The impact of metabolic syndrome on left ventricular myocardial performance

Single-nucleus transcriptomics reveal cardiac cell type-specific diversification in metabolic disease transgenic pigs

Cardiac damage is widely present in patients with metabolic diseases, but the exact pathophysiological mechanisms involved remain unclear. The porcine heart is an ideal material for cardiovascular research due to its similarities to the human heart. This study evaluated pathological features and performed single-nucleus RNA sequencing (snRNA-seq) on myocardial samples from both wild-type and metabolic disease-susceptible transgenic pigs (previously established). We found that transgenic pigs exhibited lipid metabolism disturbances and myocardial injury after a high-fat high-sucrose diet intervention. snRNA-seq reveals the cellular landscape of healthy and metabolically disturbed pig hearts and identifies the major cardiac cell populations affected by metabolic diseases. Within metabolic disorder hearts, metabolically active cardiomyocytes exhibited impaired function and reduced abundance. Moreover, massive numbers of reparative LYVE1+ macrophages were lost. Additionally, proinflammatory endothelial cells were activated with high expression of multiple proinflammatory cytokines. Our findings provide insights into the cellular mechanisms of metabolic disease-induced myocardial injury.

Predictors of early heart failure rehospitalization among older adults with preserved and reduced ejection fraction: A review and derivation of a conceptual model

BACKGROUND

Heart failure (HF) is prevalent among older adults who suffer with either heart failure preserved ejection fraction (HFpEF) or heart failure reduced ejection fraction (HFrEF) and have a high rate of early HF rehospitalization. Preventing early rehospitalization is complex because of major differences between the two subtypes of HF as well as inadequate predictive models to identify key contributing factors.

OBJECTIVE

To present research addressing relationships between selected clinical, hemodynamic, social factors, and early (≤ 60-day) HF rehospitalization in older adults with HFpEF and HFrEF, derive a conceptual model of predictors of rehospitalization, and understand to what extent the literature addresses these predictors among older women.

METHODS

Four computerized databases were searched for research addressing clinical, hemodynamic, and social factors relevant to early HF rehospitalization and older adults post index hospitalization for HF.

RESULTS

21 full-text articles were included in the final review and organized thematically. Most studies focused on early (≤ 30-day) HF rehospitalizations, with limited attention given to the 31 to 60-day period. Specific clinical, hemodynamic, and social factors which influenced early HF rehospitalization were identified. The existing literature confirms that risk predictors or their combinations which influence early (≤ 60-day) HF rehospitalization after an index HF hospitalization remains inconsistent. Further, the literature fails to capture the influence of these predictors solely among older women. A conceptual model of risk predictors is proposed for clinical intervention.

CONCLUSION

Further evaluation to understand risk predictors of early (31 to 60-day) HF rehospitalizations among older women is needed.

Bimodal Effects of P2Y12 Antagonism on Matrix Metalloproteinase-Associated Contractile Dysfunction in İnsulin-Resistant Mammalian Heart

The matrix metalloproteinases (MMPs) contribute to matrix remodeling in diabetes via tissue degradation; however, their contributions can be different depending on the pathology. For instance, MMPs are elevated in acute stress hyperglycemia, whereas they can be degraded in chronic hyperglycemia. Since studies emphasize the possible cardioprotective effect of ticagrelor (Tica) beyond its antiplatelet action, we aimed to examine whether Tica treatment can reverse the depressed heart function of metabolic syndrome (MetS) rats via affecting the expression levels of MMPs. Tica treatment of high-carbohydrate-induced MetS rats could not affect significantly the depressed contractile activity of Langendorff-perfused heart preparations. On the other hand, the Tica treatment provided a significant recovery in the reduced relaxation activity of the aortic preparations from the same animals. Histological examination of the hearts demonstrated marked damages in Mets rats, such as increases in the number of foamy cells and accumulation of collagen fiber and increases in the elastic lamellar irregularity of tunica media, while Tica treatment provided a slight improvement in the structure of left ventricle tissue. We also could not obtain a significant reverse in the high cytosolic labile Zn²⁺ ([Zn²⁺]_i) with the treatment of cardiomyocytes with Tica. Furthermore, Tica treatment of MetS rats could not significantly reverse the degraded protein levels of MMP-2 and MMP-9 in the heart, as well. Overall, we demonstrated that Tica treatment of MetS rats has no significant benefits on the depressed heart function, although provide a significant beneficial impact on vascular relaxation. This action of Tica may be through its lack of action on both MMP degradation and high [Zn²⁺]_i, which can further precipitate in cleavage of extracellular matrix in the heart.

