Weight Loss with Sleeve Gastrectomy in Obese Type 2 Diabetes Mellitus: Impact on Cardiac Function

The effects of bariatric surgery on cardiac function: a systematic review and meta-analysis

INTRODUCTION

Obesity is associated with alterations in cardiac structure and haemodynamics leading to cardiovascular mortality and morbidity. Culminating evidence suggests improvement of cardiac structure and function following bariatric surgery.

OBJECTIVE

To evaluate the effect of bariatric surgery on cardiac structure and function in patients before and after bariatric surgery.

METHODS

Systematic review and meta-analysis of studies reporting pre- and postoperative cardiac structure and function parameters on cardiac imaging in patients undergoing bariatric surgery.

RESULTS

Eighty studies of 3332 patients were included. Bariatric surgery is associated with a statistically significant improvement in cardiac geometry and function including a decrease of 12.2% (95% CI 0.096-0.149; p < 0.001) in left ventricular (LV) mass index, an increase of 0.155 (95% CI 0.106-0.205; p < 0.001) in E/A ratio, a decrease of 2.012 mm (95% CI 1.356-2.699; p < 0.001) in left atrial diameter, a decrease of 1.16 mm (95% CI 0.62-1.69; p < 0.001) in LV diastolic dimension, and an increase of 1.636% (95% CI 0.706-2.566; p < 0.001) in LV ejection fraction after surgery.

CONCLUSION

Bariatric surgery led to reverse remodelling and improvement in cardiac geometry and function driven by metabolic and haemodynamic factors.

Normalization of Cardiac Function After Bariatric Surgery Is Related to Autonomic Function and Vitamin D

PURPOSE

Subclinical cardiac dysfunction is common in patients with obesity. Bariatric surgery is associated with normalization of subclinical cardiac function in 50% of the patients with obesity. The aim of this study was to identify predictors for a lack of improvement of subclinical cardiac dysfunction 1-year post-bariatric surgery.

METHODS

Patients who were referred for bariatric surgery were enrolled in a longitudinal study. Inclusion criteria were age 35-65 years and BMI ≥ 35 kg/m². Patients with a suspicion of or known cardiovascular disease were excluded. Conventional and advanced echocardiography, Holter monitoring, and blood tests were performed pre- and 1-year post-bariatric surgery. Subclinical cardiac dysfunction was defined as either a reduced left ventricular ejection fraction, decreased global longitudinal strain (GLS), diastolic dysfunction, arrhythmia, or an increased BNP or hs Troponin I.

RESULTS

A total of 99 patients were included of whom 59 patients had cardiac dysfunction at baseline. Seventy-two patients completed the 1-year follow-up after bariatric surgery. There was a significant reduction in weight and cardiovascular risk factors. Parameters of cardiac function, such as GLS, improved. However, in 20 patients cardiac dysfunction persisted. Multivariate analysis identified a decreased heart rate variability (which is a measure of autonomic function), and a decreased vitamin D pre-surgery as predictors for subclinical cardiac dysfunction after bariatric surgery.

CONCLUSION

Although there was an overall improvement of cardiac function 1-year post-bariatric surgery, autonomic dysfunction and a decreased vitamin D pre-bariatric surgery were predictors for a lack of improvement of subclinical cardiac dysfunction.

Attenuation of ROS/Chloride Efflux-Mediated NLRP3 Inflammasome Activation Contributes to Alleviation of Diabetic Cardiomyopathy in Rats after Sleeve Gastrectomy

Diabetic cardiomyopathy (DCM) can develop in diabetes mellitus and is a major cause of morbidity and mortality. Surgical bariatric surgery procedures, such as sleeve gastrectomy (SG), result in remission of type 2 diabetes and have benefits regarding systolic and diastolic myocardial function. The NLR family pyrin domain containing 3 (NLRP3) inflammasome appears to participate in the development of DCM. However, whether SG surgery affects myocardial NLRP3 inflammasome-related pyroptosis to improve cardiac function remains unclear. This study was aimed at investigating the effect of SG surgery on NLRP3-associated pyroptosis in rats with DCM. We also examined cellular phenotypes and molecular mechanisms in high glucose-stimulated myocytes. The rat model of DCM was established by high-fat diet feeding and low-dose streptozotocin injection. We observed a metabolic benefit of SG, including a reduced body weight, food intake, and blood glucose levels and restored glucose tolerance and insulin sensitivity postoperatively. We observed a marked decline in glucose uptake in rats with DCM, and this was restored after SG. Also, SG alleviated the dysfunction of myocardial contraction and diastole, delayed the progression of DCM, and reduced the NLRP3 inflammasome-mediated myocardial pyroptosis in vivo. H9c2 cardiomyocytes showed membrane disruption and DNA damage under a high glucose stimulus, which suggested myocardial pyroptosis. Using a ROS scavenger or chloride channel blocker in vitro restored myocardial NLRP3-mediated pyroptosis. Furthermore, we found that chloride efflux acted downstream of ROS generation. In conclusion, SG may ameliorate or even reverse the progression of DCM. Our study provides evidence that the SG operation alleviates NLRP3 inflammasome dysregulation in DCM. Clearance of ROS overburden and suppression of chloride efflux due to SG might act as the proximal event before inhibition of NLRP3 inflammasome in the myocardium, thus contributing to morphological and functional alleviation of DCM.

