Cardiovascular benefits of bariatric surgery in morbidly obese patients

The Impact of Bariatric Surgery on Cardiovascular Risk Factors and Outcomes: A Systematic Review

Obesity and its complications are increasing in today's era, with cardiovascular health being one of the most significant obesity-related comorbidities. Hypertension in obesity is considered one of the major causes of death and disability due to their negative repercussions on cardiovascular health. Bariatric surgery is an approved therapeutic modality for obese people in classes II and III who have a body mass index (BMI) of more than 35 kg/m² and 40 kg/m², respectively. These weight loss surgeries are procedures that alter metabolism by causing weight reduction and altering gastrointestinal physiology, thereby considerably decreasing cardiometabolic risk factors that have been poorly understood to date. The purpose of this review is to explore the impact of bariatric surgery on reducing cardiac risk factors, in turn protecting the heart from succumbing to premature death. A literature search was done in the following databases: PubMed, Google Scholar, and PubMed Central (PMC). The studies taken into account for this review were observational studies published between 2016 and 2021 in the English language, where the quality was assessed using relevant quality appraisal methodologies. Finally, 10 reports were selected as definitive studies. Upon extensive evaluation of the final studies, it can be concluded that bariatric surgery results in significant weight loss, which lowers metabolic syndrome prevalence, cardiovascular risk factors, and major adverse cardiovascular events, particularly acute coronary events, and a favorable improvement in cardiac structure and function, altogether steering to reduced mortality due to cardiovascular diseases in obese patients. It is also worth noting that, while metabolic surgery can help patients with various metabolic comorbidities, the impact on individuals with hypertension is still debatable. Although the studies show significant effects on the cardiovascular system, these were only observational studies in geographically dispersed locations where each patient's lifestyle patterns and motivational levels could vary. Since real-world data are not fully explored due to the limited randomized controlled trials, it is suggested that further human trials on a larger scale be conducted to provide an even more factual conclusion.

Physical activity, patient-reported symptoms, and clinical events: Insights into postprocedural recovery from personal digital devices

Background

Personal digital devices may offer insights into patient recovery and an approach for remote monitoring after procedures.

Objective

To examine associations between activity measured using personal digital devices, patient-reported outcome measures (PROMs), and clinical events among patients after catheter ablation for atrial fibrillation (AF) or bariatric surgery.

Methods

We aggregated personal digital device, PROM, and electronic health record data in a study conducted at 2 health systems. We used Fitbit devices for step count assessments, KardiaMobile for cardiac rhythm assessments, and PROMs for pain and palpitations over 5 weeks.

Results

Among 59 patients, 30 underwent AF ablation and 29 bariatric surgery. Thirty-six patients (63%) reported pain. There was no difference in median [interquartile range] daily steps between patients with and those without pain (4419 [3286–7041] vs 3498 [2609–5888]; P = .23). Among AF ablation patients, 21 (70%) reported palpitations. Median daily steps were lower among those with palpitations than among those without (4668 [3021–6116] vs 8040 [6853–10,394]; P = .03). When accounting for within-subject correlation, recordings of AF were associated with a significant mean decrease in median daily steps (–351; 95% confidence interval –524 to –177; P <.01). Patients who received a new antiarrhythmic drug prescription had AF recorded in a median of 5 [5–5] of 5 total weeks, whereas patients who did not receive a new antiarrhythmic recorded AF in a median of 1 [0–3] week (P = .02).

Conclusion

Personal digital device and PROM data can provide insight into postprocedural recovery outside of usual clinical settings and may inform follow-up and clinical decision-making. (ClinicalTrials.gov Identifier: NCT03436082)

Standard Biliopancreatic Limb (50 cm) Roux-en-Y Gastric Bypass Versus Long Biliopancreatic Limb (100 cm) Roux-en-Y Gastric Bypass in Patients with Body Mass Index 40-50 kg/m2: a Randomized Prospective Study

BACKGROUND

Roux-en-Y gastric bypass (RYGB) is a widely performed procedure worldwide especially with the presence of associated medical conditions. Patients with body mass index (BMI) 40-50 kg/m² are at more risk of weight regain and relapse of comorbidities. There is a controversy on the optimum alimentary (AL) and biliopancreatic (BPL) limb lengths to be used in RYGB to achieve weight loss and remission of comorbidities without causing nutritional deficiencies in those patients.

STUDY DESIGN

hundred-and-fifty patients with BMI between 40 and 50 kg/m² were divided equally into 2 groups undergoing standard RYGB (S-RYGB) with AL:150 cm and BPL: 50 cm and long biliopancreatic RYGB (L-RYGB) with AL: 100 cm and BPL: 100 cm. BMI, % of total weight loss (%TWL), effect on diabetes (DM), hypertension (HTN), dyslipidemia, and nutritional statuses were recorded at 1, 2, and 3 years.

RESULTS

Only 64/75 patients in S-RYGB and 57/75 patients in L-RYGB completed the study. L-RYGB had faster weight loss, higher %TWL, and less BMI than S-RYGB with the maintenance of achieved weight. L-RYGB had better control of DM and dyslipidemia than S-RYGB. There were no significant differences in nutritional status between S-RYGB and L-RYGB rather than lower levels of calcium and Hb and higher levels of PTH in L-RYGB yet they remain within the normal range.

CONCLUSION

The application of L-RYGB helps in achieving faster weight loss for a longer period with better remission of associated comorbidities as DM, HTN, and dyslipidemia in patients with BMI 40-50 kg/m² but with effects on the nutritional status.

Outcome of Sleeve Gastrectomy Versus Roux-en-Y Gastric Bypass for Patients with Super Obesity (Body Mass Index > 50 kg/m2)

PURPOSE

With increasing BMI, the complexity of treating patients with obesity rises. The focus of this study is to investigate the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on perioperative morbidity and remission of comorbidities at 3 years in patients with a BMI > 50 kg/m².

MATERIALS AND METHODS

A retrospective multicenter analysis of a prospectively maintained database was performed to enroll patients with a 3-year follow-up after SG or RYGB between 2005 and 2019 and a BMI of > 50 kg/m² preoperatively. Patients' BMI and comorbidity status were recorded preoperatively.

RESULTS

We analyzed data from 2939 patients who had at least a preoperative BMI > 50 kg/m². A total of 1278 patients underwent RYGB surgery, and 1661 underwent SG. The distribution of sex, BMI, hypertension, reflux, and sleep apnea was significant between the two groups. Three years after surgery, the percent excess weight loss (%EWL) was 62.21% in RYGB and 55.87% in SG (p < 0.001). The change in hypertension (p < 0.001) and reflux (p < 0.001) was significantly in favor of RYGB. The change in diabetes mellitus was not significant between the two groups (p > 5%). There was a minimal difference in sleep apnea in favor of SG (p < 0.001). Mortality and overall complication rates were not significant in either group.

CONCLUSION

Both procedures positively affected comorbidities, BMI, and %EWL in patients with super obesity 3 years after surgery. In some categories, RYGB was better than SG. Nevertheless, the decision between the two methods remains a matter of the surgeon's experience and the patient's general condition.

