receptor signaling in the heart, with emphasis on molecular insights regarding its role in diabetic cardiomyopathy.

Inhibition of dipeptidyl peptidase-4 ameliorates cardiac ischemia and systolic dysfunction by up-regulating the FGF-2/EGR-1 pathway

Dipeptidyl peptidase 4 inhibitors are used worldwide in the management of diabetes, but their role in the prevention or treatment of cardiovascular disorders has yet to be defined. We found that linagliptin, a DPP-4 inhibitor, suppressed capillary rarefaction in the hearts of mice with dietary obesity. Metabolomic analysis performed with capillary electrophoresis/mass spectrometry (LC-MS/MS) showed that linagliptin promoted favorable metabolic remodeling in cardiac tissue, which was characterized by high levels of citrulline and creatine. DNA microarray analysis revealed that the cardiac tissue level of early growth response protein 1 (EGR-1), which activates angiogenesis, was significantly reduced in untreated mice with dietary obesity, while this decrease was inhibited by administration of linagliptin. Mature fibroblast growth factor 2 (FGF-2) has a putative truncation site for DPP-4 at the NH2-terminal, and LC-MS/MS showed that recombinant DPP-4 protein cleaved the NH2-terminal dipeptides of mature FGF-2. Incubation of cultured neonatal rat cardiomyocytes with FGF-2 increased Egr1 expression, while it was suppressed by recombinant DPP-4 protein. Furthermore, vascular endothelial growth factor-A had a critical role in mediating FGF-2/EGR-1 signaling. In conclusion, pharmacological inhibition of DPP-4 suppressed capillary rarefaction and contributed to favorable remodeling of cardiac metabolism in mice with dietary obesity.

Circulating endothelial-derived apoptotic microparticles and insulin resistance in non-diabetic patients with chronic heart failure

BACKGROUND

The objective of this study was to assess the relationship between insulin resistance and apoptotic endothelial-derived microparticles (EMPs) in patients with chronic heart failure (CHF).

METHODS

The study involved 300 CHF patients (186 males) aged 48-62 years with angiographically proven coronary artery disease and/or previously defined myocardial infarction. Insulin resistance was assessed by the homeostasis model assessment for insulin resistance (HOMA-IR). EMPs phenotype was determined by flow cytofluorometry.

RESULTS

Depending on HOMA-IR cut-off point (over and <2.77 mmol/L×μU/mL) all patients were divided into two cohorts with (n=171) or without (n=129) IR, respectively. Circulating EMPs were higher in CHF patients with IR than in patients without IR. Interestingly, EMPs were directly related to NYHA functional class of CHF, HOMA-IR, NT-pro-BNP, hs-CRP and BMI. There was a significant association between the level of EMPs and HbA1c, gender (r=0.318, p<0.001 for male), age and smoking. On univariate and multivariate regression analysis we found that the NYHA class of CHF,NT-pro-BNP, hs-CRP, and left ventricular ejection fraction (LVEF) appeared to be independent predictors of increased circulatory apoptotic EMPs. The addition of HOMA-IR to the standard model (NYHA class CHF) improved the relative IDI by 19.9% for increased EMPs. For category-free NRI, 10% of events and 24% of non-events were correctly reclassified by the addition of HOMA-IR to the standard model for increased circulating EMPs.

CONCLUSIONS

IR may be a contributing factor increasing circulating levels of apoptotic EMPs in non-diabetic CHF patients.

Midlife blood pressure predicts future diastolic dysfunction independently of blood pressure

OBJECTIVES

High blood pressure (BP) is associated with diastolic dysfunction, but the consequence of elevated BP over the adult life course on diastolic function is unknown. We hypothesised that high BP in earlier adulthood would be associated with impaired diastolic function independent of current BP.

METHODS

Participants in the Medical Research Council National Survey of Health and Development birth cohort (n=1653) underwent investigations including echocardiography at age 60-64 years. The relationships between adult BP, antihypertensive treatment (HTT) and echocardiographic measures of diastolic function were assessed using adjusted regression models.

RESULTS

Increased systolic BP (SBP) at ages 36, 43 and 53 years was predictive of increased E/e' and increased left atrial volume. These effects were only partially explained by SBP at 60-64 years and increased left ventricular mass. HTT was also associated with poorer diastolic function after adjustment for SBP at 60-64 years. Faster rates of increase in SBP in midlife were also associated with increased poorer diastolic function.

CONCLUSIONS

High SBP in midlife is associated with poorer diastolic function at age 60-64 years. Early identification of individuals with high BP or rapid rises in BP may be important for prevention of impaired cardiac function in later life.

Association of Insulin Resistance and Glycemic Metabolic Abnormalities With LV Structure and Function in Middle Age: The CARDIA Study

OBJECTIVES

This study sought to investigate how cumulative exposure to glycemic abnormalities and trajectories of insulin resistance (IR) relate to left ventricular (LV) remodeling and function during young to middle adulthood.

BACKGROUND

Cumulative exposure to glycemic abnormalities and trajectories of IR may adversely influence LV remodeling and function over a 25-year period in subjects who were young adults, predisposing individuals to heart failure later in life.

METHODS

In the CARDIA (Coronary Artery Risk Development in Young Adults) Year 25 examination, 3,179 participants were identified with information on glucose metabolism; these participants were stratified into 4 subgroups: group 1 normal glucose tolerance (NGT), group 2 impaired glucose tolerance (IGT) or impaired fasting glucose, group 3 late diabetes mellitus (DM) (DM diagnosed at year 15 or later), and group 4 early DM (DM diagnosed at year 0 to year 15). Among the subgroup without DM, 3 trajectory groups of change in the homeostasis model assessment of IR were identified: low IR, moderate IR, and high IR. LV mass, relative wall thickness, LV ejection fraction (LVEF), longitudinal systolic strain (Ell), and early diastolic strain rate (Ell_SRe) at year 25 were assessed by echocardiography. Clinically relevant systolic and diastolic dysfunction were defined as LVEF <50% for systolic dysfunction, and E/e' ≥13 for diastolic dysfunction.