Assessment of left ventricular global longitudinal strain in patients with type 2 diabetes: Relationship with microvascular damage and glycemic control

BACKGROUND AND AIMS

Type 2 Diabetes mellitus (T2DM) is associated with a higher risk of Heart Failure; Left Ventricular (LV) diastolic dysfunction is often considered the first marker of Diabetic cardiomyopathy; however, early preclinical LV systolic dysfunction has also been observed by means of echocardiographic measurement of strain. This study is aimed at assessing determinants of impaired strain and diastolic ventricular dysfunction in patients with T2DM.

METHODS AND RESULTS

Cross-sectional study, performed on a consecutive series of patients with T2DM aged 30-80 years, BMI<40 kg/m², free of cardiovascular disease, assessing metabolic control, microvascular complications, echocardiographic measures. Out of 206 patients, 19.6% had GLS lower than 18. GLS showed a significant inverse correlation with HBA1c, (p = 0.016), BMI (p = 0.002), waist (p < 0.0001), and mean L:H Ratio (p = 0.019). In a multivariate regression for LV GLS including HbA1c, age, sex, BMI and mean RR SDNN index, only HbA1c retained statistical significance: (B = -0.050 [-0.091; -0.009], p = 0.01. Among markers of LV diastolic function, only the E/E' ratio was associated with HbA1c at a univariate analysis, and it retained statistical significance in a multivariate regression including HbA1c, age, sex and disease duration (B = 0.038 [0.03; -0.073], p = 0.032). No significant difference in any parameter of systolic or diastolic function was observed between patients with or without microalbuminuria or diabetic retinopathy.

CONCLUSION

In patients with T2DM, a reduced left ventricular global longitudinal strain appears to be independently associated with impaired glucose control and autonomic neuropathy, regardless of microvascular complications.

Sleeve Gastrectomy-Induced AMPK Activation Attenuates Diabetic Cardiomyopathy by Maintaining Mitochondrial Homeostasis via NR4A1 Suppression in Rats

Diabetic cardiomyopathy (DCM) is characterized by impaired diastolic and systolic myocardial performance and is a major cause of morbidity and mortality in patients with diabetes. Surgical bariatric procedures, such as sleeve gastrectomy (SG), result in remission of type 2 diabetes (T2DM) and have benefits with myocardial function. Maintaining cardiac mitochondrial homeostasis is a promising therapeutic strategy for DCM. However, whether SG surgery affects mitochondrial function and its underlying mechanism remains unclear. This study aimed to investigate the effect of SG surgery on mitochondrial homeostasis and intracellular oxidative stress in rats with DCM. We also examined cellular phenotypes and molecular mechanisms in high glucose and high fat-stimulated myocytes. The rat model of DCM was established by high-fat diet feeding and low-dose streptozotocin injection. We observed a remarkably metabolic benefit of SG, including a reduced body weight, food intake, blood glucose levels, and restored glucose tolerance and insulin sensitivity post-operatively. Also, SG ameliorated the pathological cardiac hypertrophy, myocardial fibrosis and the dysfunction of myocardial contraction and diastole, consequently delayed the progression of DCM. Also, SG restored the mitochondrial dysfunction and fragmentation through the AMPK signaling activation mediated nuclear receptor subfamily 4 group A member 1 (NR4A1)/DRP1 suppression in vivo. H9c2 cardiomyocytes showed that activation of AMPK could reverse the mitochondrial dysfunction somehow. Collectively, our study provided evidence that SG surgery could alleviate mitochondrial dysfunction in DCM. Moreover, AMPK-activated NR4A1/DRP1 repression might act as a significant reason for maintaining mitochondrial homeostasis in the myocardium, thus contributing to morphological and functional alleviation of DCM.

Effects of bariatric surgery on cardiorespiratory fitness: A systematic review and meta-analysis

Although bariatric surgery (BS) is recognized as an effective strategy for body weight loss, its impact on cardiorespiratory fitness (CRF) is still unclear. We aimed to examine postoperative changes in CRF (VO_2max/peak ) and its relationship with weight loss among adults undergoing BS. We systematically searched the WoS, PubMed, MEDLINE, and Scopus databases. Observational and intervention studies were selected reporting the presurgery and postsurgery CRF, measured by breath-by-breath VO₂ or its estimation. Eleven articles (312 patients) revealed that BS leads to a reduction in absolute VO_2max/peak in the short term (effect size, ES = -0.539; 95%CI = -0.708, -0.369; p < 0.001), and those patients who suffered a more significant decrease in BMI after BS also had a greater loss of absolute VO_2max/peak . However, VO_2max/peak relative to body weight increased after surgery (ES = 0.658; 95%CI = 0.473, 0.842; p < 0.001). An insufficient number of studies were found investigating medium and long-term changes in CRF after BS. This study provides moderate-quality evidence that the weight loss induced by BS can reduce CRF in the short term, which represents a therapeutic target to optimize BS outcomes. More high-quality studies are needed to evaluate the impact of BS on VO_2max/peak in the short, medium, and long term including normalized values for fat-free mass.

Effect of Bariatric Surgery on Glycaemic Control in King Fahad Hospital

BACKGROUND

Laparoscopic Sleeve Gastrectomy (LSG) is an approved procedure for weight reduction in obese patients. This outcome of weight loss is essential to achieve optimal control in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVES

This study was designed to evaluate the effect of LSG on glycemic control among a sample of obese patients in Al-Madinah Al-Munawwarah, Saudi Arabia, through assessment of reduction in hemoglobin A1c (HbA1c) associated with weight loss following LSG.

