Bariatric surgery and cardiovascular risk factors: a scientific statement from the American Heart Association

Timing of bariatric surgery in people with obesity and diabetes

The use of bariatric surgery in the clinical management of type 2 diabetes in severely obese subjects has been included in the clinical practice recommendations released by the most influential diabetologic associations. However, the timing during the diabetic course in which this use may have the better benefit/risk ratio remains debated. Is it better to use surgery very early in the course of the disease in order to anticipate clinical deterioration, or we should favour a delayed approach in which we reserve the more risky surgery only to patients not adequately controlled with the maximal pharmacologic strategy? In this paper, past and recent evidences about the role of bariatric surgery in the different stages of the clinical course of type 2 diabetes have been revised, starting from pre-diabetes and ending to long-standing diabetic state with established or end-stage macro- and micro-vascular complications. Available evidences strongly advocate in favor of the application of bariatric surgery in the early phase of this course, possibly in the pre-diabetic or in very early diabetic stages. To reserve surgery to more advanced and complicated stages of the disease seems to confer less benefits for the clinical course of diabetes and exposes these more frail patients to the possible side effects of a rapid weight loss.

Rapid and body weight-independent improvement of endothelial and high-density lipoprotein function after Roux-en-Y gastric bypass: role of glucagon-like peptide-1

BACKGROUND

Roux-en-Y gastric bypass (RYGB) reduces body weight and cardiovascular mortality in morbidly obese patients. Glucagon-like peptide-1 (GLP-1) seems to mediate the metabolic benefits of RYGB partly in a weight loss-independent manner. The present study investigated in rats and patients whether obesity-induced endothelial and high-density lipoprotein (HDL) dysfunction is rapidly improved after RYGB via a GLP-1-dependent mechanism.

METHODS AND RESULTS

Eight days after RYGB in diet-induced obese rats, higher plasma levels of bile acids and GLP-1 were associated with improved endothelium-dependent relaxation compared with sham-operated controls fed ad libitum and sham-operated rats that were weight matched to those undergoing RYGB. Compared with the sham-operated rats, RYGB improved nitric oxide (NO) bioavailability resulting from higher endothelial Akt/NO synthase activation, reduced c-Jun amino terminal kinase phosphorylation, and decreased oxidative stress. The protective effects of RYGB were prevented by the GLP-1 receptor antagonist exendin9-39 (10 μg·kg(-1)·h(-1)). Furthermore, in patients and rats, RYGB rapidly reversed HDL dysfunction and restored the endothelium-protective properties of the lipoprotein, including endothelial NO synthase activation, NO production, and anti-inflammatory, antiapoptotic, and antioxidant effects. Finally, RYGB restored HDL-mediated cholesterol efflux capacity. To demonstrate the role of increased GLP-1 signaling, sham-operated control rats were treated for 8 days with the GLP-1 analog liraglutide (0.2 mg/kg twice daily), which restored NO bioavailability and improved endothelium-dependent relaxations and HDL endothelium-protective properties, mimicking the effects of RYGB.

CONCLUSIONS

RYGB rapidly reverses obesity-induced endothelial dysfunction and restores the endothelium-protective properties of HDL via a GLP-1-mediated mechanism. The present translational findings in rats and patients unmask novel, weight-independent mechanisms of cardiovascular protection in morbid obesity.

Bari-Active: a randomized controlled trial of a preoperative intervention to increase physical activity in bariatric surgery patients

BACKGROUND

Habitual physical activity (PA) may help to optimize bariatric surgery outcomes; however, objective PA measures show that most patients have low PA preoperatively and make only modest PA changes postoperatively. Patients require additional support to adopt habitual PA. The objective of this study was to test the efficacy of a preoperative PA intervention (PAI) versus standard presurgical care (SC) for increasing daily moderate-to-vigorous PA (MVPA) in bariatric surgery patients.

METHODS

Outcomes analysis included 75 participants (86.7% women; 46.0±8.9 years; body mass index [BMI]=45.0±6.5 kg/m2) who were randomly assigned preoperatively to 6 weeks of PAI (n=40) or SC (n=35). PAI received weekly individual face-to-face sessions with tailored instruction in behavioral strategies (e.g., self-monitoring, goal-setting) to increase home-based walking exercise. The primary outcome, pre- to postintervention change in daily bout-related (≥10 min bouts) and total (≥1 min bouts) MVPA minutes, was assessed objectively via a multisensor monitor worn for 7 days at baseline- and postintervention.

RESULTS

Retention was 84% at the postintervention primary endpoint. In intent-to-treat analyses with baseline value carried forward for missing data and adjusted for baseline MVPA, PAI achieved a mean increase of 16.6±20.6 min/d in bout-related MVPA (baseline: 4.4±5.5 to postintervention: 21.0±21.4 min/d) compared to no change (-0.3±12.7 min/d; baseline: 7.9±16.6 to postintervention: 7.6±11.5 min/d) for SC (P=.001). Similarly, PAI achieved a mean increase of 21.0±26.9 min/d in total MVPA (baseline: 30.9±21.2 to postintervention: 51.9±30.0 min/d), whereas SC demonstrated no change (-0.1±16.3 min/d; baseline: 33.7±33.2 to postintervention: 33.6±28.5 minutes/d) (P=.001).