RESULTS

The early DM group had less favorable LV mass (coefficient = 11.04; p < 0.001), LVEF (coefficient = -2.72; p < 0.05), Ell (coefficient = 1.53; p < 0.001), and Ell_SRe (coefficient = -0.09; p < 0.05) than did the NGT group. Being in the early DM group and having high hemoglobin A_1c were independently associated with greater odds of having systolic dysfunction (odds ratio = 5.44; p < 0.005) compared with the NGT group. High IR was associated with worse relative wall thickness (coefficient = 0.019; p < 0.0001) and worse Ell, E', and Ell_SRe, depending on obesity level.

CONCLUSIONS

Cumulative exposure to DM or higher IR beginning in early adulthood adversely impacts LV remodeling and function at middle age.

New Molecular Insights of Insulin in Diabetic Cardiomyopathy

Type 2 diabetes mellitus (T2DM) is a highly prevalent disease worldwide. Cardiovascular disorders generated as a consequence of T2DM are a major cause of death related to this disease. Diabetic cardiomyopathy (DCM) is characterized by the morphological, functional and metabolic changes in the heart produced as a complication of T2DM. This cardiac disorder is characterized by constant high blood glucose and lipids levels which eventually generate oxidative stress, defective calcium handling, altered mitochondrial function, inflammation and fibrosis. In this context, insulin is of paramount importance for cardiac contractility, growth and metabolism and therefore, an impaired insulin signaling plays a critical role in the DCM development. However, the exact pathophysiological mechanisms leading to DCM are still a matter of study. Despite the numerous questions raised in the study of DCM, there have also been important findings, such as the role of micro-RNAs (miRNAs), which can not only have the potential of being important biomarkers, but also therapeutic targets. Furthermore, exosomes also arise as an interesting variable to consider, since they represent an important inter-cellular communication mechanism and therefore, they may explain many aspects of the pathophysiology of DCM and their study may lead to the development of therapeutic agents capable of improving insulin signaling. In addition, adenosine and adenosine receptors (ARs) may also play an important role in DCM. Moreover, the possible cross-talk between insulin and ARs may provide new strategies to reverse its defective signaling in the diabetic heart. This review focuses on DCM, the role of insulin in this pathology and the discussion of new molecular insights which may help to understand its underlying mechanisms and generate possible new therapeutic strategies.

Prevalence and Prognostic Impact of Metabolic Syndrome in Asymptomatic (Stage A and B Heart Failure) Patients

BACKGROUND

Metabolic syndrome (MS) has an increased risk of cardiovascular events. Its relationship with asymptomatic left ventricular dysfunction (LVD) and prognosis has not been completely clarified.

OBJECTIVES

To determine, in asymptomatic patients (Stage A, B heart failure, HF), whether MS is associated with left ventricular systolic dysfunction (LVSD) and left ventricular diastolic dysfunction and its predictive role for cardiovascular events.

MATERIALS AND METHODS

We included 1920 nonconsecutive patients without symptoms of HF, with at least one cardiovascular risk factor, undergoing echocardiographic evaluation as preventive screening. We subdivided the study population according to the presence (Group 1) or absence (Group 2) of MS. The primary endpoint was a composite of cardiac death, myocardial infarction, coronary artery revascularization, stroke, and acute pulmonary edema. Secondary endpoints were hospitalization for HF and HF progression.

RESULTS

Overall prevalence of MS was 13.4% (n = 262, Group 1). In Group 2 (n = 1658), the prevalence of LVSD was 12.2%, while the prevalence of LVSD was 21.8% in Group 1 (relative risk [RR] 2.01; 95% confidence interval 1.4-2.8; P < 0.001). Adjusting for age and gender, MS resulted an independent predictor of LVSD (P < 0.001). After a median follow-up of 22 months, Group 1 patients had a significantly higher incidence of primary events (P < 0.001), including cardiac death (P = 0.04), and secondary events (P < 0.001). Both primary and secondary endpoints were more frequent in patients with LVSD (P < 0.001). In multivariate survival analysis, MS (but not its specific components) and LVSD were independently associated both with primary and secondary events (P ≤ 0.003). Incremental chi-square analysis showed the presence of combined LVD added to MS, and age raised significantly the predictive value of the model for the primary endpoint (Incremental chi-square = 8.6).

CONCLUSIONS

In stage A and B HF subjects, the coexistence of MS with functional or structural cardiac abnormalities, detected by echocardiography, showed a significant incremental value in predicting clinical cardiovascular events.

[Left and right ventricular diastolic dysfunction in patients with early rheumatoid arthritis before prescribing disease-modifying antirheumatic therapy]

AIM

To estimate the rate of diastolic dysfunction (DD) of the left and right ventricles (LV and RV) in patients with early rheumatoid arthritis (RA) before using disease-modifying antirheumatic drugs (DMARDs) therapy and to investigate its association with traditional risk factors (TRFs) for cardiovascular diseases (CVD) and inflammatory markers.

SUBJECTS AND METHODS

The investigation enrolled 74 patients with a valid diagnosis of RA, including 56 (74%) women (median age, 54 years; disease duration, 7 months); the patients who were seropositive for rheumatoid factor (RF) (87%) and/or anti-cyclic citrullinated peptide (anti-CCP) antibodies (100%) who had not been on DMARDs or glucocorticosteroids. TRFs for CVD and carotid artery atherosclerosis were assessed from duplex scanning data and echocardiography was performed in all the patients with early RA before starting the therapy. The ratio of the maximum blood flow velocity during early diastolic filling (E) to that during atrial systole (A) was used as a criterion for LVDD and RVDD. There were 3 types of impaired ventricular filling: 1) E/A <1; 2) E/A = 1-2; 3) E/A > 2.