METHODS

In this cross-sectional study, we studied 102 patients with a body mass index (BMI) of ≥30 kg/m2 and aged ≥18 years who underwent LSG between January 2017 and December 2019. Patient age, characteristics, preoperative and postoperative records of BMI and HbA1c were collected. The data of BMI and HbA1c were analyzed based on baseline and mean postoperative readings with variable postoperative visits after LSG.

RESULTS

There was a 30% reduction in BMI and a 26.4% reduction in HbA1c following LSG from baseline in all patients. We noted 44 patients achieved BMI <40kg/m2 with HbA1c <6.5% and 32 patients achieved BMI <40kg/m2 with HbA1c <5.7% within a mean follow-up time of 10 months.

CONCLUSIONS

Laparoscopic Sleeve Gastrectomy (LSG) has a positive effect on glycemic control in obese patients in short term, evidenced by the significant reduction of weight and HbA1c. Larger longitudinal studies are needed to assess the long-term impact of LSG glycemic control and the related factors associated with maintaining weight reduction and optimal glycemic control in Saudi Arabia for patients with obesity.

Obesity and Cardiomyopathy

While much has been written about the syndrome of diabetic cardiomyopathy, clinicians and research scientists are now beginning to realize that an entirely unique syndrome exists, albeit with several commonalities to the diabetic syndrome, that being obesity cardiomyopathy. This syndrome develops independent of such comorbidities as hypertension, myocardial infarction and coronary artery disease; and it is characterized by specific alterations in adipose tissue function, inflammation and metabolism. Recent insights into the etiology of the syndrome and its consequences have focused on the roles played by altered intracellular calcium homeostasis, reactive oxygen species, and mitochondrial dysfunction. A timely and comprehensive review by Ren, Wu, Wang, Sowers and Zhang (1) identifies unique mechanisms underlying this syndrome, its relationship to heart failure and the recently identified incidence of COVID-19-related cardiovascular mortality. Importantly, the review concludes by advancing recommendations for novel approaches to the clinical management of this dangerous form of cardiomyopathy.

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.

Assessment of subclinical diabetic cardiomyopathy by speckle-tracking imaging

BACKGROUND

Diastolic dysfunction is traditionally believed to be the first subclinical manifestation of diabetic cardiomyopathy (DCM), leading to systolic dysfunction and then overt heart failure. However, in the last few years, several studies suggested that systolic subclinical dysfunction measured by speckle-tracking echocardiography (STE) may appear ahead of diastolic dysfunction. In this review, the main endpoint is to show whether subclinical myocardial systolic dysfunction appears ahead of diastolic dysfunction and the implication this may have on the evolution and management of DCM.

MATERIALS AND METHODS

We performed a search in PubMed for all relevant publications on the assessment of DCM by STE from 1 June 2015 to 1 June 2020.

RESULTS AND CONCLUSIONS

The results illustrate that subclinical systolic dysfunction assessed by STE is present in early DCM stages, with or without the association of diastolic dysfunction. This could be a promising perspective for the early management of patients with DCM leading to the prevention of the overt form of disease.

Evaluation of Myocardial Function Following SADI-S

PURPOSE

The aim of this study was to compare myocardial mechanics using global longitudinal strain (GLS) before and after single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S).

MATERIALS AND METHODS

A total of 21 obese patients undergoing SADI-S were prospectively included. Transthoracic echocardiography was performed before and after the procedure, and left ventricle (LV) and right ventricle (RV) strain was assessed by two-dimensional speckle-tracking imaging (2DST).

RESULTS

Mean time between pre-procedural and post-procedural echocardiograms was 9.2 ± 3.3 months. Postoperatively, %total weight loss (%TWL) was 33.0 ± 1.7 and % excess weight loss (%EWL) was 75.5 ± 3.6. Body mass index (BMI) significantly decreased after surgery (45.6 ± 1.2 vs 29.6 ± 1.0; p < 0.001). Postoperatively, LV GLS experienced a significant improvement (-19.8% ± 0.5 vs -22.2% ± 0.4; p < 0.001). Regarding other relevant functional parameters, RV free-wall strain was equally recovered (-19.1% ± 0.7 vs -21.0% ± 0.8; p 0.047).

CONCLUSIONS

This study demonstrates important and favourable changes in cardiac deformation parameters after performing SADI-S. Malabsorptive bariatric techniques such as SADI-S induce significant weight loss, leading to an improvement in subclinical myocardial function in patients with obesity.

Diabesity: the combined burden of obesity and diabetes on heart disease and the role of imaging

Diabesity is a term used to describe the combined adverse health effects of obesity and diabetes mellitus. The worldwide dual epidemic of obesity and type 2 diabetes is an important public health issue. Projections estimate a sixfold increase in the number of adults with obesity in 40 years and an increase in the number of individuals with diabetes to 642 million by 2040. Increased adiposity is the strongest risk factor for developing diabetes. Early detection of the effects of diabesity on the cardiovascular system would enable the optimal implementation of effective therapies that prevent atherosclerosis progression, cardiac remodelling, and the resulting ischaemic heart disease and heart failure. Beyond conventional imaging techniques, such as echocardiography, CT and cardiac magnetic resonance, novel post-processing tools and techniques provide information on the biological processes that underlie metabolic heart disease. In this Review, we summarize the effects of obesity and diabetes on myocardial structure and function and illustrate the use of state-of-the-art multimodality cardiac imaging to elucidate the pathophysiology of myocardial dysfunction, prognosticate long-term clinical outcomes and potentially guide treatment strategies.

