The influence of body composition, fat distribution, and sustained weight loss on left ventricular mass and geometry in obesity

Bariatric surgeries and cardiac structure and function: Systematic review and network meta-analysis

BACKGROUND

Obesity, a global health problem, is causally implicated in the development of cardiovascular disease. Bariatric surgeries are effective treatment options for obesity; however, the effectiveness of different bariatric surgeries on cardiac structure and function is not fully understood. We undertook a systematic review and network meta-analysis to comprehensively assess this effectiveness.

DATA SOURCE

PubMed, Web of Science, and EMBASE were searched from their inception until November 11, 2023. Studies that compared bariatric surgeries vis-à-vis non-surgical treatment, placebo, and other bariatric surgeries, as well as reported changes in left ventricular mass or its index (LVM or LVMI) or left ventricular ejection fraction (LVEF), were summarized.

RESULTS

Total 19 studies (17 cohort studies and 2 randomized controlled trials) and 2012 adults were meta-analyzed. Patients receiving gastric bypass had appreciably lowered LVM (weighted mean difference [WMD]: -43.86 g, 95% confidence interval [CI] -61.09 to -26.63, p < 0.01) and LVMI (standardized mean difference: -0.67, 95% CI -1.03 to -0.32, p < 0.01) compared with other bariatric surgeries. No significant improvement in LVEF was noted across all surgeries. The drop in body mass index was most pronounced for biliopancreatic diversion with duodenal switch (WMD -16.33 kg/m2, 95% CI -21.60 to -11.05, p < 0.01).

CONCLUSIONS

Our findings of this network meta-analysis indicated that gastric bypass proved best for the improvement in cardiac structure, and there was no obvious improvement in cardiac function for all bariatric surgeries. Further studies are required to better understand the differing effectiveness of bariatric surgeries on cardiac structure and function and the underlying molecular mechanisms.

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.

Mechanically induced alterations in chromatin architecture guide the balance between cell plasticity and mechanical memory

Phenotypic plasticity, or adaptability, of a cell determines its ability to survive and function within changing cellular environments. Changes in the mechanical environment, ranging from stiffness of the extracellular matrix (ECM) to physical stress such as tension, compression, and shear, are critical environmental cues that influence phenotypic plasticity and stability. Furthermore, an exposure to a prior mechanical signal has been demonstrated to play a fundamental role in modulating phenotypic changes that persist even after the mechanical stimulus is removed, creating stable mechanical memories. In this mini review, our objective is to highlight how the mechanical environment alters both phenotypic plasticity and stable memories through changes in chromatin architecture, mainly focusing on examples in cardiac tissue. We first explore how cell phenotypic plasticity is modulated in response to changes in the mechanical environment, and then connect the changes in phenotypic plasticity to changes in chromatin architecture that reflect short-term and long-term memories. Finally, we discuss how elucidating the mechanisms behind mechanically induced chromatin architecture that lead to cell adaptations and retention of stable mechanical memories could uncover treatment methods to prevent mal-adaptive permanent disease states.

Higher body mass index and disease duration are associated with increased risk of left ventricular diastolic dysfunction in women with systemic lupus erythematosus

BACKGROUND

Patients with systemic lupus erythematosus (SLE) have an increased cardiovascular (CV) risk. Insulin resistance (IR), which is higher in patients with SLE, adversely impacts left ventricular (LV) remodeling and function. The aims were to determine LV dysfunction and evaluate the influence of potential risk factors on subclinical LV dysfunction in women with SLE, including IR.

METHODS

This cross-sectional study included adult women with SLE without diabetes mellitus (DM), hypertension or severe obesity. Diastolic dysfunction (DD) was verified according to current guidelines. Insulin resistance was estimated using the Quantose score.

RESULTS

We included 77 women. The frequency of IR was 65%. All participants had a normal ejection fraction (EF), and 11 (15.7%) had abnormal LV global longitudinal strain (GLS). Twenty-three (32.8%) had DD. The GLS% and global circumferential strain (GCS)% did not differ in patients with and without IR (-20.8 ± 3.1 vs -20.5 ± 2.1; p = 0.61 and -27.9 ± 4.4 vs -27.4 ± 3.7; p = 0.57, respectively). The prevalence of DD was 38.1% in patients with IR versus 25% in those without (p = 0.30). E/e' and E/A ratios did not differ between groups (6.6 ± 1.9 vs 6.6 ± 1.5; p = 0.98 and 1.3 ± 0.3 vs 1.3 ± 0.2; p = 0.27). Higher BMI (OR: 1.2, 95% CI 1.1-1.5) and disease duration (OR: 1.2, 95% CI 1.1-1.4) were associated with DD.