Comparison of the one-year outcomes of bariatric surgery in adolescents and young adults: a matched case-control study, Tehran Obesity Treatment Study (TOTS)

PURPOSES

The increasing use of bariatric surgery in adolescents has raised some concerns regarding the postoperative outcomes and the optimal time of surgery at young ages. However, no study has yet compared the weight loss and comorbidity resolution following bariatric surgery between adolescents and young adults.

METHODS

This study was conducted on a case group of adolescents (aged 11-18) and a control group of young adults (aged 19-29) undergoing bariatric surgery (sleeve gastrectomy or gastric bypass). The two groups were matched in terms of gender, body mass index (BMI), and surgery type and were assessed regarding the surgical outcomes at 1 year after surgery.

RESULTS

The baseline characteristics of the adolescents (n = 118, mean age: 17.0 ± 1.6 years) and young adults (n = 236, mean age: 25.2 ± 3.2 years) were similar, as well as surgery-associated complications. The mean loss of BMI (- 15.4 ± 3.6 vs. -15.8 ± 4.6 kg/m²) and 12-month percentage of excess weight loss (80.4 ± 20.1 vs. 80.2 ± 20.1%) were similar in the two groups. Both groups showed parallel reductions in the cardiovascular risk factors. The remission of hypertension, diabetes mellitus, and dyslipidemia was similar between the groups. The increase in the hemoglobin level and copper deficiency was greater in young adults, whereas the increase in ferritin deficiency was greater in adolescents.

CONCLUSION

Similar to young adults, bariatric surgery is an effective and safe method to achieve weight loss, resolve obesity-related comorbidities, and improve cardiovascular risk factors in the adolescents.

Effects of bariatric surgery in different obesity phenotypes: Tehran Obesity Treatment Study (TOTS)

BACKGROUND

Not all morbid obese patients suffer from metabolic co-morbidities; thus, a sub-group of metabolically healthy morbid obese (MHMO) individuals are identified. However, the role of bariatric surgery is not well understood in this subgroup.

METHODS

A total of 2244 morbid obese individuals aged 18-65 years undergoing bariatric surgery were selected. Patients were considered MHMO according to the joint interim statement (JIS) definition, as having two or less abnormalities in these five parameters: waist circumference (WC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), systolic or diastolic blood pressure (SBP or DBP), and fasting plasma glucose (FPG). Otherwise, they were considered metabolically unhealthy morbid obese (MUMO). Follow-up data were collected at 6, 12, and 24 months post-surgery.

RESULTS

Prior to surgery, 36.2% of participants were MHMO and had significantly lower BMI, WC, TG, FPG, SBP, and DBP and higher HDL-C compared to MUMO. Both MHMO and MUMO participants showed a significant decrease in BMI, WC, TG, SBP, DBP, and FPG and increase in HDL-C and the percentage of excess weight loss (%EWL). Two-year post-operative changes (from baseline) of BMI, WC, and %EWL were greater in MHMO subjects and changes of TG, HDL-C, DBP, SBP, and FPG were greater in MUMO subjects. Further multivariate regression analysis for delta (∆) change in these characteristics revealed that only the delta (∆) changes of WC and %EWL were statistically different between the two phenotypes and were greater in MHMO subjects, 2 years after the surgery (- 3.077 cm decrease in WC and + 3.612% higher %EWL compared to MUMO subjects).

CONCLUSION

Bariatric surgery is an effective method for reduction of metabolic abnormalities and weight loss in both MUMO and MHMO phenotypes. Benefits of this intervention are comparable between patients with these two obesity phenotypes.

Dietary Energy Partition: The Central Role of Glucose

Humans have developed effective survival mechanisms under conditions of nutrient (and energy) scarcity. Nevertheless, today, most humans face a quite different situation: excess of nutrients, especially those high in amino-nitrogen and energy (largely fat). The lack of mechanisms to prevent energy overload and the effective persistence of the mechanisms hoarding key nutrients such as amino acids has resulted in deep disorders of substrate handling. There is too often a massive untreatable accumulation of body fat in the presence of severe metabolic disorders of energy utilization and disposal, which become chronic and go much beyond the most obvious problems: diabetes, circulatory, renal and nervous disorders included loosely within the metabolic syndrome. We lack basic knowledge on diet nutrient dynamics at the tissue-cell metabolism level, and this adds to widely used medical procedures lacking sufficient scientific support, with limited or nil success. In the present longitudinal analysis of the fate of dietary nutrients, we have focused on glucose as an example of a largely unknown entity. Even most studies on hyper-energetic diets or their later consequences tend to ignore the critical role of carbohydrate (and nitrogen disposal) as (probably) the two main factors affecting the substrate partition and metabolism.

Bariatric Surgery: Remission of Inflammation, Cardiometabolic Benefits, and Common Adverse Effects

Obesity is associated with increased mortality as a result of several comorbidities which occur in tandem with the obese state. Chronic inflammation is well documented in obesity, and evidence from numerous studies support the notion that the increased inflammation in individuals with obesity accentuates the comorbidities seen in this condition. The remission of comorbidities such as metabolic, cardiovascular, and neurological complications occurs following bariatric procedures. Bariatric surgery significantly reduces mortality and results in remarkable weight loss and reversal in several obesity-related comorbidities. There is indisputable evidence that the resolution of inflammation that occurs after bariatric surgery mitigates some of these comorbidities. With the increasing use of bariatric surgery for the treatment of severe obesity, it is pivotal to elucidate the underlying mechanisms responsible for the notable improvements seen after the procedure. This review summarizes underlying mechanisms responsible for the remission of obesity-related abnormalities and discusses the common adverse effects of bariatric surgery. Well-stratified, large-scale studies are still needed for a proper evaluation of these underlying mechanisms.

The Effect of One Anastomosis Gastric Bypass on Branched-Chain Fatty Acid and Branched-Chain Amino Acid Metabolism in Subjects with Morbid Obesity

BACKGROUND

Subjects with morbid obesity have low levels of serum branched-chain fatty acids (BCFAs), which correlate inversely with insulin resistance, hypertriglyceridemia, and inflammation. Recent evidence suggests BCFAs are produced during branched-chain amino acid (BCAA) catabolism in human adipose tissue. Elevated concentrations of BCAAs are associated with insulin resistance.

OBJECTIVES

In this single-center study, we evaluated the effect of one anastomosis gastric bypass (OAGB) on circulating BCFA and BCAA. Moreover, we determined the expression of genes involved in BCAA catabolism in adipose tissue of patients with obesity and lean controls.

METHODS

Fasting levels of BCFAs and BCAAs were determined by gas and liquid chromatography, respectively, coupled with mass spectrometry, in 50 patients with morbid obesity before and 6-9 months after surgery, and in 32 lean controls. Visceral and subcutaneous adipose tissue (VAT and SAT, respectively) biopsies were collected at baseline to determine mRNA levels for enzymes involved in BCAA catabolism.

RESULTS

Before surgery, patients with obesity had lower BCFAs and greater BCAAs than control subjects. OAGB increased BCFA and decreased BCAA levels. Insulin resistance (assessed by HOMA) correlated inversely with BCFAs and positively with BCAAs. Expression of genes involved in BCAA catabolism in VAT (but not SAT) was lower in patients with obesity than in lean controls.

