Surgical management of obesity and the relationship to cardiovascular disease

Impact of Bariatric Surgery on the Prevalence and Outcomes of Atrial Fibrillation in Obese Patients

Obesity has been identified as a significant factor contributing to the development of numerous cardiovascular conditions and as a result, the cardiovascular community has prioritized efforts to address obesity and reduce its associated risks. However, despite these efforts, the prevalence of obesity continues to rise steadily, and is projected to double in the upcoming years. Atrial fibrillation is among the most prevalent and extensively researched cardiovascular comorbidities associated with obesity. Several mechanisms have been postulated, including scar tissue formation and fat deposition, which ultimately leads to atrial remodeling and subsequent arrhythmogenesis. Numerous strategies have been implemented to prevent and manage obesity, encompassing lifestyle adjustments, dietary modifications, pharmacological treatments, and surgical interventions. Bariatric surgery has garnered significant recognition over the years due to its promising outcomes, including a decrease in the overall prevalence of atrial fibrillation and other cardiovascular comorbidities in general in obese patients. This study focuses on the current trends regarding the impact of bariatric surgery on obese patients with atrial fibrillation.

Despite regression of healthy lifestyle habits, weight loss after bariatric surgery is not affected during the COVID-19 pandemic

BACKGROUND

The coronavirus pandemic has caused a worldwide health crisis. Bariatric patients require extensive pre- and post-operative follow-up, which may be less feasible during public health social distancing mandates. We assessed the impact of the pandemic on the behaviors and weight loss outcomes of our pre- and post-operative bariatric patients.

METHODS

A retrospective review of a prospectively maintained database identified patients who underwent either sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) at a single institution between March 2018 and May 2020. A cohort undergoing surgery within 12 months before the pandemic as well as a cohort undergoing a medically supervised diet prior to surgery was surveyed regarding pre- and post-COVID-19 lifestyle habits. Excess weight loss (EWL) outcomes from a group of pre-COVID surgical patients were compared to that of a group of post-COVID surgical patients. Primary outcome was whether the lockdown changed 1-year weight loss outcomes. Secondary outcome was whether patient lifestyle behaviors were changed during the pandemic.

RESULTS

There was no difference in 1-year EWL between pre- and post-COVID SG patients (51.7% versus 55.9%, p = 0.35), or between pre- and post-COVID RYGB patients (88.9% versus 80.4%, p = 0.42). Pre-stay-at-home order, 91.8% endorsed physical activity compared to 80.3% post-stay-at-home order (p = 0.0025). Mean physical activity decreased from 4.2 h/week to 2.7 h/week after the stay-at-home order (p < 0.0001). Additionally, 41.3% reported worsened dietary habits post-stay-at-home order.

CONCLUSION

The COVID-19 pandemic has greatly impacted the behaviors of bariatric surgery patients. Despite deterioration of lifestyle habits, 1-year weight loss outcomes after bariatric surgery remained the same before and after the instatement of social distancing measures. In the short term, the biological effect of metabolic procedures may mask the effects of suboptimal diet and physical activity, but more studies are necessary to better assess the impact of COVID-19 on outcomes after bariatric surgery.

Rate of post-bariatric hypoglycemia using continuous glucose monitoring: A meta-analysis of literature studies

AIMS

Hypoglycemia is a serious complication of bariatric surgery. The aim of the present meta-analysis was to evaluate the rate and the timing of post-bariatric hypoglycemia (PBH) with different bariatric procedures using reliable data from continuous glucose monitoring (CGM).

DATA SYNTHESIS

Studies were systematically searched in the Web of Science, Scopus and PubMed databases according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The prevalence of PBH was expressed as weighted mean prevalence (WMP) with pertinent 95% confidence intervals (95%CI). A total of 8 studies (16 datasets) enrolling 280 bariatric subjects were identified. The total WMP of PBH was 54.3% (95%CI: 44.5%-63.8%) while the WMP of nocturnal PBH was 16.4% (95%CI: 7.0%-34%). We found a comparable rate of PBH after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) (OR 1.62, 95%CI: 0.71-3.7; P = 0.248); likewise, the percent time spent in hypoglycemia was similar with the two procedures (mean difference 5.3%, 95%CI: -1.4%-12.0%; P = 0.122); however, RYGB was characterized by a higher glycemic variability than SG. Regression models showed that the time elapsed from surgical intervention was positively associated with a higher rate of both total PBH (Z-value: 3.32, P < 0.001) and nocturnal PBH (Z-value: 2.15, P = 0.013).

CONCLUSIONS

PBH, both post-prandial and nocturnal, is more prevalent than currently believed. The rate of PBH increases at increasing time from surgery and is comparable after RYGB and SG with a higher glucose variability after RYGB.

OUP accepted manuscript

Aims

Obesity is a global health problem, associated with significant morbidity and mortality, often due to cardiovascular (CV) diseases. While bariatric surgery is increasingly performed in patients with obesity and reduces CV risk factors, its effect on CV disease is not established. We conducted a systematic review and meta-analysis to evaluate the effect of bariatric surgery on CV outcomes, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline.

Methods and results

PubMed and Embase were searched for literature until August 2021 which compared bariatric surgery patients to non-surgical controls. Outcomes of interest were all-cause and CV mortality, atrial fibrillation (AF), heart failure (HF), myocardial infarction, and stroke. We included 39 studies, all prospective or retrospective cohort studies, but randomized outcome trials were not available. Bariatric surgery was associated with a beneficial effect on all-cause mortality [pooled hazard ratio (HR) of 0.55; 95% confidence interval (CI) 0.49–0.62, P < 0.001 vs. controls], and CV mortality (HR 0.59, 95% CI 0.47–0.73, P < 0.001). In addition, bariatric surgery was also associated with a reduced incidence of HF (HR 0.50, 95% CI 0.38–0.66, P < 0.001), myocardial infarction (HR 0.58, 95% CI 0.43–0.76, P < 0.001), and stroke (HR 0.64, 95% CI 0.53–0.77, P < 0.001), while its association with AF was not statistically significant (HR 0.82, 95% CI 0.64–1.06, P = 0.12).