CONCLUSION

With behavioral intervention, patients can significantly increase MVPA before bariatric surgery compared to SC. Future studies should determine whether preoperative increases in PA can be maintained postoperatively and contribute to improved surgical outcomes.

If not dieting, how to lose weight? Tips and tricks for a better global and cardiovascular health

Weight loss is a popular topic and may be of serious concern for many patients. Even with the abundant literature on obesity and cardiometabolic risk, it is always challenging to demystify and reinforce the determinants of safe approaches to lose weight. Measures of central obesity are essential to characterize the patient's adiposity distribution and should be part of the routine medical examination. Beyond this, screening for fasting lipids and glucose are important for the assessment of the cardiometabolic risk which may lead to increased cardiovascular morbidity and mortality. Differences in adiposity as well as in weight loss exist between sexes and should be taken into consideration. Rather than avoiding some food or following certain type of diet, any planned weight loss interventions should promote lifestyle and environmental modifications with healthy eating and appropriate physical activity. With clear objectives, this appears to be the best way in order to achieve weight loss goals permanently.

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.

Cardiovascular disease prevention

Cardiovascular diseases remain the first killer in the Western countries. Equivalent contributions of prevention initiatives, pharmaceutical developments and technological improvements have led to an important success in the reduction of mortality related to cardiovascular diseases in some of the countries of the Western world. However, increase in life expectance, incomplete adherence to guidelines, difficulties in convincing governments and the population to support and adhere to prevention measures make that the burden of cardiovascular diseases is still extremely high. This review gives a restricted summary of the most important prevention guidelines supported by the European Society of Cardiology. It also illustrates the still very incomplete adherence to these guidelines in the different European countries as published in the EUROASPIRE surveys.

Laparoscopic gastric banding resolves the metabolic syndrome and improves lipid profile over five years in obese patients with body mass index 30-40 kg/m(2.)

BACKGROUND

Obesity, metabolic syndrome (MS) and dyslipidemia are independent risk factors for cardiovascular disease. Bariatric surgery is increasingly recognized as an effective intervention for improving each of these risk factors. There are sparse data on the long-term durability of metabolic changes associated with bariatric surgery, in particular with laparoscopic gastric banding (LGB). Our objective was to evaluate the durability of metabolic changes associated with LGB in nonmorbid obesity.

METHODS

Fifty obese patients (BMI 30-40) with ≥1 obesity-related comorbidity were prospectively followed for five years. At follow-up, subjects underwent fasting blood measures, including lipid NMR spectroscopy and standard lipid profile.

RESULTS

Forty-seven patients (45 female, mean age 43.8 years) completed four years follow-up (46 completed five years). Baseline BMI was 35.1 ± 2.6. Subjects exhibited mean weight loss of 22.3 ± 7.9 kg (22.9 ± 7.4%) at year one and maintained this (19.8 ± 10.2%) over five years. At baseline, 43% (20/47) of subjects met criteria for MS. This was reduced to 15% (7/47) at year one and remained reduced over five years (13%, 6/46) (p < 0.001). There were reductions in triglycerides (p < 0.001) and increases in HDL cholesterol (HDL-C, p < 0.001) and HDL particle concentration (p = 0.02), with a trend toward increased HDL particle size (p = 0.06) at year five. Changes in triglycerides and HDL-C were more prominent in patients with MS at baseline, but unassociated with weight loss or waist circumference. Changes in HDL particle size and concentration were not associated with MS status, weight loss, waist circumference, or statin use.

CONCLUSIONS

LGB produces significant weight loss, resolution of MS and changes in lipid profile suggestive of beneficial HDL remodeling. These changes persist five years following LGB.

Obesity and heart failure: epidemiology, pathophysiology, clinical manifestations, and management

Obesity is a risk factor for heart failure (HF) in both men and women. The mortality risk of overweight and class I and II obese adults with HF is lower than that of normal weight or underweight adults with HF of comparable severity, a phenomenon referred to as the obesity paradox. Severe obesity produces hemodynamic alterations that predispose to changes in cardiac morphology and ventricular function, which may lead to the development of HF. The presence of systemic hypertension, sleep apnea, and hypoventilation, comorbidities that occur commonly with severe obesity, may contribute to HF in such patients. The resultant syndrome is known as obesity cardiomyopathy. Substantial weight loss in severely obese persons is capable of reversing most obesity-related abnormalities of cardiac performance and morphology and improving the clinical manifestations of obesity cardiomyopathy.

Omentin changes following bariatric surgery and predictive links with biomarkers for risk of cardiovascular disease

BACKGROUND

Although no receptor has yet been identified, changes in circulating levels of the adipokine designated as Omentin have been demonstrated in obesity and related comorbidities such as cardiovascular disease, insulin resistance, metabolic syndrome and chronic inflammation.

METHODS

Changes in Omentin levels at 1 and 5 days and 6 and 12 months in response to biliopancreatic diversion with duodenal switch bariatric surgery were evaluated, specifically to investigate if changes preceded gain of insulin sensitivity.