CONCLUSIONS

OAGB-induced weight loss increases circulating BCFAs and decreases circulating BCAAs in patients with morbid obesity, perhaps by altering BCAA catabolism in VAT. We speculate that this shift may be related to the improvement in insulin sensitivity after surgery.

Exploring Therapeutic Targets to Reverse or Prevent the Transition from Metabolically Healthy to Unhealthy Obesity

The prevalence of obesity and obesity-related metabolic comorbidities are rapidly increasing worldwide, placing a huge economic burden on health systems. Excessive nutrient supply combined with reduced physical exercise results in positive energy balance that promotes adipose tissue expansion. However, the metabolic response and pattern of fat accumulation is variable, depending on the individual’s genetic and acquired susceptibility factors. Some develop metabolically healthy obesity (MHO) and are resistant to obesity-associated metabolic diseases for some time, whereas others readily develop metabolically unhealthy obesity (MUO). An unhealthy response to excess fat accumulation could be due to susceptibility intrinsic factors (e.g., increased likelihood of dedifferentiation and/or inflammation), or by pathogenic drivers extrinsic to the adipose tissue (e.g., hyperinsulinemia), or a combination of both. This review outlines the major transcriptional factors and genes associated with adipogenesis and regulation of adipose tissue homeostasis and describes which of these are disrupted in MUO compared to MHO individuals. It also examines the potential role of pathogenic insulin hypersecretion as an extrinsic factor capable of driving the changes in adipose tissue which cause transition from MHO to MUO. On this basis, therapeutic approaches currently available and emerging to prevent and reverse the transition from MHO to MUO transition are reviewed.

Obesity and cardiovascular disease in women

As the prevalence of obesity continues to grow worldwide, the health and financial burden of obesity-related comorbidities grows too. Cardiovascular disease (CVD) is clearly associated with increased adiposity. Importantly, women are at higher risk of CVD when obese and insulin resistant, in particular at higher risk of developing heart failure with preserved ejection fraction and ischemic heart disease. Increased aldosterone and mineralocorticoid receptor activation, aberrant estrogenic signaling and elevated levels of androgens are among some of the proposed mechanisms explaining the heightened CVD risk. In addition to traditional cardiovascular risk factors, understanding nontraditional risk factors specific to women, like excess weight gain during pregnancy, preeclampsia, gestational diabetes, and menopause are central to designing personalized interventions aimed to curb the epidemic of CVD. In the present review, we examine the available evidence supporting a differential cardiovascular impact of increased adiposity in women compared with men and the proposed pathophysiological mechanisms behind these differences. We also discuss women-specific cardiovascular risk factors associated with obesity and insulin resistance.

Understanding and managing cardiovascular outcomes in liver transplant recipients

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a common cause of mortality after liver transplantation. The transplant community is focused on improving long-term survival. Understanding the prevalence of CVD in liver transplant recipients, precipitating factors as well as prevention and management strategies is essential to achieving this goal.

RECENT FINDINGS

CVD is the leading cause of death within the first year after transplant. Arrhythmia and heart failure are the most often cardiovascular morbidities in the first year after transplant which could be related to pretransplant diastolic dysfunction. Pretransplant diastolic dysfunction is reflective of presence of cirrhotic cardiomyopathy which is not as harmless as it was thought. Multiple cardiovascular risk prediction models have become available to aid management in liver transplant recipients.

SUMMARY

A comprehensive prevention and treatment strategy is critical to minimize cardiovascular morbidity and mortality after liver transplant. Weight management and metabolic syndrome control are cornerstones to any prevention and management strategy. Bariatric surgery is an underutilized tool in liver transplant recipients. Awareness of 'metabolic-friendly' immunosuppressive regimens should be sought. Strict adherence to the cardiology and endocrine society guidelines with regard to managing metabolic derangements post liver transplantation is instrumental for CVD prevention until transplant specific recommendations can be made.

Influence of Morbid Obesity and Bariatric Surgery Impact on the Carotid Adventitial Vasa Vasorum Signal

INTRODUCTION/PURPOSE

Adventitial vasa vasorum (VV) expansion to the avascular intima precedes an increase in carotid intima-media thickness. However, factors involved in the development of the atherosclerotic process and its reversibility remain unclear. We aimed to evaluate the VV signal in both morbid obesity and after bariatric surgery (BS).

MATERIALS/METHODS

We conducted a case-control study to examine the VV signal in the carotid of 40 morbidly obese patients and 40 non-obese controls. The effect of BS was evaluated in 33 patients. Contrast-enhanced carotid ultrasound was used to assess the VV signal.

RESULTS

The mean VV density was higher in obese than in non-obese subjects (0.739 ± 0.117 vs. 0.570 ± 0.111, p < 0.001). The VV signal positively correlated with BMI (p < 0.001) and waist circumference (p = 0.001) but was not related to cIMT. The stepwise multivariate regression analysis revealed that waist circumference (beta = 0.507, p < 0.001) together with fasting plasma glucose (beta = 0.229, p = 0.024) were independently associated with the VV signal (R² = 0.382). Before BS, the median VV signal correlated with soluble intercellular adhesion molecule 1 (p = 0.022). After a 12-month follow-up, a 12.0% decrease in VV (0.731 ± 0.126 vs. 0.643 ± 0.115, p = 0.003) was observed. In the univariate analysis, the decrease in VV was associated with the baseline VV density (p < 0.001), baseline systolic blood pressure (p = 0.019) and a decrease in sICAM (p = 0.005). However, only baseline systolic pressure (beta = 0.417, p = 0.024) independently predicted the absolute change in VV signal (R² = 0.174).

CONCLUSIONS

Morbidly obesity is associated with increased VV density. In addition, BS appears to reduce the earlier expansion of the adventitial vasa vasorum.

Neuroimaging correlates of cognitive changes after bariatric surgery

BACKGROUND

Obesity has been associated with cognitive deficits and increased risk for developing dementia. Bariatric surgery may result in improved cognitive function; however, the underlying structural and functional brain correlates are unclear.

OBJECTIVES

This longitudinal study explores the hypothesis that specific brain regions and networks underlie cognitive changes after bariatric surgery.

SETTING

University Hospital, United States.

METHODS

Seventeen patients were recruited for this prospective cohort study, including 9 patients undergoing bariatric surgery, and 8 age-, sex-, and education level-matched healthy, nonobese control patients. Bariatric patients underwent longitudinal neuropsychologic tests and magnetic resonance imaging (MRI) scans both before and 6 months after surgery. One patient was lost to follow-up. The same neuropsychologic tests and MRI scans were performed for control patients. Differences in MRI and neuropsychologic testing between bariatric patients and control patients, and longitudinal changes within bariatric patients were assessed.

RESULTS

At baseline, bariatric patients demonstrated deficits in cognitive function relative to control patients, including pattern comparison (P = .009) and picture sequence memory (P = .004), which improved after significant weight loss. Baseline cognitive deficits in bariatric patients were accompanied by significantly lower left executive control network connectivity on resting-state functional MRI relative to control patients (P = .028), but differences resolved or diminished after bariatric surgery. Longitudinal improvements in pattern comparison performance correlated significantly with increases in left executive control network connectivity (r = .819; P = .013). No significant group or longitudinal differences were found in brain perfusion or brain white matter lesions.