CONCLUSIONS

Patients with overweight/obesity may be at higher risk of LV dysfunction. Although IR was high in our patients with SLE was not associated with systolic dysfunction or DD. Body mass index and disease duration were associated with an increased risk of DD.

Bariatric Surgery Improves Heart Geometry and Plasticity

BACKGROUND

Obesity is commonly associated with increased sympathetic tone, changes in heart geometry, and mortality. The aforementioned translates into a higher and potentially modifiable mortality risk for this specific population.

OBJECTIVES

The aim of the study was to analyze the extent of changes in the heart ventricular structure following rapid weight loss after bariatric surgery.

SETTING

Academic, university-affiliated hospital.

METHODS

We retrospectively reviewed all the patients that underwent bariatric surgery at our institution between 2010 and 2015. Data analyzed included demographics, BMI, and associated medical problems. Preoperative and postoperative echography readings were compared looking at the heart geometry, cardiac volumes, and wall thickness.

RESULTS

Fifty-one patients who had bariatric surgery and had echocardiography before and after the surgery were identified. There were 33 females (64.7%). The mean age was 63.4 ± 12.0 years with an average BMI of 40.3 ± 6.3. The mean follow-up was 1.2 years after the procedure. At 1 year follow-up 25 patients (49%, p = 0.01) showed normal left ventricular geometry. The left ventricular mass (229 ± 82.1 vs 193.2 ± 42.5, p<0.01) and the left ventricular end diastolic volume (129.4 ± 53 vs 96.4 ± 36.5, p = 0.01) showed a significant modification following the procedure. There was a significant improvement in the interventricular septal thickness (p = 0.01) and relative wall thickness (p < 0.01) following surgery.

CONCLUSION

The patients with obesity present a significant cardiac remodeling from concentric remodeling to normal geometry after bariatric surgery. The decrease in BMI has a direct effect on improvement of the left ventricular structure. Further studies must be carried out to define the damage of obesity to diastolic function.

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.

The Efficacy of School-Based Interventions in Preventing Adolescent Obesity in Australia

Current trends suggest that adolescent obesity is an on-going and recurrent decimal that is still on the rise in Australia and the social burden associated with it can significantly cause low self-esteem and lack of confidence in personal body image in adulthood. Nonetheless, evidence-based prevention programs are not widely implemented in schools, even though they are commonplace for easy access to adolescents. The primary objective of this systematic review was to assess the scope and efficacy of adolescent obesity intervention strategies in Australian schools, to guide future research. Seven electronic databases were searched for peer-reviewed school-based intervention articles written in the English language and targeting 12-18-year-old adolescents. Intervention characteristics were extracted, and quality, efficacy and outcome measures were assessed utilizing thirteen studies that met the inclusion criteria for this review. Most of the Australian adolescent obesity research emanated from the State of New South Wales and none were nationwide. Five studies successfully met all the requirements in all measured outcomes, four met at least one measured outcome and the remaining four were unsuccessful. Despite the weak evidence of intervention efficacy for most of the reviewed studies, school-based interventions with multi-component combinations of physical activity, nutrition and alignment to a theory yielded promising results. Our findings point to the need for future research to assess the perceptions of school stakeholders in relation to the barriers and enablers to establishing school-based prevention and intervention programs for adolescents.

Does Weight Loss Improve Clinical Outcomes in Overweight and Obese Patients with Heart Failure?

PURPOSE OF REVIEW

Obesity increases the risk of new onset heart failure (HF), and particularly HF with preserved ejection fraction (HFpEF). Despite the observations of favorable clinical outcomes in HF patients with obesity in general, sometimes referred to as the "obesity paradox," it is important to recognize that severe obesity is associated with worse clinical outcomes. This review summarizes the effects of obesity treatment on cardiovascular health and HF clinical outcomes.

RECENT FINDINGS

Treatment for obesity utilizes a variety of modalities to achieve purposeful weight loss including lifestyle intervention, medications, and bariatric surgery. There are a cluster of benefits of obesity treatment in terms of clinical outcomes in HF. The mechanisms of these benefits include both weight loss-dependent and weight loss-independent mechanisms. Obesity treatment is safe and associated with favorable clinical outcomes across the spectrum of the HF population. The potential benefits are facilitated through multiple mechanisms.

