Metabolic surgery: A clinical update

Metabolic and bariatric surgery has grown beyond 'experimental' weight-loss surgery. As techniques have advanced over the last few decades, so has the growing body of research and evidence, proving that both weight-loss and metabolic health improvement are induced. Metabolic surgery has become the more appropriate term for weight-loss surgery because of the altered gastrointestinal anatomy and subsequent beneficial metabolic effects. Although the tool of metabolic surgery has been well refined, a large portion of the global population does not have adequate access to it. This clinical update aims to (a) inform healthcare providers from all disciplines about the myriad of benefits of metabolic surgery and (b) equip them with the necessary knowledge to bridge the gap between patients in need of metabolic treatment and the therapies in metabolic surgery available to them.

Presence of Liver Steatosis Is Associated With Greater Diabetes Remission After Gastric Bypass Surgery

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance (IR) and β-cell dysfunction. Ectopic fat accumulation in liver and muscle causes IR. Since bariatric and metabolic surgery significantly improves fatty liver disease, we hypothesized that coexistence of liver steatosis (i.e., when hepatic IR contributes in T2DM) would be associated with greater diabetes improvement after surgery.

RESEARCH DESIGN AND METHODS

A total of 519 patients with T2DM who underwent Roux-en-Y gastric bypass and simultaneous liver biopsy and had a minimum 5-year follow-up were analyzed to assess the independent association between biopsy-proven liver steatosis and postoperative long-term diabetes remission (glycated hemoglobin <6.5% [48 mmol/mol] off medications).

RESULTS

Of the 407 patients with biopsy-proven liver steatosis, long-term diabetes remission was achieved in 211 (52%) patients compared with remission in 44 out of 112 (39%) patients without steatosis (P = 0.027). In multivariable analysis, presence of liver steatosis was an independent predictor of long-term diabetes remission (odds ratio 1.96 [95% CI 1.04-3.72]; P = 0.038). Hepatocyte ballooning, lobular inflammation, or fibrosis at baseline did not predict diabetes remission.

CONCLUSIONS

This study, for the first time, suggests that in patients with T2DM who are considering bariatric and metabolic surgery, coexistence of liver steatosis is associated with better long-term glycemic outcomes. Furthermore, our data suggest that there are distinct variants of T2DM in which metabolic responses to surgical weight loss are different. A subgroup of patients whose T2DM is characterized by the presence of hepatic steatosis (presumably associated with worse IR) experience better postoperative metabolic outcomes.

Roux-en-Y gastric bypass restores islet function and morphology independent of body weight in ZDF rats

Reductions in β-cell number and function contribute to the onset type 2 diabetes (T2D). Roux-en-Y gastric bypass (RYGB) surgery can resolve T2D within days of operation, indicating a weight-independent mechanism of glycemic control. We hypothesized that RYGB normalizes glucose homeostasis by restoring β-cell structure and function. Male Zucker Diabetic Fatty (fa/fa; ZDF) rats were randomized to sham surgery (n = 16), RYGB surgery (n = 16), or pair feeding (n = 16). Age-matched lean (fa/+) rats (n = 8) were included as a secondary control. Postprandial metabolism was assessed by oral glucose tolerance testing before and 27 days after surgery. Fasting and postprandial plasma GLP-1 was determined by mixed meal tolerance testing. Fasting plasma glucagon was also measured. β-cell function was determined in isolated islets by a glucose-stimulated insulin secretion assay. Insulin and glucagon positive areas were evaluated in pancreatic sections by immunohistochemistry. RYGB reduced body weight (P < 0.05) and improved glucose tolerance (P < 0.05) compared with sham surgery. RYGB reduced fasting glucose compared with both sham (P < 0.01) and pair-fed controls (P < 0.01). Postprandial GLP-1 (P < 0.05) was elevated after RYGB compared with sham surgery. RYGB islets stimulated with 20 mM glucose had higher insulin secretion than both sham and pair-fed controls (P < 0.01) and did not differ from lean controls. Insulin content was greater after RYGB compared with the sham (P < 0.05) and pair-fed (P < 0.05) controls. RYGB improves insulin secretion and pancreatic islet function, which may contribute to the remission of type 2 diabetes following bariatric surgery.NEW & NOTEWORTHY The onset and progression of type 2 diabetes (T2D) results from failure to secrete sufficient amounts of insulin to overcome peripheral insulin resistance. Here, we demonstrate that Roux-en-Y gastric bypass (RYGB) restores islet function and morphology compared to sham and pair-fed controls in ZDF rats. The improvements in islet function were largely attributable to enhanced insulin content and secretory function in response to glucose stimulation.