Caloric restriction in heart failure: A systematic review

BACKGROUND AND AIMS

Nutrition exerts a determinant role in maintaining cardiac function, regulating insulin and mitochondrial efficiency, that are essential to support energy production for contractility. In patients with heart failure (HF), myocardial tissue efficiency is reduced because of decreased mitochondrial oxidative capacity. In HF conditions, cardiomyocytes shift toward glucose and a reduction in fatty acid utilization. Calorie restriction induces weight loss in obese patients and can be beneficial in some HF patients, although this has generated some controversy. This study aims to evaluate the impact of the CR diet on myocardial efficiency in HF patients.

METHODS

On Pubmed and Embase, articles related to the keywords: "chronic heart failure" with "diet," "nutrition," "insulin resistance," and "caloric restriction" have been searched, Studies, including exercise or food supplementation, were excluded.

RESULTS

The retrieved articles showed that weight loss, through the activation of insulin and various kinase pathways, regulates the efficiency of myocardial tissue. In contrast, insulin resistance represents a strong cardiovascular risk factor that reduces myocardial function.

CONCLUSION

CR diet represents the first therapy in overweight HF patients, both with preserved ejection fraction (HFpEF) and with reduced ejection fraction (HFrHF) because reducing body fat, the myocardial function increased. Insulin activity is the critical hormone that regulates mitochondrial function and cardiac efficiency. However, a severely restricted diet may represent a severe risk factor correlated with all-cause mortality, particularly in underweight HF patients. Long-term studies conducted on large populations are necessary to evaluate the effects of CR on myocardial function in HF patients.

[Variations in echocardiography after bariatric surgery. Biliopancreatic diversion vs vertical gastrectomy]

Introduction

Introduction: obesity has become a worldwide health problem due to its relationship with cardiovascular morbimortality, thus bariatric surgery is considered as one of the main solutions for the correction of excess weight and, consequently, the improvement of its associated heart diseases. Objective: to compare vertical gastrectomy (VG) and biliopancreatic diversion (BPD) by observing echocardiographic characteristics both before and after surgery, as well as to evaluate surgical outcome in terms of the BAROS scale. Methods: results were collected from the echocardiographic testing requested for the preoperative study of patients who underwent surgery over the course of 24 months (from January 2014 to December 2015), as well as their anthropometric data. These were compared with postoperative parameters measured at 3 years after surgery. Results: finally, 26 patients were selected (13 VG and 13 BPD) with a mean age of 42 yrs. VG: initial BMI: 44.6 ± 7.1; final BMI: 31.8 ± 11.3 (p < 0.01); BPD: initial BMI: 48.1 ± 14.2; final BMI: 32.7 ± 10.4 (p < 0.01). Echocardiography: normal systolic function: 100% vs 92%; normal diastolic function: 88.5% vs 69.2%; no valvulopathy: 80% vs 69%; normal left atrium: 76.9% vs 73.1% (p > 0.05); HTA: 38.5% vs 19.2% (p < 0.05), preoperatively and postoperatively, respectively. Conclusions: no significant differences were found between the two groups studied with different techniques, although a slight deterioration in diastolic function was found in both groups. The comorbidities associated with obesity improved in both groups, and the surgery was scored as positive. The scant variation revealed by echocardiography prompts to reconsider its systematic preoperative use in these patients given the low cost-benefit ratio.

Short- and mid-term effects of sleeve gastrectomy on left ventricular function with two-dimensional speckle tracking echocardiography in obese patients

AIM

This study aimed to investigate left ventricular functions of obese patients with no known heart disease who underwent laparoscopic sleeve gastrectomy by speckle tracking echocardiography in their early and medium-term postoperative follow-up.

PATIENTS AND METHOD

Thirty-seven obese patients (10 M, 27 F) without coronary artery disease or heart failure who had undergone LSG were included in the study. Apical four-, three-, and two-chamber images were analyzed longitudinally by conventional methods and speckle tracking echocardiography (STE) for left ventricle functions preoperatively, at the postoperative Month 1 and at the postoperative Month 6 (QLAB 6.0), using current software.

RESULTS

No difference was found between standard echocardiography and Doppler parameters in terms of the 1-month versus 6-month follow-up values compared to baseline. Left ventricular STE longitudinal measurements demonstrated significantly higher longitudinal strain and strain velocity parameters in the follow-up values at Month 6 compared to the values at Month 1 and at baseline. Global longitudinal strain (GLS) was -17.48 ± 1.09% in 6-month follow-up, -16.16 ± 1.26% in 1-month follow-up, and -16.06 ± 1.25% at baseline (P < .001). A significant correlation was found between delta GLS, which represents patients' GLS change in 6 months, and delta weight, which represents patients' body weight change in 6 months.

CONCLUSION

Obese patients who had undergone LSG were observed to have improved left ventricular function in the mid-term.