Conclusion

The present systematic review and meta-analysis suggests that bariatric surgery is associated with reduced all-cause and CV mortality, and lowered incidence of several CV diseases in patients with obesity. Bariatric surgery should therefore be considered in these patients.

Safety of Bariatric Surgery in Patients With Congestive Heart Failure: Results of an 11-Year Retrospective Study

INTRODUCTION

Congestive heart failure (CHF) is a known risk factor for increased postoperative morbidity. However, the safety in patients with CHF has not been well established. The objective of this study was to assess the safety of surgery in patients with a history of CHF undergoing bariatric surgical procedures.

METHODS

Retrospective review of a prospectively maintained Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) Center of Excellence database. Patients with known CHF undergoing bariatric procedures over an 11-year period were reviewed.

RESULTS

Over the 11-year period, 4470 total bariatric surgeries were performed, of which 41 (.92%) patients had known CHF. Twenty-one patients were men (51.2%) with a mean age of 55.8 years and mean body mass index (BMI) of 51.9. Comorbidities included hypertension (87.8%), obstructive sleep apnea (80.5%), osteoarthritis (63.4%), gastroesophageal reflux disease (56%), and diabetes (53.7%). Surgical procedures included 16 sleeve gastrectomies (SGs) (39%), 11 Roux-en-Y gastric bypasses (RYGBs) (26.8%), 10 laparoscopic adjustable gastric bands (LAGBs) (24.4%), 1 removal of a gastric band and conversion to SG (2.4%), 1 removal of a gastric band to RYGB (2.4%), 1 gastric band over RYGB pouch (2.4%), and 1 gastric band replacement (2.4%). All cases were performed minimally invasively (73.2% laparoscopic and 26.8% robotic). Mean LOS was 2.53 days. Thirty-day complications included 2 readmissions (4.9% [1 small bowel obstruction and 1 pulmonary edema]), 1 reoperation (2.4% [small bowel obstruction]), and 1 mortality (2.4%) on postoperative day 30 unrelated to the surgery.

CONCLUSIONS

Bariatric surgery can be performed safely in patients with CHF.

Bariatric Surgery Induces a Differential Effect on Plasma Aldosterone in Comparison to Dietary Advice Alone

BACKGROUND AND OBJECTIVES

The pathophysiological mechanisms linking weight loss to blood pressure (BP) reduction are not completely understood. The objective of this study was to compare the effect of weight loss after Roux-en-Y gastric bypass (RYGB) on BP, renin-angiotensin-aldosterone system (RAAS), and urinary electrolytes excretion to those of dietary advice.

METHODS

This was a case-control prospective study including obese patients referred for RYGB (cases) and obese receiving diet advice only (controls). Ambulatory BP, plasma renin activity (PRA), plasma aldosterone concentration (PAC), and urinary electrolytes were measured before (M0) and after intervention (M3: 3 months and M12: 12 months).

RESULTS

Twenty-five patients were included in the RYGB group and twelve patients in the control group. After 12 months, weight loss (-42 ± 11.5 vs -12.3 ± 6.3 kg in the control group, p=0.001) and decrease in PAC were more pronounced in the RYGB group (-34 ± 76 vs +14 ± 45 pg/ml in the control group, p=0.002). There was no difference in PRA between both groups (-0.08 ± 1.68 vs 0.01 ± 0.37 ng/ml/h, p=0.31). Sodium excretion was more marked in the RYGB group after 3 months only (-89 ± 14.9 vs -9.9 ± 27.9 mmol/day, p=0.009). The decrease in SBP was similar between both groups (-6.9 ± 9.9 vs -7.1 ± 11.9 mmHg in the control group, p=0.96).

CONCLUSIONS

Bariatric-induced weight loss induces a progressive decrease in PAC independently of PRA and sodium excretion. Whether this decrease in PAC affects target organ damage in the long term remains to be determined.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT02218112.

Continuous glucose monitoring in subjects undergoing bariatric surgery: Diurnal and nocturnal glycemic patterns

BACKGROUND AND AIMS

Although the use of Continuous Glucose Monitoring (CGM) is rapidly extending, little evidence is currently available on daily glycemic excursions after different bariatric procedures. We assessed glycemic patterns after sleeve gastrectomy (SG) and roux-en-Y gastric bypass (RYGB) using CGM.

METHODS AND RESULTS

Cross-sectional study in subjects who had undergone RYGB (n = 22) or SG (n = 29) since at least 1 year, without pre-surgery or in current diabetes (T2DM) remission. All subjects underwent 7 day-CGM (Dexcom G4 PLATINUM), which provides glucose variability (GV), number and time spent in hypoglycemia, hypoglycemia patterns (postprandial, nocturnal or mixed). All indexes of GV were higher after RYGB than after SG (p < 0.001). Twenty-eight (55%) subjects experienced hypoglycemia. The number of events was higher after RYGB than SG (p = 0.017) while it did not differ in subjects with or without pre-surgery T2DM (p = 0.129). Overall, 9 (32%) subjects presented hypoglycemia exclusively during the postprandial period, 8 (29%) an exclusively nocturnal pattern and 11 (39%) a mixed pattern. The nocturnal pattern was more frequent after SG than RYGB (53.8% vs 6.7%, p = 0.036) while no difference was observed in subjects with or without pre-surgery T2DM (p = 0.697). Hypoglycemia symptoms were more frequent in subjects with postprandial than in those with nocturnal pattern (77.8% vs 12.5%, p = 0.015).

CONCLUSIONS

RYGB is characterized by a greater GV and a higher number of hypoglycemia events mostly post-prandial and symptomatic, while SG is associated with nocturnal and often asymptomatic hypoglycemia. These findings suggest that post-bariatric hypoglycemia is a more complex, not exclusively, postprandial phenomenon.