RESULTS

LVDD and RVDD were detected in 35 (48%) and 17 (23%) patients, respectively. RVDD was recorded only in conjunction with LVDD. Among LVDD and RVDD, the former was prevalent. All the patients with early RA were divided into 3 groups: 1) patients with LVDD and RVDD; 2) those with LVDD; 3) those without ventricular DD. All the three groups were matched for the level of DAS28, anti-CCP antibodies, and RF. The incidence of arterial hypertension, dyslipidemia, and abdominal obesity was higher in the patients of Groups 1 and 2 than in those of Group 3. There was a progressive decrease in high-density lipoprotein (HDL) cholesterol concentrations and increases in triglyceride (TG) levels and atherogenic index from Group 3 to Group 1, with the concentrations of total cholesterol and low-density lipoprotein cholesterol being similar in the 3 groups. Coronary heart disease was recorded more frequently in Group 2 than in Group 3. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) proved to be also significantly higher in the patients with DD than in those without DD. Correlations were found between LV E/A and ESR, CRP, HDL cholesterol, TG, RV E/A and ESR, DAS28, TG.

CONCLUSION

The patients with early-stage RA were found to have high incidence rates of LVDD and RVDD, which is related to the high prevalence of CVD, the high spread of TRF for CVD, and the high activity of an inflammatory process.

Nigella sativa: A potential natural protective agent against cardiac dysfunction in patients with type 2 diabetes mellitus

OBJECTIVES

To study the effect of Nigella sativa supplementation on cardiac functions in Type 2 diabetic patients treated with oral hypoglycemic agents.

BACKGROUND

Diabetes mellitus is associated with a high risk of cardiovascular morbidity and mortality. A number of reported beneficial effects of N. sativa on cardiovascular function were the inspiration for this study.

MATERIALS AND METHODS

Sixty patients with uncontrolled diabetes (hemoglobin A1c [HbA1c] >7%) and with no known cardiovascular complications were recruited from the outpatient diabetes clinic. They were assigned, by convenience, to two groups; the control group received activated charcoal as placebo while the test group received 2 g/day of powdered N. sativa for 1-year. All patients continued with their standard oral hypoglycemic agents. Echocardiography was used to evaluate the diastolic function, systolic function, and left ventricular mass (LVM) before the intervention and after 6 and 12 months of the treatment.

RESULTS

HbA1c decreased significantly in the N. sativa group but did not change in the control group. Echocardiographic assessment in the control group showed impairment in diastolic function after 12 months, but there were no significant changes in fractional shortening (FS) or ejection fraction (EF). Furthermore, left ventricular (LV) dimensions at diastole and systole, LVM, and LVM index were significantly increased. In N. sativa group, no significant changes were found in diastolic function or LVM. LV dimension at systole was decreased while FS and EF were significantly increased after 6 and 12 months.

CONCLUSION

N. sativa supplementation may protect the hearts of type 2 diabetic patients from diastolic dysfunction while improving LV systolic function.

Pathological role of adipose tissue dysfunction in cardio-metabolic disorders

Obesity has dramatically increased throughout the world, and has become one of the chief healthcare problems in many societies. Evidence has emerged that adipose tissue dysfunction associated with obesity is critically involved in the development of cardiovascular and metabolic disorders. In this review, we delineate the link between adipose tissue abnormalities and systemic metabolic dysfunction in patients with cardio-metabolic diseases and discuss the underlying mechanisms.

Heart failure and loss of metabolic control

Heart failure is a leading cause of morbidity and mortality worldwide, currently affecting 5 million Americans. A syndrome defined on clinical terms, heart failure is the end result of events occurring in multiple heart diseases, including hypertension, myocardial infarction, genetic mutations and diabetes, and metabolic dysregulation, is a hallmark feature. Mounting evidence from clinical and preclinical studies suggests strongly that fatty acid uptake and oxidation are adversely affected, especially in end-stage heart failure. Moreover, metabolic flexibility, the heart's ability to move freely among diverse energy substrates, is impaired in heart failure. Indeed, impairment of the heart's ability to adapt to its metabolic milieu and associated metabolic derangement are important contributing factors in the heart failure pathogenesis. Elucidation of molecular mechanisms governing metabolic control in heart failure will provide critical insights into disease initiation and progression, raising the prospect of advances with clinical relevance.

Ca(2+) mishandling and cardiac dysfunction in obesity and insulin resistance: role of oxidative stress

Obesity and insulin resistance (IR) are strongly connected to the development of subclinical cardiac dysfunction and eventually can lead to heart failure, which is the main cause of morbidity and death in patients having these metabolic diseases. It has been considered that excessive fat tissue may play a critical role in producing systemic IR and enhancing reactive oxygen species (ROS) generation. This oxidative stress (OS) may elicit or exacerbate IR. On the other hand, evidence suggests that some of the cellular mechanisms involved in the pathophysiology of obesity and IR-related cardiomyopathy are excessive myocardial ROS production and abnormal Ca(2+) homeostasis. In addition, emerging evidence suggests that augmented ROS production may contribute to Ca(2+) mishandling by affecting the redox state of key proteins implicated in this process. In this review, we focus on the role of Ca(2+) mishandling in the development of cardiac dysfunction in obesity and IR and address the evidence suggesting that OS might also contribute to cardiac dysfunction by affecting Ca(2+) handling.