Utility of strain imaging in conjunction with heart failure stage classification for heart failure patient management

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) classification, based on structural changes and symptoms, classifies stages of heart failure (HF) development as Stages A-D. This HF classification emphasizes the development and progression of the disease and can be used to describe individuals and populations. Since HF is considered a progressive disorder that can be represented as a clinical continuum, individuals at a particular HF stage require specific management with the long-term goal of avoiding HF development and progression. Although early detection of subclinical left ventricular (LV) dysfunction is essential for delaying progression to HF, the assessment of such dysfunction can be challenging. While echocardiography plays a pivotal role in the quantification and early detection of LV structural findings, two-dimensional speckle-tracking echocardiographic parameters, especially global longitudinal strain (GLS), have recently been reported to be sensitive markers of early subtle abnormalities of LV myocardial performance. They are thus helpful for prediction of outcomes for various cardiac diseases, and superior to conventional echocardiographic indices such as LV ejection fraction, mitral inflow E and mitral e' annular velocities ratio. Strain imaging, especially GLS-guided management for patients at a particular stage of HF, may therefore have the potential to prevent progression to later HF stages and may offer new insights into the management of HF patients. This article reviews the utility of strain imaging, especially GLS in conjunction with HF stage classification, and future perspectives for HF patient management.

Impact of Nutrition on Cardiovascular Function

The metabolic sources of energy for myocardial contractility include mainly free fatty acids (FFA) for 95%, and in lesser amounts for 5% from glucose and minimal contributions from other substrates such lactate, ketones, and amino acids. However, myocardial efficiency is influenced by metabolic condition, overload, and ischemia. During cardiac stress, cardiomyocytes increase glucose oxidation and reduce FFA oxidation. In patients with ischemic coronary disease and heart failure, the low oxygen availability limits myocardial reliance on FFA and glucose utilization must increase. Although glucose uptake is fundamental to cardiomyocyte function, an excessive intracellular glucose level is detrimental. Insulin plays a fundamental role in maintaining myocardial efficiency and in reducing glycemia and inflammation; this is particularly evident in obese and type-2 diabetic patients. An excess of F availability increase fat deposition within cardiomyocytes and reduces glucose oxidation. In patients with high body mass index, a restricted diet or starvation have positive effects on cardiac metabolism and function while, in patients with low body mass index, restrictive diets, or starvation have a deleterious effect. Thus, weight loss in obese patients has positive impacts on ventricular mass and function, whereas, in underweight heart failure patients, such weight reduction adds to the risk of heart damage, predisposing to cachexia. Nutrition plays an essential role in the evolution of cardiovascular disease and should be taken into account. An energy-restricted diet improves myocardial efficiency but can represent a potential risk of heart damage, particularly in patients affected by cardiovascular disease. Micronutrient integration has a marginal effect on cardiovascular efficiency.

Facilitated Ca2+ homeostasis and attenuated myocardial autophagy contribute to alleviation of diabetic cardiomyopathy after bariatric surgery

Bariatric surgery has been reported to relieve diabetic cardiomyopathy (DCM) effectively. However, the mechanisms remain largely unknown. To determine the effects of bariatric surgery on DCM via modulation of myocardial Ca²⁺ homeostasis and autophagy, sleeve gastrectomy (SG), duodenal-jejunal bypass (DJB), and sham surgeries were performed in diabetic rats induced by high-fat diet and a low dose of streptozotocin. Cardiac remodeling was assessed by a series of morphometric and histological analyses. Transthoracic echocardiography and hemodynamic measurements were performed to determine cardiac function. Ca²⁺ homeostasis was evaluated by measuring Ca²⁺ transients with fura-2 AM in isolated ventricular myocytes along with detection of the abundance of Ca²⁺ regulatory proteins in the myocardium. Myocardial autophagic flux was determined by expression of autophagy-related proteins in the absence and presence of chloroquine. Both SG and DJB surgery alleviated DCM morphologically and functionally. Ca²⁺ transients exhibited a significantly higher amplitude and faster decay after SG and DJB, which could be partially explained by increased expression of ryanodine receptor 2, sarco(endo)plasmic reticulum Ca²⁺-2ATPase, 12.6-kDa FK506-binding protein, and hyperphosphorylation of phospholamban. In addition, a lower level of light chain 3B and higher level of p62 were detected after both SG and DJB, which was not reversed by chloroquine treatment and associated with activated mammalian target of rapamycin and attenuated AMP-activated protein kinase signaling pathway. Collectively, these results provided evidence that bariatric surgery could alleviate DCM effectively, which may result, at least in part, from facilitated Ca²⁺ homeostasis and attenuated autophagy, suggesting a potential choice for treatment of DCM when properly implemented. NEW & NOTEWORTHY The present study is the first to investigate the modulation of myocardial Ca²⁺ homeostasis and autophagy after bariatric surgery and to examine its effects on diabetic cardiomyopathy. Bariatric surgery could facilitate myocardial Ca²⁺ homeostasis and attenuate myocardial autophagy, contributing to the alleviation of cardiomyopathy morphologically and functionally in a diabetic rat model.