The effect of a duodenal-jejunal bypass liner on lipid profile and blood concentrations of long chain polyunsaturated fatty acids

BACKGROUND & AIMS

Duodenal-jejunal bypass liners (DJBLs) prevent absorption in the proximal small intestine, the site of fatty acid absorption. We sought to investigate the effects of a DJBL on blood concentrations of essential fatty acids (EFAs) and bioactive polyunsaturated fatty acids (PUFAs).

METHODS

Sub-study of a multicentre, randomised, controlled trial with two treatment groups. Patients aged 18-65 years with type-2 diabetes mellitus and body mass index 30-50 kg/m² were randomised to receive a DJBL for 12 months or best medical therapy, diet and exercise. Whole plasma PUFA concentrations were determined at baseline, 10 days, 6 and 11.5 months; data were available for n = 70 patients per group.

RESULTS

Weight loss was significantly greater in the DJBL group compared to controls after 11.5 months: total body weight loss 11.3 ± 5.3% versus 6.0 ± 5.7% (mean difference [95% CI] = 5.27% [3.75, 6.80], p < 0.001). Absolute concentrations of both EFAs, linoleic acid and α-linolenic acid, and their bioactive derivatives, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, were significantly lower in the DJBL group than in the control group at 6 and 11.5 months follow-up. Total serum cholesterol, LDL-cholesterol and HDL-cholesterol were also significantly lower in the DJBL group.

CONCLUSION

One year of DJBL therapy is associated with superior weight loss and greater reductions in total serum cholesterol and LDL-cholesterol, but also depletion of EFAs and their longer chain derivatives. DJBL therapy may need to be offset by maintaining an adequate dietary intake of PUFAs or by supplementation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02459561.

The leptin to adiponectin ratio (LAR) is reduced by sleeve gastrectomy in adults with severe obesity: a prospective cohort study

Bariatric surgery is known to reduce leptin and increase adiponectin levels, but the influence of sleeve gastrectomy on the leptin: adiponectin ratio (LAR), a measure of insulin sensitivity and cardiovascular risk, has not previously been described. We sought to determine the influence of sleeve gastrectomy on LAR in adults with severe obesity.In a single centre prospective cohort study of adults undergoing laparoscopic sleeve gastrectomy over a four-month period in our unit, we measured LAR preoperatively and 12 months after surgery. Of 22 patients undergoing sleeve gastrectomy, 17 (12 females, 12 with type 2 diabetes) had follow-up LAR measured at 12.1 ± 1 months. Mean body weight decreased from 130.6 ± 30.8 kg to 97.6 ± 21.6 kg, body mass index (BMI) from 46.9 ± 7.8 to 35.3 ± 7.2 kg m^-2 and excess body weight from 87.5 ± 31.3 to 41.3 ± 28.8% (all p < 0.001). The reduction in leptin from 40.7 ± 24.9 to 30.9 ± 30.5 ng/ml was not significant (p = 0.11), but adiponectin increased from 4.49 ± 1.6 to 8.93 ± 6.36 µg/ml (p = 0.005) and LAR decreased from 8.89 ± 4.8 to 5.26 ± 6.52 ng/µg (p = 0.001), equivalent to a 70.9% increase in insulin sensitivity. The correlation with the amount of weight lost was stronger for LAR than it was for leptin or adiponectin alone. In this single-centre, interventional prospective cohort, patients undergoing laparoscopic sleeve gastrectomy had a substantial reduction in their LAR after 12 months which was proportional to the amount of weight lost. This may indicate an improvement in insulin sensitivity and a reduction in cardiovascular risk.

Safety of bariatric surgery in patients with coronary artery disease

BACKGROUND

Patients with obesity and established coronary artery disease (CAD) may benefit from surgical weight loss; however, its safety is unknown in this population.

OBJECTIVE

To assess the association between CAD and the incidence of 30-day postoperative mortality and major adverse cardiac events (MACEs) in patients undergoing bariatric surgery.

SETTINGS

Multicenter cohort study.

METHODS

We used the 2017 MBSAQIP database to study patients undergoing bariatric surgery from accredited centers in the United States and Canada between Jan 1, 2017, and Dec 31, 2017. Multivariate logistic regression was used to determine whether established CAD was independently associated with 30-day mortality and MACE, a composite endpoint that included myocardial infarction and/or cardiac arrest.

RESULTS

We reviewed data from 167,819 patients from 832 centers. There were 4172 patients with diagnosed CAD, and 163,647 without it. At 30-day follow-up, the endpoints of mortality, cardiac arrest, myocardial infarction, and MACE occurred in 172 (.10%), 82 (.05%), 57 (.03%), and 135 (.08%) patients, respectively. The endpoints occurred more significantly in patients with CAD compared with patients without CAD; 22 (.53%) versus 150 (.09%) for mortality, 13 (.31%) versus 69 (.04%) for cardiac arrest, 17 (.41%) versus 40 (.02%) for myocardial infarction, and 28 (.67%) versus 107 (.07%) for MACE (P < .001 for all comparisons).

CONCLUSIONS

Postoperative mortality and MACE following bariatric surgery are higher in patients with CAD than those without; however, the absolute incidence is low (<1%). The decision to pursue bariatric surgery and/or preoperative cardiac testing in patients with CAD should include consideration of the overall incidence of adverse cardiac outcomes and the stability of CAD.