Titin and CK2α are New Intracellular Targets in Acute Insulin Application-Associated Benefits on Electrophysiological Parameters of Left Ventricular Cardiomyocytes From Insulin-Resistant Metabolic Syndrome Rats

BACKGROUND

Previous studies have demonstrated that a high-carbohydrate intake could induce metabolic syndrome (MetS) in male rats with marked cardiac functional abnormalities. In addition, studies mentioned some benefits of insulin application on these complications, but there are considerable disagreements among their findings. Therefore, we aimed to extend our knowledge on the in-vitro influence of insulin on left ventricular dysfunction and also in the isolated cardiomyocytes from MetS rats.

RESULTS

At the organ function level, an acute insulin application (100-nM) provided an important beneficial effect on the left ventricular developed pressure in MetS rats. Furthermore, to treat the freshly isolated cardiomyocytes from MetS rats with insulin provided marked recoveries in elevated resting intracellular Ca²⁺-level, as well as significant prevention of prolonged action potential through an augmentation in depressed K⁺-channel currents. Insulin also normalized the cellular levels of increased ROS and phosphorylation of PKCα, together with normalizations of apoptotic markers in MetS cardiomyocytes through the insulin-mediated regulation of phospho-Akt. Since not only elevated PKCα-activity but also reductions in phospho-Akt are key modulators of titin-based cardiomyocyte stiffening in hyperglycemia, insulin treatment of the cardiomyocytes prevented the activation of titin via the above pathways. Furthermore, CK2α-activation and NOS-phosphorylation could be prevented with insulin treatment. Mechanistically, we found that impaired insulin signaling and elevated PKCα and CK2α activities, as well as depressed Akt phosphorylation, are key modulators of titin-based cardiomyocyte stiffening in MetS rats.

CONCLUSION

We propose that restoring normal kinase activities and also increases in phospho-Akt by insulin can contribute marked recoveries in MetS heart function, indicating a promising approach to modulate titin-associated factors in heart dysfunction associated with type-2 diabetes mellitus. Graphical Abstract.

The association of the metabolic syndrome with target organ damage: focus on the heart, brain, and central arteries

INTRODUCTION

The metabolic syndrome (MetS) is an adverse metabolic state composed of obesity, hyperglycemia/pre-diabetes, hypertension, and dyslipidemia. It substantially increases the risk of type 2 diabetes, cardiovascular disease (CVD) and mortality, and has a huge impact on public health.

AREA COVERED

The present review gives an update on the definition and prevalence of MetS, and its impact on cardiac structure and function as well as on the brain and central arteries. The association with CVD and mortality risk is discussed. Focus is mainly directed toward the subclinical target organ damage related to MetS. Data is also critically reviewed to provide evidence on the incremental prognostic value of overall MetS over its individual components.

EXPERT COMMENTARY

MetS is a clinical risk condition associated with subclinical and clinical CVD and mortality. Roughly, 30% of the world population suffer from MetS. As all components of the MetS are modifiable, optimal preventive and therapeutic measures should be initiated to improve CV risk control, particularly aggressively treating hypertension and hyperglycemia, and encouraging people to adopt healthy lifestyle as early as possible is of great importance.

Blockade of mineralocorticoid receptor ameliorates oral contraceptive-induced insulin resistance by suppressing elevated uric acid and glycogen synthase kinase-3 instead of circulating mineralocorticoid

Context: Estrogen-progestin combined oral contraceptive (COC) has been connected to mineralocorticoid receptor (MR) activation and adverse cardiometabolic events. We consequently hypothesised that insulin resistance (IR), hyperuricemia, and elevated circulating GSK-3 induced by COC is through activation of MR via mineralocorticoid and glucocorticoid pathways.Methods: Female Wistar rats aged 12 weeks received (po) vehicle and COC (1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel) with or without MR blocker (0.25 mg/kg spironolactone; Spl), daily for eight weeks.Results: Data showed that COC treatment led to increased IR, 1-hour postload glucose level, insulinemia, triglyceride/HDL-cholesterol ratio, total cholesterol/HDL-cholesterol ratio, uric acid, GSK-3, aldosterone, corticosterone values, impaired glucose tolerance and pancreatic β-cell function. However, MR blockade by Spl ameliorated all these alterations except that of aldosterone.Conclusion: The results demonstrate that COC induces IR, hyperuricemia and high GSK-3 levels through activation of MR via glucocorticoid dependent pathway.

