Impact of glucose intolerance and insulin resistance on cardiac structure and function: sex-related differences in the Framingham Heart Study

Cardiovascular abnormalities already occurred in newly-diagnosed patients with early-onset type 2 diabetes

BACKGROUND

The prevalence of early-onset type 2 diabetes (EOD) is rapidly increasing. This study intends to screen for early cardiovascular abnormalities in patients newly diagnosed with EOD and evaluate the cardiovascular risk across cluster phenotypes.

METHOD

A total of 400 patients ≤ 40 years old with newly diagnosed type 2 diabetes were enrolled from the START cohort (the Study of The newly diAgnosed eaRly onset diabeTes). Cluster classification was performed using the K-means method based on age, BMI, HbA1c, HOMA2-β, HOMA2-IR, and GAD antibodies. Echocardiography and carotid ultrasound were performed within 3 months of diabetes diagnosis. Carotid ultrasound abnormalities included intimal thickening and plaque formation, while echocardiography assessed changes in cardiac structure and systolic/diastolic function. Cluster-specific partitioned polygenic scores (pPS) were used to validate our findings from a genetic perspective.

RESULT

Carotid artery abnormalities were detected in 26.3% of patients, and echocardiography abnormalities were observed in 20.0%. Patients with severe insulin resistant diabetes (SIRD) had the highest incidence of carotid artery abnormality (40.0%). After adjusting for relevant risk factors, fasting C-peptide levels were significantly associated with a 1.247-fold increase in the risk of carotid artery abnormalities. Left atrial enlargement was more prevalent in the SIRD (16.7%) and mild obesity-related diabetes (MOD) (18.5%) classifications. A high proportion of patients with SIRD had abnormal left ventricular geometry (36.1%). Increases in BMI, fasting C-peptide level and HOMA2IR were accompanied by a further increase in left atrial enlargement risk by 1.136-, 1.781- and 1.687-fold respectively. The pPS for lipodystrophy was higher in the EOD group with plaque formation, and showed a significant linear correlation with the ratio of the left atrial anteroposterior diameter to body surface area (LAAP/BSA) (R = 0.344, p < 0.001).

CONCLUSION

Heart and carotid artery abnormalities are common in patients with early-onset T2DM at the time of diagnosis. Patients with obesity and insulin resistance are at higher risk for cardiovascular abnormalities. Cluster classification based on clinical characteristics enables more accurate identification of patients at increased risk of cardiovascular complications at an early stage.

The role of estrogen in the sex difference for the risk factors of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a major subtype of heart failure, primarily characterized by a normal or mildly reduced left ventricular ejection fraction along with left ventricular diastolic dysfunction. Recent studies have shown that the prevalence of HFpEF is higher in women than that in men, particularly in postmenopausal women. Concurrently, it has been observed that the incidence of risk factors contributing to HFpEF (such as obesity, hypertension, diabetes, and atrial fibrillation) also notably increases post-menopause, affecting the incidence of HFpEF. This review aimed to examine the relationship between estrogen and risk factors associated with HFpEF, clarifying the underlying mechanisms through which estrogen affects these risk factors from epidemiological and pathophysiological perspectives. This review also provides a comprehensive understanding of the association between estrogen and the risk factors for HFpEF, thus helping explore potential targets for HFpEF treatment.

Right ventricular dysfunction in preclinical models of type I and type II diabetes

Diabetic cardiomyopathy (DCM) is a growing clinical entity and major health burden characterized by comorbid diabetes mellitus and heart failure. DCM has been commonly associated with impaired function of the left ventricle (LV); however, DCM likely also occurs in the right ventricle (RV) which has distinct physiology and pathophysiology from the LV. RV dysfunction is the strongest determinant of mortality in several clinical contexts yet remains poorly studied in diabetes. We investigated RV-specific pathophysiology using two models of diabetes-a well-characterized type 2 diabetes (T2DM) model of high-fat diet and low-dose streptozotocin (STZ) in the mouse and a large animal model of type I diabetes in domestic pigs rendered diabetic with STZ. RV global and systolic function deteriorated with diabetes, alongside hypertrophic and fibrotic remodeling. We report evidence of impaired RV insulin sensitivity, dysregulated RV metabolic gene expression, and impaired mitochondrial dynamics. Importantly, while some of these outcomes were similar to those widely reported in the LV, others were not, such as unchanged antioxidant gene expression and regulators of fatty acid uptake. Importantly, these RV-specific changes occurred in both male and female T2DM mice, together emphasizing the importance of distinguishing the RV from the LV when studying DCM and begging the consideration of RV-specific therapies.

Effects of Metabolic Factors on Left Ventricular Diastolic Function in Patients with Obstructive Sleep Apnea

Purpose

The effect of metabolic factors on cardiovascular risk in obstructive sleep apnea (OSA) is unclear. This study aimed to investigate the effect of metabolic factors on the left ventricular diastolic function in patients with OSA.

Patients and Methods

This cross-sectional study included a total of 478 patients with OSA from September 2018 to September 2023. After propensity score matching, wherein 193 patients with OSA with metabolic syndrome (MS) were 1:1 matched to patients with OSA without MS by sex and age, data from 386 patients were ultimately analyzed. Furthermore, all patients were divided into mild, moderate, and severe OSA groups according to their sleep apnea-hypopnea index (AHI). Measurements included nocturnal polysomnography, biochemical testing, and transthoracic echocardiography data.

Results

The AHI in the MS group was higher (30.24±21.69 vs 23.19±17.65, p<0.001) and the lowest oxygen saturation at night was lower (77.67±9.23 vs 80.59±9.26, p<0.001) than those in the non-MS group. Additionally, the left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), end-diastolic ventricular septal thickness (IVST), left ventricular end-diastolic posterior wall thickness (LVPWT), left atrial internal diameter (LAD), and E peak to A peak velocity ratio (E/A) in the MS group were higher than those in the non-MS group (P<0.05). The E peak to e' peak velocity ratio (E/e') in the MS group was higher than that in the non-MS group (12.02±3.68 vs 11.13±3.12, P=0.011) and was positively correlated with the diagnosis of MS and metabolic factors (r=0.115, p=0.024; r=0.131, p=0.010, respectively). Patients with five metabolic factors had a significantly higher risk of E/e' elevation than patients in the non-MS group (odds ratio=4.238, p=0.007).

Conclusion

MS may be related to OSA severity and left ventricular diastolic dysfunction. An increase in metabolic factors may increase the risk of diastolic dysfunction. Among metabolic factors, blood pressure may be the most important.

Diabetic cardiomyopathy: pathophysiology, imaging assessment and therapeutical strategies

Diabetes mellitus (DM) is one of the most prevalent cardiovascular risk factors in the general population, being associated with high morbidity and socioeconomic burden. Diabetic cardiomyopathy (DCM) is a non-negligible complication of DM, whose pathophysiological fundaments are the altered cardiac metabolism, the hyperglycemia-triggered formation of advanced glycation end-products (AGEs) and the inflammatory milieu which are typical in diabetic patients. These metabolic abnormalities lead to cardiomyocytes apoptosis, interstitial fibrosis and mechanical cardiac dysfunction, which can be identified with non-invasive imaging techniques, like echocardiography and cardiac magnetic resonance. This review aims to: 1) describe the major imaging features of DCM; 2) highlight how early identification of DCM-related anatomical and functional remodeling might allow patients' therapy optimization and prognosis improvement.

Association between single-point insulin sensitivity estimator and heart failure in older adults: A cross-sectional study

BACKGROUND

Heart failure (HF) is a condition caused by a malfunction of the heart's pumping function. The single-point insulin sensitivity estimator (SPISE) index is a novel indicator for assessing insulin resistance in humans. However, the connection between the SPISE index and the risk of HF in the elderly is unknown. Therefore, our study aims to evaluate the connection between the SPISE index and HF in older adults.

METHODS

The study was based on data collected from the 1999-2020 National Health and Nutrition Examination Survey database and included 6165 participants aged ≥60 years. The multivariable linear regression model and the smooth fitting curve model were applied to investigate the connection between the SPISE index and HF in the elderly. Furthermore, the subgroup analysis was performed to investigate the interactive factors.

RESULTS

In this study, the mean age of the population was 69.38 years. After adjusting for all covariates, we observed that the SPISE index was inversely related to the prevalence of HF (OR = 0.87, 95 % CI = 0.80-0.94, P < 0.001) in older adults. The interaction analysis showed that the association might be affected by diabetes mellitus and smoking status. Additionally, an inflection point between the SPISE index and HF was found among older women.

CONCLUSIONS

An inverse correlation was detected between the SPISE index and HF in the elderly. This could provide new insight into the prevention and management of HF in the elderly population.

Mild renal dysfunction causes aggravated cardiac damage in type 2 diabetic patients: a comprehensive echocardiography study

PURPOSE

We sought to detect left ventricular (LV) adverse alterations in structure and function in type 2 diabetes mellitus (T2DM) patients with or without mild renal dysfunction (MRD) using comprehensive echocardiography techniques and to explore the independent risk factors for LV remodeling (LVR) and dysfunction in these patients.