Effect of Bariatric Surgery on Cardiovascular Function and Heart Failure Outcomes

In this article, we explore the influence of obesity on cardiovascular health and the role of bariatric surgery in reducing cardiovascular comorbidities, preventing the onset of heart failure and improving mortality and quality of life in those with cardiac dysfunction. We highlight the mechanisms by which obesity leads to cardiovascular remodeling, diastolic dysfunction, and eventual heart failure. These mechanisms include systemic inflammation, local lipotoxicity by way of ectopic fat deposition, and hemodynamic alterations that have significant effects on cardiac structure and function. Bariatric surgery has been shown to reverse these mechanisms, thereby leading to the reversal of adverse cardiac remodeling, improved diastolic function, and in some cases, improved systolic function in patients with systolic heart failure. Most importantly, bariatric surgery leads to significant improvements in cardiovascular outcomes, including the risks of myocardial infarction and stroke, heart failure incidence, and mortality. In patients with heart failure, bariatric surgery has been shown to decrease heart failure exacerbations and admissions and improve quality of life. Furthermore, in advanced heart failure patients, including those requiring mechanical circulatory support, bariatric surgery has been successfully and safely used for weight loss, as a bridge to cardiac transplantation. Therefore, bariatric surgery should be considered as a treatment for conditions ranging from subclinical cardiac dysfunction to symptomatic, advanced heart failure.

Impact of Metabolic Surgery on Type 2 Diabetes Mellitus, Cardiovascular Risk Factors, and Mortality: A Review

BACKGROUND

The association between obesity and a reduction in life expectancy is well established, and cardiovascular disease is a leading cause of mortality. Bariatric surgery has long been established as the most effective and durable intervention for obesity, and is the only intervention for obesity that consistently improves multiple comorbidities, reduces cardiovascular disease and long-term mortality. The purpose of this review is to describe the impact of metabolic/bariatric surgery on type 2 diabetes mellitus and cardiometabolic parameters, including cardiovascular mortality.

METHODS

A systematic literature search of Pubmed, MEDLINE, and Cochrane Central Register was performed. We included randomized controlled trials, meta-analysis, case-control trials, and cohort studies that contain data on reductions in cardiovascular risk factors and cardiovascular mortality in subjects who underwent metabolic/bariatric surgery from January 1, 2005 to June 1, 2020.

CONCLUSION

There is sufficient evidence from randomized controlled trials that metabolic/bariatric surgery is associated with a significant improvement of all cardiovascular risk factors. Although studies are showing a reduction of macrovascular events and cardiovascular mortality, these findings come from observational studies and should be confirmed in randomized clinical trials.

Bariatric Surgery as a Long-Term Treatment for Type 2 Diabetes/Metabolic Syndrome

Metabolic surgery is increasingly becoming recognized as a more effective treatment for patients with type 2 diabetes (T2D) and obesity as compared to lifestyle modification and medical management alone. Both observational studies and clinical trials have shown metabolic surgery to result in sustained weight loss (20–30%), T2D remission rates ranging from 23% to 60%, and improvement in cardiovascular risk factors such as hypertension and dyslipidemia. Metabolic surgery is cost-effective and relatively safe, with perioperative risks and mortality comparable to low-risk procedures such as cholecystectomy, hysterectomy, and appendectomy. International diabetes and medical organizations have endorsed metabolic surgery as a standard treatment for T2D with obesity.

A Population-Based Study of Early Postoperative Outcomes in Patients with Heart Failure Undergoing Bariatric Surgery

BACKGROUND

Weight loss following bariatric surgery can improve cardiac function among patients with heart failure (HF). However, perioperative morbidity of bariatric surgery has not been evaluated in patients with HF.

STUDY DESIGN

The National Surgical Quality Improvement Project (NSQIP) database for 2006-2014 was queried to identify patients undergoing adjustable gastric band, gastric bypass, sleeve gastrectomy, and biliopancreatic diversion-duodenal switch. Patients with HF were propensity matched to a control group without HF (1:5). Univariate analyses evaluated differences in complications, and multivariate analysis was completed to predict all-cause morbidity.

RESULTS

There were 237 patients identified with HF (mean age 52.8 years, 59.9% female, mean body mass index 50.6 kg/m²) matched to 1185 controls without HF who underwent bariatric surgery. Preoperatively, patients with HF were more likely to be taking antihypertensive medication and have undergone prior percutaneous cardiac intervention and cardiac surgery. There was no difference in operative time, surgical site infections, acute renal failure, re-intubation, or myocardial infarction. HF was associated with increased likelihood of length of stay more than 7 days, likelihood to remain ventilated > 48 h, venous thromboembolism, and reoperation. For patients with HF, the adjusted odds ratio for all-cause morbidity was 2.09 (1.32-3.22).

CONCLUSION

The NSQIP definition of HF, which includes recent hospitalization for HF exacerbation or new HF diagnosis 30 days prior to surgery, predicts a more than two-fold increase in odds of morbidity following bariatric surgery. This must be balanced with the longer-term potential benefits of weight loss and associated improvement in cardiac function in this population.

Metabolic Surgery: Weight Loss, Diabetes, and Beyond

The alarming rise in the worldwide prevalence of obesity is paralleled by an increasing burden of type 2 diabetes mellitus. Metabolic surgery is the most effective means of obtaining substantial and durable weight loss in individuals with obesity. Randomized trials have recently shown the superiority of surgery over medical treatment alone in achieving improved glycemic control, as well as a reduction in cardiovascular risk factors. The mechanisms seem to extend beyond the magnitude of weight loss alone and include improvements in incretin profiles, insulin secretion, and insulin sensitivity. Moreover, observational data suggest that the reduction in cardiovascular risk factors translates to better patient outcomes. This review describes commonly used metabolic surgical procedures and their current indications and summarizes the evidence related to weight loss and glycemic outcomes. It further examines their potential effects on cardiovascular outcomes and mortality and discusses future perspectives.