Evaluation oF Epicardial Fat and Carotid Intima-Media Thickness in Obese Children

Background:

Epicardial fat has a role in cardiovascular diseases.

Objectives:

To assess epicardial fat and its relation with carotid intima-media thickness (IMT) in obese adolescents with metabolic syndrome (MetS).

Patients and Methods:

The study included 60 obese adolescents and 25 control subjects. According to the presence or absence of MetS, obese subjects were divided into two subgroups. We measured weight, height, calculated Body Mass Index, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure and biochemical parameters (fasting glucose, total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol, High sensitivity C-reactive protein, fasting insulin, a homeostasis model assessment index of insulin resistance. plus an echocardiographic examination with measurement of epicardial adipose tissue thickness (EATT).

Results:

Left ventricular mass index measurements were significantly higher in MetS group than both non-MS and control groups. The MetS and non-MetS obese patients had significantly higher carotid IMT in comparison to the control group. Carotid IMT measurements were significantly higher in MetS group had than both non-MetS and control groups. Also, EATT was significantly increased in patients with MetS compared to control group. Among MetS obese group, EATT was positively correlated with body mass index-standard deviation score, waist circumference, fasting glucose, fasting insulin, insulin resistance, triglyceride levels, left ventricular thickness, left ventricular mass index and myocardial performance index. EATT was found to be the only predictor of carotid IMT.

Conclusions:

EATT is closely related to carotid IMT and early cardiac dysfunction in obese adolescents with MetS.

Present Insights on Cardiomyopathy in Diabetic Patients

The pathogenesis of diabetic cardiomyopathy (DCM) is partially understood and is likely to be multifactorial, involving metabolic disturbances, hypertension and cardiovascular autonomic neuropathy (CAN). Therefore, an important need remains to further delineate the basic mechanisms of diabetic cardiomyopathy and to apply them to daily clinical practice. We attempt to detail some of these underlying mechanisms, focusing in the clinical features and management. The novelty of this review is the role of CAN and reduction of blood pressure descent during sleep in the development of DCM. Evidence has suggested that CAN might precede left ventricular hypertrophy and diastolic dysfunction in normotensive patients with type 2 diabetes, serving as an early marker for the evaluation of preclinical cardiac abnormalities. Additionally, a prospective study demonstrated that an elevation of nocturnal systolic blood pressure and a loss of nocturnal blood pressure fall might precede the onset of abnormal albuminuria and cardiovascular events in hypertensive normoalbuminuric patients with type 2 diabetes. Therefore, existing microalbuminuria could imply the presence of myocardium abnormalities. Considering that DCM could be asymptomatic for a long period and progress to irreversible cardiac damage, early recognition and treatment of the preclinical cardiac abnormalities are essential to avoid severe cardiovascular outcomes. In this sense, we recommend that all type 2 diabetic patients, especially those with microalbuminuria, should be regularly submitted to CAN tests, Ambulatory Blood Pressure Monitoring and echocardiography, and treated for any abnormalities in these tests in the attempt of reducing cardiovascular morbidity and mortality.

Myocardial performance is impaired in patients with branch retinal vein occlusion

OBJECTIVE

To investigate whether the Tei index, which is an indicator of global myocardial function and an independent predictor of cardiac death, is increased in patients with branch retinal vein occlusion (BRVO).

METHODS

The Tei index was used to evaluate myocardial performance, in addition to conventional echocardiographic evaluation of myocardial structural and functional changes, in patients with BRVO, patients with hypertension and healthy controls.

RESULTS

Out of 36 patients with BRVO (18 female, 18 male; 17 hypertensive, 19 normotensive), 29 patients with hypertension (15 female, 14 male) and 28 healthy controls (15 female, 13 male), there were no significant between-group differences in age and sex. The mitral A wave was higher and mitral E/A ratio, mitral E wave and ejection time were lower, in patients with BRVO than in healthy controls. Mean Tei index was significantly higher in the BRVO group than in patients with hypertension or healthy controls. Compared with healthy controls, the Tei index was significantly higher in hypertensive and normotensive patients with BRVO.