RESULTS

Pre-operative plasma Omentin was not different between men (n = 18) vs women (n = 48), or diabetic status but correlated with body mass index (BMI). Altogether, Omentin increased as early as 24-h post-surgery, with changes maintained up to 1-year. Fifty-nine percent of subjects increased Omentin >10% by 24-H following surgery (OmentinINC p < 0.0001), while 18% of subjects decreased (OmentinDEC p < 0.0001), with changes maintained throughout one-year. These two groups had comparable age, sex distribution, diabetes, BMI, waist circumference and fat mass, however OmentinDEC had elevated levels of cardiovascular risk markers; homocysteine (p = 0.019), NT-proBNP (p = 0.006) and total bilirubin (p = 0.0001) while red blood cell (RBC) count was lower (p = 0.0005) over the one-year period. Omentin levels at 1-DAY also correlated with immune parameters (white blood cell count, % neutrophil, % monocytes, % lymphocytes).

CONCLUSION

OmentinDEC at 1 day following surgery may be a marker of cardiovascular "at-risk" group before weight loss or insulin sensitivity restoration.

Association between class III obesity (BMI of 40-59 kg/m2) and mortality: a pooled analysis of 20 prospective studies

BACKGROUND

The prevalence of class III obesity (body mass index [BMI]≥40 kg/m2) has increased dramatically in several countries and currently affects 6% of adults in the US, with uncertain impact on the risks of illness and death. Using data from a large pooled study, we evaluated the risk of death, overall and due to a wide range of causes, and years of life expectancy lost associated with class III obesity.

METHODS AND FINDINGS

In a pooled analysis of 20 prospective studies from the United States, Sweden, and Australia, we estimated sex- and age-adjusted total and cause-specific mortality rates (deaths per 100,000 persons per year) and multivariable-adjusted hazard ratios for adults, aged 19-83 y at baseline, classified as obese class III (BMI 40.0-59.9 kg/m2) compared with those classified as normal weight (BMI 18.5-24.9 kg/m2). Participants reporting ever smoking cigarettes or a history of chronic disease (heart disease, cancer, stroke, or emphysema) on baseline questionnaires were excluded. Among 9,564 class III obesity participants, mortality rates were 856.0 in men and 663.0 in women during the study period (1976-2009). Among 304,011 normal-weight participants, rates were 346.7 and 280.5 in men and women, respectively. Deaths from heart disease contributed largely to the excess rates in the class III obesity group (rate differences = 238.9 and 132.8 in men and women, respectively), followed by deaths from cancer (rate differences = 36.7 and 62.3 in men and women, respectively) and diabetes (rate differences = 51.2 and 29.2 in men and women, respectively). Within the class III obesity range, multivariable-adjusted hazard ratios for total deaths and deaths due to heart disease, cancer, diabetes, nephritis/nephrotic syndrome/nephrosis, chronic lower respiratory disease, and influenza/pneumonia increased with increasing BMI. Compared with normal-weight BMI, a BMI of 40-44.9, 45-49.9, 50-54.9, and 55-59.9 kg/m2 was associated with an estimated 6.5 (95% CI: 5.7-7.3), 8.9 (95% CI: 7.4-10.4), 9.8 (95% CI: 7.4-12.2), and 13.7 (95% CI: 10.5-16.9) y of life lost. A limitation was that BMI was mainly ascertained by self-report.

CONCLUSIONS

Class III obesity is associated with substantially elevated rates of total mortality, with most of the excess deaths due to heart disease, cancer, and diabetes, and major reductions in life expectancy compared with normal weight. Please see later in the article for the Editors' Summary.

Obesity Disease and Surgery

Obesity is a medical disease that is increasing significantly nowadays. Worldwide obesity prevalence doubled since 1980. Obese patients are at great risk for complications with physical and psychological burdens, thus affecting their quality of life. Obesity is well known to have higher risk for cardiovascular diseases, diabetes mellitus, musculoskeletal diseases and shorter life expectancy. In addition, obesity has a great impact on surgical diseases, and elective surgeries in comparison to general population. There is higher risk for wound infection, longer operative time, poorer outcome, and others. The higher the BMI (body mass index), the higher the risk for these complications. This literature review illustrates the prevalence of obesity as a diseases and complications of obesity in general as well as, in a surgical point of view, general surgery perioperative risks and complications among obese patients. It will review the evidence-based updates in these headlines.

Bariatric surgery in morbidly obese patients improves the atherogenic qualitative properties of the plasma lipoproteins

OBJECTIVE

The purpose of this study was to evaluate the effect of weight loss induced in morbidly obese subjects by Roux-en-Y gastric bypass bariatric surgery on the atherogenic features of their plasma lipoproteins.

METHODS

Twenty-one morbidly obese subjects undergoing bariatric surgery were followed up for up to 1 year after surgery. Plasma and lipoproteins were assayed for chemical composition and lipoprotein-associated phospholipase A2 (Lp-PLA2) activity. Lipoprotein size was assessed by non-denaturing polyacrylamide gradient gel electrophoresis, and oxidised LDL by ELISA. Liver samples were assayed for mRNA abundance of oxidative markers.