Effects of Bariatric Surgery on Cardiovascular Disease: A Concise Update of Recent Advances

Patients with obesity often have multiple cardiovascular comorbidities as obesity is an established risk factor for various cardiovascular diseases (CVDs)—e. g., heart failure (HF), coronary artery disease (CAD), hypertension, dysrhythmia, and venous thromboembolism. In the United States, obesity is the nationwide public health issue of the day with the prevalence exceeding 30%. It has become a substantial health and financial burden to the society and national healthcare system; the direct cost accounted for 150 billion US dollars in 2014. Lifestyle interventions have been shown to be successful in the short term, however their long-term results are still equivocal likely due to modest weight reduction and high recurrence rates. For instance, the mean weight reduction in a randomized controlled trial of patients with type 2 diabetes mellitus (DM) and either overweight or obesity was 6.0% in the intensive lifestyle modification arm and 3.5% in the control arm. On the contrary, bariatric surgery is known to be the most effective in achieving substantial and long-term weight loss and can prevent the development of CVD risk factors such as DM, hypertension, and dyslipidemia. Bariatric surgery induces prompt weight loss within a few months which lasts for at least 12–18 months, with mean weight loss of ~35% (~70% loss of excess weight), lowering the risk of all-cause mortality, myocardial infarction, and stroke. Furthermore, recent studies demonstrated that bariatric surgery contributed to the reduction of acute care use for HF, CAD, and hypertension. On the other hand, it was reported that bariatric surgery may worsen the control of certain types of CVD (e.g., dysrhythmia), especially in the early postoperative period. Additionally, the notion that being overweight or obese could contribute to higher survival rate in certain populations (e.g., patients with HF)—also known as “obesity paradox”—has been repetitively documented in the past, while most recent investigations suggested that the observed paradox may be attributable to confounding factors including pre-existing comorbidities. Considering the aforementioned advances in the field, this paper reviews a series of recent studies with regard to the short-term and long-term effects of bariatric surgery on various types of CVDs.

Reduced biliverdin reductase-A levels are associated with early alterations of insulin signaling in obesity

Biliverdin reductase-A (BVR-A) is a serine/threonine/tyrosine kinase involved in the regulation of insulin signaling. In vitro studies have demonstrated that BVR-A is a substrate of the insulin receptor and regulates IRS1 by avoiding its aberrant activation, and in animal model of obesity the loss of hepatic BVR-A has been associated with glucose/insulin alterations and fatty liver disease. However, no studies exist in humans. Here, we evaluated BVR-A expression levels and activation in peripheral blood mononuclear cells (PBMC) from obese subjects and matched lean controls and we investigated the related molecular alterations of the insulin along with clinical correlates. We showed that BVR-A levels are significantly reduced in obese subjects and associated with a hyper-activation of the IR/IRS1/Akt/GSK-3β/AS160/GLUT4 pathway. Low BVR-A levels also associate with the presence of obesity, metabolic syndrome, NASH and visceral adipose tissue inflammation. These data suggest that the reduction of BVR-A may be responsible for early alterations of the insulin signaling pathway in obesity and in this context may represent a novel molecular target to be investigated for the comprehension of the process of insulin resistance development in obesity.

Circulating ANGPTL8/Betatrophin Concentrations Are Increased After Surgically Induced Weight Loss, but Not After Diet-Induced Weight Loss

BACKGROUND

ANGPTL8/betatrophin is a secreted protein reported to be involved in β-cell replication that has recently been shown to be more related to lipid metabolism. Weight loss represents a clinical situation of improvement of glucose homeostasis and overall metabolic control. The aim of the present study was to analyze the impact of weight loss induced by either a conventional dietary treatment or bariatric surgery on ANGPTL8/betatrophin concentrations.

METHODS

Serum concentrations of ANGPTL8/betatrophin were measured by ELISA in 158 subjects before and 1 year after weight loss induced either by conventional dietary treatment (n = 38) or bariatric surgery (sleeve gastrectomy, n = 20, or Roux-en-Y gastric bypass, n = 100).

RESULTS

Massive surgery-induced weight loss after SG or RYGB was accompanied by a statistically significant increase in circulating levels of ANGPTL8/betatrophin (28.1 ± 13.9 to 40.3 ± 22.8 ng/mL, P = 0.001 after SG; 24.6 ± 10.9 to 41.7 ± 19.4 ng/mL, P < 0.001 after RYGB), while remaining unchanged 25.6 ± 13.3 to 25.4 ± 10.7 ng/mL (P = 0.891) after diet-induced weight loss. The change in ANGPTL8/betatrophin levels was positively correlated with the change in HDL-C concentrations.

CONCLUSIONS

Our study showed that serum ANGPTL8/betatrophin concentrations were increased in obese subjects after surgically induced weight loss, but not after weight loss achieved by conventional dietary treatment. The change in ANGPTL8/betatrophin concentrations emerged as a significant predictor of the change in HDL-C levels after weight loss.

A Murine Model of Vertical Sleeve Gastrectomy

Bariatric surgery, such as vertical sleeve gastrectomy (VSG), is a surgery of the gastrointestinal tract that is performed for the purpose of weight loss. Bariatric surgery is currently the most effective long-term treatment for obesity. In addition to weight loss, bariatric surgery produces additional health benefits such as remission of type 2 diabetes, remission of hypertension, and decreased risk of developing certain types of cancer. The mechanisms beyond weight loss for these benefits remain incompletely defined. Therefore, animal models of bariatric surgery are being developed and validated to identify the mechanisms leading to these benefits, with the goal of improving understanding of gastrointestinal physiology and identifying new therapeutic targets. VSG has become the most commonly performed bariatric procedure in the clinic in the United States because it is highly effective at producing weight loss and metabolic improvement, and is simpler to perform than other bariatric procedures. Therefore, we have developed and validated a murine model of VSG. This murine VSG model recapitulates many of the effects of VSG seen in humans, including improved glucose and blood pressure regulation. The method is based on isolation of the stomach, ligation of gastric vessels, and removal of 70% of the stomach by transecting along the greater curvature of the stomach. We have successfully applied this surgical protocol to various genetically modified mouse lines to define the mechanistic contributors to the benefits of VSG. Furthermore, this murine VSG model has been combined with other surgical techniques, to achieve deeper mechanistic insight. Therefore, this is a simple and versatile model for studying gastrointestinal physiology and the health benefits of bariatric surgery.