Echocardiography in the Era of Obesity

Patients with obesity are at increased risk for coronary artery disease and heart failure and often present with symptoms of dyspnea, fatigue, edema, or chest pain. Echocardiography is frequently used to help distinguish whether these symptoms are due to cardiac disease. Unfortunately, obesity has a significant impact on image quality because of signal attenuation. Ultrasound-enhancing agents may improve the detection of structural remodeling and subclinical left ventricular dysfunction in patients with obesity. Assessment of chamber sizes and cardiac remodeling in severely obese subjects must be interpreted with caution, however, as the current recommendations for indexing cardiac chamber sizes to body size may lead to false conclusions about chamber volumes or mass, particularly in settings in which weight is changing. As a result of increases in stroke volume and cardiac output, obesity may exacerbate hemodynamic compromise in obstructive structural or valvular disease. With regard to assessment of ischemic heart disease, stress echocardiography can effectively risk-stratify patients with obesity and may have advantages over other noninvasive modalities. In general, transesophageal echocardiography is safe in patients with obesity, although some precautions should be observed. Stress echocardiography using the transesophageal approach is an alternative for preoperative or ischemia evaluation in patients with suboptimal transthoracic views.

Different Patterns of Left Ventricular Hypertrophy in Metabolically Healthy and Insulin-Resistant Obese Subjects

Obese subjects showed different cardiovascular risk depending by different insulin sensitivity status. We investigated the difference in left ventricular mass and geometry between metabolically healthy (MHO) and unhealthy (MUHO) obese subjects. From a cohort of 876 obese subjects (48.3 ± 14.1 years) without cardio-metabolic disease and stratified according to increasing values of Matsuda index after 75 g oral glucose tolerance test, we defined MHO (n = 292) those in the upper tertile and MUHO (n = 292) those in the lower tertile. All participants underwent echocardiographic measurements. Left ventricular mass was calculated by Devereux equation and normalized by height^2,7 and left ventricular hypertrophy (LVH) was defined by values >44 g/m^2.7 for females and >48 g/m^2.7 for males. Left ventricular geometric pattern was defined as concentric or eccentric if relative wall thickness was higher or lower than 0.42, respectively. MHO developed more commonly a concentric remodeling (19.9 vs. 9.9%; p = 0.001) and had a reduced risk for LVH (OR 0.46; p < 0.0001) than MUHO, in which the eccentric type was more prevalent (40.4 vs. 5.1%; p < 0.0001). We demonstrated that obese subjects-matched for age, gender and BMI-have different left ventricular mass and geometry due to different insulin sensitivity status, suggesting that diverse metabolic phenotypes lead to alternative myocardial adaptation.

Bariatric Surgery and the Risk of New-Onset Atrial Fibrillation in Swedish Obese Subjects

BACKGROUND

Obesity is a risk factor for atrial fibrillation, which in turn is associated with stroke, heart failure, and increased all-cause mortality.

OBJECTIVES

The authors investigated whether weight loss through bariatric surgery may reduce the risk of new-onset atrial fibrillation.

METHODS

SOS (Swedish Obese Subjects) is a prospective matched cohort study conducted at 25 surgical departments and 480 primary healthcare centers in Sweden. The cohort was recruited between 1987 and 2001. Among 4,021 obese individuals with sinus rhythm and no history of atrial fibrillation, 2,000 underwent bariatric surgery (surgery group), and 2,021 matched obese control subjects received usual care (control group). The outcome, first-time atrial fibrillation, was ascertained by crosschecking the SOS database with the Swedish National Patient Register on inpatient and outpatient diagnosis codes.

RESULTS

During a median follow-up of 19 years, first time atrial fibrillation occurred in 247 patients (12.4%) in the surgical group, and in 340 (16.8%) control subjects. The risk of developing atrial fibrillation was 29% lower in the surgery group versus the control group (hazard ratio: 0.71; 95% confidence interval: 0.60 to 0.83; p < 0.001). Younger individuals benefited more from surgical intervention than those who were older (p value for interaction 0.001). Also, those with a high diastolic blood pressure benefitted more from surgery than did those with a low diastolic blood pressure (p for interaction = 0.028).

CONCLUSIONS

Compared with usual care, weight loss through bariatric surgery reduced the risk of atrial fibrillation among persons being treated for severe obesity. The risk reduction was more apparent in younger people and in those with higher blood pressure.