Relationship between circulating endothelial progenitor cells and insulin resistance in non-diabetic patients with ischemic chronic heart failure

AIM

The objective of this study was to assess a relationship between insulin resistance (IR) and counts of CD45(-)CD34(+), CD14(+)CD309(+), and CD14(+)CD309(+)Tie2(+) phenotyped circulating endothelial progenitor cells (EPCs) in patients with ischemic chronic heart failure (CHF).

METHODS

The study involved 300 CHF patients (186 males) aged 48-62 years with angiografically proven coronary artery disease and/or previously defined myocardial infarction. Insulin resistance was assessed by the homeostasis model assessment for insulin resistance (HOMA-IR). EPC populations were phenotyped by flow cytofluorimetry.

RESULTS

Circulating EPCs counts were statistically significantly lower in CHF patients with IR than in patients without IR. We found that the most valuable multivariable predictors of the depletion of the CD45(+)CD34(+) EPCs were NT-pro-brain natriuretic peptide (BNP) (1.32; 95% CI=1.19-2.77; P=0.001), left ventricular ejection fraction (OR=1.30; 95% CI=1.09-1.60; P=0.002), NYHA class (OR=1.12; 95% CI=1.02-1.19; P=0.001). NT-pro-BNP (OR=1.45; 95% CI=1.15-2.90; P=0.003), left ventricular ejection fraction (OR=1.32; 95% CI=1.11-1.65; P=0.001) were found as powerful predictors for depletion in CD45(-)CD34(+) EPCs. We also identified six independent variables with high predictive value for depletion of CD14(+)CD309(+) EPCs: NT-pro-BNP (OR=1.41; 95% CI=1.15-2.90; P=0.003), left ventricular ejection fraction (OR=1.18; 95% CI=1.10-1.76; P=0.036), NYHA class (OR=1.15; 95% CI=1.07-1.22; P=0.001), hs-C reactive protein (OR=1.02; 95% CI=1.01-1.05; P=0.012). As independent multivariable predictors for depletion in CD14(+)CD309(+)Tie2(+) EPCs were selected five variables: NT-pro-BNP (OR=1.65; 95% CI=1.44-4.70; P=0.006), left ventricular ejection fraction (OR=1.07; 95% CI=1.02-1.12; P=0.018), NYHA class (OR=1.13; 95% CI=1.06-1.21; P=0.001), hs-C-reactive protein (OR=1.08; 95% CI=1.03-1.16; P=0.002).

CONCLUSION

IR may be an additional factor contributing decreased circulating level of proangiogenic EPCs in non-diabetic CHF patients.

Cardiovascular Risk Factors from Early Life Predict Future Adult Cardiac Structural and Functional Abnormalities: A Systematic Review of the Published Literature

Background

Clinical practice evaluates cardiovascular risk based on current risk factor (RF) levels [Blood pressure (BP), body mass index (BMI) and glycaemic control] largely disregarding previous risk-factor history over the totality of the life course. RFs are related to contemporaneous echocardiographic measures of cardiac structure and function which in turn are independently related to cardiovascular morbidity and mortality in cross-sectional studies. However, the effect of lifetime or earlier RF history on future echocardiographic changes has never been systematically examined.

Methods

A systematic review of the published literature identified 24 studies relating either earlier BP, BMI, glycaemic control or a combination to future cardiac structure and/or function.

Results

The majority of studies showed that elevated BP and BMI in earlier life and greater cumulative burden of these factors resulted in worse cardiac structure up to 24 years later. Studies examining glycaemic control as RF were few, but poorer glycaemic control in young adults was associated with increased future left ventricular mass.

While only 5 papers related RFs to future cardiac function, all RFs were positively associated with worse future diastolic function.

Conclusions

BP, BMI and glycaemic control measures in childhood, adolescence and early adulthood and subsequent longitudinal trajectories of BP and BMI are predictive of future abnormalities in cardiac structure and function. Lifetime RF history should be used to inform clinical practice. Further research is required to enable the identification of any sensitive periods in the life course to enable prevention when it is most likely to be effective.

The efficacy and tolerability of azilsartan in obese insulin-resistant mice with left ventricular pressure overload

Angiotensin II receptor blockers (ARBs) are used widely for the treatment of heart failure. However, their use in obese and insulin-resistant patients remains controversial. To clarify their potential efficacy in these conditions, we administered azilsartan medoxomil (azilsartan), a prodrug of an angiotensin II receptor blocker to mice fed a high-fat diet (HFD) with left ventricular (LV) pressure overload (aortic banding). LV fibrosis (hydroxyproline), cardiac plasminogen activator inhibitor-1 (PAI-1; a marker of profibrosis), and creatine kinase (a marker of myocardial viability and energetics) were assessed. LV wall thickness and cardiac function were assessed echocardiographically. Mice given a HFD were obese and insulin resistant. Their LV hypertrophy was accompanied by greater LV PAI-1 and reduced LV creatine kinase compared with normal diet controls. Drug treatment reduced LV wall thickness, hypertrophy, and PAI-1 and increased cardiac output after aortic banding compared with results in HFD vehicle controls. Thus, azilsartan exerted favorable biological effects on the hearts of obese insulin-resistant mice subjected to LV pressure overload consistent with its potential utility in patients with analogous conditions.

Obesity and Cardiac Function - The Role of Caloric Excess and its Reversal

Obesity is recognized as an independent and increasingly prevalent risk factor for cardiovascular morbidity and mortality. This stems in part from the contribution of obesity towards insulin resistance and diabetes, which associate with premature atherosclerosis, enhanced thrombogenicity and activation of systemic inflammatory programs with resultant cardiovascular dysfunction. This review will focus on the more direct mechanisms underpinning obesity-associated cardiac pathophysiology including the metabolic consequences of lipid accumulation in the myocardium and the consequences of direct systemic effects of lipid toxicity. Furthermore, there is growing recognition that metabolic intermediates, which may be perturbed with caloric excess, may play an important role in intracellular signal transduction and on the post-translational control of metabolic functioning within the heart. As strategies to reverse obesity appear to have ameliorative cardiac effects, surgical and therapeutic approaches to facilitate weight reduction this will also be discussed.