Management of cardiovascular diseases in patients with obesity

The management of cardiovascular diseases (CVD) in patients with obesity presents numerous challenges. Obesity has a negative effect on almost all of the major CVD risk factors, and adversely influences cardiovascular structure and function. Patients who are overweight or obese have a higher incidence of almost all CVDs compared with patients who are of normal weight. However, those who are overweight or obese seem to have a better short-term and medium-term prognosis after major CVD events and interventional procedures or cardiac surgeries than leaner patients, a phenomenon termed the 'obesity paradox'. In considering the mechanisms underlying this paradox, we review evidence of the deleterious consequences of obesity in patients with coronary heart disease, and the limited data on the benefits of weight loss in patients with CVD. Additional studies are needed on the efficacy of purposeful weight loss on cardiovascular outcomes to determine the ideal body composition for patients with CVD.

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.

Long-term effects of bariatric surgery on peripheral endothelial function and coronary microvascular function

BACKGROUND

We previously demonstrated that bariatric surgery (BS) leads to a short-term significant improvement of endothelial function and coronary microvascular function. In this study we assessed whether BS maintains its beneficial effect at long-term follow up.

DESIGN

We studied 19 morbidly obese patients (age 43±9years, 12 women) without any evidence of cardiovascular disease who underwent BS. Patients were studied before BS, at 3 months and at 4.0±1.5years follow up.

METHODS

Peripheral vascular function was assessed by flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD), i.e., brachial artery diameter changes in response to post-ischemic forearm hyperhaemia and to nitroglycerin administration, respectively. Coronary microvascular function was assessed by measuring coronary blood flow (CBF) response to intravenous adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery.

RESULTS

Together with improvement of anthropometric and metabolic profile, at long-term follow-up patients showed a significant improvement of FMD (6.43±2.88 vs. 8.21±1.73%, p=0.018), and CBF response to both adenosine (1.73±0.48 vs. 2.58±0.54; p<0.01) and CPT (1.43±0.30 vs. 2.23±0.48; p<0.01), compared to basal values. No differences in vascular end-points were shown at 3-month and 4-year follow-up after BS.

CONCLUSIONS

Our data show that, in morbidly obese patients, BS exerts beneficial and long lasting effects on peripheral endothelial function and on coronary microvascular dilator function.

An Untargeted Metabolomics Approach to Characterize Short-Term and Long-Term Metabolic Changes after Bariatric Surgery

Bariatric surgery is currently one of the most effective treatments for obesity and leads to significant weight reduction, improved cardiovascular risk factors and overall survival in treated patients. To date, most studies focused on short-term effects of bariatric surgery on the metabolic profile and found high variation in the individual responses to surgery. The aim of this study was to identify relevant metabolic changes not only shortly after bariatric surgery (Roux-en-Y gastric bypass) but also up to one year after the intervention by using untargeted metabolomics. 132 serum samples taken from 44 patients before surgery, after hospital discharge (1-3 weeks after surgery) and at a 1-year follow-up during a prospective study (NCT01271062) performed at two study centers (Austria and Switzerland). The samples included 24 patients with type 2 diabetes at baseline, thereof 9 with diabetes remission after one year. The samples were analyzed by using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS, HILIC-QExactive). Raw data was processed with XCMS and drift-corrected through quantile regression based on quality controls. 177 relevant metabolic features were selected through Random Forests and univariate testing and 36 metabolites were identified. Identified metabolites included trimethylamine-N-oxide, alanine, phenylalanine and indoxyl-sulfate which are known markers for cardiovascular risk. In addition we found a significant decrease in alanine after one year in the group of patients with diabetes remission relative to non-remission. Our analysis highlights the importance of assessing multiple points in time in subjects undergoing bariatric surgery to enable the identification of biomarkers for treatment response, cardiovascular benefit and diabetes remission. Key-findings include different trend pattern over time for various metabolites and demonstrated that short term changes should not necessarily be used to identify important long term effects of bariatric surgery.

Oxytocin and cardioprotection in diabetes and obesity

Oxytocin (OT) emerges as a drug for the treatment of diabetes and obesity. The entire OT system is synthesized in the rat and human heart. The direct myocardial infusion with OT into an ischemic or failing heart has the potential to elicit a variety of cardioprotective effects. OT treatment attenuates cardiomyocyte (CMs) death induced by ischemia-reperfusion by activating pro-survival pathways within injured CMs in vivo and in isolated cells. OT treatment reduces cardiac apoptosis, fibrosis, and hypertrophy. The OT/OT receptor (OTR) system is downregulated in the db/db mouse model of type 2 diabetes which develops genetic diabetic cardiomyopathy (DC) similar to human disease. We have shown that chronic OT treatment prevents the development of DC in the db/db mouse. In addition, OT stimulates glucose uptake in both cardiac stem cells and CMs, and increases cell resistance to diabetic conditions. OT may help replace lost CMs by stimulating the in situ differentiation of cardiac stem cells into functional mature CMs. Lastly, adult stem cells amenable for transplantation such as MSCs could be preconditioned with OT ex vivo and implanted into the injured heart to aid in tissue regeneration through direct differentiation, secretion of protective and cardiomyogenic factors and/or their fusion with injured CMs.