METHODS

The study included 82 T2DM patients with normal LV ejection fraction (presence (n = 42)/absence (n = 40) of MRD). Age- and gender-matched controls (n = 40) were also recruited. LV structure and function were evaluated using conventional echocardiography and three-dimensional speckle tracking echocardiography (3DSTE). Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS), and global radial strain (GRS) were all measured using 3DSTE.

RESULTS

Compared with the controls with absolute advantage of LV normal geometry, LVR was more frequently present in the two T2DM groups, with the largest proportion in those with T2DM and MRD (P < 0.001). Fasting plasma glucose (FPG) and MRD were both significant risk factors for LVR in T2DM patients. The detection rates of LV diastolic dysfunction and subclinical systolic dysfunction were significantly higher in the T2DM groups than in the controls (P = 0.000). Moreover, the two case groups also showed significantly lower strain values in multiple directions than the controls (all P < 0.05). FPG was significantly associated with LV diastolic dysfunction, whereas FPG and MRD were both significantly associated with subclinical LV systolic dysfunction in T2DM patients.

CONCLUSIONS

The combined use of conventional echocardiography and 3DSTE allowed the timely detection of early cardiac damage in T2DM patients with or without MRD.

Insulin resistance in the adipose tissue predicts future vascular resistance: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases

BACKGROUND AND AIMS

Diameter, plaque score, and resistance index (RI) in the common carotid artery (CCA) are indicators of arterial remodeling, atherosclerosis, and vascular resistance, respectively. This study investigated the longitudinal association between adipose tissue insulin resistance or serum free fatty acid (FFA) levels and the CCA parameters.

METHODS

This retrospective cohort analysis included 1089 participants (mean age 57.6 years; 40.0 % women) with data on health checkups from January 1982 to March 2003 and carotid artery ultrasonography from January 2015 to June 2019. Baseline serum FFA and immunoreactive insulin levels were assessed before and 30, 60, and 120 min after glucose ingestion. Adipose insulin resistance index (Adipo-IR) was calculated as the product of fasting serum insulin and FFA levels. An RI value >0.75 was defined as high RI.

RESULTS

A significant association was found between Adipo-IR and RI; however, Adipo-IR showed no association with CCA diameter or plaque score. The incidence of high RI increased with Adipo-IR quartile (Q) groups (47.3 % in Q1, 52.8 % in Q2, 53.3 % in Q3, 62.4 % in Q4; Cochrane-Armitage test for trend, p < 0.001). In multivariate analysis, Adipo-IR levels (Q4 vs. Q1 odds ratio: 1.67, 95 % confidence interval: 1.12-2.51) were positively associated with high RI incidence. Moreover, a significant association was found between RI and serum FFA levels after glucose intake, but not fasting FFA levels.

CONCLUSIONS

Future vascular resistance was predicted by insulin resistance in the adipose tissue. After glucose intake, serum FFA levels may significantly impact vascular resistance development.

Associations between long-term averages of metabolic parameters in adulthood and cardiac structure and function in later life

The effects of long-term levels of body mass index (BMI), blood pressure (BP), plasma lipids and fasting blood glucose (FBG) on the cardiac structure and function in later life in general population are to evaluate. We included adult participants without heart failure from Framingham Heart Study. The respective averages over a span of 30-36 years of seven parameters were pooled into linear regression models simultaneously to evaluate their associations with subsequent left atrial internal dimension (LAID), left ventricular mass index (LVMi), internal dimension (LVID), ejection fraction (LVEF), global longitudinal strain (GLS) and mitral inflow velocity to early diastolic mitral annular velocity (E/é). In 1838 participants (56.0% female, mean age 66.1 years), per 1-standard deviation (SD) increment of mean BMI correlated with larger LAID and LVID (β 0.05~0.17, standard error [SE] 0.01 for all), greater LVMi (β [SE], 1.49 [0.46]), worse E/é (β [SE], 0.28 [0.05]). Per 1-SD increment of mean systolic BP correlated with greater LVMi (β [SE], 4.70 [0.69]), LVEF (β [SE], 0.73 [0.24]), E/é (β [SE], 0.52 [0.08]), whereas increase of mean diastolic BP correlated with smaller LVMi (β [SE], -1.61 [0.62]), LVEF (β [SE], -0.46 [0.22]), E/é (β [SE], -0.30 [0.07]). Per 1-SD increment of mean high density lipoprotein cholesterol (HDL-c) correlated with smaller LVID (β [SE], -0.03 [0.01]) and better systolic function (LVEF, β [SE], 0.63 [0.19]; GLS, β [SE], -0.20 [0.10]). The variabilities of BMI, BP and HDL-c also correlated with certain cardiac measurements. In long-term, BMI affected the size and mass of heart chambers, systolic and diastolic BP differently influenced left ventricular mass and function, higher HDL-c linked to better systolic function. Clinical trial registration: URL: https://clinicaltrials.gov . Identifier: NCT00005121.

Cardiac Abnormalities in Hispanic/Latina Women With Prior De Novo Hypertensive Disorders of Pregnancy

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are associated with long-term maternal risks for cardiovascular disease for reasons that remain incompletely understood.

METHODS

The HCHS/SOL (Hispanic Community Health Study/Study of Latinos), a multi-center community-based cohort of Hispanic/Latino adults recruited 2008 to 2011, was used to evaluate the associations of history of de novo HDP (gestational hypertension, preeclampsia, eclampsia) with echocardiographic measures of cardiac structure and function in Hispanic/Latina women with ≥1 prior pregnancy and the proportion of association mediated by current hypertension (>140/90 mm Hg or antihypertensive therapy).

RESULTS.

The study cohort included 5168 Hispanic/Latina women with an average age (SD) of 58.7 (9.7) years at time of echocardiogram. Prior de novo HDP was reported by 724 (14%) of the women studied and was associated with lower left ventricle (LV) ejection fraction -0.66 (95% confidence interval [CI], -1.21 to -0.11), higher LV relative wall thickness 0.09 (95% CI, 0-0.18), and 1.39 (95% CI, 1.02-1.89) higher risk of abnormal LV geometry after adjusting for blood pressure and other confounders. The proportion of the association mediated by current hypertension between HDP and LV ejection fraction was 0.09 (95% CI, 0.03-0.45), LV relative wall thickness was 0.28 (95% CI, 0.16-0.51), abnormal LV geometry was 0.14 (95% CI, 0.12-0.48), concentric left ventricular hypertrophy was 0.31 (95% CI, 0.19-0.86), and abnormal LV diastolic dysfunction was 0.58 (95% CI, 0.26-0.79).

CONCLUSIONS.

In a large cohort of Hispanic/Latina women those with history of de novo HDP had detectable and measurable subclinical alterations in cardiac structure and both systolic and diastolic dysfunction that were only partially mediated by current hypertension.

High left ventricular mass associated with increased risk of incident diabetes

Evidence for the role of electrocardiography or echocardiography in determining left ventricular hypertrophy for the risk of diabetes is still controversial. We aimed to explore whether left ventricular mass, as measured by these methods, is associated with the risk of diabetes in a community population. We recruited 2696 participants aged 35 years or older without diabetes who had undergone screening with electrocardiography and echocardiography. Left ventricular mass index (LVMI) was calculated using a formula, and participants were divided into tertiles based on their LVMI tertiles. During a median follow-up period of median, 8.9 years, a total of 405 participants developed diabetes. The incidence and risk of diabetes significantly increased with higher LVMI tertiles. Multivariate Cox regression analysis demonstrated that individuals in the highest LVMI tertile had a greater likelihood of developing incident diabetes, with a hazard ratio of 1.40 (95% CI 1.06-1.91), even after adjusting related covariates. The highest risk of diabetes was observed in the presence of both the uppermost LVMI tertile and electrocardiographically determined left ventricular hypertrophy for the Chinese population. Left ventricular hypertrophy identified by either electrocardiography or echo may serve as a surrogate marker for identifying the risk of diabetes in clinical practice.

Evaluation of association between time in range, a continuous glucose monitoring metric, and cardiac autonomic neuropathy in type 2 diabetes patients

Introduction

Time in range (TIR), a metric of continuous glucose monitoring (CGM) provides better information regarding the individual's glycemic variability than a static measure like glycated hemoglobin (HbA1c). TIR is emerging as an independent risk factor for diabetic complications, both microvascular and macrovascular complications independent of HbA1c. Hence, this study evaluates the association between TIR and cardiac autonomic neuropathy (CAN) in type 2 diabetic patients.

Materials and Methods

A total of 42 patients with type 2 diabetes mellitus were enrolled in this study and underwent a 3-day CGM using the "FreeStyle Libre Pro Flash Glucose Monitoring System Sensor" along with tests for CAN within the 3 days of attaching the CGM.