Obesity and hypertensive heart disease: focus on body composition and sex differences

There is evidence that hypertension is frequently associated with overweight/obesity even in kids and adolescents. Either conditions influence development of left ventricular (LV) hypertrophy (LVH), through different biological and hemodynamic mechanisms: obesity is conventionally thought to elicit a coherent growth of LV chamber dimensions and myocardial wall thickness (eccentric LV geometry), whereas a more accentuated increase in wall-thickness (concentric LV geometry) is attributed to hypertension. While during youth these differences are visible, proportion of LV concentric geometry, the most harmful LV geometric pattern, sharply raises in obese individuals during middle age, and becomes the most frequent geometric patterns among obese-hypertensive individuals. Two conditions with elevated hemodynamic impact, severe obstructive sleep apnea and masked hypertension contribute to the development of such a geometric pattern, but non-hemodynamic factors, and specifically body composition, also influence prevalence of concentric LV geometry. Contrasting a general belief, it has been observed that adipose mass strongly influences LV mass, particularly in women, especially when fat-free mass is relatively deficient. Thus, though blood pressure control is mandatory for prevention and reduction of LVH in obese hypertensive patients, without reduction of visceral adiposity regression of LVH is difficult. Future researches should be addressed on (1) assessing whether LVH resulting from alteration of body composition carries the same prognosis as pressure overload LVH; (2) defining tissue characterization of the hypertrophic heart in obese-hypertensive patients; (3) evaluating whether assessment of hemodynamic loading conditions and biological markers can help defining management of the association of obesity with hypertension.

The presence and impact of diastolic dysfunction on physical function and body composition in hemodialysis patients

BACKGROUND

Cardiovascular (CV) diseases are the main cause of death in maintenance hemodialysis (MHD) patients. Muscle wasting and physical function decline are common in MHD patients, and significantly impair their quality of life. These can result from abnormalities in cardiac function, which can be further worsened by physical deconditioning. Left ventricular diastolic function parameters were recently shown to be a better predictor of exercise capacity than systolic measures in patients with CV complications. But little is known about the relationship between cardiac function and physical function in MHD patients.

METHODS

In 82 MHD patients, left ventricular systolic dysfunction (LVSD) was assessed by ejection fraction and fractional shortening with echocardiography, and left ventricular diastolic dysfunction (LVDD) was assessed by pulse wave and tissue Doppler indices. Physical function was assessed by gait speed, performance on a shuttle walk test, and leg muscle strength. Dual-emission X-ray absorptiometry (DXA) was used to measure whole body lean mass (WBLM).

RESULTS

The prevalence of LVDD and LVSD was 48.8 and 12.2%, respectively. Gait speed, shuttle walk time, leg strength, and WBLM% were significantly higher in the group without LVDD than with LVDD (p < 0.05 for all). However, there was no significant difference in any measure of physical function or body composition between patients with and without LVSD.

CONCLUSION

These data suggest that LVDD is more closely related to physical function and body composition than LVSD in MHD patients, and hence that LVDD may be an important therapeutic target.

Bariatric and metabolic surgery: a shift in eligibility and success criteria

The obesity epidemic, combined with the lack of available and effective treatments for morbid obesity, is a scientific and public health priority. Worldwide, bariatric and metabolic surgeries are increasingly being performed to effectively aid weight loss in patients with severe obesity, as well as because of the favourable metabolic effects of the procedures. The positive effects of bariatric surgery, especially with respect to improvements in type 2 diabetes mellitus, have expanded the eligibility criteria for metabolic surgery to patients with diabetes mellitus and a BMI of 30-35 kg/m(2). However, the limitations of BMI, both in the diagnosis and follow-up of patients, need to be considered, particularly for determining the actual adiposity and fat distribution of the patients following weight loss. Understanding the characteristics shared by bariatric and metabolic surgeries, as well as their differential aspects and outcomes, is required to enhance patient benefits and operative achievements. For a holistic approach that focuses on the multifactorial effects of bariatric and metabolic surgery to be possible, a paradigm shift that goes beyond the pure semantics is needed. Such a shift could lead to profound clinical implications for eligibility criteria and the definition of success of the surgical approach.

The impact of obesity on the relationship between epicardial adipose tissue, left ventricular mass and coronary microvascular function

Purpose

Epicardial adipose tissue (EAT) has been linked to coronary artery disease (CAD) and coronary microvascular dysfunction. However, its injurious effect may also impact the underlying myocardium. This study aimed to determine the impact of obesity on the quantitative relationship between left ventricular mass (LVM), EAT and coronary microvascular function.