The first modified Delphi consensus statement on sleeve gastrectomy

INTRODUCTION

Sleeve gastrectomy (SG) is the commonest bariatric procedure worldwide. Yet there is significant variation in practice concerning its various aspects. This paper report results from the first modified Delphi consensus-building exercise on SG.

METHODS

We established a committee of 54 globally recognized opinion makers in this field. The committee agreed to vote on several statements concerning SG. An agreement or disagreement amongst ≥ 70.0% experts was construed as a consensus.

RESULTS

The committee achieved a consensus of agreement (n = 71) or disagreement (n = 7) for 78 out of 97 proposed statements after two rounds of voting. The committee agreed with 96.3% consensus that the characterization of SG as a purely restrictive procedure was inaccurate and there was 88.7% consensus that SG was not a suitable standalone, primary, surgical weight loss option for patients with Barrett's esophagus (BE) without dysplasia. There was an overwhelming consensus of 92.5% that the sleeve should be fashioned over an orogastric tube of 36-40 Fr and a 90.7% consensus that surgeons should stay at least 1 cm away from the angle of His. Remarkably, the committee agreed with 81.1% consensus that SG patients should undergo a screening endoscopy every 5 years after surgery to screen for BE.

CONCLUSION

A multinational team of experts achieved consensus on several aspects of SG. The findings of this exercise should help improve the outcomes of SG, the commonest bariatric procedure worldwide, and guide future research on this topic.

Association of prior metabolic and bariatric surgery with severity of coronavirus disease 2019 (COVID-19) in patients with obesity

Background

Obesity is a risk factor for poor clinical outcomes in patients with coronavirus disease 2019 (COVID-19).

Objectives

To investigate the relationship between prior metabolic surgery and the severity of COVID-19 in patients with severe obesity.

Setting

Cleveland Clinic Health System in the United States.

Methods

Among 4365 patients who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between March 8, 2020 and July 22, 2020 in the Cleveland Clinic Health System, 33 patients were identified who had a prior history of metabolic surgery. The surgical patients were propensity matched 1:10 to nonsurgical patients to assemble a cohort of control patients (n = 330) with a body mass index (BMI) ≥ 40 kg/m² at the time of SARS-CoV-2 testing. The primary endpoint was the rate of hospital admission. The exploratory endpoints included admission to the intensive care unit (ICU), need for mechanical ventilation and dialysis during index hospitalization, and mortality. After propensity score matching, outcomes were compared in univariate and multivariate regression models.

Results

The average BMI of the surgical group was 49.1 ± 8.8 kg/m² before metabolic surgery and was down to 37.2 ± 7.1 at the time of SARS-CoV-2 testing, compared with the control group’s BMI of 46.7 ± 6.4 kg/m². In the univariate analysis, 6 (18.2%) patients in the metabolic surgery group and 139 (42.1%) patients in the control group were admitted to the hospital (P = .013). In the multivariate analysis, a prior history of metabolic surgery was associated with a lower hospital admission rate compared with control patients with obesity (odds ratio, 0.31; 95% confidence interval, 0.11−0.88; P = .028). While none of the 4 exploratory outcomes occurred in the metabolic surgery group, 43 (13.0%) patients in the control group required ICU admission (P = .021), 22 (6.7%) required mechanical ventilation, 5 (1.5%) required dialysis, and 8 (2.4%) patients died.

Conclusion

Prior metabolic surgery with subsequent weight loss and improvement of metabolic abnormalities was associated with lower rates of hospital and ICU admission in patients with obesity who became infected with SARS-CoV-2. Confirmation of these findings will require larger studies.

•

Is there an association between prior metabolic surgery and severity of COVID-19 in patients with obesity?