Results

Out of 42 patients, 36 patients (85.7%) were diagnosed with CAN (early CAN 57.1% and definite CAN 28.6%) and the mean TIR was 64.4% ±23.5%. Out of those with TIR <70%, 42.9% were affected with definite CAN compared to only 14.3% among those with TIR >70%. Patients with more severe CAN were found to have a lower TIR (P = 0.115).

Conclusion

The study found a high prevalence of cardiac autonomic neuropathy (CAN) of around 85.7% in type 2 diabetes patients. Lower TIR values were associated with a higher incidence of definite CAN (42.9% vs. 14.3% in TIR <70% vs. >70% groups). The findings suggest TIR is inversely associated with the presence and severity of cardiac autonomic neuropathy in type 2 diabetic patients and also a potential link between TIR and CAN severity.

Insulin resistance and metabolic flexibility as drivers of liver and cardiac disease in T2DM

Metabolic flexibility refers to the ability of tissues to adapt their use of energy sources according to substrate availability and energy demands. This review aims to disentangle the emerging mechanisms through which altered metabolic flexibility and insulin resistance promote NAFLD and heart disease progression. Insulin resistance and metabolic inflexibility are central drivers of hepatic and cardiac diseases in individuals with type 2 diabetes. Both play a critical role in the complex interaction between glucose and lipid metabolism. Disruption of metabolic flexibility results in hyperglycemia and abnormal lipid metabolism, leading to increased accumulation of fat in the liver, contributing to the development and progression of NAFLD. Similarly, insulin resistance affects cardiac glucose metabolism, leading to altered utilization of energy substrates and impaired cardiac function, and influence cardiac lipid metabolism, further exacerbating the progression of heart failure. Regular physical activity promotes metabolic flexibility by increasing energy expenditure and enabling efficient switching between different energy substrates. On the contrary, weight loss achieved through calorie restriction ameliorates insulin sensitivity without improving flexibility. Strategies that mimic the effects of physical exercise, such as pharmacological interventions or targeted lifestyle modifications, show promise in effectively treating both diabetes and NAFLD, finally reducing the risk of advanced liver disease.

Sex Differences in Cardiovascular Risk Associated With Prediabetes and Undiagnosed Diabetes

INTRODUCTION

Women with Type 2 diabetes (T2D) face up to 50% higher risk of cardiovascular disease than men. This study evaluated the extent to which prediabetes and undiagnosed T2D are associated with a greater excess risk of cardiovascular disease in women versus in men.

METHODS

Data were pooled from 18,745 cardiovascular disease-free individuals from the Atherosclerosis Risk in Communities Study, the Multi-Ethnic Study of Atherosclerosis, and the Jackson Heart Study. The risk of coronary heart disease, ischemic stroke, and atherosclerotic cardiovascular disease (coronary heart disease or stroke) associated with prediabetes or undiagnosed T2D was estimated using Cox models adjusting for sociodemographic factors, concomitant risk factors, medication use, and menopausal status. Data were collected in 2022, and the analysis was performed in 2023.

RESULTS

During a median follow-up of 18.6 years, the associations between prediabetes and risk of atherosclerotic cardiovascular disease were only significant in women (hazard ratio=1.18, 95% CI=1.01, 1.34, p=0.03) but not in men (hazard ratio=1.08, 95% CI=1.00, 1.28, p=0.06) (p-interaction=0.18). The associations between undiagnosed T2D and cardiovascular disease outcomes were significant in both sexes, but the effect was more pronounced in women (coronary heart disease: hazard ratio=1.83, 95% CI=1.4, 2.41, p<0.0001 in women vs hazard ratio=1.6, 95% CI=1.38, 2.07, p=0.007 in men; stroke: hazard ratio=1.99, 95% CI=1.39, 2.72, p<0.0001 vs hazard ratio=1.81, 95% CI=1.36, 2.6, p<0.0001; atherosclerotic cardiovascular disease: hazard ratio=1.86, 95% CI=1.5, 2.28, p<0.0001 vs hazard ratio=1.65, 95% CI=1.4, 1.98, p<0.0001) (all p-interactions≤0.2). Both White and Black patients exhibit similar sex differences.

CONCLUSIONS

Prediabetes or undiagnosed T2D was associated with a greater excess risk of cardiovascular disease in women than in men. The sex differential in cardiovascular disease risk among those without the T2D diagnosis suggests the need for sex-specific guidelines in T2D screening and treatment.

Gut-derived short-chain fatty acids bridge cardiac and systemic metabolism and immunity in heart failure

Heart failure (HF) represents a group of complex clinical syndromes with high morbidity and mortality and has a significant global health burden. Inflammation and metabolic disorders are closely related to the development of HF, which are complex and depend on the severity and type of HF and common metabolic comorbidities such as obesity and diabetes. An increasing body of evidence indicates the importance of short-chain fatty acids (SCFAs) in regulating cardiac function. In addition, SCFAs represent a unique class of metabolites and play a distinct role in shaping systemic immunity and metabolism. In this review, we reveal the role of SCFAs as a link between metabolism and immunity, which regulate cardiac and systemic immune and metabolic systems by acting as energy substrates, inhibiting the expression of histone deacetylase (HDAC) regulated genes and activating G protein-coupled receptors (GPCRs) signaling. Ultimately cardiac efficiency is improved, cardiac inflammation alleviated and cardiac function in failing hearts enhanced. In conclusion, SCFAs represent a new therapeutic approach for HF.

Cardiac lipid metabolism, mitochondrial function, and heart failure

A fine balance between uptake, storage, and the use of high energy fuels, like lipids, is crucial in the homeostasis of different metabolic tissues. Nowhere is this balance more important and more precarious than in the heart. This highly energy-demanding muscle normally oxidizes almost all the available substrates to generate energy, with fatty acids being the preferred source under physiological conditions. In patients with cardiomyopathies and heart failure, changes in the main energetic substrate are observed; these hearts often prefer to utilize glucose rather than oxidizing fatty acids. An imbalance between uptake and oxidation of fatty acid can result in cellular lipid accumulation and cytotoxicity. In this review, we will focus on the sources and uptake pathways used to direct fatty acids to cardiomyocytes. We will then discuss the intracellular machinery used to either store or oxidize these lipids and explain how disruptions in homeostasis can lead to mitochondrial dysfunction and heart failure. Moreover, we will also discuss the role of cholesterol accumulation in cardiomyocytes. Our discussion will attempt to weave in vitro experiments and in vivo data from mice and humans and use several human diseases to illustrate metabolism gone haywire as a cause of or accomplice to cardiac dysfunction.

Driving force of deteriorated cellular environment in heart failure: Metabolic remodeling

Heart Failure (HF) has been one of the leading causes of death worldwide. Though its latent mechanism and therapeutic manipulation are updated and developed ceaselessly, there remain great gaps in the cognition of heart failure. High morbidity and readmission rates among HF patients are waiting to be addressed. Recent studies have found that myocardial energy metabolism was closely related to heart failure, in which substrate utilization, as well as intermediate metabolism disorders, insulin resistance, oxidative stress, and mitochondrial dysfunction, might underlie systolic dysfunction and progression of HF. This article centers on the changes and counteraction of cardiac energy metabolism in the failing heart. Therefore, targeting impaired energy provision is of great potential in the treatment of HF. And shifting the objective from traditional neurohormones to improving the cellular environment is expected to further optimize the management of HF.

Sex Differences in Heart Failure: What Do We Know?

Heart failure (HF) remains an important global health issue, substantially contributing to morbidity and mortality. According to epidemiological studies, men and women face nearly equivalent lifetime risks for HF. However, their experiences diverge significantly when it comes to HF subtypes: men tend to develop HF with reduced ejection fraction more frequently, whereas women are predominantly affected by HF with preserved ejection fraction. This divergence underlines the presence of numerous sex-based disparities across various facets of HF, encompassing aspects such as risk factors, clinical presentation, underlying pathophysiology, and response to therapy. Despite these apparent discrepancies, our understanding of them is far from complete, with key knowledge gaps still existing. Current guidelines from various professional societies acknowledge the existence of sex-based differences in HF management, yet they are lacking in providing explicit, actionable recommendations tailored to these differences. In this comprehensive review, we delve deeper into these sex-specific differences within the context of HF, critically examining associated definitions, risk factors, and therapeutic strategies. We provide a specific emphasis on aspects exclusive to women, such as the impact of pregnancy-induced hypertension and premature menopause, as these unique factors warrant greater attention in the broader HF discussion. Additionally, we aim to clarify ongoing controversies and knowledge gaps pertaining to the pharmacological treatment of HF and the sex-specific indications for cardiac implantable electronic devices. By shining a light on these issues, we hope to stimulate a more nuanced understanding and promote the development of more sex-responsive approaches in HF management.

Metabolic syndrome and risk of incident heart failure in non-diabetic patients with established cardiovascular disease

BACKGROUND

In patients with established cardiovascular disease (CVD), the relation between metabolic syndrome (MetS) and incident heart failure (HF) in the absence of diabetes mellitus (DM) is largely unknown. This study assessed this relation in non-diabetic patients with established CVD.