Methods

A total of 208 (94 men, 45 %) patients evaluated for CAD but free of coronary obstructions underwent quantitative [¹⁵O]H₂O hybrid positron emission tomography (PET)/CT imaging. Coronary microvascular resistance (CMVR) was calculated as the ratio of mean arterial pressure to hyperaemic myocardial blood flow.

Results

Obese patients [body mass index (BMI) > 25, n = 133, 64 % of total] had more EAT (125.3 ± 47.6 vs 93.5 ± 42.1 cc, p < 0.001), a higher LVM (130.1 ± 30.4 vs 114.2 ± 29.3 g, p < 0.001) and an increased CMVR (26.6 ± 9.1 vs 22.3 ± 8.6 mmHg×ml⁻¹×min⁻¹×g⁻¹, p < 0.01) as compared to nonobese patients. Male gender (β = 40.7, p < 0.001), BMI (β = 1.61, p < 0.001), smoking (β = 6.29, p = 0.03) and EAT volume (β = 0.10, p < 0.01) were identified as independent predictors of LVM. When grouped according to BMI status, EAT was only independently associated with LVM in nonobese patients. LVM, hypercholesterolaemia and coronary artery calcium score were independent predictors of CMVR.

Conclusion

EAT volume is associated with LVM independently of BMI and might therefore be a better predictor of cardiovascular risk than BMI. However, EAT volume was not related to coronary microvascular function after adjustments for LVM and traditional risk factors.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-015-3087-5) contains supplementary material, which is available to authorized users.

Which measures of adiposity predict subsequent left ventricular geometry? Evidence from the Bogalusa Heart Study

BACKGROUND AND AIMS

Left ventricular (LV) hypertrophy increases the risk of future cardiovascular events. The relationship between obesity in young adulthood and later LV geometry is unknown. We examined the association between long-term changes in measures of adiposity and subsequent LV geometry among 1073 young adults from the Bogalusa Heart Study.

METHODS AND RESULTS

Echocardiography-measured LV geometry was classified into normal (N = 796), concentric remodeling (N = 124), eccentric hypertrophy (N = 99), and concentric hypertrophy (N = 54) by integrating relative wall thickness and LV mass index. The mean age of our population was 38 years when the LV geometry was measured. Body mass index (BMI) increased by a mean of 4.9 kg/m(2) over a median of 20 years, waist circumference (WC) by 10.9 cm over 17 years, waist/hip ratio by 0.02 over 10 years, waist/height ratio by 0.06 over 17 years, abdominal height by 0.9 cm over 10 years, body fat (BF) percentage by 12.7% over 20 years, and Visceral Adiposity Index by 0.30 over 17 years. In polytomous logistic regression models corrected for multiple comparisons, participants with one-standard-deviation increases in BMI, WC, waist/height ratio, and BF had 2.00 (95% confidence interval (CI): 1.53-2.61), 1.33 (1.06-1.68), 1.35 (1.07-1.70), and 1.60 (1.26-2.03) times the risk of eccentric hypertrophy, respectively, after adjustment for demographic, lifestyle, metabolic risk factors, and follow-up time. Likewise, the rates of change in BMI, WC, waist/height ratio, and BF were associated with eccentric hypertrophy. There was no association with concentric remodeling or concentric hypertrophy.

CONCLUSIONS

Our findings suggest that increases in BMI, WC, waist/height ratio, and BF were strong predictors of eccentric hypertrophy in middle age.

Nonalcoholic fatty liver disease as a potential risk factor of cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic component of the metabolic syndrome. The aim of this review is to summarize the available data linking NAFLD with cardiovascular disease (CVD). The following topics are reviewed: (a) the clinical evidence linking NAFLD to increased prevalence of CVD; (b) the relationship between NAFLD (which is diagnosed by liver biopsy, serum liver enzymes, or ultrasonography) and incidence of CVD; (c) the mechanism linking NAFLD to CVD and clinical implication; and (d) the potential impact of NAFLD treatment on cardiac complications. CVD dictates the outcome (or outcomes) in patients with NAFLD more frequently and to a greater extent than does the progression of liver disease. NAFLD patients have a higher risk of all-cause death than the general population, mainly because of CVD or liver-related causes. The biologic mechanism linking NAFLD and CVD might be associated with various factors, involving a complex interaction among insulin resistance, oxidative stress, abnormal adipocytokine profile, endothelial dysfunction, lipid abnormalities, and activation of inflammatory cascade. Lifestyle modifications and pharmacotherapy are helpful to treat patients with NAFLD. NAFLD is likely to be associated with an increased risk of CVD, and raises the possibility that NAFLD may not only be a marker but also an early mediator of CVD.