•

In this matched cohort study of 363 patients with COVID-19 (including 33 patients who underwent metabolic surgery and 330 matched controls with obesity), metabolic surgery was significantly associated with near three times lower odds of hospital admission (odds ratio 0.31, P=0.028).

•

While none of the 4 exploratory outcomes occurred in the metabolic surgery group, 43 (13.0%) patients in the control group required ICU admission (P=0.021), 22 (6.7%) required mechanical ventilation, 5 (1.5%) required dialysis, and 8 (2.4%) patients died.

•

Among patients with obesity, metabolic surgery was significantly associated with a lower risk of hospital and intensive care unit admission.

Diabetic patients treated with novel thin composite-wire strut zotarolimus-eluting stents versus ultrathin strut sirolimus-eluting stents in the BIONYX trial: 2-year results of a prespecified analysis

Background/Introduction

The novel thin composite-wire strut zotarolimus-eluting stent (ZES) is a drug-eluting stent that is frequently used for treating patients with obstructive coronary artery disease, but so far no clinical outcome data have been published in patients with diabetes. In all-comer patients, the BIONYX trial (NCT02508714) has established non-inferiority of the ZES versus the ultrathin strut biodegradable-polymer sirolimus-eluting stent (SES) regarding the primary composite endpoint of target vessel failure at 1 year follow-up.

Purpose

To assess in patients with diabetes, the 2-year safety and efficacy of the current generation thin composite-wire strut ZES, compared to the ultrathin strut SES.

Methods

In the international, multicentre BIONYX trial, randomisation was stratified for sex and the presence of diabetes mellitus. We performed a prespecified subgroup analysis of patients with diabetes. The main endpoint target vessel failure was a composite of safety and efficacy, consisting of cardiac death, target vessel-related myocardial infarction or clinically indicated target vessel revascularisation. Secondary endpoints, such as target lesion revascularisation and stent thrombosis were also assessed.

Results

A total of 510/2488 (20.5%) BIONYX trial participants had diabetes, and were therefore included in this analysis. Patients were on average 66.4±10.3 years old, and 28.6% were female. Most participants presented with acute coronary syndromes (65.1%), and 182/510 (35.7%) patients were insulin dependent. Two-year follow up was available in 500 of 510 (98.0%) patients. Target vessel failure occurred in 31/260 (12.2%) patients assigned to ZES versus 26/250 (10.7%) patients assigned to SES (HR 1.14, 95%-CI 0.68–1.92; P-logrank=0.63). Kaplan Meier curves of target vessel failure are displayed in Figure 1. There were no significant between-stent differences in the individual components of this endpoint. Target lesion revascularisation occurred in 15/260 (6.0%) patients treated with ZES versus 9/250 (3.7%) patients treated with SES (HR 1.61, 95%-CI 0.71–3.68; P-logrank=0.25). Definite stent thrombosis was an infrequent event and did not differ significantly between stent-arms (0.4% vs. 1.2%; HR 0.32, 95%-CI 0.03–3.06; P-logrank=0.30).

Conclusion

In patients with diabetes, the novel thin composite-wire strut durable polymer ZES was similarly safe and efficacious as compared to the ultrathin cobalt-chromium strut biodegradable-polymer SES at 2-year follow-up.

Figure1. Target vessel failure at 2 years

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): The BIONYX trial was equally funded by Biotronik and Medtronic.

Comparison of two iterations of the zotarolimus-eluting stents: an analysis of all-comer patients from two consecutive randomised clinical trials

Background

The newest iteration of the durable polymer zotarolimus-eluting stents (ZES) is designed with thin swaged shape composite-wire struts (inner platinum–iridium core and outer cobalt–chromium layer). It is of interest to compare the clinical performance of this novel device with its predecessor in all-comers.

Purpose

The purpose of the present study is to assess 2-year clinical outcome in all-comer patients who were treated with the novel ZES versus the previous iteration ZES.

Methods

We did a post-hoc analysis of clinical outcome data of 2374 patients who were treated with the novel or the previous generation ZES (only nominal stent diameters that were available for both devices) in two consecutive large-scale randomised all-comer trials. A total of 1201 trial participants were treated with the novel ZES, and 1173 were treated with the previous generation ZES. The main outcome parameter target vessel failure is a composite of safety (cardiac death, target vessel myocardial infarction) and efficacy (target vessel revascularisation). Clinical outcome data were analysed with Kaplan-Meier methods and hazard ratios were computed with Cox regression analysis. An additional analysis was done in a subgroup of patients who presented with chronic coronary syndromes.