METHODS

Patients from the prospective UCC-SMART cohort with established CVD, but without DM or HF at baseline were included (n = 4653). MetS was defined according to the Adult Treatment Panel III criteria. Insulin resistance was quantified using the homeostasis model of insulin resistance (HOMA-IR). The outcome was a first hospitalization for HF. Relations were assessed using Cox proportional hazards models adjusted for established risk factors: age, sex, prior myocardial infarction (MI), smoking, cholesterol, and kidney function.

RESULTS

During a median follow-up of 8.0 years, 290 cases of incident HF were observed (0.81/100 person years). MetS was significantly related to an increased risk of incident HF independent of established risk factors (hazard ratio [HR] 1.32; 95% confidence interval [CI] 1.04-1.68, HR per criterion 1.17; 95% CI 1.06-1.29), as was HOMA-IR (HR per standard deviation [SD] 1.15; 95% CI 1.03-1.29). Of the individual MetS components, only higher waist circumference independently increased the risk of HF (HR per SD 1.34; 95% CI 1.17-1.53). Relations were independent of the occurrence of interim DM and MI, and were not significantly different for HF with reduced vs preserved ejection fraction.

CONCLUSION

In CVD patients without a current diagnosis of DM, MetS and insulin resistance increase the risk of incident HF independent of established risk factors.

The interplay of inflammation, exosomes and Ca2+ dynamics in diabetic cardiomyopathy

Diabetes mellitus is one of the prime risk factors for cardiovascular complications and is linked with high morbidity and mortality. Diabetic cardiomyopathy (DCM) often manifests as reduced cardiac contractility, myocardial fibrosis, diastolic dysfunction, and chronic heart failure. Inflammation, changes in calcium (Ca²⁺) handling and cardiomyocyte loss are often implicated in the development and progression of DCM. Although the existence of DCM was established nearly four decades ago, the exact mechanisms underlying this disease pathophysiology is constantly evolving. Furthermore, the complex pathophysiology of DCM is linked with exosomes, which has recently shown to facilitate intercellular (cell-to-cell) communication through biomolecules such as micro RNA (miRNA), proteins, enzymes, cell surface receptors, growth factors, cytokines, and lipids. Inflammatory response and Ca²⁺ signaling are interrelated and DCM  has been known to adversely affect many of these signaling molecules either qualitatively and/or quantitatively. In this literature review, we have demonstrated that Ca²⁺ regulators are tightly controlled at different molecular and cellular levels during various biological processes in the heart. Inflammatory mediators, miRNA and exosomes are shown to interact with these regulators, however how these mediators are linked to Ca²⁺ handling during DCM pathogenesis remains elusive. Thus, further investigations are needed to understand the mechanisms to restore cardiac Ca²⁺ homeostasis and function, and to serve as potential therapeutic targets in the treatment of DCM.

Value of estimated glucose disposal rate to detect prevalent left ventricular hypertrophy: implications from a general population

BACKGROUND

Insulin resistance plays a pivotal role in developing left ventricular hypertrophy (LVH). Researchers have identified the estimated glucose disposal rate (eGDR) as a simple and cost-effective surrogate of insulin resistance. Our work aims to investigate the association between eGDR and the prevalent LVH and explore the incremental value of eGDR to detect prevalent LVH.

METHODS

The present work enrolled 3839 subjects from a cross-sectional survey conducted between October 2019 to April 2020 in the rural areas of southeastern China. eGDR was calculated based on waist-to-hip circumference ratio, hypertension, and glycated hemoglobin.

RESULTS

The prevalence of LVH was 17.30%. After adjusting demographic, anthropometric, laboratory, and medical history co-variates, each standard deviation increase of eGDR decreased a 29.6% risk of prevalent LVH. When dividing eGDR into quartiles, the top quartile had a 38.4% risk compared to the bottom quartile. Moreover, smooth curve fitting revealed that the association between eGDR and prevalent LVH was linear in the whole range of eGDR. Additionally, subgroup analysis demonstrated that our main finding was robust to age, sex, BMI, hypertension, and diabetes subgroups. Finally, ROC analysis exhibited a significant improvement by adding eGDR into LVH risk factors (0.780 vs. 0.803, P < 0.001), and category-free net reclassification index (0.702, P < 0.001) and integrated discrimination index (0.027, P < 0.001) also confirmed the improvement from eGDR to detect prevalent LVH.

CONCLUSION

Our analysis revealed a linear, robust association between eGDR and prevalent LVH and demonstrated the incremental value of eGDR to optimize the detection of prevalent LVH.

The Complex Relation between Atrial Cardiomyopathy and Thrombogenesis

Heart disease, as well as systemic metabolic alterations, can leave a ‘fingerprint’ of structural and functional changes in the atrial myocardium, leading to the onset of atrial cardiomyopathy. As demonstrated in various animal models, some of these changes, such as fibrosis, cardiomyocyte hypertrophy and fatty infiltration, can increase vulnerability to atrial fibrillation (AF), the most relevant manifestation of atrial cardiomyopathy in clinical practice. Atrial cardiomyopathy accompanying AF is associated with thromboembolic events, such as stroke. The interaction between AF and stroke appears to be far more complicated than initially believed. AF and stroke share many risk factors whose underlying pathological processes can reinforce the development and progression of both cardiovascular conditions. In this review, we summarize the main mechanisms by which atrial cardiomyopathy, preceding AF, supports thrombogenic events within the atrial cavity and myocardial interstitial space. Moreover, we report the pleiotropic effects of activated coagulation factors on atrial remodeling, which may aggravate atrial cardiomyopathy. Finally, we address the complex association between AF and stroke, which can be explained by a multidirectional causal relation between atrial cardiomyopathy and hypercoagulability.

Triglyceride glucose index and its combination with the Get with the Guidelines-Heart Failure score in predicting the prognosis in patients with heart failure

Background

Heart failure (HF) is associated with generalized insulin resistance (IR). Recent studies demonstrated that triglyceride glucose (TyG) is an effective alternative index of IR. However, the relationship between the TyG index and in-hospital mortality in patients with HF is unclear. In the present study, we aimed to clarify the association between the TyG index and in-hospital mortality in patients with HF.

Methods

A retrospective study consisting of 4,411 patients diagnosed with HF from 2015 to 2018 was conducted. All-cause mortality during hospitalization was the primary endpoint. The association between the TyG index and in-hospital mortality was assessed using the logistic regression analysis.

Results

The risk of in-hospital mortality was significantly associated with increased TyG index (OR: 1.886, 95% CI: 1.421–2.501, p < 0.001) under logistic regression with multivariable adjustment. When divided into three groups based on the TyG index, Tertile 3 demonstrated significantly higher in-hospital mortality than the other two Tertiles (OR: 2.076, 95% CI: 1.284–3.354, p = 0.001). Moreover, the TyG index improved the prediction efficiency of the Get with the Guidelines-Heart Failure (GWTG-HF) score (absolute integrated discrimination improvement = 0.006, p < 0.001; category-free net reclassification improvement = 0.075, p = 0.005). In subgroup analysis, the TyG index exhibited similar predictive performance of in-hospital mortality when groups were stratified based on type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD).

Conclusion

TyG is a potential index for predicting in-hospital mortality in patients with HF, independent of T2DM or CAD status. The TyG index may be combined with the GWTG-HF score to further improve its predictive efficacy.

A New Hope: Sodium-Glucose Cotransporter-2 Inhibition to Prevent Atrial Fibrillation

Atrial arrhythmias are common in patients with diabetes mellitus (DM), and despite recent advances in pharmaceutical and invasive treatments, atrial fibrillation (AF) and atrial flutter (AFl) are still associated with substantial mortality and morbidity. Clinical trial data imply a protective effect of sodium-glucose cotransporter-2 inhibitors (SGLT2is) on the occurrence of AF and AFl. This review summarizes the state of knowledge regarding DM-mediated mechanisms responsible for AF genesis and recurrence but also discusses the recent data from experimental studies, published trials and metanalyses.

Determinants of Left Atrial Compliance in the Metabolic Syndrome: Insights from the "Linosa Study"

The association between left atrial (LA) impairment and cardiovascular diseases (CVD) and between dyslipidaemia and CVD are well known. The present study aims to investigate the relationships between metabolic factors and LA dimensions and compliance, as well as test the hypothesis that metabolic factors influence LA function independent from hemodynamic mechanisms. Arterial blood pressure (BP), waist and hip circumference, metabolic indices, and a complete echocardiographic assessment were obtained from 148 selected inhabitants (M/F 89/59; age 20−86 years) of Linosa Island, who had no history of CVD. At enrollment, 27.7% of the subjects met the criteria for metabolic syndrome (MetS) and 15.5% for arterial hypertension (HTN). LA compliance was reduced in subjects with MetS compared to those without (53 ± 27% vs. 71 ± 29%, p = 0.04) and was even lower (32 ± 17%, p = 0.01) in those with MetS and HTN. At multiple regression analysis, the presence of MetS independently determined LA maximal area (r = 0.56, p < 0.001), whereas systolic BP and the total cholesterol/HDL cholesterol ratio determined LA compliance (r = 0.41, p < 0.001). In an apparently healthy population with a high prevalence of MetS, dyslipidaemia seems to independently influence LA compliance. At a 5-year follow-up, LA compliance was reduced in both all-cause and CVD mortality groups, and markedly impaired in those who died of CVD. These findings may contribute to understanding the prognostic role of LA function in CVD and strengthen the need for early and accurate lipid control strategies.