CONCLUSION

Myocardial performance is decreased in patients with BRVO, independent of whether or not they have hypertension.

Late Cardiotoxicity in Aging Adult Survivors of Childhood Cancer

The survival rate for childhood cancer is steadily improving, and the current estimate for the prevalence of childhood cancer survivors in the United States is 420,000. With this encouraging trend and the aging of this population, there is an ever-increasing responsibility to identify adult survivors of childhood cancer with adverse health outcomes related to cancer treatment across the span of their lives. To accomplish this, large cohort studies have been developed to follow survivors longitudinally. Compared to siblings, survivors have a higher cumulative incidence of morbidity and mortality, and this gap in incidence only widens with age. One of the most significant late toxicities in survivors is late onset cardiotoxicity, largely due to anthracycline and chest-directed radiation exposure. Survivors also have an increased prevalence of traditional cardiovascular risk factors as they age, which potentiates the risk for major cardiac events. Prevention is essential. Minimizing anthracycline dose exposure in pediatric cancer patients is a primary method of cardioprotection. Dexrazoxane and enalapril have also been studied as primary (pre-exposure) and secondary (post-exposure) cardioprotecant agents, respectively. Additionally, the Children's Oncology Group has published exposure-driven, risk-based screening guidelines for long-term follow-up, which may be a cost-effective way to identify subclinical cardiac disease before progression to clinical presentation. Ongoing research is needed to determine the most effective diagnostic modality for screening (e.g. echocardiography), and the most effective intervention strategies to improve long-term outcomes.

Impact of metabolic syndrome on global left ventricular function: As evaluated by the myocardial performance index

BACKGROUND

Metabolic syndrome is associated with the development of diabetes mellitus and cardiovascular disease. The impact of metabolic syndrome on the progression of atherosclerosis has been well documented. This study was designed to evaluate the impact of metabolic syndrome on global left ventricular function by using left ventricular myocardial performance index (LVMPI).

METHODS

The diagnosis of metabolic syndrome was made as per the criteria of the International Diabetes Federation. Echocardiography was performed with a Philips IE33 machine using a 1-5 MHz transthoracic probe. LVMPI was calculated by adding isovolumic contraction time with isovolumic relaxation time and dividing it by ejection time.

RESULTS

The mean LVMPI value in metabolic syndrome was 0.64 ± 0.09, while that in controls was 0.48 ± 0.06 (p < 0.001). Metabolic syndrome was seen to have more significant influence on LVMPI.

CONCLUSIONS

Metabolic syndrome is a strong predictor of sub-clinical myocardial dysfunction in subjects free of clinically apparent heart disease.

Relationship of epicardial adipose tissue thickness with early indicators of atherosclerosis and cardiac functional changes in obese adolescents with metabolic syndrome

OBJECTIVE

Epicardial adipose tissue thickness (EATT) is suggested as a new cardiometabolic risk factor. Carotid intima-media thickness (IMT) is a potential indicator of subclinical atherosclerosis in patients with metabolic syndrome (MS). We investigated the association of EATT with carotid IMT and cardiac functional changes in obese adolescents with MS.

METHODS

One hundred thirty-eight obese adolescents and 63 lean subjects were enrolled in the study. The obese subjects were divided into two subgroups based on the presence or absence of MS (MS group and non-MS group). All subjects underwent transthoracic echocardiographic examination for determination of left ventricular (LV) function, LV mass index (LVMI), and myocardial performance index (MPI). EATT and carotid IMT were also measured during echocardiography.

RESULTS

The average LVMI measurements were higher in both MS and non-MS obese patients in comparison with the lean children. The MS group had significantly higher LVMI measurements than the non-MS and lean groups (88.5±23.0, 67.5±24.8 g/m2, and 62.4±18.2 g/m2, respectively; p<0.01). Carotid IMT was higher in both the MS and non-MS obese patients in comparison with the lean group. The MS group had significantly higher carotid IMT measurements than the non-MS and lean groups (0.91±0.23, 0.78±0.18, and 0.52±0.08 mm, respectively; p<0.01). The EATT was also increased significantly in patients with MS compared to lean adolescents (7.42±1.55 vs. 4.28±0.79mm; p=0.001). EATT was positively correlated with body mass index-SDS, waist circumference, fasting glucose, insulin, homeostasis model assessment-insulin resistance, triglyceride levels, LV thickness, LVMI, and MPI in the MS obese group. EATT was the only independent predictor of carotid IMT in the multivariate analysis (β= 0.69, p<0.001).