How to choose and use bariatric surgery in 2015

Severe obesity is associated with increased morbidity and mortality and represents a major health care problem with increasing incidence worldwide. Bariatric surgery, through its efficacy and improved safety, is emerging as an important available treatment for patients with severe obesity. Classically, bariatric surgery has been described as either a restrictive or a hybrid surgery, which is a combination of restriction and malabsorption. For most severely obese patients, bariatric surgery results in the remission of major obesity-related comorbidities including type 2 diabetes mellitus, sleep apnea, hypertension, and dyslipidemia. Thus, bariatric surgery reduces cardiovascular risk burden, and overall mortality risk. Early complications (< 30 days) after bariatric surgery were reported to be < 10% and tend to be lower in restrictive surgeries compared with hybrid surgeries. Most common early complications reported are gastric and anastomosis leak (1.6%-5.1%), bleeding (0.5%-3.5%), and pulmonary embolism (0.2%-1%). Long-term complications (> 30 days) might differ depending on the type of bariatric surgery. According to the type of surgery and the type of study, the 30-day operative mortality rates differ from 0.1% to 1.2%. Studies on postoperative outcomes, investigations on weight loss physiology, and mechanism of action after bariatric surgery provide a better understanding of the bariatric surgery metabolic benefits. In this article, we present an overview of bariatric procedures with their effects, including risks and benefits, on the severely obese patients' health. It provides evidence to support surgical treatment of severe obesity to achieve cardiovascular disease risk reduction in severely obese patients.

Carotid artery remodelling in relation to body fat distribution, inflammation and sustained weight loss in obesity

BACKGROUND

Obesity is known to be associated with carotid artery remodelling, but less is known about how body fat distribution, inflammation and weight loss may affect this relation.

METHODS

Ultrasonography, dual-energy X-ray absorptiometry and computed tomography were performed to evaluate carotid artery intima-media thickness (IMT), body composition and fat distribution, respectively. Participants were divided into three matched study groups (n = 44 per group): obese patients with sustained weight loss 10 years after bariatric surgery [surgery group, body mass index (BMI) 31.5 kg m(-2)]; obese patients who maintained stable weight during the same time period (obese group, BMI 42.5 kg m(-2)); and normal weight subjects (lean group, BMI 24.4 kg m(-2)).

RESULTS

Patients in the surgery group, compared with those in the obese group, had slightly lower common carotid artery (CCA) IMT (0.75 ± 0.18 vs. 0.78 ± 0.17 mm) and common carotid bulb (CCB) IMT (0.92 ± 0.32 vs. 0.97 ± 0.32 mm); however, these differences were not statistically significant. Lean individuals, compared with those in the surgery group, had significantly lower CCA and CCB IMT values (P < 0.001). In forward stepwise multiple regression analyses including all subjects (n = 132), CCA IMT was predicted mainly by visceral adipose tissue, but was also related to blood pressure and levels of triglycerides and high-sensitivity C-reactive protein. Carotid lumen diameter was primarily influenced by lean body mass.

CONCLUSION

Visceral adiposity was the main determinant of premature carotid artery atherosclerosis, possibly through elevated blood pressure, dyslipidaemia and inflammation. Lean body mass predicted carotid artery lumen diameter. Obese patients with long-term sustained weight loss did not have thinner carotid artery walls compared with their weight-stable obese counterparts.

Risk of cardiovascular, cardiac and arrhythmic complications in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a public health problem of epidemic proportions worldwide. Accumulating clinical and epidemiological evidence indicates that NAFLD is not only associated with liver-related morbidity and mortality but also with an increased risk of coronary heart disease (CHD), abnormalities of cardiac function and structure (e.g., left ventricular dysfunction and hypertrophy, and heart failure), valvular heart disease (e.g., aortic valve sclerosis) and arrhythmias (e.g., atrial fibrillation). Experimental evidence suggests that NAFLD itself, especially in its more severe forms, exacerbates systemic/hepatic insulin resistance, causes atherogenic dyslipidemia, and releases a variety of pro-inflammatory, pro-coagulant and pro-fibrogenic mediators that may play important roles in the pathophysiology of cardiac and arrhythmic complications. Collectively, these findings suggest that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions to decrease the risk for CHD and other cardiac/arrhythmic complications. The purpose of this clinical review is to summarize the rapidly expanding body of evidence that supports a strong association between NAFLD and cardiovascular, cardiac and arrhythmic complications, to briefly examine the putative biological mechanisms underlying this association, and to discuss some of the current treatment options that may influence both NAFLD and its related cardiac and arrhythmic complications.