Diabetes and Progression of Heart Failure: The Atherosclerosis Risk In Communities (ARIC) Study

BACKGROUND

The influence of diabetes on progression from preclinical heart failure (HF) stages to overt HF is poorly understood.

OBJECTIVES

The purpose of this study was to characterize the influence of diabetes on the progression from preclinical HF stages (A or B based on the 2021 Universal Definition) to overt HF.

METHODS

We included 4,774 adults with preclinical HF (stage A [n = 1,551] or B [n = 3,223]) who attended the ARIC (Atherosclerosis Risk In Communities) study Visit 5 (2011-2013). Within each stage (A or B), we assessed the associations of diabetes and glycemic control (hemoglobin A1C [HbA1C] <7% vs ≥7%) with progression to HF, and of cross-categories of HF stages (A vs B), diabetes, and glycemic control with incident HF.

RESULTS

Among the participants (mean age 75.4 years, 58% women, 20% Black), there were 470 HF events during 8.6 years of follow-up. Stage B participants with HbA1C ≥7% experienced clinical HF at a younger age than those with controlled diabetes or without diabetes (mean age 80 years vs 83 years vs 82 years; P < 0.001). HbA1C ≥7% was more strongly associated with HF in stage B (HR: 1.83; 95% CI: 1.33-2.51) compared with stage A (HR: 1.52; 95% CI: 0.53-4.38). In cross-categories of preclinical HF stage and HbA1C, participants with stage B and HbA1C ≥7% had increased risk of HF progression compared with stage A without diabetes (HR: 7.56; 95% CI: 4.68-12.20).

CONCLUSIONS

Among older adults with preclinical HF stages, uncontrolled diabetes was associated with substantial risk of HF progression. Our results suggest that targeting diabetes early in the HF process is critical.

Patients phenotypes and cardiovascular risk in type 2 diabetes: the Jackson Heart Study

Background

Cardiovascular prognosis related to type 2 diabetes may not be adequately captured by information on comorbid conditions such as obesity and hypertension. To inform the cardiovascular prognosis among diabetic individuals, we conducted phenotyping using a clustering approach based on clinical data, echocardiographic indices and biomarkers.

Methods

We performed a cluster analysis on clinical, biochemical and echocardiographic variables from 529 Blacks with diabetes in the Jackson Heart Study. An association between identified clusters and major adverse cardiovascular events (MACE- composite of coronary heart disease, stroke, heart failure and atrial fibrillation) was assessed using Cox proportional hazards modeling.

Results

Cluster analysis separated individuals with diabetes (68% women, mean age 60 ± 10 years) into three distinct clusters (Clusters 1,2 &3 - with Cluster 3 being a hypertrophic cluster characterized by highest LV mass, levels of brain natriuretic peptide [BNP] and high-sensitivity cardiac troponin-I [hs-cTnI]). After a median 12.1 years, there were 141 cardiovascular events. Compared to Cluster1, Clusters 3 had an increased risk of cardiovascular disease (hazard ratio [HR] 1.60; 95% confidence interval [CI] 1.08, 2.37), while Cluster 2 had a similar risk of outcome (HR 1.11; 95% CI 0.73, 168).

Conclusions

Among Blacks with diabetes, cluster analysis identified three distinct echocardiographic and biomarkers phenotypes, with cluster 3 (high LV mass, high cardiac biomarkers) associated with worse outcomes, thus highlighting the prognostic value of subclinical myocardial dysfunction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01501-z.

Double life: How GRK2 and β-arrestin signaling participate in diseases

G-protein coupled receptor (GPCR) kinases (GRKs) and β-arrestins play key roles in GPCR and non-GPCR cellular responses. In fact, GRKs and arrestins are involved in a plethora of pathways vital for physiological maintenance of inter- and intracellular communication. Here we review decades of research literature spanning from the discovery, identification of key structural elements, and findings supporting the diverse roles of these proteins in GPCR-mediated pathways. We then describe how GRK2 and β-arrestins partake in non-GPCR signaling and briefly summarize their involvement in various pathologies. We conclude by presenting gaps in knowledge and our prospective on the promising pharmacological potential in targeting these proteins and/or downstream signaling. Future research is warranted and paramount for untangling these novel and promising roles for GRK2 and arrestins in metabolism and disease progression.

Association of ambulatory blood pressure with coronary microvascular and cardiac dysfunction in asymptomatic type 2 diabetes

Background

Type 2 diabetes (T2D) and hypertension commonly coexist and are associated with subclinical myocardial structural and functional changes. We sought to determine the association between blood pressure (BP) and left ventricular (LV) remodeling, systolic/diastolic function, and coronary microvascular function, among individuals with T2D without prevalent cardiovascular disease.

Methods

Participants with T2D and age-, sex-, and ethnicity-matched controls underwent comprehensive cardiovascular phenotyping including fasting bloods, transthoracic echocardiography, cardiovascular magnetic resonance imaging with quantitative adenosine stress/rest perfusion, and office and 24-h ambulatory BP monitoring. Multivariable linear regression was performed to determine independent associations between BP and imaging markers of remodeling and function in T2D.

Results

Individuals with T2D (n = 205, mean age 63 ± 7 years) and controls (n = 40, mean age 61 ± 8 years) were recruited. Mean 24-h systolic BP, but not office BP, was significantly greater among those with T2D compared to controls (128.8 ± 11.7 vs 123.0 ± 13.1 mmHg, p = 0.006). Those with T2D had concentric LV remodeling (mass/volume 0.91 ± 0.15 vs 0.82 ± 0.11 g/mL, p < 0.001), decreased myocardial perfusion reserve (2.82 ± 0.83 vs 3.18 ± 0.82, p = 0.020), systolic dysfunction (global longitudinal strain 16.0 ± 2.3 vs 17.2 ± 2.1%, p = 0.004) and diastolic dysfunction (E/e’ 9.30 ± 2.43 vs 8.47 ± 1.53, p = 0.044) compared to controls. In multivariable regression models adjusted for 14 clinical variables, mean 24-h systolic BP was independently associated with concentric LV remodeling (β = 0.165, p = 0.031), diastolic dysfunction (β = 0.273, p < 0.001) and myocardial perfusion reserve (β = − 0.218, p = 0.016). Mean 24-h diastolic BP was associated with LV concentric remodeling (β = 0.201, p = 0.016).

Conclusion

24-h ambulatory systolic BP, but not office BP, is independently associated with cardiac remodeling, coronary microvascular dysfunction, and diastolic dysfunction among asymptomatic individuals with T2D. (Clinical trial registration. URL: https://clinicaltrials.gov/ct2/show/NCT03132129 Unique identifier: NCT03132129).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01528-2.

Effect of Preablation Glycemic Control on Outcomes of Atrial Fibrillation Patients With Diabetes Mellitus Following Valvular Surgery Combined With the Cox-Maze IV Procedure

Background

This study was performed to assess the effect of preablation glycemic control on atrial fibrillation recurrence rates after heart valve surgery concomitant with Cox-Maze IV ablation.

Methods

Twelve-month preablation trends in glycemic control were studied. Recurrence and clinical outcome data were obtained during a mean follow-up period of 36.7 ± 23.3 months postablation.

Results

Higher glycated hemoglobin (HbA1c) at the time of ablation was associated with higher postablation recurrence rates. The cumulative atrial fibrillation recurrence-free survival of patients with HbA1c ≥7.5% at the time of operation at 12, 24, 36 and 48 months was 97.1, 78.3, 54.2, and 36.3%, respectively (P < 0.001), and 100, 84.9, 37.2, and 16.2% for patients who preoperatively had an upward trend in HbA1c, respectively (P < 0.001).

Conclusion

Maintaining a downward trend in HbA1c during the 12-month period before the operation and an HbA1c value < 7.5% at the time of the operation reduced the recurrence of AF among patients who underwent heart valve surgery concomitant with the Cox-Maze IV procedure.

Impact of insulin therapy on outcomes of diabetic patients with heart failure: A systematic review and meta-analysis

OBJECTIVE

To compare clinical outcomes in diabetic patients with heart failure managed by insulin with those managed by non-insulin (oral hypoglycemic agents and/or lifestyle modification) based therapy.

METHODS

PubMed and Scopus databases were searched for studies conducted on diabetic patients with heart failure. Studies were to compare outcomes of patients managed by insulin versus non-insulin therapies.