Heart failure in North America

Heart failure is a major health problem that affects patients and healthcare systems worldwide. Within the continent of North America, differences in economic development, genetic susceptibility, cultural practices, and trends in risk factors and treatment all contribute to both inter-continental and within-continent differences in heart failure. The United States and Canada represent industrialized countries with similar culture, geography, and advanced economies and infrastructure. During the epidemiologic transition from rural to industrial in countries such as the United States and Canada, nutritional deficiencies and infectious diseases made way for degenerative diseases such as cardiovascular diseases, cancer, overweight/obesity, and diabetes. This in turn has resulted in an increase in heart failure incidence in these countries, especially as overall life expectancy increases. Mexico, on the other hand, has a less developed economy and infrastructure, and has a wide distribution in the level of urbanization as it becomes more industrialized. Mexico is under a period of epidemiologic transition and the etiology and incidence of heart failure is rapidly changing. Ethnic differences within the populations of the United States and Canada highlight the changing demographics of each country as well as potential disparities in heart failure care. Heart failure with preserved ejection fraction makes up approximately half of all hospital admissions throughout North America; however, important differences in demographics and etiology exist between countries. Similarly, acute heart failure etiology, severity, and management differ between countries in North America. The overall economic burden of heart failure continues to be large and growing worldwide, with each country managing this burden differently. Understanding the inter-and within-continental differences may help improve understanding of the heart failure epidemic, and may aid healthcare systems in delivering better heart failure prevention and treatment.

Dipeptidyl peptidase 4 inhibition increases myocardial glucose uptake in nonischemic cardiomyopathy

BACKGROUND

Glucose and fatty acids comprise the primary substrates for myocardial energy metabolism. The normal myocardium switches toward glucose metabolism in the setting of stress; the inability to affect such a switch is a fundamental mechanism behind "diabetic" or "insulin-resistant" cardiomyopathy. The purpose of this mechanistic study was to evaluate the effects of treatment with the dipeptidyl peptidase (DPP) 4 inhibitor sitagliptin on myocardial glucose uptake in patients with nonischemic cardiomyopathy.

METHODS AND RESULTS

Twelve nondiabetic subjects with nonischemic cardiomyopathy underwent metabolic testing and assessment of myocardial glucose uptake by (18)F-fluorodeoxyglucose positron-emission tomographic/computerized tomographic imaging at baseline and after 4 weeks of sitagliptin therapy. Sitagliptin therapy resulted in a significant increase in myocardial glucose uptake (19% increase; P = .04). Although most patients had at least a slight increase in glucose uptake, there was an overall bimodal response, with 6 patients ("responders") demonstrating large increases (>20%) in glucose uptake and 6 patients ("nonresponders") demonstrating <5% increases or slight decreases. Triglyceride-high-density lipoprotein ratios significantly dropped in the 6 responders compared with the 6 nonresponders (P < .02).

CONCLUSIONS

Therapy with the DPP-4 inhibitor sitagliptin results in increased myocardial glucose uptake in nondiabetic patients with nonischemic cardiomyopathy.

Similar patterns of myocardial metabolism and perfusion in patients with type 2 diabetes and heart disease of ischaemic and non-ischaemic origin

AIMS/HYPOTHESIS

Type 2 diabetes and insulin resistance are often associated with the co-occurrence of coronary atherosclerosis and cardiac dysfunction. The aim of this study was to define the independent relationships between left ventricular dysfunction or ischaemia and patterns of myocardial perfusion and metabolism in type 2 diabetes.

METHODS

Twenty-four type 2 diabetic patients--12 with coronary artery disease (CAD) and preserved left ventricular function and 12 with non-ischaemic heart failure (HF)--were enrolled in a cross-sectional study. Positron emission tomography (PET) was used to assess myocardial blood flow (MBF) at rest, after pharmacological stress and under euglycaemic hyperinsulinaemia. Insulin-mediated myocardial glucose disposal was determined with 2-deoxy-2-[(18)F]fluoroglucose PET.

RESULTS

There was no difference in myocardial glucose uptake (MGU) between the healthy myocardium of CAD patients and the dysfunctional myocardium of HF patients. MGU was strongly influenced by levels of systemic insulin resistance in both groups (CAD, r = 0.85, p = 0.005; HF, r = 0.77, p = 0.01). In HF patients, there was an inverse association between MGU and the coronary flow reserve (r = -0.434, p = 0.0115). A similar relationship was observed in non-ischaemic segments of CAD patients. Hyperinsulinaemia increased MBF to a similar extent in the non-ischaemic myocardial of CAD and HF patients.

CONCLUSIONS/INTERPRETATION

In type 2 diabetes, similar metabolic and perfusion patterns can be detected in the non-ischaemic regions of CAD patients with normal cardiac function and in the dysfunctional non-ischaemic myocardium of HF patients. This suggests that insulin resistance, rather than diagnosis of ischaemia or left ventricular dysfunction, affects the metabolism and perfusion features of patients with type 2 diabetes.