Clinical Outcomes of Metabolic Surgery: Efficacy of Glycemic Control, Weight Loss, and Remission of Diabetes

Since the 2007 Diabetes Surgery Summit in Rome, Italy, and the subsequent publishing of the world's first guidelines for the surgical treatment of type 2 diabetes (T2D), much new evidence regarding the efficacy and safety of metabolic surgery has emerged. Additional observational cohort studies support the superior effects of surgery over medical treatment with respect to glycemic control, weight loss, and even reduction in mortality and microvascular complications associated with T2D. Furthermore, new safety data suggest that the perioperative morbidity and mortality of metabolic surgery (5% and 0.3%, respectively) are now similar to that of common low-risk procedures, such as cholecystectomy and hysterectomy. The largest advance, however, has been the completion of 11 randomized controlled trials from around the globe that compare surgery with medical treatment of T2D. These studies with follow-up duration of 1-5 years involve nearly 800 patients without surgical mortality and with major complication rates of less than 5% and a reoperation rate of 8%. All but 1 of the 11 randomized controlled trials have shown the superiority of surgery over medical management at achieving remission or glycemic improvement. Surgery was also superior to medical treatment with respect to improving cardiovascular risk factors, such as weight loss and dyslipidemia, while reducing medication burden. This new efficacy and safety evidence should help guide physicians across the globe to the appropriate use of surgery as an effective treatment for patients suffering from T2D and obesity.

Bariatric Left Gastric Artery Embolization for the Treatment of Obesity: A Review of Gut Hormone Involvement in Energy Homeostasis

OBJECTIVE

The global population is becoming more overweight and obese, leading to increases in associated morbidity and mortality rates. Advances in catheter-directed embolotherapy offer the potential for the interventional radiologist to make a contribution to weight loss. Left gastric artery embolization reduces the supply of blood to the gastric fundus and decreases serum levels of ghrelin. Early evidence suggests that this alteration in gut hormone balance leads to changes in energy homeostasis and weight reduction. The pathophysiologic findings and current evidence associated with the use of left gastric artery embolization are reviewed.

CONCLUSION

The prevalence of obesity continues to increase at an alarming rate, and, thus far, advances in medical management have been relatively ineffective in slowing this trend. Lifestyle modifications such as diet and exercise are effective initially, but most patients regain the weight in the long term. Bariatric surgery is the most effective strategy for achieving long-term weight loss; however, as with all surgical procedures, it has potential complications.

Endoluminal vacuum therapy for gastrojejunal anastomotic leaks after Roux-en-Y gastric bypass: a pilot study in a swine model

BACKGROUND

Roux-en-Y gastric bypass (RYGB) consistently produces the most sustainable weight loss among common interventions for morbid obesity. Anastomotic leaks at the gastrojejunal (GJ) connection result in severe morbidity. We apply endoluminal negative pressure vacuum devices (EVD) to heal anastomotic leaks in a swine model.

METHODS

RYGB was performed in 10 pigs (3 control, 7 experimental). GJ anastomoses were fashioned, and a 2-cm defect was made across the staple line. In controls, the defects remained open. In experimental pigs, the EVD was placed across the defect and kept at continuous 50 mmHg suction. All pigs were euthanized on postoperative day seven unless they displayed signs of peritonitis or sepsis. Fluoroscopy and necropsy were performed to assess a persistent leak, and tissue specimens were sent to histology to evaluate for degree of inflammation and ischemia.

RESULTS

All three control pigs' GJ anastomoses demonstrated evidence of a persistent leak. All seven experimental pigs with the EVD in place showed evidence that their leak had sealed at time of fluoroscopy (p value 0.008).

CONCLUSIONS

Endoluminal vacuum therapy is well tolerated in a swine model. GJ anastomotic leaks were consistently sealed with our device in place compared to controls. This therapy shows promise as a method to address GJ leaks in the bariatric population, and thus, we believe additional evaluation is warranted.

Cardiometabolic Profile Related to Body Adiposity Identifies Patients Eligible for Bariatric Surgery More Accurately than BMI

BACKGROUND

Eligibility criteria for bariatric surgery (BS) are based on BMI and the presence of major comorbidities. Our aim was to analyze the usefulness of body adiposity determination in establishing the indication for BS.

METHODS

In order to analyze the cardiometabolic risk according to eligibility criteria for BS, four groups were studied. Morbidly obese patients with BMI ≥ 40 kg/m(2) (n = 360), and obese subjects with BMI ≥ 35 kg/m(2) and at least one comorbidity (n = 431), represented two groups of patients meeting original NIH criteria for BS. A third group included two cohorts of patients with a high body fat (BF)% that do not meet the original NIH eligibility criteria for BS: patients with either a BMI <35 kg/m(2) or a BMI ≥ 35 kg/m(2) without comorbidities (n = 266, NEHF). Lean subjects by BMI were the reference group (n = 140). BMI, BF% and markers of insulin sensitivity, lipid profile, and cardiovascular risk were measured.

RESULTS

Individuals from the NEHF group exhibited increased HbA1c (P < 0.05) and decreased insulin sensitivity evidenced by a significant reduction in QUICKI (P < 0.001). Triglyceride concentrations were similarly increased (P < 0.05) in the three groups of obese patients. Uric acid concentrations were significantly elevated (P < 0.01) to a similar extent in the obese groups. Levels of the inflammatory marker CRP and hepatic enzymes were significantly increased in the three obese groups.

CONCLUSION

The present study provides evidence for the existence of an adverse cardiometabolic profile in subjects currently considered to be outside traditional NIH guidelines but exhibiting a highly increased adiposity. It is concluded that body composition analysis yields valuable information to be incorporated into indication criteria for BS and that adiposity may be an independent indicator for BS.

Cardiovascular risk profile in Mediterranean patients submitted to bariatric surgery and intensive lifestyle intervention: impact of both interventions after 1 year of follow-up

BACKGROUND

The aim was to compare obesity-related cardiovascular (CV) risk factors (classic and emerging) and the estimated CV risk at 10 years (calculated by REGICOR) in obese Mediterranean patients submitted to bariatric surgery and intensive lifestyle intervention at baseline and after 1 year of follow-up.

METHODS

Patients submitted to bariatric surgery (n = 108) and standardized program of therapeutic changes in lifestyle (n = 90) were retrospectively included. Clinical history, physical examination, and laboratory analysis were routinely determined before weight loss intervention and at 1 year follow-up.