RESULTS

15 studies were included. Compared to those who were managed using non-insulin therapy, insulin-treated patients had increased risk of all-cause mortality (RR 1.46, 95% CI: 1.14, 1.88) and cardiovascular specific mortality (RR 1.62, 95% CI: 1.33, 1.96). Those managed using insulin also had increased risk of hospitalization (RR 1.45, 95% CI: 1.09, 1.93) and readmission (RR 1.49, 95% CI: 1.32, 1.67). There was no additional risk for stroke (RR 1.07, 95% CI: 0.91, 1.27) or myocardial infarction (MI) (RR 1.10, 95% CI: 0.96, 1.27) between the two groups of patients.

CONCLUSIONS

Receipt of insulin among diabetic patients with heart failure was associated with an increased risk of mortality, hospitalization and readmission compared to management using oral hypoglycemic agents and/or lifestyle modification. Such patients should be closely monitored for any adverse events.

Glycemic control and atrial fibrillation: an intricate relationship, yet under investigation

Atrial fibrillation (AF) and diabetes mellitus (DM) constitute two major closely inter-related chronic cardiovascular disorders whose concurrent prevalence rates are steadily increasing. Although, the pathogenic mechanisms behind the AF and DM comorbidity are still vague, it is now clear that DM precipitates AF occurrence. DM also affects the clinical course of established AF; it is associated with significant increase in the incidence of stroke, AF recurrence, and cardiovascular mortality. The impact of DM on AF management and prognosis has been adequately investigated. However, evidence on the relative impact of glycemic control using glycated hemoglobin levels is scarce. This review assesses up-to-date literature on the association between DM and AF. It also highlights the usefulness of glycated hemoglobin measurement for the prediction of AF and AF-related adverse events. Additionally, this review evaluates current anti-hyperglycemic treatment in the context of AF, and discusses AF-related decision-making in comorbid DM. Finally, it quotes significant remaining questions and sets some future strategies with the potential to effectively deal with this prevalent comorbidity.

Pathophysiological aspects of insulin resistance in Atrial Fibrillation: novel therapeutic approaches

Background

Insulin resistance is associated with metabolic disorders including diabetes, obesity, hypertension, and inflammation which are the risk factors for Atrial Fibrillation. Many studies have reported that type 2 diabetes and AF are related and also their prevalence is increasing globally. Moreover, insulin resistance begins the type 2 diabetes.

Main body

This review explains the pathophysiological aspects of insulin resistance in AF patients and discusses the drugs that are used to manage insulin resistance including Biguanides (metformin), thiazolidinediones (TZDs) [Pioglitazone, rosiglitazone], Sodium-glucose cotransporter 2 (SGLT2) inhibitors, Concentrated Insulin Products, Dipeptidyl peptidase-4 (DPP-4) Inhibitors, Glucagon-like peptide 1 (GLP-1) receptor Agonists, Pramlintide, Sulfonylureas, Meglitinides, α-Glucosidase Inhibitors, Colesevelam, Bromocriptine. This review will highlight a few major drugs that played a significant role in AF patients. For this purpose, many databases were used for reviewing the literature and keywords are used such as Insulin Resistance, Pathophysiology, Atrial Fibrillation, and Drugs.

Conclusion

This review article concludes that insulin resistance is related to AF. It also provides an outlook on the recent pathophysiological aspects of insulin resistance in AF; however, more studies are needed to clarify the management of insulin resistance in AF patients to prevent the development of type 2 diabetes.

Effect of sodium-glucose cotransporter protein-2 inhibitors on left ventricular hypertrophy in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis was performed to compare the effect of sodium-glucose cotransporter protein-2 inhibitors (SGLT-2i) and placebo on left ventricular hypertrophy (LVH) in patients with type 2 diabetes.

METHOD

Randomized controlled trials (RCTs) comparing the LVH parameters of SGLT-2i to placebo in patients with type 2 diabetes were included. Our primary outcomes were the changes in left ventricular mass (LVM) and left ventricular mass index (LVMI) from baseline to the study endpoint. Secondary outcomes were the changes in left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and the ratio of early mitral inflow velocity to atrial inflow velocity (E/A). Summary odds ratios were estimated using a fixed-effect or random-effect model.

RESULTS

A total of 11 articles were included. Data were extracted from 11 original studies matching our inclusion criteria. In our meta-analysis, there were significant improvement in LVM (SMD -0.23, 95% CI -0.44 to -0.02, I ² = 22.6%, p = 0.034), LVMI (SMD -0.25, 95% CI -0.38 to -0.12, I ² = 0.0%, p = 0.000), LVEDV (SMD -0.19, 95% CI -0.36 to -0.01, I ² = 62.3%, p = 0.035), and LVESV (SMD -0.21, 95% CI -0.39 to -0.04, I ² = 32.9%, p = 0.017) in the SGLT-2i group compared with the placebo group. Furthermore, no significant differences were found in LVEF (SMD 0.13, 95% CI 0.00 to 0.26, I ² = 0.0%, p = 0.050) and E/A (SMD -0.01, 95% CI -0.22 to 0.20, I ² = 0%, p = 0.908) between the two groups.

CONCLUSIONS

This meta-analysis confirmed the beneficial effects of SGLT-2i on reversal of left ventricular remodeling. The LVH regression was more pronounced in studies of type 2 diabetes patients receiving SGLT-2i than placebo.

Why take organ damage in hypertension seriously?

The focus of recent European guidelines has been early initiation of antihypertensive therapy in risk groups, rapid achievement of target blood pressure with fixed combinations of antihypertensive drugs, and the best possible management of an individuals cardiovascular risk. Early intervention in the development of hypertension-mediated organ damage (HMOD) has been shown to have an effect on the subsequent reduction in the risk of cardiovascular events. The point of HMOD origination correlates with the magnitude and duration of blood pressure elevation, and there is no clearly defined boundary from which vascular damage begins to develop. A reduction in blood pressure with pharmacotherapy demonstrably decreases the risk of ischaemic heart disease, stroke, as well as the mortality rate (1). Large clinical trials have consistently shown a significant reduction in the risk of these complications with antihypertensive medications across the entire spectrum from mild to severe hypertension, including hypertension in the elderly as well as isolated systolic hypertension (2). Based on the latest knowledge, a reduction in blood pressure by a mere 5 mm Hg has a cardioprotective effect even in normotensive individuals, which fundamentally changes the view on the diagnosis and definition of hypertension as a disease (3).

The Effect of Obesity, Hypertension, Diabetes Mellitus, Alcohol, and Sleep Apnea on the Risk of Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia associated with a two-fold increase in mortality caused by a higher risk of stroke and heart failure. Currently, AF is present in ~ 2 % of the general population, and its incidence and prevalence are increasing. Obesity, hypertension, diabetes mellitus, obstructive sleep apnea, and alcohol consumption increase the risk of AF. Each unit of increase in BMI increases the risk of AF by 3 %, and intensive weight loss is also associated with reduced AF recurrence. Hypertension increases the risk of AF by 50 % in men and by 40 % in women, and explains ≈ 20 % of new AF cases. Patients with obstructive sleep apnea are at four times higher risk of developing AF than subjects without sleep apnea. Higher concentrations of pro-inflammatory cytokines, higher amounts of epicardial adipose tissue, and a higher degree of ventricular diffuse myocardial fibrosis are present in AF patients and patients with the aforementioned metabolic disorders. Several prospective cohort studies and randomized trials have been initiated to show whether weight loss and treatment of other risk factors will be associated with a reduction in AF recurrences.

Association of diabetes with atrial fibrillation types: a systematic review and meta-analysis

Background

Atrial fibrillation (AF) is a common arrhythmia classified as paroxysmal and non-paroxysmal. Non-paroxysmal AF is associated with an increased risk of complications. Diabetes contributes to AF initiation, yet its role in AF maintenance is unclear. We conducted a systematic review and meta-analysis to summarize the evidence regarding the association of diabetes with AF types.

Methods

We searched 5 databases for observational studies investigating the association of diabetes with the likelihood of an AF type (vs another type) in humans. Study quality was evaluated using the Newcastle–Ottawa Scale. Studies classifying AF types as paroxysmal (reference) and non-paroxysmal were pooled in a meta-analysis using random effects models.

Results

Of 1997 articles we identified, 20 were included in our systematic review. The population sample size ranged from 64 to 9816 participants with mean age ranging from 40 to 75 years and percentage of women from 24.8 to 100%. The quality of studies varied from poor (60%) to fair (5%) to good (35%). In the systematic review, 8 studies among patients with AF investigated the cross-sectional association of diabetes with non-paroxysmal AF (vs paroxysmal) of which 6 showed a positive association and 2 showed no association. Fourteen studies investigated the longitudinal association of diabetes with “more sustained” AF types (vs “less sustained”) of which 2 showed a positive association and 12 showed no association. In the meta-analysis of cross-sectional studies, patients with AF and diabetes were 1.31-times more likely to have non-paroxysmal AF than those without diabetes [8 studies; pooled OR (95% CI), 1.31 (1.13–1.51), I² = 82.6%]. The meta-analysis of longitudinal studies showed that for patients with paroxysmal AF, diabetes is associated with 1.32-times increased likelihood of progression to non-paroxysmal AF [five studies; pooled OR (95% CI), 1.32 (1.07–1.62); I² = 0%].