CONCLUSIONS

Individuals with obesity undergoing bariatric surgery exhibit deficits in cognitive function and specific alterations of brain networks; however, cognitive performance can improve, and executive control network connectivity can increase after weight loss from bariatric surgery.

Evidence That the Length of Bile Loop Determines Serum Bile Acid Concentration and Glycemic Control After Bariatric Surgery

BACKGROUND

Bariatric surgery contributes to the improvement in glucose metabolism that may be related to a postoperative increase in serum bile acids (BAs). Three commonly used types of bariatric procedures, laparoscopic sleeve gastrectomy (LSG) (without creation of a bile loop), Roux-en-Y gastric bypass (RYGB), and omega-loop gastric bypass (OLGB) (with creation of shorter 100-150 cm and longer 200-280 cm bile loops, respectively), differ in their effects on glycemic control. The aim of the study was to compare the effects of various bariatric procedures on serum BA concentration and glucose homeostasis.

METHODS

Serum BAs in 26 obese patients were determined by liquid chromatography-mass spectrometry prior to bariatric surgery, as well as 4 days and 3 months thereafter.

RESULTS

Four days after the surgery, serum concentrations of BAs in LSG and OLGB groups were similar as prior to the procedure, and a slight decrease in serum BAs was observed in the RYGB group. Serum BA level in the LSG group remained unchanged also at 3 months after the surgery, whereas a significant 0.5- and 3-fold increase in this parameter was noted in the RYGB and OLGB groups, respectively. Serum concentration of BAs correlated positively with the length of the bile loop (R = 0.47, p < 0.05).

CONCLUSION

The evident improvement of glycemic control observed 3 months after OLGB might be associated with a postoperative increase in serum BAs, resulting from their better absorption from the longer bile loop. However, the changes in serum BAs probably had little or no impact on insulin sensitivity improvement at 4 days post-surgery.

Length of stay by uncomplicated diabetes bariatric surgery patients: A laparoscopic adjustable banding versus laparoscopic sleeve gastrectomy

RATIONALE, AIMS, AND OBJECTIVE

Bariatric surgery is an effective procedure for morbidly obese patients when all else fails. The purpose of this study was to compare the hospital length of stay (LOS) for two surgical procedures, laparoscopic adjustable gastric banding (LAGB) and laparoscopic sleeve gastrectomy (LSG).

METHODS

This study was a retrospective cross-sectional analysis of the Nationwide Inpatient Sample (NIS) from 2009 to 2014. Patients who received bariatric surgery as indicated by International Classification of Diseases, Ninth Revision (ICD-9) procedure codes were selected (N = 4001). Cases were limited to uncomplicated diabetic patients. Differences in the odds of long vs short (2< and ≥2) stay for a patient receiving LSG were compared with LAGB while adjusting for hospital volume, hospital size, patient age, gender, ethnicity, season, and year using logistic regression analysis.

RESULTS

The odds for LSG (odds ratio [OR] = 0.100, 0.066-0.150, P < 0.001) patients for long LOS are lower when compared with LAGB. In the stratified logistic regression model, both male (OR = 0.157, 0.074-0.333, P < 0.001) and female (OR = 0.077, 0.046-0.127, P < 0.001) had reduced odds of extended LOS for LSG. Discharged patients in the year 2012 (OR = 0.660, 0.536-0.813, P < 0.001) had decreased odds of having a longer LOS when compared with the year 2014. Both government, nonfederal (OR = 0.452, 0.251-0.816, P = 0.008), and private investor-owned (OR = 0.421, 0.244-0.726, P < 0.001) patients had similar odds for long duration of stay when compared with government or private. Urban non-teaching (OR = 1.954, 1.653-2.310, P < 0.001) patients had higher odds for long LOS in comparison with urban teaching. New England patients' (OR = 0.365, 0.232-0.576, P < 0.001) odds for extended LOS were lower when compared with pacific. Both patients who received care in low (OR = 1.330, 1.109-1.595, P = 0.002) and medium (OR = 1.639, 1.130-2.377, P = 0.009) volume hospital had increased odds for long duration of stay. Female patients in the stratified logistic regression model with high (OR = 1.330, 1.109-1.595, P < 0.002) volume had elevated odds of extended LOS when compared with very low volume hospital.

CONCLUSION

Among the uncomplicated diabetic patients, LSG provides a substantially low odds of extended LOS after adjusting for covariates when compared with LAGB. The finding of the relative reduction in LOS for LSG suggests opportunities for improvement both for cost reduction for third party insurance payers and greater efficacy and outcomes for patients.

Effect of Roux-en-Y gastric bypass on pharmacologic dependence in obese patients with type 2 diabetes

Background

More than half the diabetes-related health care costs in Canada relate to drug costs. We aimed to determine the effect of Roux-en-Y gastric bypass (RYGB) on the use of insulin and orally administered hypoglycemic medications in patients with diabetes. We also looked to determine overall cost savings with the procedure.

Methods

We reviewed the bariatric clinic records of all patients with a confirmed diagnosis of type 2 diabetes mellitus who underwent RYGB between 2010/11 and 2014/15. Percentage estimated weight loss was recorded at 1 year, along with reductions in glycated hemoglobin (HbA1c) level and use of oral hypoglycemic therapy and insulin. We estimated medication costs using Manitoba-specific pricing data.

Results

Fifty-two patients with at least 12 months of complete follow-up data were identified. The mean percentage estimated weight loss was 50.2%. The mean HbA1c level decreased from 7.6% to 6.0%, the mean number of orally administered hypoglycemics declined from 1.6 to 0.2, and the number of patients receiving insulin decreased from 18 (35%) to 3 (6%) (all p < 0.001). The rate of resolution of type 2 diabetes was 71%. Estimated mean annual per-patient medication costs decreased from $508.56 to $79.17 (p < 0.001). Potential overall health care savings could total $3769 per patient in the first year, decreasing to $1734 at 10 years.

Conclusion

Roux-en-Y gastric bypass resulted in significant improvement in diabetic control, with a reduction in hypoglycemic medication use and associated costs in the early postoperative period. Potentially, large indirect and direct cost savings can be realized in the longer term.

Current Progress of Lipid Analysis in Metabolic Diseases by Mass Spectrometry Methods

BACKGROUND

Obesity, insulin resistance, diabetes, and metabolic syndrome are associated with lipid alterations, and they affect the risk of long-term cardiovascular disease. A reliable analytical instrument to detect changes in the composition or structures of lipids and the tools allowing to connect changes in a specific group of lipids with a specific disease and its progress, is constantly lacking. Lipidomics is a new field of medicine based on the research and identification of lipids and lipid metabolites present in human organism. The primary aim of lipidomics is to search for new biomarkers of different diseases, mainly civilization diseases.

OBJECTIVE

We aimed to review studies reporting the application of mass spectrometry for lipid analysis in metabolic diseases.

METHOD

Following an extensive search of peer-reviewed articles on the mass spectrometry analysis of lipids the literature has been discussed in this review article.