RESULTS

Lipid profile analysis revealed a reduction in the plasma concentrations of cholesterol and triglycerides, which were mainly associated with a significant reduction in the plasma concentration of circulating apoB-containing lipoproteins rather than with changes in their relative chemical composition. All patients displayed a pattern A phenotype of LDL subfractions and a relative increase in the antiatherogenic plasma HDL-2 subfraction (>2-fold; P < 0.001). The switch towards predominantly larger HDL particles was due to an increase in their relative cholesteryl ester content. Excess weight loss also led to a significant decrease in the plasma concentration of oxidised LDL (∼-25%; P < 0.01) and in the total Lp-PLA2 activity. Interestingly, the decrease in plasma Lp-PLA2 was mainly attributed to a decrease in the apoB-containing lipoprotein-bound Lp-PLA2.

CONCLUSION

Our data indicate that the weight loss induced by bariatric surgery ameliorates the atherogenicity of plasma lipoproteins by reducing the apoB-containing Lp-PLA2 activity and oxidised LDL, as well as increasing the HDL-2 subfraction.

Identifying Patients at Risk for High Medical Costs and Good Candidates for Obesity Intervention

Purpose.

To develop a risk-scoring tool to identify in a base year patients likely to have high medical spending in the subsequent year and to understand the role obesity and obesity reduction may play in mitigating this risk.

Design.

Cross-sectional analysis, using commercial claims and health risk assessment data.

Setting.

United States, 2004–2009.

Subjects.

Panel of 192,750 person-year observations from 116,868 unique working-age employees of large companies.

Measures.

Probability of high medical expenses (80th percentile or above) in the following year; adjusted body mass index (BMI).

Analysis.

Generate risk scores by modeling the likelihood of high next-year expenses as a function of base-year age, sex, medical utilization, comorbidities, and BMI. Estimate the effect of simulated bariatric intervention on patient risk scores.

Results.

Individuals with higher BMI were more likely to be categorized in the very high risk group, in which the average annual medical expense was $8621. A weight-loss intervention transitioning a patient to the next lower obesity class was predicted to reduce this risk by 1.5% to 27.4%—comparable to hypothetically curing a patient of depression or type 2 diabetes.

Conclusion.

A logistic model was used to capture the effect of BMI on the risk of high future medical spending. Weight-loss interventions for obese patients may generate significant savings by reducing this risk.

Acute post-bariatric surgery increase in orexin levels associates with preferential lipid profile improvement

Context

Orexin is a recently identified neuropeptide hormone.

Objectives

Acute and long-term post-bariatric changes in Orexin and relationship to post-operative metabolic outcomes.

Design and Participants

Men and women undergoing biliopancreatic diversion with duodenal switch bariatric surgery (n = 76, BMI≥35 kg/m²) were evaluated for body composition and plasma parameters at baseline, acutely (1 and 5 days) and long-term (6 and 12 months) post-surgery.

Setting

University Hospital Centre, Canada.

Interventions and Main Outcome Measures

Groups were subdivided based on acute (average 1 and 5 day) changes in Orexin prior to weight loss: (i)>10% Orexin decrease (n = 33, Orexin_DEC) and (ii)>10% Orexin increase (n = 20, Orexin_INC), to evaluate impact on long-term changes.

Results

Both groups had comparable preoperative Orexin levels, BMI, age, sex distribution, diabetes and lipid lowering medication, plasma glucose and lipid parameters except for apolipoproteinB (p<0.007). Orexin increase was rapid and maintained throughout one year, while Orexin_DEC subjects remained significantly lower throughout. Over 12 months, changes in BMI, fat mass, and %fat mass were comparable. Fasting glucose and insulin increased immediately 1-day post-operatively, decreasing rapidly (5-day) and declining thereafter with the Orexin_INC group remaining lower than the Orexin_DEC group throughout (p = 0.001). Similarly, plasma cholesterol, triglyceride, LDL-C and HDL-C decreased at 1-day, increased slightly (5-day), except HDL-C, then decreased over 1 year, with greater decreases in Orexin_INC group relative to Orexin_DEC group.

Conclusion

Rapid postoperative increases in plasma Orexin are associated with better improvement of glucose and lipid profiles following bariatric surgery.

Older adults fighting obesity with bariatric surgery: Benefits, side effects, and outcomes

The aging population is growing exponentially worldwide. Associated with this greater life expectancy is the increased burden of chronic health conditions, many of which are exacerbated by the continued rise in obesity. In the US, the prevalence of obesity in adults aged 60 years and older increased from 23.6% to 37% in 2010.

Changes in predicted cardiovascular disease risk after biliopancreatic diversion surgery in severely obese patients

OBJECTIVE

To determine the impact of biliopancreatic diversion with duodenal switch (BPD-DS) surgery on cardiovascular risk profile and predicted cardiovascular risk in severely obese patients.

MATERIALS/METHODS

We compared 1-year follow-up anthropometric and metabolic profiles in severely obese who underwent BPD-DS (n = 73) with controls (severely obese without surgery) (n =3 3). The 10-year predicted risk for coronary heart disease (CHD) was estimated using the Framingham risk-tool. We assigned 10-year and lifetime predicted risks to stratify subjects into 3 groups: 1) high short-term predicted risk (≥ 10% 10-year risk or diagnosed diabetes), 2) low short-term (<10% 10-year risk)/low lifetime predicted risk or 3) low short-term/high lifetime predicted risk.