CONCLUSION

The findings of the present study demonstrate a close relationship of EATT with carotid IMT and early cardiac dysfunction in obese adolescents with MS. Assessment of EATT and carotid IMT in routine echocardiographic examinations is suggested as a feasible and reliable method for the evaluation of obesity with MS and its related cardiovascular risks in children and adolescents.

Diabetic cardiomyopathy: ongoing controversies in 2012

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

Cardiac dysfunction and oxidative stress in the metabolic syndrome: an update on antioxidant therapies

The metabolic syndrome (MetS) is a cluster of risk factors including obesity, insulin resistance, dyslipidemia, elevated blood pressure and glucose intolerance. The MetS increases the risk for cardiovascular disease (CVD) and type 2 diabetes. Each component of the MetS causes cardiac dysfunction and their combination carries additional risk. The mechanisms underlying cardiac dysfunction in the MetS are complex and might include lipid accumulation, increased fibrosis and stiffness, altered calcium homeostasis, abnormal autophagy, altered substrate utilization, mitochondrial dysfunction and increased oxidative stress. Mitochondrial and extra-mitochondrial sources of reactive oxygen species (ROS) and reduced antioxidant defense mechanisms characterize the myocardium of humans and animals with the MetS. The mechanisms for increased cardiac oxidative stress in the MetS are not fully understood but include increased fatty acid oxidation, mitochondrial dysfunction and enhanced NADPH oxidase activity. Therapies aimed to reduce oxidative stress and enhance antioxidant defense have been employed to reduce cardiac dysfunction in the MetS in animals. In contrast, large scale clinical trials using antioxidants therapies for the treatment of CVD have been disappointing because of the lack of efficacy and undesired side effects. The focus of this review is to summarize the current knowledge about the mechanisms underlying cardiac dysfunction in the MetS with a special interest in the role of oxidative stress. Finally, we will update the reader on the results obtained with natural antioxidant and mitochondria-targeted antioxidant therapies for the treatment of CVD in the MetS.

[Echocardiography in diabetic cardiomyopathy]

The term diabetic cardiomyopathy was initially introduced in the 1980s when evidence was found that diabetes leads to a distinct cardiomyopathy, independent of coronary artery disease or hypertension. The detection of diabetic cardiomyopathy using echocardiography is challenging because no pathognomonic signs exist; however, it is the merit especially of the newer echocardiographic techniques, such as deformation imaging, that it is now possible to describe the morphology and function of diabetic hearts. Unfortunately, no long-term echocardiography studies are available describing disease progression in detail. Therefore, staging and differential diagnosis of diabetic cardiomyopathy remains challenging. This review tries to fill this gap by presenting a possible echocardiographic staging algorithm. Early stages of diabetic cardiomyopathy are marked by a deterioration of longitudinal systolic function and a compensative elevated radial function. Diastolic dysfunction is another early sign. When the disease progresses the functional deterioration is accompanied by morphological changes, such as left ventricular concentric hypertrophy and fibrosis. End stage disease is characterized by reduced ejection fraction and ventricular dilatation. Very late stage can mimic dilative cardiomyopathy.

Do diabetes, metabolic syndrome or their association equally affect biventricular function? A tissue Doppler study

Metabolic syndrome (MetS) and type 2 diabetes (T2DM) have been associated with an impairment of left (LV) and right ventricular (RV) function as well as an increased risk of heart failure (HF). However, it remains unclear whether these clinical entities or their associations promote a similar derangement of biventricular function. Overall, 345 patients without overt cardiovascular disease consecutively underwent routine blood chemistry including high-sensitivity C reactive protein (hs-CRP) and echocardiographical examination with conventional and tissue Doppler imaging (TDI) of both ventricles. According to the ATP III criteria and fasting glucose levels, the study population was stratified into four groups: (1) healthy controls (n=120); (2) MetS without T2DM (n=84); (3) T2DM without MetS (n=49); and (4) MetS+T2DM (n=92). The Myocardial performance index (MPI) of the RV and LV was obtained with a multi-segmental approach using TDI. Patients with MetS and T2DM exhibited a similar impairment of biventricular function compared with healthy controls, whereas a further decline was observed in patients having both MetS and T2DM. In addition to MetS markers, hs-CRP exhibited the strongest association with the MPI of both ventricles. Regression analyses indicated that individual MetS markers were inferior to MetS in identifying subtle cardiac dysfunction. Independent associations of MetS and T2DM with biventricular dysfunction were comparable, and the coexistence of MetS and T2DM exhibited the highest risk for biventricular dysfunction. Our findings emphasize the importance of MetS as an equivalent of T2DM and support a synergic effect of these clinical conditions on cardiac organ damage requiring more aggressive therapeutic strategies to prevent HF.