Adiposity and incident heart failure in older adults: the cardiovascular health study

While several studies have reported a positive association between overall adiposity and heart failure (HF) risk, limited and inconsistent data are available on the relation between central adiposity and incident HF in older adults. We sought to examine the association between waist circumference (WC) and incident HF and assess whether sex modifies the relation between WC and HF. Prospective study using data on 4,861 participants of the Cardiovascular Health Study (1989-2007). HF was adjudicated by a committee using information from medical records and medications. We used Cox proportional hazard models to compute hazard ratio (HR). The mean age was 73.0 years for men and 72.3 years for women; 42.5% were men and 15.3% were African Americans. WC was positively associated with an increased risk of HF: each standard deviation of WC was associated with a 14% increased risk of HF (95% CI: 3%-26%) in a multivariable model. There was not a statistically significant sex-by-WC interaction (P = 0.081). BMI was positively associated with incident HF (HR: 1.22 (95% CI: 1.15-1.29) per standard deviation increase of BMI); however, this association was attenuated and became nonstatistically significant upon additional adjustment for WC (HR: 1.09 (95% CI: 0.99-1.21)). In conclusion, a higher WC is associated with an increased risk of HF independent of BMI in community-living older men and women.

Plasma phospholipid fatty acid composition and estimated desaturase activity in heart failure patients with metabolic syndrome

Metabolic syndrome is one of the major factors to increase the incidence of heart failure. In our study, we compared plasma fatty acid compositions among heart failure patients with and without Metabolic syndrome. Fatty acid (FA) composition of plasma phospholipids was analyzed and the activities of desaturase were estimated as the ratio of substrate and product fatty acids in 85 stable heart failure patients. Fatty acid and estimated desaturase activities were further examined for their associations with Metabolic syndrome components. Heart failure patients with Metabolic syndrome showed significant changes in fatty acid composition in comparison to those without Metabolic syndrome, which had a decreased proportion of lauric acid (C12:0) and an increased proportion of dihomo-γ-linolenic acid (C20:3n-6). Also, estimated desaturase activities (D5D and D6D) were closely related to Metabolic syndrome condition among heart failure patients. The content of dihomo-γ-linolenic acid showed positive correlations with BMI, waist circumference, and plasma triglyceride levels. D6D were positively associated with plasma triglyceride levels, whereas D5D showed a negative correlation with plasma triglyceride levels and waist circumferences. The content of dihomo-γ-linolenic acid as well as estimated D6D and D5D were altered in heart failure patients with Metabolic syndrome.

Care and outcomes of Hispanic patients admitted with heart failure with preserved or reduced ejection fraction: findings from get with the guidelines-heart failure

BACKGROUND

Although individuals of Hispanic ethnicity are at high risk for developing heart failure (HF), little is known about differences between Hispanic HF patients stratified by left ventricular ejection fraction (EF). We compared characteristics, quality of care, and outcomes between Hispanic and non-Hispanic white patients hospitalized for HF with preserved EF (PEF) or reduced EF (REF).

METHODS AND RESULTS

From 247 hospitals in Get With The Guidelines-Heart Failure between 2005-2010, 6117 Hispanics were compared with 71 859 non-Hispanic whites. Forty-six percent of Hispanics had PEF (EF >40%), whereas 54% had REF (EF <40%); 55% and 45% of non-Hispanic whites had PEF and REF, respectively. Relative to non-Hispanic whites, Hispanics with PEF or REF were more likely to be younger and to have diabetes, hypertension, and overweight/obesity. In multivariate analysis, a lower mortality risk was observed among Hispanics with PEF (odds ratio, 0.50; 95% confidence interval, 0.31-0.81; P=0.005) but not in Hispanics with REF (odds ratio, 0.94; 95% confidence interval, 0.62-1.43; P=0.784) compared with non-Hispanic whites. In all groups, composite performance improved within the study period (Hispanics PEF: 75.2-95.1%; non-Hispanic whites PEF: 79.0-92.7%; Hispanics REF: 67.7-88.4%; non-Hispanic whites REF: 60.8-85.6%, P<0.0001).

CONCLUSIONS

Hispanic HF patients with PEF had better in-hospital survival than non-Hispanic whites with PEF. Inpatient mortality was similar between groups with REF. Quality of care was similar and improved over time irrespective of ethnicity, highlighting the potential benefit of performance improvement programs in promoting equitable care.

p53-induced adipose tissue inflammation is critically involved in the development of insulin resistance in heart failure

Several clinical studies have shown that insulin resistance is prevalent among patients with heart failure, but the underlying mechanisms have not been fully elucidated. Here, we report a mechanism of insulin resistance associated with heart failure that involves upregulation of p53 in adipose tissue. We found that pressure overload markedly upregulated p53 expression in adipose tissue along with an increase of adipose tissue inflammation. Chronic pressure overload accelerated lipolysis in adipose tissue. In the presence of pressure overload, inhibition of lipolysis by sympathetic denervation significantly downregulated adipose p53 expression and inflammation, thereby improving insulin resistance. Likewise, disruption of p53 activation in adipose tissue attenuated inflammation and improved insulin resistance but also ameliorated cardiac dysfunction induced by chronic pressure overload. These results indicate that chronic pressure overload upregulates adipose tissue p53 by promoting lipolysis via the sympathetic nervous system, leading to an inflammatory response of adipose tissue and insulin resistance.

Diabetes and the risk of heart failure

Prevalence of diabetes and heart failure are increasing exponentially worldwide. Diabetes is well-known to increase the risk of heart failure independent of other traditional risk factors and ischemia. Current evidence indicates the presence of several biochemical and molecular changes associated with diabetes that lead to diastolic dysfunction or American Heart Association stage B heart failure. Some, if not all, changes may also predate the development of frank diabetes. In this review, the authors present some of the epidemiologic evidence and a brief description of major mechanistic pathways that favor the development of heart failure in prediabetic and diabetic states.