RESULTS

During the follow-up period, body weight and body mass index decreased markedly in the surgical group (-52.1 ± 1.9 kg and -19.0 ± 0.6 kg/m(2) respectively, p<0.001) vs. (-0.7 ± 1.0 kg and -0.3 ± 0.4 kg/m(2), p = 0.51). Weight loss in the surgical group was associated with a reduction in HbA1C (6.2% vs. 5.1%), HOMA-IR (61.5 vs. 9.3), all lipoprotein levels, as well as blood pressure (p<0.001). The 10-year CHD predicted risk decreased by 43% in women and 33% in men, whereas the estimated CHD risk in the non surgical group did not change. Before surgery, none of the women and only 18% of men showed low short-term/low lifetime predicted risk, whereas a significant proportion of subjects had high short-term predicted risk (36% in women and 12% in men). Following surgery, 52% of women and 55% of men have a low short-term/low lifetime predicted risk.

CONCLUSIONS

These results highlight the cardiovascular benefits of BPD-DS and suggest a positive impact on predicted CHD risk in severely obese patients. Long-term studies are needed to confirm our results and to ascertain the effects on CHD risk estimates after BPD-DS surgery.

Blood pressure assessment in severe obesity: validation of a forearm approach

OBJECTIVE

Obesity is frequently associated with systemic hypertension. Blood pressure measure is inaccurate in severely obese patients because of poor cuff size fitting. The aim of the study is to assess the degree of agreement between the intra-arterial method as the gold standard vs. noninvasive methods, i.e., forearm blood pressure and upper-arm blood pressure measures.

DESIGN AND METHODS

A total of 1285 measures of intra-arterial and forearm blood pressure were taken in 51 severely obese patients in a supine position in the operating and the recovery room. A subset of 352 upper-arm measures were taken in the recovery room and compared to the intra-arterial and the forearm methods.

RESULTS

Correlation between the intra-arterial and the forearm measures was 0.90 (P < 0.001) for the 2570 data (systolic and diastolic). Compared to intra-arterial, the forearm method overestimated systolic (6 ± 16 mm Hg, P < 0.001) and underestimated diastolic blood pressure (2 ± 11 mm Hg, P = 0.03). Compared to intra-arterial, upper-arm underestimated systolic (8 ± 16 mm Hg, P < 0.01) and overestimated diastolic blood pressure (9 ± 7 mm Hg, P < 0.001).

CONCLUSION

The magnitude of differences between the intra-arterial and forearm method was less than differences between the intra-arterial and upper-arm method. Our results suggest that forearm method may be a more accurate alternative to upper-arm measurement to assess blood pressure in severely obese patients.

Jejunoileal bypass as the main procedure in the onset of immune-related conditions: the model of BADAS

Bariatric surgery represents a common approach for the control of severe morbid obesity, reducing caloric intake by modifying the anatomy of the gastrointestinal tract. Following jejunoileal bypass, a large spectrum of complications has been described, with rheumatic manifestation present in up to 20% of cases. Although bowel bypass syndrome, also called blind loop syndrome, is a well-recognized complication of jejunoileal bypass, the same syndrome was recognized in patients who had not had intestinal bypass surgery, and the term the 'bowel-associated dermatosis-arthritis syndrome' (BADAS) was coined. The pathogenesis of BADAS is as yet poorly understood and only few data concerning this issue have been published in the literature. The aim of the present paper is to review the literature and to discuss putative pathogenic mechanisms of BADAS, focusing on the immune system.

Overview of epidemiology and contribution of obesity to cardiovascular disease

The prevalence of obesity has increased worldwide and is a source of concern since the negative consequences of obesity start as early as in childhood. The most commonly used anthropometric tool to assess relative weight and classify obesity is the body mass index (BMI); BMI alone shows a U- or a J-shaped association with clinical outcomes and mortality. Such an inverse relationship fuels a controversy in the literature, named the 'obesity paradox', which associates better survival and fewer cardiovascular (CV) events in patients with elevated BMI afflicted with chronic diseases compared to non-obese patients. However, BMI cannot make the distinction between an elevated body weight due to high levels of lean vs. fat body mass. Generally, an excess of body fat (BF) is more frequently associated with metabolic abnormalities than a high level of lean body mass. Another explanation for the paradox is the absence of control for major individual differences in regional BF distribution. Adipose tissue is now considered as a key organ regarding the fate of excess dietary lipids, which may determine whether or not body homeostasis will be maintained (metabolically healthy obesity) or a state of inflammation/insulin resistance will be produced, with deleterious CV consequences. Obesity, particularly visceral obesity, also induces a variety of structural adaptations/alterations in CV structure/function. Adipose tissue can now be considered as an endocrine organ orchestrating crucial interactions with vital organs and tissues such as the brain, the liver, the skeletal muscle, the heart and blood vessels themselves. Thus, the evidence reviewed in this paper suggests that adipose tissue quality/function is as important, if not more so, than its amount in determining the overall health and CV risks of overweight/obesity.