Future Perspectives for Management of Stage A Heart Failure

Patients with Stage A heart failure (HF) show no HF symptoms but have related comorbid diseases with a high risk of progressing to HF. Screening for comorbid diseases warrants closer attention because of the growing interest in addressing Stage A HF as the best means of preventing eventual progression to overt HF such as Stages C and D. The identification of individuals of Stage A HF is potentially useful for the implementation of HF-prevention strategies; however, not all Stage A HF patients develop left ventricular (LV) structural heart disease or symptomatic HF, which lead to advanced HF stages. Therefore, Stage A HF requires management with the long-term goal of avoiding HF development; likewise, Stage B HF patients are ideal targets for HF prevention. Although the early detection of subclinical LV dysfunction is, thus, essential for delaying the progression to HF, the assessment of subclinical LV dysfunction can be challenging. Global longitudinal strain (GLS) as assessed by speckle-tracking echocardiography has recently been reported to be a sensitive marker of early subtle LV myocardial abnormalities, helpful for the prediction of the outcomes for various cardiac diseases, and superior to conventional echocardiographic indices. GLS reflects LV longitudinal myocardial systolic function, and can be assessed usually by means of two-dimensional speckle-tracking. This article reviews the importance of the assessment of subclinical LV dysfunction in Stage A HF patients by means of GLS, and its current potential to prevent progression to later stage HF.

Weight Loss and Glycemic Control after Sleeve Gastrectomy: Results from a Middle Eastern Center of Excellence

Obesity and its associated metabolic disorders are strongly linked to both morbidity and mortality. Sleeve gastrectomy (SG) has been established as an effective means of weight loss for obese patients as well as a treatment for type 2 diabetes mellitus (T2DM). This study was designed to examine the short- and midterm outcomes of patients who underwent SG in a Middle Eastern Center of Excellence, a military training teaching hospital. The clinical outcomes of 59 patients with impaired glucose tolerance and T2DM who underwent SG between 2011 and 2014 with at least one and up to four years of follow-up were studied. Data were collected and compared, including the pre- and post-surgery measures of weight, body mass index, glycosylated hemoglobin (HbA1c), and fasting blood glucose. Complete remission was defined as a fasting blood glucose level ≤100 mg/dL, an HbA1c ≤6 mg/dL, without use of antidiabetic medications. All patients showed significant reduction in body mass index following SG. Tight glycemic control was achieved among both diabetic and prediabetic patients. In this study, 88.14 per cent of all patients (diabetic and prediabetic) achieved complete resolution from their impaired glucose tolerance and T2DM and maintained normal blood glucose and HbA1C levels from one to four years post-operatively. SG is beneficial both in terms of short- and midterm weight loss and glucose control in both diabetic and prediabetic obese patients.

Subclinical Myocardial Impairment in Metabolic Diseases

Type 2 diabetes mellitus (T2DM) and obesity are important contributors to nonischemic heart failure (HF) and atrial fibrillation. There is a 2- to 5-fold increase in HF associated with T2DM, and there is a 5% in HF risk in men and 7% increment in women for every unit increment in body mass index, after adjustment for traditional cardiovascular risk factors. Likewise, the risk of atrial fibrillation increases by about 6% per unit increase in body mass index. Metabolic cardiomyopathy leads to a number of changes in cardiac structure and function that can be recognized by imaging in the asymptomatic phase, and these parameters can be used for monitoring the progression of disease or the response to therapy. The purpose of this review is to familiarize clinicians with the potential benefits of early detection of preclinical myocardial abnormalities, as well as the mechanisms that might inform interventions to prevent disease progression in patients with T2DM and obesity.

The influences of bariatric surgery on hemoglobin A1c in a sample of obese patients in Saudi Arabia

BACKGROUND

Although the frequency of surgical weight loss interventions has increased in Saudi Arabia, literature describing the clinical outcomes of bariatric surgery in Saudi Arabia is limited. This study aimed to assess whether weight loss intervention improves hemoglobin A1c (HbA1c) in obese patients and to identify its associated factors.

PATIENTS AND METHODS

A retrospective study was carried out on 318 patients with obesity class 1 or higher (body mass index [BMI] ≥ 30 kg/m²) who underwent laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass at King Abdulaziz Medical City in Riyadh, Saudi Arabia, between January 1, 2001 and March 31, 2017. Preoperatively and 12 months postoperatively, characteristics of patients were collected. BMI reduction was calculated, based on which patients were divided into three groups (0-9, 10-14, and >14 kg/m²).

RESULTS

The postoperative HbA1c was 5.83±0.9, while the baseline level was 6.74±2.1 (P=0.001). Fifty-eight of the 318 patients had diabetes. We observed significantly higher HbA1c in diabetic than in non-diabetic patients preoperatively, whereas an insignificantly different HbA1c was observed postoperatively. Among those who had minimal reduction in BMI (0-9 kg/m²), we observed significantly higher HbA1c in diabetic than in non-diabetic patients, whereas among those who had large reduction in BMI (10-14 kg/m²) and (>14 kg/m²), we observed insignificant differences in HbA1c in diabetic than in non-diabetic patients.

CONCLUSION

Being a diabetic patient was related to a significant reduction in HbA1c levels postoperatively. The study suggests that the reduction in HbA1c levels could be modified by BMI, wherein greater reduction in BMI leads to greater reduction in HbA1c levels.

Impact of overweight on left ventricular function in type 2 diabetes mellitus

Background

Coexistence of left ventricular (LV) longitudinal myocardial systolic dysfunction with LV diastolic dysfunction could lead to heart failure with preserved ejection fraction (HFpEF). Diabetes mellitus (DM) is known as a significant factor associated with HFpEF. Although the mechanisms of DM-related LV myocardial injury are complex, it has been postulated that overweight contributes to the development of LV myocardial injury in type 2 diabetes mellitus (T2DM) patients. However, the precise impact of overweight on LV longitudinal myocardial systolic function in T2DM patients remains unclear.