Targeting fatty acid and carbohydrate oxidation--a novel therapeutic intervention in the ischemic and failing heart

Cardiac ischemia and its consequences including heart failure, which itself has emerged as the leading cause of morbidity and mortality in developed countries are accompanied by complex alterations in myocardial energy substrate metabolism. In contrast to the normal heart, where fatty acid and glucose metabolism are tightly regulated, the dynamic relationship between fatty acid β-oxidation and glucose oxidation is perturbed in ischemic and ischemic-reperfused hearts, as well as in the failing heart. These metabolic alterations negatively impact both cardiac efficiency and function. Specifically there is an increased reliance on glycolysis during ischemia and fatty acid β-oxidation during reperfusion following ischemia as sources of adenosine triphosphate (ATP) production. Depending on the severity of heart failure, the contribution of overall myocardial oxidative metabolism (fatty acid β-oxidation and glucose oxidation) to adenosine triphosphate production can be depressed, while that of glycolysis can be increased. Nonetheless, the balance between fatty acid β-oxidation and glucose oxidation is amenable to pharmacological intervention at multiple levels of each metabolic pathway. This review will focus on the pathways of cardiac fatty acid and glucose metabolism, and the metabolic phenotypes of ischemic and ischemic/reperfused hearts, as well as the metabolic phenotype of the failing heart. Furthermore, as energy substrate metabolism has emerged as a novel therapeutic intervention in these cardiac pathologies, this review will describe the mechanistic bases and rationale for the use of pharmacological agents that modify energy substrate metabolism to improve cardiac function in the ischemic and failing heart. This article is part of a Special Issue entitled: Mitochondria and Cardioprotection.

Improved diabetic control in advanced heart failure patients treated with left ventricular assist devices

AIMS

Left ventricular assist devices (LVADs) are increasingly used as therapeutic options for patients with advanced congestive heart failure (CHF), many of whom suffer from diabetes mellitus (DM). The aim of this study was to evaluate the effect of restoration of normal cardiac output using LVAD support on diabetes control in patients with advanced CHF.

METHODS AND RESULTS

A retrospective chart review of all clinic patients supported with long-term LVADs between July 2008 and July 2009 at Columbia University Medical Center was performed. Patients with DM diagnosed prior to device implantation were included in this analysis. Clinical and laboratory data within 1 month preceding and 6 months following LVAD implantation were collected. Of 43 LVAD patients followed in our clinic during the study period, 15 had a diagnosis of DM. Thirteen of the 15 patients were male, mean age was 63 ± 11 years, and the pre-LVAD left ventricular ejection fraction (LVEF) was 16.5 ± 5.7%. Fasting glucose levels, HbA1c, and daily insulin requirement within 1 month before and an average of 4.0 ± 2.3 months after LVAD placement were 157.7 ± 50.6 vs. 104.1 ± 21.4 mg/dL, 7.7 ± 0.9 vs. 6.0 ± 0.8.%, and 53.3 ± 51.7 vs. 24.2 ± 27.2 IU, respectively (P < 0.05 for all comparisons). Six of the 15 patients were completely free of antidiabetic medications and had blood glucose < 126 mg/dL as well as HbA1c < 6% after LVAD. Body mass index (BMI) was slightly increased after LVAD (28.7 ± 5.3 vs. 30.2 ± 4.1 kg/m², P NS).

CONCLUSION

Restoration of normal cardiac output after LVAD implantation improves diabetic control in patients with advanced CHF. Additional studies are warranted to determine the mechanisms that worsen or possibly induce DM in patients with advanced CHF.

The early origins of chronic heart failure: impaired placental growth and initiation of insulin resistance in childhood

AIMS

Low birth weight and low placental weight predict later coronary heart disease and hypertension. This has led to the hypothesis that these diseases are initiated by foetal programming, the process by which foetal malnutrition leads to permanent changes in the body in ways that lead to chronic disease in later life. Here we examine the association between body and placental size at birth and later chronic heart failure.

METHODS AND RESULTS

We identified 187 patients taking medications for chronic heart failure in a birth cohort of 13,345 people born in Helsinki, Finland during 1934-44. Chronic heart failure was associated with a small placental surface area. In people born with a placental area less than 225 cm(2), the odds ratio for chronic heart failure was 1.7 (1.1-2.5), compared with people born with a placental area greater than 295 cm(2). The risk of heart failure was further increased by rapid gain in body mass index after the age of 2 years, a path of growth known to be linked to insulin resistance in later life. In a simultaneous regression, low body mass index at 2 years and high body mass index at 11 years were each associated with chronic heart failure (P = 0.008 and 0.001, respectively).

CONCLUSION

Chronic heart failure in adult life may be initiated by impaired placental growth which adversely affects cardiac development. People born with a vulnerable heart are more likely to develop chronic heart failure if they become insulin resistant.

Excessive cardiac insulin signaling exacerbates systolic dysfunction induced by pressure overload in rodents

Although many animal studies indicate insulin has cardioprotective effects, clinical studies suggest a link between insulin resistance (hyperinsulinemia) and heart failure (HF). Here we have demonstrated that excessive cardiac insulin signaling exacerbates systolic dysfunction induced by pressure overload in rodents. Chronic pressure overload induced hepatic insulin resistance and plasma insulin level elevation. In contrast, cardiac insulin signaling was upregulated by chronic pressure overload because of mechanical stretch-induced activation of cardiomyocyte insulin receptors and upregulation of insulin receptor and Irs1 expression. Chronic pressure overload increased the mismatch between cardiomyocyte size and vascularity, thereby inducing myocardial hypoxia and cardiomyocyte death. Inhibition of hyperinsulinemia substantially improved pressure overload-induced cardiac dysfunction, improving myocardial hypoxia and decreasing cardiomyocyte death. Likewise, the cardiomyocyte-specific reduction of insulin receptor expression prevented cardiac ischemia and hypertrophy and attenuated systolic dysfunction due to pressure overload. Conversely, treatment of type 1 diabetic mice with insulin improved hyperglycemia during pressure overload, but increased myocardial ischemia and cardiomyocyte death, thereby inducing HF. Promoting angiogenesis restored the cardiac dysfunction induced by insulin treatment. We therefore suggest that the use of insulin to control hyperglycemia could be harmful in the setting of pressure overload and that modulation of insulin signaling is crucial for the treatment of HF.