Conclusions

Our findings suggest that diabetes is associated with an increased likelihood of non-paroxysmal AF rather than paroxysmal AF. However, further high quality studies are needed to replicate these findings, adjust for potential confounders, elucidate mechanisms linking diabetes to non-paroxysmal AF, and assess the impact of antidiabetic medications on AF types. These strategies could eventually help decrease the risk of non-paroxysmal AF among patients with diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01423-2.

Sex Differences in Heart Failure

Heart failure (HF) continues to be a major contributor of morbidity and mortality for men and women alike, yet how the predisposition for, course and management of HF differ between men and women remains underexplored. Sex differences in traditional risk factors as well as sex-specific risk factors influence the prevalence and manifestation of HF in unique ways. The pathophysiology of HF differs between men and women and may explain sex-specific differences in clinical presentation and diagnosis. This in turn contributes to variation in response to both pharmacologic and device/surgical therapy. This review examines sex-specific differences in HF spanning prevalence, risk factors, pathophysiology, presentation, and therapies with a specific focus on highlighting gaps in knowledge with calls to action for future research efforts.

Increased myofilament calcium sensitivity is associated with decreased cardiac troponin I phosphorylation in the diabetic rat heart

NEW FINDINGS

What is the central question of this study? In Zucker Diabetic Fatty rats, does cardiomyocyte myofilament function change through the time course of diabetes and what are the mechanisms behind alterations in calcium sensitivity? What is the main finding and its importance? Zucker Diabetic Fatty rats had increased myofilament calcium sensitivity and reduced phosphorylation at cardiac troponin I without differential O-GlcNAcylation.

ABSTRACT

The diabetic heart has impaired systolic and diastolic function independent of other comorbidities. The availability of calcium is altered, but does not fully explain the cardiac dysfunction seen in the diabetic heart. Thus, we explored if myofilament calcium regulation of contraction is altered while also categorizing the levels of phosphorylation and O-GlcNAcylation in the myofilaments. Calcium sensitivity (pCa₅₀ ) was measured in Zucker Diabetic Fatty (ZDF) rat hearts at the initial stage of diabetes (12 weeks old) and after 8 weeks of uncontrolled hyperglycaemia (20 weeks old) and in non-diabetic (nDM) littermates. Skinned cardiomyocytes were connected to a capacitance-gauge transducer and a torque motor to measure force as a function of pCa (-log[Ca²⁺ ]). Fluorescent gel stain (ProQ Diamond) was used to measure total protein phosphorylation. Specific phospho-sites on cardiac troponin I (cTnI) and total cTnI O-GlcNAcylation were quantified using immunoblot. pCa₅₀ was greater in both 12- and 20-week-old diabetic (DM) rats compared to nDM littermates (P = 0.0001). Total cTnI and cTnI serine 23/24 phosphorylation were lower in DM rats (P = 0.003 and P = 0.01, respectively), but cTnI O-GlcNAc protein expression was not different. pCa₅₀ is greater in DM rats and corresponds with an overall reduction in cTnI phosphorylation. These findings indicate that myofilament calcium sensitivity is increased and cTnI phosphorylation is reduced in ZDF DM rats and suggests an important role for cTnI phosphorylation in the DM heart.

Disturbed Glucose Metabolism and Left Ventricular Geometry in the General Population

Background: This study sought to investigate the prevalence and clinical outcome of left ventricular (LV) geometry in prediabetes and type 2 diabetes mellitus (T2DM) and the impact of glucose metabolism on the incidence of left ventricular hypertrophy (LVH). Methods: 15,010 subjects (35–74 years) of the population-based Gutenberg Health Study were categorized into euglycemia, prediabetes, and T2DM according to clinical and metabolic (HbA1c) information. Clinical outcome was assessed via structured follow-up. Results: The study comprised 12,121 individuals with euglycemia (81.6%), 1415 with prediabetes (9.5%), and 1316 with T2DM (8.9%). Prevalence of LVH increased from euglycemia (10.2%) over prediabetes (17.8%) to T2DM (23.8%). Prediabetes and T2DM were associated with increased LV mass index (prediabetes: β1.3 (95% CI 0.78–1.81), p < 0.0001; T2DM: β2.37 (95% CI 1.81; 2.92), p < 0.0001) independent of age, sex, and cardiovascular risk factors (CVRF). The frequency of LVH was related to the presence of T2DM (prevalence ratio (PR)T2DM 1.2 (95% CI 1.06–1.35), p = 0.0038). T2DM was related to mortality independent of age, sex, and CVRF regardless of LVH (hazard ratio (HR)T2DM-LVH 2.67 (95% CI 1.94–3.66), p < 0.0001; HRT2DM-noLVH 1.59 (95% CI 1.29–1.96), p < 0.0001), prediabetes was only associated with outcome in individuals with LVH independent of age and sex (HRprediabetes-LVH 1.51 (95% CI 1.01–2.25), p = 0.045). Neither T2DM nor prediabetes were predictors of incident LVH after adjustment for clinical covariates. Conclusions: Prediabetes and T2DM promote alterations of cardiac geometry. T2DM and particularly the coprevalence of T2DM with LVH substantially reduce life expectancy. These findings highlight the need for new therapeutic and screening approaches to prevent and detect cardiometabolic diseases at an early stage.

Sex-specific pattern of left ventricular hypertrophy and diastolic function in patients with type 2 diabetes mellitus

AIMS

Few prospective studies have evaluated sex-specific pattern, natural progression of left ventricular (LV) remodelling, and diastolic dysfunction in patients with type 2 diabetes (T2DM). The aim of this study was to study the sex-specific prevalence, longitudinal changes of LV remodelling, and diastolic dysfunction in patients with T2DM. Further, the prognostic value of diastolic function in women and men was also evaluated.

METHODS AND RESULTS

A total of 350 patients with T2DM (mean age 61 ± 11 years; women, 48.3%) was recruited. Detailed echocardiography was performed at baseline and after 25 months. A major adverse cardiovascular event (MACE) was defined as cardiovascular death, heart failure hospitalization, or myocardial infarction. Despite a similar age, prevalence of hypertension and body mass index, women had a higher prevalence of LV hypertrophy and diastolic dysfunction at baseline and follow-up compared with men. A total of 21 patients developed MACE (5 cardiovascular death, 9 hospitalization for heart failure, and 7 myocardial infarction) during a median follow-up of 56 months. Women with diastolic dysfunction had a higher incidence of MACE than those with normal diastolic function but this association was neutral in men. Multivariable Cox-regression analysis indicated that diastolic dysfunction was associated with MACE in women [hazard ratio = 6.30; 95% confidence interval (CI) = 1.06-37.54; P < 0.05] but not men (hazard ratio = 2.29, 95% CI = 0.67-7.89; P = 0.19).

CONCLUSION

LV hypertrophy and diastolic dysfunction, both at baseline and follow-up, were more common in women than men. Pre-clinical diastolic dysfunction was independently associated with MACE only in women with T2DM but was neutral in men.

Prediabetes and the risk of heart failure: A meta-analysis

AIM

To determine the role of prediabetes in the incidence of heart failure (HF).

MATERIALS AND METHODS

We searched electronic databases (PubMed, Embase, Google Scholar and OpenGrey) for studies up to 31 December 2020. Studies were included for meta-analysis if they reported adjusted relative risks (RRs) and 95% confidence intervals (CIs) for the risk of HF for prediabetes compared with normoglycaemia. Prediabetes was defined as impaired fasting glucose (IFG) according to the World Health Organization (WHO) criteria (IFG-WHO), or according to the American Diabetes Association (ADA) definition (IFG-ADA), impaired glucose tolerance (IGT), raised HbA1c according to the ADA criteria (HbA1c-ADA), or according to the International Expert Committee (IEC) recommendation (HbA1c-IEC).

RESULTS

A total of 15 studies comprising 9,827,430 individuals provided data for this analysis. The median follow-up duration of the included studies was 8.0 years. Compared with normoglycaemia, prediabetes was associated with an increased risk for HF: IFG-ADA (RR: 1.09, 95% CI: 1.05-1.13), IFG-WHO (RR: 1.18, 95% CI: 1.07-1.30), IGT (RR 1.58, 95% CI 1.04-2.39), HbA1c-ADA (RR 1.28, 95% CI 1.16-1.41) or HbA1c-IEC (RR 1.40, 95% CI 1.09-1.79), respectively.

CONCLUSIONS

Prediabetes is associated with an increased risk of HF. Future studies are needed to evaluate effective treatments for prediabetes to prevent the development and progression of HF.