Bariatric surgery versus non-surgical treatment for obesity: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To quantify the overall effects of bariatric surgery compared with non-surgical treatment for obesity.

DESIGN

Systematic review and meta-analysis based on a random effects model.

DATA SOURCES

Searches of Medline, Embase, and the Cochrane Library from their inception to December 2012 regardless of language or publication status.

ELIGIBILITY CRITERIA

Eligible studies were randomised controlled trials with ≥ 6 months of follow-up that included individuals with a body mass index ≥ 30, compared current bariatric surgery techniques with non-surgical treatment, and reported on body weight, cardiovascular risk factors, quality of life, or adverse events.

RESULTS

The meta-analysis included 11 studies with 796 individuals (range of mean body mass index at baseline 30-52). Individuals allocated to bariatric surgery lost more body weight (mean difference -26 kg (95% confidence interval -31 to -21)) compared with non-surgical treatment, had a higher remission rate of type 2 diabetes (relative risk 22.1 (3.2 to 154.3) in a complete case analysis; 5.3 (1.8 to 15.8) in a conservative analysis assuming diabetes remission in all non-surgically treated individuals with missing data) and metabolic syndrome (relative risk 2.4 (1.6 to 3.6) in complete case analysis; 1.5 (0.9 to 2.3) in conservative analysis), greater improvements in quality of life and reductions in medicine use (no pooled data). Plasma triglyceride concentrations decreased more (mean difference -0.7 mmol/L (-1.0 to -0.4) and high density lipoprotein cholesterol concentrations increased more (mean difference 0.21 mmol/L (0.1 to 0.3)). Changes in blood pressure and total or low density lipoprotein cholesterol concentrations were not significantly different. There were no cardiovascular events or deaths reported after bariatric surgery. The most common adverse events after bariatric surgery were iron deficiency anaemia (15% of individuals undergoing malabsorptive bariatric surgery) and reoperations (8%).

CONCLUSIONS

Compared with non-surgical treatment of obesity, bariatric surgery leads to greater body weight loss and higher remission rates of type 2 diabetes and metabolic syndrome. However, results are limited to two years of follow-up and based on a small number of studies and individuals.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42012003317 (www.crd.york.ac.uk/PROSPERO).

Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association

Severe obesity afflicts between 4% and 6% of all youth in the United States, and the prevalence is increasing. Despite the serious immediate and long-term cardiovascular, metabolic, and other health consequences of severe pediatric obesity, current treatments are limited in effectiveness and lack widespread availability. Lifestyle modification/behavior-based treatment interventions in youth with severe obesity have demonstrated modest improvement in body mass index status, but participants have generally remained severely obese and often regained weight after the conclusion of the treatment programs. The role of medical management is minimal, because only 1 medication is currently approved for the treatment of obesity in adolescents. Bariatric surgery has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage. To begin to address these challenges, the purposes of this scientific statement are to (1) provide justification for and recommend a standardized definition of severe obesity in children and adolescents; (2) raise awareness of this serious and growing problem by summarizing the current literature in this area in terms of the epidemiology and trends, associated health risks (immediate and long-term), and challenges and shortcomings of currently available treatment options; and (3) highlight areas in need of future research. Innovative behavior-based treatment, minimally invasive procedures, and medications currently under development all need to be evaluated for their efficacy and safety in this group of patients with high medical and psychosocial risks.

A systematic review of musculoskeletal pain among bariatric surgery patients: implications for physical activity and exercise

BACKGROUND

Physical activity (PA) can play an integral role in protecting the success of bariatric surgery by promoting weight loss and preventing weight regain. Although engagement in PA before surgery predicts postoperative PA levels, this may be undermined by weight-related co-morbidities. The importance of preoperative and postoperative musculoskeletal pain as a limitation to PA is unknown. The objective of this study was to review evidence on preoperative and postoperative pain in bariatric surgery patients, summarize the relationship between musculoskeletal pain and PA, and discuss areas of future research.

METHODS

The MEDLINE database was searched for published articles on musculoskeletal pain in bariatric surgery patients from January 1946 through December 2012. Outcomes of interest included preoperative pain prevalence, postoperative pain prevalence and incidence, and preoperative to postoperative changes in pain.

RESULTS

Preoperative musculoskeletal pain is highly common among candidates for bariatric surgery. Most individuals with presurgical pain experience significant improvement postoperatively. However, the characteristics of pain sufferers vary and few risk factors have been identified. New pain issues that present postsurgically are limited primarily to neurologic complications and are not common. To date, no study has tested the hypothesis that pain is a barrier to PA levels in bariatric surgery patients.

CONCLUSIONS

Gaps in knowledge regarding pain in bariatric surgery patients may present challenges for clinicians and exercise professionals on how to best advise patients about increasing their PA. Future research should include prospective evaluation of musculoskeletal pain via validated measures at multiple time points. This data will inform the time course of pain resolution, potential onset, and correlation with surgical weight loss.

Ectopic fat: the true culprit linking obesity and cardiovascular disease?