Methods

We studied 145 asymptomatic T2DM patients with preserved LV ejection fraction (LVEF) without coronary artery disease. LV longitudinal myocardial systolic function was assessed by global longitudinal strain (GLS), which was defined as the average peak strain of 18-segments obtained from standard apical views. Overweight was defined as body mass index (BMI) ≥ 25 kg/m². Ninety age-, gender- and LVEF-matched healthy volunteers served as controls.

Results

GLS of overweight T2DM patients was significantly lower than that of non-overweight patients (17.9 ± 2.4% vs. 18.9 ± 2.6%, p < 0.05), whereas GLS of both overweight and non-overweight controls was similar (19.8 ± 1.3% vs. 20.4 ± 2.1%, p = 0.38). Furthermore, multiple regression analysis revealed that for T2DM patients, BMI was the independent determinant parameters for GLS as well as LV mass index.

Conclusions

Overweight has a greater effect on LV longitudinal myocardial systolic function in T2DM patients than on that in non-DM healthy subjects. Our finding further suggests that the strict control of overweight in T2DM patients may be associated with prevention of the development of HFpEF.

Bariatric surgery as a treatment for heart failure: review of the literature and potential mechanisms

Heart failure due to severe obesity is a complex disease due to multiple mechanisms, including increased body mass, inflammation, and impaired cardiac metabolism that is complicated by obesity-associated co-morbidities, such as type 2 diabetes and obstructive sleep apnea. Bariatric surgery significantly improves cardiac geometry, function, and symptoms related to obesity cardiomyopathy. There is a consistently positive impact of bariatric surgery on diastolic function with the potential to significantly improve systolic function as measured by ejection fraction in patients with advanced heart failure. For end-stage heart failure patients, including those requiring mechanical circulatory support who are ineligible for organ transplant due to morbid obesity, bariatric surgery has been successfully used for weight loss as a bridge to cardiac transplantation.

Sleeve Gastrectomy Efficacy on Metabolic and Cardiovascular Dysfunction With a Focus on the Role of Comorbidities

We evaluated the effects of sleeve gastrectomy (SG) on metabolic/cardiovascular parameters according to weight loss, visceral fat area (VFA), and homeostasis model assessment (HOMA)-insulin resistance index; we also assessed the influence of SG on comorbidities (diabetes/hypertension). At baseline and 10 to 12 months after SG, we assessed anthropometric and biochemical parameters, bioimpedentiometry, ultrasonographic VFA, liver steatosis, flow-mediated dilation, and echocardiography in 110 patients with obesity. We found that 23 (21%) patients had diabetes. Diabetic patients who normalized their glycated hemoglobin A_1C (HbA_1C) level experienced greater total weight loss (TWL), and the probability of normalizing HbA_1C levels directly correlated with TWL. Diabetic patients experienced a greater improvement in systolic blood pressure, VFA, and high-density lipoprotein cholesterol than nondiabetics, while patients with hypertension experienced a greater improvement in VFA, triglycerides, HOMA, and HbA_1C than nonhypertensive patients. The most important determinant of glucose control in diabetic patients was weight loss. Patients with diabetes and hypertension experienced a greater improvement in vascular and metabolic status after SG.

Changes in Body Weight and Composition Are Associated With Changes in Left Ventricular Geometry and Function in the General Population

Background—

The different effects of total body weight (TBW), fat-free mass (FFM), and fat mass (FM) on left ventricular (LV) geometry and function are complex. We investigated the associations of changes over time in TBW, FM, and FFM with changes in LV geometry and function.

Methods and Results—

We analyzed data from 1189 subjects (694 women), aged 44 to 86 years, from the baseline and the 5-year follow-up examination of the population-based SHIP (Study of Health in Pomerania). TBW was measured, and FFM and FM were calculated based on height-weight models derived from bioelectrical impedance studies. Echocardiographic measurements of LV geometry and function were performed according to the guidelines of the American Society of Echocardiography. Changes in body composition measures were associated with changes in LV geometry and function by multivariable-adjusted linear regression models. A 1-kg increase/decrease in TBW or FM was associated, respectively, with an increase/decrease of 0.89 g or 1.84 g in LV mass, whereas there was no such association on changes in FFM. Moreover, an increase in FM was associated with LV concentric remodeling and impairment of systolic and diastolic function parameters, whereas an increase in FFM was associated with LV eccentric remodeling and improved systolic and diastolic functional variables.

Conclusions—

Our findings indicate that changes in LV morphology and function depend on the type of body mass composition. Prospective data need to address whether specific changes in body composition over time may affect the risk for heart dysfunction more precisely than the change in TBW.

Improvement of impaired diastolic left ventricular function after diet-induced weight reduction in severe obesity

BACKGROUND/OBJECTIVES

Obesity is independently associated with left ventricular (LV) diastolic dysfunction and altered cardiac morphology. Morbidity and mortality in patients with diastolic dysfunction are similar to values observed in patients with systolic heart failure. We hypothesized that dysfunctional cardiac responses in people with obesity are reversible after weight loss. Thus, we studied the effect of dietary weight reduction on LV diastolic function as well as on cardiac structure using transthoracic echocardiography and tissue Doppler imaging (TDI).

SUBJECTS/METHODS

Thirty-two subjects with obesity underwent a 12-week low-calorie fasting phase of a formula diet. Echocardiographic tissue Doppler indices of diastolic function and measurements of cardiac size were obtained prior to and after the fasting phase.