RESULTS

The lipid group contains around 1.7 million species; they are totally different, in terms of the length of aliphatic chain, amount of rings, additional functional groups. Some of them are so complex that their complex analyses are a challenge for analysts. Their qualitative and quantitative analysis of is based mainly on mass spectrometry.

CONCLUSION

Mass spectrometry techniques are excellent tools for lipid profiling in complex biological samples and the combination with multivariate statistical analysis enables the identification of potential diagnostic biomarkers.

Alterations of specific lipid groups in serum of obese humans: a review

Obesity is a major contributor to the dysfunction of liver, cardiac, pulmonary, endocrine and reproductive system, as well as a component of metabolic syndrome. Although development of obesity-related disorders is associated with lipid abnormalities, most previous studies dealing with the problem in question were limited to routinely determined parameters, such as serum concentrations of triacylglycerols, total cholesterol, low-density and high-density lipoprotein cholesterol. Many authors postulated to extend the scope of analysed lipid compounds and to study obesity-related alterations in other, previously non-examined groups of lipids. Comprehensive quantitative, structural and functional analysis of specific lipid groups may result in identification of new obesity-related alterations. The review summarizes available evidence of obesity-related alterations in various groups of lipids and their impact on health status of obese subjects. Further, the role of diet and endogenous lipid synthesis in the development of serum lipid alterations is discussed, along with potential application of various lipid compounds as risk markers for obesity-related comorbidities.

Critical review: CPAP and weight management of obstructive sleep apnea cardiovascular co-morbidities

The cardiovascular co-morbidities of obstructive sleep apnea (OSA) are similar to those of obesity. Cardiovascular co-morbidities often are the cause of adverse outcomes in overweight/obese OSA patients. Continuous positive airway pressure (CPAP) therapy resolves the symptoms of OSA, but may, or may not lead to improvement of a given cardiovascular co-morbidity. The impact of CPAP on cardiovascular risk variables, adverse cardiovascular events in overweight/obese OSA patients has been evaluated primarily in prospective, uncontrolled cohort studies. These studies show improvement in myocardial and endothelial function, blood pressure, left ventricular performance and stroke survival. Randomized controlled studies (RCTs) examining the effect of weight management on cardiovascular risk factors and disease outcomes show that intentional weight loss leads to improvement in cardiovascular risk, hypertension, coronary artery disease, but not in stroke. Weight loss improves mortality in relatively healthy overweight/obese populations, but possibly not in all groups with cardiometabolic diseases. Clinicians caring for overweight/obese OSA patients should consider the advantages of incorporating weight management into their treatment programs for such patients.

Quality criteria in bariatric surgery: Consensus review and recommendations of the Spanish Association of Surgeons and the Spanish Society of Bariatric Surgery

Bariatric surgery has proven to be highly effective in controlling obesity and metabolic syndrome; the results of this surgery are not only expressed in terms of weight loss, but also in terms of resolution of comorbidities, improved quality of life and complications. The different parameters used to measure these outcomes require uniformity and reference patterns. Therefore, it is essential to identify those indicators and quality criteria that are helpful in defining the «best practice» principles in bariatric surgery. In this regard, the Section of Obesity of the Spanish Association of Surgeons, in collaboration with the Spanish Society for Bariatric Surgery (SECO), present as an objective to identify the key points that define «quality» in this type of surgery. We describe the main indicators based on the published literature as well as the criteria for referral of the main comorbidities according to the evidence found and grades of recommendation.

All-Cause and Cause-Specific Mortality Associated with Bariatric Surgery: A Review

The question of whether or not nonsurgical intentional or voluntary weight loss results in reduced mortality has been equivocal, with long-term mortality following weight loss being reported as increased, decreased, and not changed. In part, inconsistent results have been attributed to the uncertainty of whether the intentionality of weight loss is accurately reported in large population studies and also that achieving significant and sustained voluntary weight loss in large intervention trials is extremely difficult. Bariatric surgery has generally been free of these conflicts. Patients voluntarily undergo surgery and the resulting weight is typically significant and sustained. These elements, combined with possible non-weight loss-related mechanisms, have resulted in improved comorbidities, which likely contribute to a reduction in long-term mortality. This paper reviews the association between bariatric surgery and long-term mortality. From these studies, the general consensus is that bariatric surgical patients have: 1) significantly reduced long-term all-cause mortality when compared to severely obese non-bariatric surgical control groups; 2) greater mortality when compared to the general population, with the exception of one study; 3) reduced cardiovascular-, stroke-, and cancer-caused mortality when compared to severely obese non-operated controls; and 4) increased risk for externally caused death such as suicide.

Posterior reversible encephalopathy syndrome (PRES) after bariatric surgery--a potential consequence associated with rapid withdrawal of antihypertensive medications

A 61-year-old woman with a medical history of intracerebral haemorrhage, hypertension, hyperlipidaemia and carotid stenosis presented to the emergency department with altered mental status 3 weeks after undergoing a vertical sleeve gastrectomy for severe obesity. She presented with a hypertensive emergency and a National Institutes of Health Stroke Scale of 4. CT of the head was unrevealing. MRI showed an abnormal signal within the bilateral posterior border-zone areas, with several foci in the parietal and occipital lobes, and thalami, suggestive of posterior reversible encephalopathy syndrome (PRES). The patient was initially placed on a labetalol drip and her preoperative antihypertensive medications--amlodipine, captopril, triamterene and hydrochlorothiazide--were gradually reintroduced. She returned to her baseline and was stable on discharge. Rapid withdrawal of antihypertensive medications in the early postoperative period of bariatric surgery was the aetiology of PRES in this patient. This case report discusses postoperative care of bariatric surgery patients having hypertension.

Obesity and liver transplantation

The percentage of overweight and obese patients (OPs) waiting for a liver transplant continues to increase. Despite the significant advances occurred in bariatric medicine, obesity is still considered a relative contraindication to liver transplantation (LT). The main aim of this review is to appraise the literature on the outcomes of OPs undergoing LT, treatments that might reduce their weight before, during or after surgery, and discuss some of the controversies and limitations of the current knowledge with the intent of highlighting areas where future research is needed.

A numerical scale to assess the outcomes of metabolic/bariatric surgery (NOMS)

Introduction

Absent today is a simple numerical system of outcomes assessment that recognizes that bariatric surgery is metabolic surgery and incorporates weight loss, hypertension control, and type 2 diabetes control.

Aim

To introduce a simple, new Numerical Scale to Assess the Outcomes of Metabolic Surgery (NOMS).

Material and methods

For the stratification of weight outcomes, we used the percentage excess weight loss (%EWL); for hypertension, the systolic blood pressure (SBP) and diastolic blood pressure (DBP) combined with medication usage; and for type 2 diabetes, the hemoglobin A_1c (HbA_1c) value combined with medication usage.