'Adiposopathy' and cardiovascular disease: the benefits of bariatric surgery

PURPOSE OF REVIEW

Obesity is an independent risk factor for cardiovascular disease (CVD) and promotes CVD risk factors. Bariatric surgery has gained much favor because it ameliorates CVD. This review examines the current evidence for the mechanism behind this, which is currently thought to occur in part by reduction of adiposopathy, or dysfunctional adipose tissue, through modulation of adipokine secretion.

RECENT FINDINGS

Increased visceral fat in obesity leads to adiposopathy, due to the chronic inflammation present in this tissue. Bariatric surgery causes weight loss as well as reduction in insulin resistance, hypertension, dyslipidemia, cardiac hypertrophy, and mortality. It also causes changes in the adipokines adiponectin, leptin, and C-reactive protein, but not in tumor necrosis factor-α. These changes contribute to improved CVD risk, possibly through decrease of chronic inflammation.

SUMMARY

The modulations in adipokine secretion that occur after bariatric surgery are involved with reduction in CVD risk factors, CVD, and CV mortality. On the basis of the known anti-inflammatory effects of adiponectin and the pro-inflammatory effects of leptin and CRP, reduction in chronic inflammation associated with less visceral fat after surgery may contribute to the reduction in CVD. This may promote improvement of endothelial dysfunction and insulin resistance. Further work is necessary to explore these relationships.

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

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

Clues from bariatric surgery: reversing insulin resistance to heal the heart

Obesity is a state of metabolic dysregulation of the whole organism and a major contributing factor to the epidemic of insulin resistant diabetes. The nonpharmacologic treatment of obesity with bariatric surgery results in a dramatic and almost instantaneous reversal of insulin resistance. The present review collectively addresses the evidence for this phenomenon in the literature and discusses potential metabolic and neurohumoral mechanisms. We propose that nutrient restriction lowers the cell's defense mechanisms for nutrient overload in insulin responsive organs.

Review of the key results from the Swedish Obese Subjects (SOS) trial - a prospective controlled intervention study of bariatric surgery

Obesity is a risk factor for diabetes, cardiovascular disease events, cancer and overall mortality. Weight loss may protect against these conditions, but robust evidence for this has been lacking. The Swedish Obese Subjects (SOS) study is the first long-term, prospective, controlled trial to provide information on the effects of bariatric surgery on the incidence of these objective endpoints. The SOS study involved 2010 obese subjects who underwent bariatric surgery [gastric bypass (13%), banding (19%) and vertical banded gastroplasty (68%)] and 2037 contemporaneously matched obese control subjects receiving usual care. The age of participants was 37-60 years and body mass index (BMI) was ≥34 kg m(-2) in men and ≥38 kg m(-2) in women. Here, we review the key SOS study results published between 2004 and 2012. Follow-up periods varied from 10 to 20 years in different reports. The mean changes in body weight after 2, 10, 15 and 20 years were -23%, -17%, -16% and -18% in the surgery group and 0%, 1%, -1% and -1% in the control group respectively. Compared with usual care, bariatric surgery was associated with a long-term reduction in overall mortality (primary endpoint) [adjusted hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.54-0.92; P = 0.01] and decreased incidences of diabetes (adjusted HR=0.17; P < 0.001), myocardial infarction (adjusted HR = 0.71; P = 0.02), stroke (adjusted HR=0.66; P = 0.008) and cancer (women: adjusted HR = 0.58; P = 0.0008; men: n.s.]. The diabetes remission rate was increased severalfold at 2 years [adjusted odds ratio (OR) = 8.42; P < 0.001] and 10 years (adjusted OR = 3.45; P < 0.001). Whereas high insulin and/or high glucose at baseline predicted favourable treatment effects, high baseline BMI did not, indicating that current selection criteria for bariatric surgery need to be revised.