Elevated Plasma Homocysteine Level Associated with Further Left Ventricular Structure and Function Damages in Type 2 Diabetic Patients: A Three-Dimensional Speckle Tracking Echocardiography Study

Aims: The aims of this study were to explore the left ventricular (LV) structural remodeling and its risk factors in type 2 diabetes mellitus (T2DM) patients with or without hyperhomocysteinemia (hHcy) and to detect the accompanied LV dysfunction using three-dimensional speckle tracking echocardiography (3DSTE). Methods: There were totally 80 T2DM patients with undamaged LV ejection fraction (≥55%) in this study, 40 of whom were also diagnosed with hHcy as co-morbidity. Forty age- and gender-matched controls were also recruited. The risk factors and corresponding diagnostic values for LV remodeling (LVR) were, respectively, determined using logistic regression and area under the receiver operating characteristic curves (AUC). The 3DSTE was used to measure global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS), and global radial strain (GRS). Results: The constituent ratio of LV geometry showed significant differences among the study populations (P = 0.01). Compared with the controls, three types of LVR accounted for larger proportion in the two T2DM groups, whereas LV hypertrophy was most prevalent in those with T2DM and hHcy. Glycosylated hemoglobin (HbA1c), total plasma homocysteine (tHcy), and HbA1c plus tHcy were all significant risk factors associated with LVR in T2DM patients (AUC values: 0.741, 0.746 and 0.851, respectively). The patients with T2DM alone had significantly lower GLS and GAS than the controls (both P < 0.05). The patients with T2DM and hHcy had significantly lower GLS, GCS, GAS, and GRS than the controls (all P < 0.001), and also had significantly lower GLS, GCS, and GRS than the patients with T2DM alone (all P < 0.05). Conclusions: The 3DSTE plus conventional echocardiography could be used as an effective supplement for detecting early and occult cardiac damages in T2DM patients with plasma homocysteine at normal or elevated levels.

The Diabetic Cardiomyopathy: The Contributing Pathophysiological Mechanisms

Individuals with diabetes mellitus (DM) disclose a higher incidence and a poorer prognosis of heart failure (HF) than non-diabetic people, even in the absence of other HF risk factors. The adverse impact of diabetes on HF likely reflects an underlying “diabetic cardiomyopathy” (DM–CMP), which may by exacerbated by left ventricular hypertrophy and coronary artery disease (CAD). The pathogenesis of DM-CMP has been a hot topic of research since its first description and is still under active investigation, as a complex interplay among multiple mechanisms may play a role at systemic, myocardial, and cellular/molecular levels. Among these, metabolic abnormalities such as lipotoxicity and glucotoxicity, mitochondrial damage and dysfunction, oxidative stress, abnormal calcium signaling, inflammation, epigenetic factors, and others. These disturbances predispose the diabetic heart to extracellular remodeling and hypertrophy, thus leading to left ventricular diastolic and systolic dysfunction. This Review aims to outline the major pathophysiological changes and the underlying mechanisms leading to myocardial remodeling and cardiac functional derangement in DM-CMP.

Development of a nomogram for screening the risk of left ventricular hypertrophy in Chinese hypertensive patients

Left ventricular hypertrophy (LVH) is an important risk factor for cardiovascular morbidity and mortality in hypertensives. Therefore, early identification of at-risk patients is necessary. The objective of this study was to estimate the risk of LVH among Chinese hypertensives by designing a nomogram. 832 hypertensives were divided into two groups based on the presence of LVH. The least absolute shrinkage and selection operator (LASSO) regression and multivariable logistic regression were successively applied for optimal variable selection and nomogram construction. Discrimination power, calibration, and clinical usefulness were evaluated using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis. Internal validation was performed using the bootstrap method. The nomogram included five predictors, namely gender, duration of hypertension, age, body mass index (BMI), and systolic blood pressure. The area under the ROC curve (AUC) was 0.724 (95% CI: 0.687-0.761), indicating moderate discrimination. The calibration curve showed an excellent agreement between the predicted LVH and the actual LVH probability. The risk threshold between 5% and 72% according to the decision curve analysis, and the nomogram is clinically beneficial. Internal validation by bootstrapping with 1000 samples showed a good C-index of 0.715, which suggested that the predictive abilities for the training set and testing set were in consistency. Our study proposed a nomogram that can be utilized to assess the LVH risk rapidly for Chinese hypertensives. This tool could be useful in identifying patients at high risk for LVH. Further studies are required to ascertain the stability and applicability of this nomogram.

The TRIB3 R84 variant is associated with increased left ventricular mass in a sample of 2426 White individuals

BACKGROUND

Prior studies in animal models showed that increased cardiac expression of TRIB3 has a pathogenic role in inducing left ventricular mass (LVM). Whether alterations in TRIB3 expression or function have a pathogenic role in inducing LVM increase also in humans is still unsettled. In order to address this issue, we took advantage of a nonsynonymous TRIB3 Q84R polymorphism (rs2295490), a gain-of-function amino acid substitution impairing insulin signalling, and action in primary human endothelial cells which has been associated with insulin resistance, and early vascular atherosclerosis.

METHODS

SNP rs2295490 was genotyped in 2426 White adults in whom LVM index (LVMI) was assessed by validated echocardiography-derived measures.

RESULTS

After adjusting for age and sex, LVMI progressively and significantly increased from 108 to 113, to 125 g/m2 in Q84Q, Q84R, and R84R individuals, respectively (Q84R vs. Q84Q, P = 0.03; R84R vs. Q84Q, P < 0.0001). The association between LVMI and the Q84R and R84R genotype remained significant after adjusting for blood pressure, smoking habit, fasting glucose levels, glucose tolerance status, anti-hypertensive treatments, and lipid-lowering therapy (Q84R vs. Q84Q, P = 0.01; R84R vs. Q84Q, P < 0.0001).

CONCLUSIONS

We found that the gain-of-function TRIB3 Q84R variant is significantly associated with left ventricular mass in a large sample of White nondiabetic individual of European ancestry.

Sex Differences of the Diabetic Heart

Type 2 diabetes is a chronic disease associated with micro- and macro-vascular complications, including myocardial ischemia, and also with a specific and intrinsic cardiac dysfunction called diabetic cardiomyopathy (DCM). Both clinical and animal studies demonstrate significant sex differences in prevalence, pathophysiology, and outcomes of cardiovascular diseases (CVDs), including those associated with diabetes. The increased risk of CVDs with diabetes is higher in women compared to men with 50% higher risk of coronary artery diseases and increased mortality when exposed to acute myocardial infarction. Clinical studies also reveal a sexual dimorphism in the incidence and outcomes of DCM. Based on these clinical findings, growing experimental research was initiated to understand the impact of sex on CVDs associated with diabetes and to identify the molecular mechanisms involved. Endothelial dysfunction, atherosclerosis, coagulation, and fibrosis are mechanisms found to be sex-differentially modulated in the diabetic cardiovascular system. Recently, impairment of energy metabolism also emerged as a determinant of multiple CVDs associated with diabetes. Therefore, future studies should thoroughly analyze the sex-specific metabolic determinants to propose new therapeutic targets. With current medicine tending toward more personalized care of patients, we finally propose to discuss the importance of sex as determinant in the treatment of diabetes-associated cardiac diseases to promote a more systemic inclusion of both males and females in clinical and preclinical studies.

Diagnostic Thresholds for Pre-Diabetes Mellitus and Diabetes Mellitus and Subclinical Cardiac Disease in the General Population: Data From the ACE 1950 Study

Background Diabetes mellitus (DM) is associated with left ventricular remodeling and incident heart failure, but the association between glycated hemoglobin A1c (HbA1c) and subclinical cardiac disease is not established. We aimed to determine the associations between HbA1c and (1) echocardiographic measures of left ventricular structure and function, and (2) cardiovascular biomarkers: cardiac troponin T, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and CRP (C-reactive protein). Methods and Results Participants (n=3688) born in 1950 from the population-based ACE (Akershus Cardiac Examination) 1950 Study were classified as DM (HbA1c≥6.5% or self-reported DM), pre-DM (HbA1c 5.7%-6.5%), and no-DM (HbA1c<5.7%). DM, pre-DM, and no-DM were classified in 380 (10%), 1630 (44%), and 1678 (46%) participants, respectively. Mean age was 63.9±0.7 years, mean body mass index was 27.2±4.4 kg/m², and 49% were women. Higher HbA1c was associated with worse left ventricular systolic (ejection fraction and global longitudinal strain) and diastolic (E/e'-ratio) function, myocardial injury (cardiac troponin T), inflammation (CRP), and impaired neurohormonal homeostasis (NT-proBNP) (P<0.001 in unadjusted and P<0.01 in adjusted analysis for all). The associations between HbA1c and cardiovascular biomarkers were independent of the echocardiographic variables, and vice versa. Associations were nonlinear (P<0.05 for nonlinearity) and appeared stronger in the pre-DM range of HbA1c than the no-DM and DM range. Conclusions HbA1c was associated with indexes of subclinical cardiovascular disease, and this was more pronounced in pre-DM. Our results suggest that cardiovascular preventive measures should be considered also in subjects with hyperglycemia and HbA1c below the established DM cutoff. Registration clinicaltrials.gov. Identifier: NCT01555411.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.