Glucose, obesity, metabolic syndrome, and diabetes relevance to incidence of heart failure

Heart failure (HF) is common, results in poor clinical outcomes, and is associated with large health care costs. The incidence of HF continues to rise, with approximately 670,000 new cases per year and a 20% lifetime risk of HF for persons 40 years and older in the U.S. Risk factors for HF have been identified, and thus preventative strategies should have a positive effect on disease burden, morbidity, and mortality. Although coronary artery disease and hypertension have traditionally been considered among the most important modifiable risk factors for the development of HF, recent studies have highlighted the importance of increasingly prevalent metabolic risk factors: glucose, diabetes, obesity, and the metabolic syndrome. This report will present evidence for the link between glucose, diabetes, obesity, metabolic syndrome, and incident HF. Furthermore, we will discuss how risk factor modification and other preventive therapies may help curb the rising incidence of HF.

Review article: Left ventricular dysfunction and heart failure in metabolic syndrome and diabetes without overt coronary artery disease--do we need to screen our patients?

The metabolic syndrome and its components, glucose intolerance, T2DM, hypertension, dyslipidaemia and obesity are increasingly common. Patients with the metabolic syndrome have a higher prevalence of chronic heart failure (CHF) and, once diagnosed, CHF in such subjects is associated with a higher mortality than in those without this co-morbidity. However, early diagnosis of LV systolic dysfunction and symptomatic heart failure may prevent deterioration of heart failure and improve prognosis. The aim of this article is to summarise the prevalence of CHF in people with obesity, hypertension and T2DM, and to review how each co-morbid condition might predispose to and complicate the clinical diagnosis of CHF.

Impaired left ventricular systolic and diastolic function in patients with metabolic syndrome as assessed by strain and strain rate imaging

The present study aimed to investigate cardiac structural and functional alterations in patients with metabolic syndrome (MS) and to compare those with control subjects. Strain and strain rate (SR) imaging were preformed in 200 patients with MS and 197 normal subjects. The patients were further divided into Group 1 (with three metabolic disorders) and Group 2 (with four metabolic disorders) to elucidate the influence of different metabolic components on left ventricular (LV) functions. LV diastolic and systolic functions were determined by the mean systolic strain, SR-LVs and SR-LVe. There were no differences in LVEF among the three groups. However, the mean systolic strain, SR-LVs and SR-LVe, were significantly decreased in Group 1 and Group2 when compared with control subjects (all P<0.001). The mean systolic strain and SR-LVe were lower in Group 2 than Group 1 (all P<0.05). Stepwise multiple regression analyses revealed that the W-H ratio was an independent predictor of the LV systolic function, whereas W-H ratio, HDL cholesterol and SBP were independent predictors of LV diastolic function. In summary, our results demonstrated that LV systolic and diastolic functions were impaired in patients with metabolic syndrome even if they have normal LVEF. Strain and SR imaging would be a sensitive and feasible method to detect subclinical abnormalities in those populations.

Abnormal cardiac structure and function in the metabolic syndrome: a population-based study

OBJECTIVE

To measure the association between cardiac structure and function abnormalities and isolated metabolic syndrome (metabolic syndrome excluding established hypertension or diabetes mellitus).

PARTICIPANTS AND METHODS

We collected data prospectively on a population-based random sample of 2042 Olmsted County, Minnesota, residents aged 45 years or older who underwent echocardiography between January 1, 1997, and September 30, 2000. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

The prevalence of isolated metabolic syndrome was 21.7% (214/984) in men and 16.7% (177/1058) in women. Left ventricular (LV) mass index was greater (91.7 vs 87.9 g/m2; P=.04) and LV diastolic dysfunction more prevalent (28.2% [50/177] vs 14.9% [81/544]; P<.001) in women with isolated metabolic syndrome than in women without metabolic syndrome; no difference was found in men. When patients with hypertension or diabetes mellitus were included in the cohort, there was a stepwise increase in LV mass index and LV diastolic dysfunction from no metabolic syndrome to isolated metabolic syndrome to metabolic syndrome in women and men.

CONCLUSION

Isolated metabolic syndrome, which is associated with increased LV mass index and LV diastolic dysfunction in women, identifies women with evidence of early ventricular dysfunction.

Abnormal cardiac structure and function in the metabolic syndrome: a population-based study

OBJECTIVE

To measure the association between cardiac structure and function abnormalities and isolated metabolic syndrome (metabolic syndrome excluding established hypertension or diabetes mellitus).

PARTICIPANTS AND METHODS

We collected data prospectively on a population-based random sample of 2042 Olmsted County, Minnesota, residents aged 45 years or older who underwent echocardiography between January 1, 1997, and September 30, 2000. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

The prevalence of isolated metabolic syndrome was 21.7% (214/984) in men and 16.7% (177/1058) in women. Left ventricular (LV) mass index was greater (91.7 vs 87.9 g/m2; P=.04) and LV diastolic dysfunction more prevalent (28.2% [50/177] vs 14.9% [81/544]; P<.001) in women with isolated metabolic syndrome than in women without metabolic syndrome; no difference was found in men. When patients with hypertension or diabetes mellitus were included in the cohort, there was a stepwise increase in LV mass index and LV diastolic dysfunction from no metabolic syndrome to isolated metabolic syndrome to metabolic syndrome in women and men.

CONCLUSION

Isolated metabolic syndrome, which is associated with increased LV mass index and LV diastolic dysfunction in women, identifies women with evidence of early ventricular dysfunction.