Obesity is a major risk factor for cardiovascular disease and its complications. However, not all fat depots share the same characteristics. Recent studies have found that ectopic rather than subcutaneous fat accumulation is associated with increased cardiometabolic risk. However, ectopic fat accumulation can be seen initially as a protective mechanism against lipotoxicity. Subsequently the adipose tissue becomes dysfunctional, thus inducing systemic metabolic alterations (through release of cytokines) or specific organ dysfunctions. The purpose of this review is to summarise the current available data on the impact of excess adiposity vs ectopic fat in the development of cardio-metabolic diseases.

Reduction in Framingham risk of cardiovascular disease in obese patients undergoing laparoscopic adjustable gastric banding

Background

Obesity is a major risk factor for cardiovascular disease (CVD), with weight loss offering improvement in CVD risk factors.

Aims

To examine whether weight loss in laparoscopic adjustable gastric band (LAGB)-treated obese patients is associated with meaningful reductions in estimated 10- and 30- year Framingham CVD risk 12–15 months post-LAGB.

Methods

Obese adult patients [body mass index (BMI) ≥30 kg/m²] treated with LAGB were identified in a large US healthcare database. Patients without CVD at baseline and with measures of BMI, systolic blood pressure, diabetes, and smoking status at baseline and follow-up were eligible. Non-LAGB patients were propensity score matched to LAGB patients on baseline BMI, age, and gender. Estimated 10- and 30-year risk of developing CVD using office-based data, including BMI, was calculated at baseline and 12–15 months follow-up.

Results

Mean BMI in LAGB patients (n = 647, average age 45.66 years, 81.1% female) decreased from 42.7 to 33.4 kg/m² (P < 0.0001), with 35.4% no longer obese; 10- and 30-year estimated CVD risk decreased from 10.8 to 7.6% (P < 0.0001) and 44.34 to 32.30% (P < 0.0001), respectively, 12–15 months post-LAGB. Improvements were significantly greater than in non-LAGB patients (N = 4,295) (P < 0.0001). In the subset with lipid data (n = 74), improvements in total (−20.6 mg/dL; P < 0.05) and high-density lipoprotein (+10.6 mg/dL, P < 0.0001) cholesterol 1 year post-LAGB were also observed.

Conclusions

Data from a US healthcare database show that individuals undergoing LAGB have significant weight loss and reductions in estimated 10- to 30-year CVD risk within 1 year post-LAGB.

Effects of bariatric surgery on human small artery function: evidence for reduction in perivascular adipocyte inflammation, and the restoration of normal anticontractile activity despite persistent obesity

Objectives

The aim of this study was to investigate the effects of bariatric surgery on small artery function and the mechanisms underlying this.

Background

In lean healthy humans, perivascular adipose tissue (PVAT) exerts an anticontractile effect on adjacent small arteries, but this is lost in obesity-associated conditions such as the metabolic syndrome and type II diabetes where there is evidence of adipocyte inflammation and increased oxidative stress.

Methods

Segments of small subcutaneous artery and perivascular fat were harvested from severely obese individuals before (n = 20) and 6 months after bariatric surgery (n = 15). Small artery contractile function was examined in vitro with wire myography, and perivascular adipose tissue (PVAT) morphology was assessed with immunohistochemistry.

Results

The anticontractile activity of PVAT was lost in obese patients before surgery when compared with healthy volunteers and was restored 6 months after bariatric surgery. In vitro protocols with superoxide dismutase and catalase rescued PVAT anticontractile function in tissue from obese individuals before surgery. The improvement in anticontractile function after surgery was accompanied by improvements in insulin sensitivity, serum glycemic indexes, inflammatory cytokines, adipokine profile, and systolic blood pressure together with increased PVAT adiponectin and nitric oxide bioavailability and reduced macrophage infiltration and inflammation. These changes were observed despite the patients remaining severely obese.

Conclusions

Bariatric surgery and its attendant improvements in weight, blood pressure, inflammation, and metabolism collectively reverse the obesity-induced alteration to PVAT anticontractile function. This reversal is attributable to reductions in local adipose inflammation and oxidative stress with improved adiponectin and nitric oxide bioavailability.

Exercise improves cardiac autonomic function in obesity and diabetes

Physical activity is a key element in the prevention and management of obesity and diabetes. Regular physical activity efficiently supports diet-induced weight loss, improves glycemic control, and can prevent or delay type 2 diabetes diagnosis. Furthermore, physical activity positively affects lipid profile, blood pressure, reduces the rate of cardiovascular events and associated mortality, and restores the quality of life in type 2 diabetes. However, recent studies have documented that a high percentage of the cardiovascular benefits of exercise cannot be attributed solely to enhanced cardiovascular risk factor modulation. Obesity in concert with diabetes is characterized by sympathetic overactivity and the progressive loss of cardiac parasympathetic influx. These are manifested via different pathogenetic mechanisms, including hyperinsulinemia, visceral obesity, subclinical inflammation and increased thrombosis. Cardiac autonomic neuropathy is an underestimated risk factor for the increased cardiovascular morbidity and mortality associated with obesity and diabetes. The same is true for the role of physical exercise in the restoration of the heart cardioprotective autonomic modulation in these individuals. This review addresses the interplay of cardiac autonomic function in obesity and diabetes, and focuses on the importance of exercise in improving cardiac autonomic dysfunction.