Results

Utilizing the guidelines of the American Diabetes Association, the Working Group of the European Society of Hypertension, the European Society of Cardiology, and the American College of Cardiology/American Heart Association, we propose for %EWL: W1 ≥ 50, W2 > 25 and < 50, and W3 ≤ 25; for hypertension H1 SBP/DPB < 140/90 mm Hg on no medication, H2 SBP/DBP ≥ 140/90 mm Hg with improvement of SBP or possible reduction of antihypertensive medication, and H3 no change or SBP higher than before surgery; for diabetes mellitus D1 HbA_1c ≤ 7% and no medication, D2 HbA_1c > 7% with a decrease of the HbA_1c level or possible reduction of medication, D3 no change in HbA_1c or HbA_1c higher than before surgery. Designations of H0 and D0 are given if hypertension or diabetes was not present before surgery. Patient examples for numerical scores are provided.

Conclusions

The introduction of our numerical scale (NOMS) can be of benefit in metabolic/bariatric outcomes assessment; communications among metabolic/bariatric surgery centers, physicians, and patients; and for more precise reporting in the evidence-based literature.

Roux-en-Y gastric bypass: limb length and weight loss

Background

Roux-en-Y gastric bypass is a surgical technique widely used in the treatment of obesity. It is unclear, however, if the length of the biliopancreatic and alimentary limb interferes with the magnitude of weight loss.

Aim

To evaluate if the length of these limbs is related to the percentage of weight loss one year after surgery.

Method

One hundred and twenty obese people underwent surgery between 2009 and 2011. Patients were inserted into four groups: A) biliopancreatic limb with 50 cm length and alimentary limb with100 cm length; B) biliopancreatic limb with 50 cm length and alimentary limb with 150 cm length; C) biliopancreatic limb with 100 cm length and alimentary limb with100 cm length; D) biliopancreatic limb with 100 cm length and alimentary limb with150 cm length. Age, gender, body mass index and the percentage of total weight loss were analyzed. Data were collected preoperatively and one year after surgery. The groups were compared and weight loss compared between groups.

Results

The follow-up occurred in 78.3% of the sample. The composition of the groups was similar, with no statistical significance. The average age was 43 years in groups A, C and D and 42 years in group B. The female gender predominated in all groups (about 60% of the sample). The mean body mass index was 46 kg/m² for groups A, C and D and 42 kg/m² in group B. The percentage of weight loss was 33% for group A and 34% for groups B, C and D. There was no significant difference among groups.

Conclusion

Different lengths of the biliopancreatic and alimentary limbs did not affect the percentage of total weight loss.

Cardiovascular benefits of bariatric surgery

The prevalence of obesity is increasing in the United States and worldwide, bringing with it an excess of morbidity and premature death. Obesity is strongly associated with both traditional cardiovascular risk factors as well as direct effects on hemodynamics and cardiovascular structure and function. In fact, cardiovascular disease is one of the major causes of morbidity and mortality in obese patients. Often, lifestyle and pharmacological weight-loss interventions are of limited efficacy in severely obese patients. Bariatric surgery has been shown to be a feasible option to achieve substantial and sustained weight loss in this group of patients. It is a safe procedure with low in-hospital and 30-day mortality rates even in groups that are considered higher risk for surgery (e.g., the elderly), especially if performed in high-volume centers. There is observational evidence that bariatric surgery in severely obese patients is associated with both a reduction of traditional cardiovascular risk factors as well as improvement in cardiac structure and function. Marked decreases in the levels of inflammatory and prothrombotic markers, as well as markers of subclinical atherosclerosis and endothelial dysfunction, are seen after bariatric surgery. This article summarizes the existing evidence regarding the cardiovascular benefits in patients following bariatric surgery.

The Association Between Reduced Inflammation and Cognitive Gains After Bariatric Surgery

OBJECTIVE

Bariatric surgery is associated with improved cognitive function, although the mechanisms are unclear. Elevated inflammation is common in obesity and associated with impaired cognition. Inflammation decreases after bariatric surgery, implicating it as a possible mechanism for cognitive improvement. The objective of this study was to examine whether reduced inflammation is a possible mechanism for postoperative cognitive improvement in bariatric surgery patients.

METHODS

Participants were 77 bariatric surgery patients who completed cognitive testing before surgery and 1 year postsurgery. Cognitive domains assessed were attention/executive function, language, and memory. High-sensitivity C-reactive protein (CRP) was assessed at both time points.

RESULTS

Patients exhibited preoperative cognitive impairment, although improvements 1 year postsurgery were seen in both attention/executive function (mean [M; standard deviation {SD}]baseline = 53.57 [8.68] versus M (SD)follow-up= 60.32 [8.19]) and memory (M [SD]baseline= 44.96 [7.98] versus M [SD]follow-up= 51.55 [8.25]). CRP was elevated at baseline and fell into the normative range postsurgery (M [SD]baseline= 0.9 [0.7] versus M [SD]follow-up= 0.2 [0.3] mg/dl). Preoperative CRP was not associated with baseline cognitive function (β values = -0.10 to 0.02) and changes in CRP also did not correspond to changes in cognition postsurgery (β values = 0.02-0.11; p values > .05 for all domains). A trend was detected for smaller improvements in memory among participants with elevated baseline CRP (>0.30 mg/dl) versus those with normal levels (group × time: p = .083).

CONCLUSIONS

Improvements in high-sensitivity CRP were not associated with postoperative cognitive benefits. Future studies are needed to explore other inflammatory markers and potential mechanisms of cognitive improvement after bariatric surgery, including improved glycemic control and neurohormone changes.

Bariatric surgery patients exhibit improved memory function 12 months postoperatively

BACKGROUND

Previous work from our group demonstrated improved memory function in bariatric surgery patients at 12 weeks postoperatively relative to controls. However, no study has examined longer-term changes in cognitive functioning following bariatric surgery.

METHODS

A total of 137 individuals (95 bariatric surgery patients and 42 obese controls) were followed prospectively to determine whether postsurgery cognitive improvements persist. Potential mechanisms of change were also examined. Bariatric surgery participants completed self-report measurements and a computerized cognitive test battery prior to surgery and at 12-week and 12-month follow-up; obese controls completed measures at equivalent time points.

RESULTS

Bariatric surgery patients exhibited cognitive deficits relative to well-established standardized normative data prior to surgery, and obese controls demonstrated similar deficits. Analyses of longitudinal change indicated an interactive effect on memory indices, with bariatric surgery patients demonstrating better performance postoperatively than obese controls.

CONCLUSIONS

While memory performance was improved 12 months postbariatric surgery, the mechanisms underlying these improvements were unclear and did not appear attributable to obvious postsurgical changes, such as reductions in body mass index or comorbid medical conditions. Future studies employing neuroimaging, metabolic biomarkers, and more precise physiological measurements are needed to determine the mechanisms underlying memory improvements following bariatric surgery.

Metabolic syndrome is less likely to resolve in Hispanics and non-Hispanic blacks after bariatric surgery

OBJECTIVE

To determine predictors of metabolic syndrome and its resolution in a large, ethnically diverse adult population undergoing bariatric surgery.

BACKGROUND

There is still limited knowledge about the impact of bariatric surgery on chronic health conditions such as metabolic syndrome.