Results

The mean age of the study population was 63.9±10.9 years, 611 (25.7%) were female and 1669 (70.3%) presented with acute coronary syndromes. Two-year follow-up was available in 2346 (98.8%) participants. After 2 years, there was no significant difference between stent-groups in the rates of target vessel failure (7.2% vs. 8.3%, HR 0.85, 95% CI 0.64–1.14, p-logrank = 0.28; Figure 1) or its individual components. Peri-procedural myocardial infarction occurred less often in patients treated with the novel ZES (0.7% vs. 2.1%, p-logrank &lt;0.01), and definite-or-probable stent thrombosis rates were low in both ZES groups (0.3% vs. 0.8%, p-logrank = 0.15). In a subgroup of 705 patients with chronic coronary syndromes, the rate of target vessel myocardial infarction tended to be lower with novel ZES (1.8% vs. 4.2%, p-logrank = 0.05).

Conclusions

The novel ZES showed similar 2-year clinical outcomes as compared to its predecessor. Furthermore, there was a positive safety signal regarding the incidence of target vessel myocardial infarction and a particularly low stent thrombosis rates with the novel ZES.

Figure 1. Target vessel failure at 2 years

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Thoraxcentrum Twente has received institutional research grants provided by Abbott Vascular, Biotronik, Boston Scientific and Medtronic. The present analysis received no funding.

A Review of the Current Evidence: Impact of Metabolic Surgery on Diabetes Outcomes and Obesity-Associated Macrovascular Complications

PURPOSE OF REVIEW

Type 2 diabetes (T2D) and obesity are comorbidities that generally progress with time even when non-invasive therapies are prescribed. Indeed, weight loss that is achieved with behavioral modification alone is generally inconsistent and often short-lived. In contrast, although patients do experience weight regain with metabolic surgery, they still benefit from a significant net decrease in weight. As a result, T2D remission can be achieved in up to 60% of patients within 2 years after surgery. However, it is unknown if the positive effects of metabolic surgery extend to macrovascular disease risk reduction.

RECENT FINDINGS

As noted in four randomized controlled trials (RCTs), Roux-en-Y gastric bypass (RYGB) facilitates partial remission of T2D in about 30% of volunteers 5 years after surgery. Of the four RCTs, only one investigated the effects of sleeve gastrectomy (SG) at 5 years; that study found that the rate of partial relapse was slightly lower with SG (23%). However, observational studies indicate that the gap between RYGB and SG may be larger than that observed in RCTs. In contrast, the rate of full remission is noted infrequently 5 years after SG or RYGB. Metabolic surgery also mitigates macrovascular disease risk as indicated by multiple observational studies. The effects of metabolic surgery on cardiometabolic parameters are clinically meaningful. The weight loss that is facilitated by metabolic surgery reduces the metabolic and inflammatory stress caused by T2D and obesity. In turn, metabolic surgery likely mitigates macrovascular disease risk. Additional evidence from RCTs is needed to substantiate the effects of metabolic surgery on macrovascular disease risk.

Effects of gastric bypass surgery on expression of glucose transporters and fibrotic biomarkers in kidney of diabetic fatty rats

BACKGROUND

Diabetic nephropathy is the leading cause of chronic kidney disease. Observational studies suggest Roux-en-Y gastric bypass (RYGB) reduces progression of diabetic nephropathy.

OBJECTIVES

To unravel the mechanisms by which RYGB is beneficial and protective for diabetic nephropathy.

SETTING

Academic laboratories.

METHODS

Forty-eight Zucker diabetic fatty rats were randomized to RYGB, sham surgery (SHAM), or pair-fed (PF) groups. An oral glucose tolerance test was performed at 25 days post intervention and kidneys were harvested at 30 days. Primary outcome measures included expression of key genes and proteins in the glucose transport, oxidative stress, inflammation, and fibrosis pathways.