Five-year changes in psychiatric treatment status and weight-related comorbidities following bariatric surgery in a veteran population

BACKGROUND

Although bariatric surgery is an established treatment for obesity, less is known regarding the long-term effects of surgery on psychiatric function. This paper reports changes in psychiatric treatment status, weight, and weight-related comorbidities over 5 years of follow-up among a population of veterans completing bariatric surgery.

METHODS

We assessed 55 veterans undergoing bariatric surgery at a single Veteran Affairs medical center for 5 years post-surgery. Patients completed a pre-surgery clinical interview with a licensed psychologist. Using computerized medical records, we tracked pre- to post-surgery involvement with antidepressants, anxiolytics, psychotherapies, and overall psychiatric treatment visits along with changes in weight and metabolic function.

RESULTS

Rates of antidepressant use and/or involvement with psychotherapy for depression declined from 56.4 % at pre-surgery to 34.6 % at 5 years post-surgery, p = 0.01. Anxiolytic use and/or involvement with psychotherapy for anxiety, however, increased from 23.6 to 32.7 % pre- to 5 years post-surgery. Average psychiatric treatment volume remained similar to pre-surgery status across follow-up. These mixed indicators of psychiatric improvement occurred despite marked metabolic improvements from surgery. Mean percent excess weight loss = 51.7 and 41.3 (1 and 5 years post-surgery, respectively), systolic blood pressure (-6.8 mmHg (14.3)/-6.1 mmHg (12.8), respectively), glucose levels (-18.6 mg/dL (30.2)/-10.0 mg/dL (25.9), respectively), triglycerides (-78.2 mg/dL (96.7)/-69.1 mg/dL (102.2), respectively) and high-density lipoproteins (+7.1 (9.9)/+11.3 (11.3), respectively) levels each improved.

CONCLUSIONS

We report evidence of decreased antidepressant use and depression therapies following bariatric surgery, but no improvements on rates of anxiolytic use and anxiety therapies or on overall psychiatric treatment involvement. Despite metabolic improvements, bariatric patients with psychiatric histories may warrant ongoing attention to mental health.

[Metabolic effects of bariatric surgery]

Bariatric surgery managing/preventing complications of severe overweight is nowadays widely accepted as a mainstay in the treatment of morbid obesity. Its role is particularly important in type 2 diabetes developing on the base of long-standing significant overweight. The glycemic control improves within days-weeks after these surgeries, when weight loss and reduction of the visceral fat mass is barely detectable. This short term effect is probably due to an increased secretion of glucagon-like peptide and, as a consequence, an improvement in hepatic insulin sensitivity as well as the whole body glucose uptake. Besides the prolonged glucagon-like peptide effects, the favourable long term effect of these operations - lasting for 10 years even after surgery - is the decrease of visceral fat mass and elimination of harmful influence of cytokines produced by the fatty tissue. The article overviews the metabolic effects of these procedures, their undoubted advantages and potential risks.

The importance of preoperative and postoperative physical activity counseling in bariatric surgery

There is increasing evidence that physical activity (PA) can enhance weight loss and other outcomes after bariatric surgery. However, most preoperative patients are insufficiently active and, without support, fail to make substantial increases in their PA postoperatively. This review provides the rationale for PA counseling in bariatric surgery and describes how to appropriately tailor strategies to preoperative and postoperative patients.

Gastric bypass surgery is followed by lowered blood pressure and increased diuresis - long term results from the Swedish Obese Subjects (SOS) study

Objective

To compare two bariatric surgical principles with regard to effects on blood pressure and salt intake.

Background

In most patients bariatric surgery induces a sustained weight loss and a reduced cardiovascular risk profile but the long-term effect on blood pressure is uncertain.

Methods

Cohort study with data from the prospective, controlled Swedish Obese Subjects (SOS) study involving 480 primary health care centres and 25 surgical departments in Sweden. Obese patients treated with non-surgical methods (Controls, n = 1636 and n = 1132 at 2 y and 10 y follow up, respectively) were compared to patients treated with gastric bypass (GBP, n = 245 and n = 277, respectively) or purely restrictive procedures (vertical banded gastroplasty or gastric banding; VBG/B, n = 1534 and n = 1064, respectively).

Results

At long-term follow-up (median 10 y) GBP was associated with lowered systolic (mean: −5.1 mm Hg) and diastolic pressure (−5.6 mmHg) differing significantly from both VBG/B (−1.5 and −2.1 mmHg, respectively; p<0.001) and Controls (+1.2 and −3.8 mmHg, respectively; p<0.01). Diurnal urinary output was +100 ml (P<0.05) and +170 ml (P<0.001) higher in GBP subjects than in weight-loss matched VBG/B subjects at the 2 y and 10 y follow-ups, respectively. Urinary output was linearly associated with blood pressure only after GBP and these patients consumed approximately 1 g salt per day more at the follow-ups than did VBG/B (P<0.01).

Conclusions

The purely restrictive techniques VBG/B exerted a transient blood pressure lowering effect, whereas gastric bypass was associated with a sustained blood pressure reduction and an increased diuresis. The daily salt consumption was higher after gastric bypass than after restrictive bariatric surgery.