METHODS

Adults having had a laparoscopic Roux-en-Y gastric bypass or a laparoscopic vertical sleeve gastrectomy between 2007 and 2009 (n = 4088) without revision during the study period of January 1, 2007 through December 31, 2011 were eligible for the study. Diagnosis and resolution of metabolic syndrome were determined using standard criteria with electronic medical records of laboratory, diagnosis, and pharmacy information.

RESULTS

Patients were primarily women (82%), non-Hispanic black (17%) or Hispanic (32%), 45 ± 11 years old, and had a body mass index (BMI) of 47.10 ± 7.73 kg/m at the time of surgery. After multivariate adjustment, metabolic syndrome was less likely to resolve in patients if they had a laparoscopic vertical sleeve gastrectomy procedure and a higher BMI at surgery, were older, were male or were either Hispanic or non-Hispanic black. The effects of age, race/ethnicity, and BMI at the time of surgery remained after accounting for weight loss.

CONCLUSIONS

On the basis of our findings, bariatric surgery may be most effective for younger, less obese patients who are early in the course of their cardiometabolic disease. Future research should investigate the factors that lead to lower rates of disease resolution after bariatric surgery for racial/ethnic minority groups.

A dietary restriction influences the progression but not the initiation of MSG-Induced nonalcoholic steatohepatitis

The metabolic syndrome is a major worldwide health care issue and a dominant risk factor for cardiovascular disease. The liver manifestations of this syndrome include nonalcoholic fatty liver disease (NAFLD) and its progressive variant nonalcoholic steatohepatitis (NASH). Although significant research has been performed, the basic pathogenesis of NAFLD/NASH remains controversial and effective treatments are still unavailable. We have previously reported on a murine model of NASH induced by the neonatal injection of monosodium glutamate (MSG), which includes the clinical manifestations of central obesity, diabetes, hyperlipidemia, and ultimately liver inflammation, fibrosis, and cancer. Although MSG is considered a safe food additive, its administration to pregnant rats increases the voracity and growth hormone levels in the offspring. To further understand the biology of this model, we have investigated the influence of the calorie intake on these clinical manifestations by feeding animals a restrictive diet. MSG-treated animals fed a restrictive diet continue to manifest obesity and early stage NASH but have improvements in serum lipid profiles. At 12 months of age, mice had manifestations of obesity, whether animals were fed a restricted or control diet, but animals fed a restrictive diet had a reduction in the progression of NASH. In conclusion, MSG appears to be a critical factor in the initiation of obesity, whereas calorie intake may modulate the progression of disease.

Bariatric surgery and its impact on cardiovascular disease and mortality: a systematic review and meta-analysis

BACKGROUND

Bariatric surgery has been shown to improve cardiovascular risk factors but long term benefits for survival and cardiovascular events are still uncertain.

METHODS

We searched MEDLINE and EMBASE for parallel group studies that evaluated the clinical outcomes associated with bariatric surgery as compared to non-surgical treatment. Relevant studies were pooled using random effects meta-analysis for risk of myocardial infarction, stroke, cardiovascular events and mortality.

RESULTS

14 studies met the inclusion criteria, which included 29,208 patients who underwent bariatric surgery and 166,200 nonsurgical controls (mean age 48 years, 30% male, follow up period ranged from 2 years to 14.7 years). Four studies were considered at moderate-high risk of bias, whilst ten studies were at moderate or lower risk of bias. Compared to nonsurgical controls there was more than 50% reduction in mortality amongst patients who had bariatric surgery (OR 0.48 95% CI 0.35-0.64, I2=86%, 14 studies). In pooled analysis of four studies with adjusted data, bariatric surgery was associated with a significantly reduced risk of composite cardiovascular adverse events (OR 0.54 95% CI 0.41-0.70, I2=58%). Bariatric surgery was also associated with significant reduction in specific endpoints of myocardial infarction (OR 0.46 95% CI 0.30-0.69, I2=79%, 4 studies) and stroke (OR 0.49 95% CI 0.32-0.75, I2=59%, 4 studies).

CONCLUSIONS

Data from observational studies indicates that patients undergoing bariatric surgery have a reduced risk of myocardial infarction, stroke, cardiovascular events and mortality compared to non-surgical controls. Future randomized studies should investigate whether these observations are reproduced in a clinical trials setting.

Mechanisms linking excess adiposity and carcinogenesis promotion

Obesity constitutes one of the most important metabolic diseases being associated to insulin resistance development and increased cardiovascular risk. Association between obesity and cancer has also been well established for several tumor types, such as breast cancer in post-menopausal women, colorectal, and prostate cancer. Cancer is the first death cause in developed countries and the second one in developing countries, with high incidence rates around the world. Furthermore, it has been estimated that 15-20% of all cancer deaths may be attributable to obesity. Tumor growth is regulated by interactions between tumor cells and their tissue microenvironment. In this sense, obesity may lead to cancer development through dysfunctional adipose tissue and altered signaling pathways. In this review, three main pathways relating obesity and cancer development are examined: (i) inflammatory changes leading to macrophage polarization and altered adipokine profile; (ii) insulin resistance development; and (iii) adipose tissue hypoxia. Since obesity and cancer present a high prevalence, the association between these conditions is of great public health significance and studies showing mechanisms by which obesity lead to cancer development and progression are needed to improve prevention and management of these diseases.

Is there evidence of early vascular disease in patients with obstructive sleep apnoea without known comorbidities? Preliminary findings

We evaluated early atherosclerotic lesions in 20 non-smokers with newly diagnosed Obstructive Sleep Apnoea (OSA) and without known comorbidities by measuring common carotid artery intima media thickness (CCA-IMT), transcranial Doppler ultrasound (TCD), and ankle brachial index (ABI). These were compared with 20 healthy age- and BMI-matched controls. In OSA patients, CCA-IMT was not significantly higher vs. controls (0.74±0.17 vs. 0.66±0.12 mm, p=0.201) and it was positively correlated with neck circumference (r=0.466, p=0.039), arousal index (r=0.663, p=0.001), gamma-glutamyl transpeptidase activity (r=0.474, p=0.035) while it was negatively correlated with Forced Expiratory Volume in 1 sec (r=-0.055, p=0.012). No difference was noted between patients and controls in terms of vascular stenosis on TCD examination, while asymptomatic peripheral artery disease was found in one patient with OSA. In conclusion, OSA patients without known comorbidities exhibit a non-significant increase in CCA-IMT without further evidence of vascular disease, but additional experience in a larger patient series is needed.

Roux-en-Y gastric bypass compared with aggressive diet and exercise therapy for morbidly obese patients awaiting renal transplant: a decision analysis

BACKGROUND

The optimal management of morbidly obese patients awaiting renal transplant is controversial and unknown. The objective of this study was to compare the impact of Roux-en-Y gastric bypass (RYGB) versus diet and exercise on the survival of morbidly obese patients with end-stage renal disease awaiting renal transplant.

METHODS

A decision analytic Markov state transition model was designed to simulate the life of morbidly obese patients with end-stage renal disease awaiting transplant. Life expectancy after RYGB and after 1 and 2 years of diet and exercise was estimated and compared in the framework of 2 clinical scenarios in which patients above a body mass index (BMI) of 35 kg/m(2) or above a BMI of 40 kg/m(2) were ineligible for transplantation, reflecting the BMI restrictions of many transplant centers. In addition to base case analysis (45 kg/m(2) BMI preintervention), sensitivity analysis of initial BMI was completed. Markov model parameters were extracted from the literature.