RESULTS

A 12-week diet significantly reduced body mass index from 40.3 ± 6.6 kg/m² to 33.2 ± 6.1 kg/m² (p < 0.01). Weight loss was associated with a significant reduction in blood pressure and heart rate. Echocardiography revealed diastolic dysfunction in subjects with obesity, which was improved by dieting. After weight loss, trans-mitral Doppler echocardiography showed a significant reduction in A-wave velocity, from 65.8 ± 19.2 cm/s to 57.0 ± 16.8 cm/s, and an increase in E/A ratio from 1.2 ± 0.4 to 1.4 ± 0.5 (p < 0.01). TDI displayed a significantly lower a'-wave velocity (10.3 ± 2.3 cm/s and 8.9 ± 1.7 cm/s; p < 0.01). Left atrial and LV dimensions were normal and remained unchanged after weight loss.

CONCLUSION

Obesity is associated with diastolic dysfunction. A 12-week low-calorie diet with successful weight loss can reduce blood pressure and heart rate and partially normalize diastolic dysfunction.

Cardiac dysfunction in type II diabetes: a bittersweet, weighty problem, or both?

AIMS

Weight loss in obese patients leads to improved left ventricular (LV) function. It is unclear whether improving glycaemic control has additional benefits to weight loss alone in patients with type 2 diabetes, or if benefits of weight loss are mediated through improving glycaemic control. This case-control study examined the incremental impact of these approaches on LV function.

METHODS

Three groups of age, gender, and baseline HbA1c-matched patients with type 2 diabetes and suboptimal glycaemic control were followed-up for 12 months. Group 1 patients did not improve HbA1c ≥ 1 % (10.9 mmol/mol) or lose weight. Group 2 improved HbA1c ≥ 1 % but did not lose weight. Group 3 improved HbA1c ≥ 1 % (10.9 mmol/mol) and lost weight. All patients underwent transthoracic echocardiogram at baseline and at follow-up.

RESULTS

At baseline, three groups were comparable in all clinical and metabolic parameters except Group 3 had highest body mass index. The three groups had similar echocardiographic parameters except Group 3 had the worst LV systolic function [global longitudinal strain (GLS)]. At follow-up, LV ejection fraction and diastolic function improved with a reduction in filling pressures in Group 2 and more so in Group 3. LV filling pressures in Group 1 increased. There was a significant improvement in GLS in Group 2 and more so in Group 3. Despite GLS being the worst in Group 3 at baseline, this was comparable between Groups 2 and 3 at follow-up.

CONCLUSIONS

In overweight patients with type 2 diabetes, weight loss and improved glycaemic control had additive beneficial effects on improving LV systolic and diastolic function.

The effects of weight loss after sleeve gastrectomy on left ventricular systolic function in men versus women

PURPOSE

To evaluate and compare the effects of weight lost after sleeve gastrectomy on left ventricular (LV) systolic function using both two-dimensional speckle tracking (2D-STE) and three-dimensional echocardiography (3DE) in men versus women.

METHODS

In 53 obese patients referred for sleeve gastrectomy, 2D-STE and 3DE were performed prior to and 6 months after surgery.

RESULTS

The study included 53 obese patients (62.3% female; mean age 36.8 ± 10.7 years). Six months after surgery, all patients demonstrated a significant decrease in body mass index, body weight, blood pressure, heart rate, LV end-diastolic dimension, myocardial wall thickness, LV mass, LV mass index, LV mass/height(2.7) , LV end-diastolic volume, LV end-systolic volume, and stroke volume as well as an increase in SV index and ejection fraction. There was no significant difference in measured variables between men and women at baseline or postsurgery, except for baseline LV end-diastolic dimension, and baseline and after surgery LV mass, LV mass index, and LV mass/height(2.7) , which were all significantly higher in men.

CONCLUSIONS

Sleeve gastrectomy improves LV systolic function and contributes to reverse LV remodeling in both genders. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:492-499, 2016.

Impact of Severe Obesity and Weight Loss on Systolic Left Ventricular Function and Morphology: Assessment by 2-Dimensional Speckle-Tracking Echocardiography

Obesity is associated with an increased risk of heart failure. Little is known about the impact of dietary changes on the cardiac sequelae in obese patients. Twenty-one obese subjects underwent a 12-week low calorie fasting phase of a formula diet. Transthoracic two-dimensional speckle-tracking echocardiography was performed to obtain systolic left ventricular strain before and after weight loss. Body mass index decreased significantly from 38.6 ± 6.2 to 31.5 ± 5.3 kg/m(2), and the total percentage fat loss was 19%. Weight reduction was associated with a reduction in blood pressure and heart rate. Left ventricular longitudinal global peak systolic strain was in the lower normal range (-18.7 ± 3.2%) before weight loss and was unchanged (-18.8 ± 2.4%) after 12 weeks on diet with substantial weight loss. Also, no significant change in global radial strain after weight loss was noted (41.1 ± 22.0 versus 43.9 ± 23.3, p = 0.09). Left atrial and ventricular dimensions were in normal range before fasting and remained unchanged after weight loss. In our study obesity was associated with normal systolic left ventricular function. A 12-week low calorie diet with successful weight loss can reduce blood pressure and heart rate. Systolic left ventricular function and morphology were not affected by rapid weight reduction.