A randomized study of the beneficial effects of aldosterone antagonism on LV function, structure, and fibrosis markers in metabolic syndrome

OBJECTIVES

The purpose of this study was to identify the effects of spironolactone on left ventricular (LV) structure and function, and serological fibrosis markers in patients with metabolic syndrome (MS) taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers.

BACKGROUND

Myocardial fibrosis may be an important contributor to myocardial impairment in MS, and aldosterone antagonism may reduce fibrosis.

METHODS

Eighty patients (age 59 ± 11 years) with MS, already being treated with angiotensin II inhibition, were randomized to spironolactone 25 mg/day or placebo for 6 months. Each patient underwent baseline and follow-up conventional echocardiography and color tissue Doppler imaging. Raw data files were used to measure calibrated integrated backscatter and to calculate radial and longitudinal strain. Blood was obtained at baseline and follow-up to measure fibrosis markers (procollagen type III amino-terminal propeptide and procollagen type I carboxy-terminal propeptide [PICP]).

RESULTS

The spironolactone group showed significant improvement of LV function, myocardial reflectivity, and LV hypertrophy, with a parallel decrease in levels of PICP and procollagen type III amino-terminal propeptide. No analogous changes were seen in the placebo group. Baseline strain (β = 0.47, p < 0.0001), spironolactone therapy (β = -0.38, p < 0.0001), and change in PICP level (β = -0.19, p < 0.03) were independently associated with LV systolic function improvement (increase in strain). Correlates of LV diastolic function improvement (increase in early diastolic mitral annular velocity) were baseline early diastolic mitral annular velocity (β = 0.47, p < 0.0001), spironolactone therapy (β = -0.21, p < 0.03), change in PICP level (β = -0.23, p < 0.02), and age (β = 0.22, p < 0.04). Favorable effects of spironolactone on cardiac function were not demonstrated in patients with less fibrosis (the lower baseline PICP tertile) or preserved function (the upper baseline strain tertile).

CONCLUSIONS

Addition of spironolactone to standard angiotensin II inhibition improved myocardial abnormalities and decreased fibrotic markers in MS. The magnitude of benefit on cardiac performance is determined mainly by baseline LV dysfunction and collagen turnover as well its response to intervention.

Increased heart failure risk in normal-weight people with metabolic syndrome compared with metabolically healthy obese individuals

OBJECTIVES

The purpose of this study was to assess whether the metabolically healthy obese phenotype is associated with lower heart failure (HF) risk compared with normal-weight individuals with metabolic syndrome (MetS).

BACKGROUND

Obesity and MetS often coexist and are associated with increased HF risk. It is controversial whether obese individuals with normal insulin sensitivity have decreased HF risk.

METHODS

A total of 550 individuals without diabetes or baseline macrovascular complications were studied during a median follow-up of 6 years. Participants were classified by presence (n = 271) or absence (n = 279) of MetS and by body mass index (body mass index: <25 kg/m(2) = normal weight, n = 177; 25 to 29.9 kg/m(2) = overweight, n = 234; ≥ 30 kg/m(2) = obese, n = 139). MetS was diagnosed with the National Cholesterol Education Program Adult Treatment Panel III criteria. Left ventricular functional capacity, myocardial structure, and performance were assessed echocardiographically.

RESULTS

Body mass index was not associated with increased HF risk. The presence of MetS conferred a 2.5-fold higher HF risk (hazard ratio [HR]: 2.5, 95% confidence interval [CI]: 1.68 to 3.40). Overweight and obese individuals without MetS had the lowest 6-year HF risk (HR: 1.12, 95% CI: 0.35 to 1.33 [corrected] and HR: 0.41, 95% CI: 0.10 to 1.31, respectively) compared with normal-weight individuals with MetS (HR: 2.33, 95% CI: 1.25 to 4.36, p < 0.001). From the individual components of MetS, impaired fasting glucose (HR: 1.09, 95% CI: 1.06 to 1.10), high BP (HR: 2.36, 95% CI: 1.03 to 5.43), low high-density lipoprotein cholesterol (HR: 1.88, 95% CI: 1.29 to -2.77), and central obesity (HR: 2.22, 95% CI: 1.02 to 1.05) were all associated with increased HF risk. Factors commonly associated with MetS such as insulin resistance and inflammation (high-sensitivity C-reactive protein and microalbuminuria) were also independently associated with HF incidence.