RESULTS

RYGB improved survival compared with diet and exercise. Patients who underwent RYGB received transplants sooner and in higher frequency. Using 40 kg/m(2) as the upper limit for transplant eligibility, base case patients who underwent RYGB gained 5.4 years of life, whereas patients who underwent 1 and 2 years of diet and exercise gained 1.5 and 2.8 years of life, respectively. Using 35 kg/m(2) as the upper limit, RYGB base case patients gained 5.3 years of life, whereas patients who underwent 1 and 2 years of diet and exercise gained .7 and 1.5 years of life, respectively.

CONCLUSIONS

In morbidly obese patients with end-stage renal disease, RYGB may be more effective than optimistic weight loss outcomes after diet and exercise, thereby improving access to renal transplantation.

Bariatric surgery as a treatment option in patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a leading cause of blindness, non-traumatic amputation and end-stage renal disease as well as a major cardiovascular risk factor. Tight glycemic control reduces the incidence of microvascular complications of T2DM whereas its effects on macrovascular complication are more controversial. However, glycemic targets are achieved by a minority of diabetic patients despite the availability of several antidiabetic agents. In the present commentary, we discuss the findings of two recent randomized studies that compared bariatric surgery with medical treatment in patients with uncontrolled T2DM. Both studies showed that bariatric surgery results in remission of T2DM in the majority of patients. However, both studies were limited to relatively young patients without comorbidities, had relatively short follow-up and did not assess the effects of surgery on T2DM complications. Moreover, the perioperative complications of bariatric surgery and its limited availability in some areas are additional barriers to the wider implementation of this therapeutic approach. On the other hand, the elucidation of the mechanisms underpinning the resolution of T2DM following bariatric surgery might result in the development of novel, more effective pharmacotherapies for this common disease.

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.

The role of psychobiological and neuroendocrine mechanisms in appetite regulation and obesity

Obesity is a multifactorial disease. Among its causes are physical inactivity and overeating. In addition, other factors may play an important role in the development of overweight/obesity. For example, certain hormones including leptin, insulin and ghrelin, may influence appetite and consequently body weight. Obesity frequently co-exists with metabolic disorders including dyslipidemia, hypertension and insulin resistance, thus constituting the metabolic syndrome which is characterized by increased cardiovascular risk. Lack of comprehensive knowledge on obesity-related issues makes both prevention and treatment difficult. This review considers the psychobiological and neuroendocrine mechanisms of appetite and food intake. Whether these factors, in terms of obesity prevention and treatment, will prove to be relevant in clinical practice (including reducing the cardiovas-cular risk associated with obesity) remains to be established.

Impact of restrictive (sleeve gastrectomy) vs hybrid bariatric surgery (Roux-en-Y gastric bypass) on lipid profile

BACKGROUND

Few studies have evaluated the impact of hybrid versus purely restrictive bariatric surgery on lipid profile, with the results being contradictory. The effect of laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) on lipid profile was compared.

METHODS

A nonrandomized prospective cohort study was conducted on severely obese patients undergoing bariatric surgery. Indication for the type of surgical procedure was based on clinical criteria. Patients on lipid-lowering drugs and those that could not be matched for age, sex, and body mass index were excluded. Finally, 51 patients who underwent LSG and 51 undergoing LRYGB completed this study.

RESULTS

During the first year post-surgery, no differences in percentage of excess weight loss and triglyceride reduction were found between groups. After LRYGR, low-density lipoprotein (LDL) cholesterol concentrations fell significantly (125.9 ± 29.3 to 100.3 ± 26.4 mg/dl, p < 0.001), whereas no significant changes were observed in the LSG group (118.6 ± 30.7 to 114.6 ± 33.5 mg/dl, p = 0.220). High-density lipoprotein (HDL) cholesterol increase was significantly greater after LSG (15.4 ± 13.1 mg/dl) compared with LRYGB (9.4 ± 14.0 mg/dl, p = 0.032). Factors independently associated with LDL cholesterol reduction were higher baseline total cholesterol and undergoing LRYGB. A greater increase in HDL cholesterol was associated with LSG, older age, and baseline HDL cholesterol.

CONCLUSIONS

LRYGB produces an overall improvement in lipid profile, with a clear benefit in all lipid fractions. Although LSG does not alter LDL cholesterol levels, its effect on HDL cholesterol is comparable to or greater than that obtained with malabsorptive techniques.

Short-term changes of the urine metabolome after bariatric surgery

Bariatric surgery leads to a loss of excess weight and to a remission of diabetes in a majority of patients. In an attempt to explain these underlying mechanisms, a broad range of metabolic alterations have been suggested. We aimed to investigate short-term changes in the urinary metabolome after bariatric surgery. Data for 50 patients who underwent bariatric surgery at the Municipal Hospital of Dresden-Neustadt, Germany, were used. Healthy controls were selected from the Study of Health in Pomerania. Non-fasting, spontaneous urine samples were collected, (1)H NMR spectroscopic analysis was performed, and metabolites were quantified (Chenomx NMR suite). Orthogonal projections to latent structures discriminant analysis (OPLS-DA) models were carried out (pre-operative versus controls, and post-operative versus controls). On the basis of the urine metabolome separations between pre-operative (predictive ability Q2Y=85.6%; total explained variance R2X=58.3%), or post-operative (Q2Y=82.1%; R2X=44.4%) and controls were possible. Metabolites including hippuric acid, 3-hydroxybutyrate, 2-hydroxyisobutyrate, and trigonelline, were altered among patients. In obese patients, 2-hydroxyisobutyrate levels were higher, whereas trigonelline and hippuric acid levels were lower than in controls. The highest levels of 3-hydroxybutyrate were found in post-operative samples, whereas the metabolite was not present in controls, and only at low levels in pre-operative samples. In conclusion, we demonstrated that the urinary metabotype differs between obese patients and healthy controls. The metabolic alterations identified after bariatric procedures increase our knowledge about the metabolic traits associated with weight reduction. Whether urinary metabotypes might be used for early prediction of a successful bariatric procedure should be evaluated in long-term observations.

Effect of gastrointestinal surgical manipulation on metabolic syndrome: a focus on metabolic surgery

Metabolic syndrome is strictly associated with morbid obesity and leads to an increased risk of cardiovascular diseases and related mortality. Bariatric surgery is considered an effective option for the management of these patients. We searched MEDLINE, Current Contents, and the Cochrane Library for papers published on bariatric surgery outcomes in English from 1 January 1990 to 20 July 2012. We reported the effect of gastrointestinal manipulation on metabolic syndrome after bariatric surgery. Bariatric surgery determines an important resolution rate of major obesity-related comorbidities. Roux-en-Y gastric bypass and biliopancreatic diversion appear to be more effective than adjustable gastric banding in terms of weight loss and comorbidities resolution. However, the results obtained in terms of weight loss and resolution of comorbidities after a “new bariatric procedure” (sleeve gastrectomy) encouraged and stimulated the diffusion of this operation.