RESULTS

Seventy-five percent of the surgery patients had a CV risk lower than 5 % and not one patient had a 10-year CV risk higher than 15 %. The percentage of patients with comorbidities (diabetes and sleep apnea syndrome) was higher in the surgery group. Seventeen of the surgery patients had no comorbidities. The improvement in CV risk profile was significant higher in the surgery group. CV risk benefit of both intervention groups was related to baseline higher CV risk, with type 2 diabetes with poor metabolic control and high cholesterol levels being the most important predictors for surgery patients. Neither body mass index nor excess of weight loss was related to CV risk improvement.

CONCLUSIONS

Mediterranean patients undergoing a weight loss intervention have a low CV risk. In comparison with lifestyle intervention, surgery induces a better improvement of CV risk. This benefit is related to estimated CV risk, presence of diabetes, and cholesterol levels at baseline. These observations should be taken into account in order to optimize health resources.

Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence: A Scientific Statement From the American Heart Association and the American Diabetes Association

Cardiovascular disease risk factor control as primary prevention in patients with type 2 diabetes mellitus has changed substantially in the past few years. The purpose of this scientific statement is to review the current literature and key clinical trials pertaining to blood pressure and blood glucose control, cholesterol management, aspirin therapy, and lifestyle modification. We present a synthesis of the recent literature, new guidelines, and clinical targets, including screening for kidney and subclinical cardiovascular disease for the contemporary management of patients with type 2 diabetes mellitus.

Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence: A Scientific Statement From the American Heart Association and the American Diabetes Association

Cardiovascular disease risk factor control as primary prevention in patients with type 2 diabetes mellitus has changed substantially in the past few years. The purpose of this scientific statement is to review the current literature and key clinical trials pertaining to blood pressure and blood glucose control, cholesterol management, aspirin therapy, and lifestyle modification. We present a synthesis of the recent literature, new guidelines, and clinical targets, including screening for kidney and subclinical cardiovascular disease for the contemporary management of patients with type 2 diabetes mellitus.

Should the sympathetic nervous system be a target to improve cardiometabolic risk in obesity?

The sympathetic nervous system (SNS) plays a key role in both cardiovascular and metabolic regulation; hence, disturbances in SNS regulation are likely to impact on both cardiovascular and metabolic health. With excess adiposity, in particular when visceral fat accumulation is present, sympathetic activation commonly occurs. Experimental investigations have shown that adipose tissue releases a large number of adipokines, cytokines, and bioactive mediators capable of stimulating the SNS. Activation of the SNS and its interaction with adipose tissue may lead to the development of hypertension and end-organ damage including vascular, cardiac, and renal impairment and in addition lead to metabolic abnormalities, especially insulin resistance. Lifestyle changes such as weight loss and exercise programs considerably improve the cardiovascular and metabolic profile of subjects with obesity and decrease their cardiovascular risk, but unfortunately weight loss is often difficult to achieve and sustain. Pharmacological and device-based approaches to directly or indirectly target the activation of the SNS may offer some benefit in reducing the cardiometabolic consequences of obesity. Preliminary evidence is encouraging, but more trials are needed to investigate whether sympathetic inhibition could be used in obesity to reverse or prevent cardiometabolic disease development. The purpose of this review article is to highlight the current knowledge of the role that SNS plays in obesity and its associated metabolic disorders and to review the potential benefits of sympathoinhibition on metabolic and cardiovascular functions.

Clinical management of comorbid diabetes and psychotic disorders

Individuals with psychotic disorders experience substantial health disparities with respect to diabetes, including increased risk of incident diabetes and of poor diabetes outcomes (eg, diabetes complications and mortality). Low-quality medical care for diabetes is a significant contributor to these poor health outcomes. A thoughtful approach to both diabetes pharmacotherapy and drug management for psychotic disorders is essential, irrespective of whether treatment is given by a psychiatrist, a primary care provider, or an endocrinologist. Exposure to drugs with high metabolic liability should be minimised, and both psychiatric providers and medical providers need to monitor patients to ensure that medical care for diabetes is adequate. Promising models of care management and team approaches to coordination and integration of care highlight the crucial need for communication and cooperation among medical and psychiatric providers to improve outcomes in these patients. Evidence-based programmes that promote weight loss or smoking cessation need to be more accessible for these patients, and should be available in all the settings where they access care.

Bariatric surgery for metabolic syndrome in obesity

Metabolic syndrome is closely associated with morbid obesity and leads to increased risk of cardiovascular diseases and related mortality. Bariatric surgery is considered an effective option for the management of this condition. We searched MEDLINE, Current Contents, and the Cochrane Library for papers published on bariatric surgery outcomes in English from January 1, 1990, to April 20, 2014. Bariatric surgery can significantly reduce body weight, resolve or cure many of the symptoms of metabolic syndrome, including type 2 diabetes, hypertension, hyperlipidemia, and improve long-term survival. Surgery, in addition to existing therapy, could therefore be considered as an optimal treatment for patients with metabolic syndrome and morbid obesity.

Weight loss strategies for treatment of obesity

Obesity is one of the most serious and prevalent non-communicable diseases of the 21st century. It is also a patient-centered condition in which affected individuals seek treatment through a variety of commercial, medical and surgical approaches. Considering obesity as a chronic medical disease state helps to frame the concept of using a three-stepped intensification of care approach to weight management. As a foundation, all patients should be counseled on evidence-based lifestyle approaches that include diet, physical activity and behavior change therapies. At the second tier, two new pharmacological agents, phentermine-topiramate and lorcaserin, were approved in 2012 as adjuncts to lifestyle modification. The third step, bariatric surgery, has been demonstrated to be the most effective and long-term treatment for individuals with severe obesity or moderate obesity complicated by comorbid conditions that is not responsive to non-surgical approaches. By using a medical model, clinicians can provide more proactive and effective treatments in assisting their patients with weight loss.