CONCLUSIONS

In contrast to normal weight insulin-resistant individuals, metabolically healthy obese individuals show decreased HF risk in a 6-year follow-up study.

Time intervals and myocardial performance index by tissue Doppler imaging

The application of tissue Doppler imaging (TDI) has shown remarkable growth in clinical practice during the past few years, especially, in risk stratification of patients with coronary heart disease or heart failure (systolic and diastolic). Myocardial performance index (MPI) is a Doppler echocardiographic parameter defined as the sum of the isovolemic contraction and relaxation times divided by the ejection time. It is considered as a reliable parameter to assess global left ventricular function. Cardiac time intervals and MPI have also been found as new applications in diagnosing cardiotoxicity from chemotherapy, COPD, valvular heart disease, pulmonary hypertension and endocrinopathies.

Global left ventricular performance in non-diabetic non-hypertensive metabolic syndrome adults

AIM

To evaluate the left ventricular structure and function in isolated metabolic syndrome.

METHODS

One hundred and fifty six consecutive adults with metabolic syndrome were enrolled in the study. Fifty nine had isolated metabolic syndrome (group A) and 97 had metabolic syndrome with hypertension and/or diabetes (group B). There was a control group of 34 healthy adults. In addition to classic echocardiographic assessment of myocardial structural and functional changes, the Tei index was used to evaluate global left ventricular performance.

RESULTS

There were no statistically significant differences between group A and controls in all parameters of left ventricular structural, systolic, and diastolic function except global myocardial performance (Tei index). On the other hand, significant differences were observed between group B and the control group in most of the parameters of left ventricular structural and global performance.

CONCLUSION

The early identification of isolated metabolic syndrome in non-diabetic, non-hypertensive adults may be an indication that aggressive preventive measures should not be postponed until overt obesity, hypertension or diabetes mellitus has developed.

The genetics of obesity and the metabolic syndrome

In this review, we discuss the genetic architecture of obesity and the metabolic syndrome, highlighting recent advances in identifying genetic variants and loci responsible for a portion of the variation in components of the metabolic syndrome, namely, adiposity traits, serum HDL and triglycerides, blood pressure, and glycemic traits. We focus particularly on recent progress from large-scale genome-wide association studies (GWAS), by detailing their successes and how lessons learned can pave the way for future discovery. Results from recent GWAS coalesce with earlier work suggesting numerous interconnections between obesity and the metabolic syndrome, developed through several potentially pleiotropic effects. We detail recent work by way of a case study on the cadherin 13 gene and its relation with adiponectin in the HyperGEN and the Framingham Heart Studies, and its association with obesity and the metabolic syndrome. We provide also a gene network analysis of recent variants related to obesity and metabolic syndrome discovered through genome-wide association studies, and 4 gene networks based on searching the NCBI database.

Diabetic cardiomyopathy: from the pathophysiology of the cardiac myocytes to current diagnosis and management strategies

Diabetic cardiomyopathy (DCM), although a distinct clinical entity, is also a part of the diabetic atherosclerosis process. It may be independent of the coexistence of ischemic heart disease, hypertension, or other macrovascular complications. Its pathological substrate is characterized by the presence of myocardial damage, reactive hypertrophy, and intermediary fibrosis, structural and functional changes of the small coronary vessels, disturbance of the management of the metabolic cardiovascular load, and cardiac autonomic neuropathy. These alterations make the diabetic heart susceptible to ischemia and less able to recover from an ischemic attack. Arterial hypertension frequently coexists with and exacerbates cardiac functioning, leading to the premature appearance of heart failure. Classical and newer echocardiographic methods are available for early diagnosis. Currently, there is no specific treatment for DCM; targeting its pathophysiological substrate by effective risk management protects the myocardium from further damage and has a recognized primary role in its prevention. Its pathophysiological substrate is also the objective for the new therapies and alternative remedies.