RESULTS

Thirty days post intervention, RYGB rats weighed 349 ± 8 g, which was lower than SHAM (436 ± 14 g, P < .001), but not PF (374 ± 18 g) rats. RYGB rats had lower fasting glucose than PF animals and improved homeostatic model assessment of insulin resistance compared with PF and SHAM groups. These enhanced metabolic outcomes were accompanied by reduced sodium-glucose co-transporter 1 (Sglt1) gene expression (-23% versus PF, P = .01) in the kidney of RYGB rats. Expression of Sglt2, Glut1, or Glut2 mRNA, or oxidative stress and inflammation markers did not differ significantly. However, RYGB surgery induced a 19% lower expression of transforming growth factor (Tgfβ) mRNA (P = .004) compared with SHAM treated animals. Notably, adenosine monophosphate-activated protein kinase phosphorylation was increased (P = .04) in kidneys of the RYGB surgery animals.

CONCLUSIONS

Improvement of hyperglycemia after RYGB may reduce the glucose load on the kidney leading to a downregulation of specific glucose transporters. RYGB surgery may also attenuate kidney fibrosis through the adenosine monophosphate-activated protein kinase/TGFβ pathway.

Assessment of empiric body mass index-based thromboprophylactic dosing of enoxaparin after bariatric surgery: evidence for dosage adjustment using anti-factor Xa in high-risk patients

BACKGROUND

Despite thromboprophylaxis, postoperative deep vein thrombosis and pulmonary embolism occur after bariatric surgery, perhaps because of failure to achieve optimal prophylactic levels in the obese population.

OBJECTIVES

The aim of this study was to evaluate the adequacy of prophylactic dosing of enoxaparin in patients with severe obesity by performing an antifactor Xa (AFXa) assay.

SETTING

An academic medical center METHODS: In this observational study, all bariatric surgery cases at an academic center between December 2016 and April 2017 who empirically received prophylactic enoxaparin (adjusted by body mass index [BMI] threshold of 50 kg/m²) were studied. The AFXa was measured 3-5 hours after the second dose of enoxaparin.

RESULTS

A total of 105 patients were included; 85% were female with a median age of 47 years. In total, 16 patients (15.2%) had AFXa levels outside the prophylactic range: 4 (3.8%) cases were in the subprophylactic and 12 (11.4%) cases were in the supraprophylactic range. Seventy patients had a BMI <50 kg/m² and empirically received enoxaparin 40 mg every 12 hours; AFXa was subprophylactic in 4 (5.7%) and supraprophylactic in 6 (8.6%) of these patients. Of the 35 patients with a BMI ≥50 who empirically received enoxaparin 60 mg q12h, no AFXa was subprophylactic and 6 (17.1%) were supraprophylactic. Five patients (4.8%) had major bleeding complications. One patient developed pulmonary embolism on postoperative day 35.

CONCLUSION

BMI-based thromboprophylactic dosing of enoxaparin after bariatric surgery could be suboptimal in 15% of patients with obesity. Overdosing of prophylactic enoxaparin can occur more commonly than underdosing. AFXa testing can be a practical way to measure adequacy of pharmacologic thromboprophylaxis, especially in patients who are at higher risk for venous thromboembolism or bleeding.

The First Modified Delphi Consensus Statement for Resuming Bariatric and Metabolic Surgery in the COVID-19 Times

The purpose of this study was to achieve consensus amongst a global panel of expert bariatric surgeons on various aspects of resuming Bariatric and Metabolic Surgery (BMS) during the Coronavirus Disease-2019 (COVID-19) pandemic. A modified Delphi consensus-building protocol was used to build consensus amongst 44 globally recognised bariatric surgeons. The experts were asked to either agree or disagree with 111 statements they collectively proposed over two separate rounds. An agreement amongst ≥ 70.0% of experts was construed as consensus as per the predetermined methodology. We present here 38 of our key recommendations. This first global consensus statement on the resumption of BMS can provide a framework for multidisciplinary BMS teams planning to resume local services as well as guide future research in this area.

COVID-19 Outbreak and Surgical Practice: Unexpected Fatality in Perioperative Period

: Little is known about surgical practice in the initial phase of coronavirus disease 2019 (COVID-19) global crisis. This is a retrospective case series of 4 surgical patients (cholecystectomy, hernia repair, gastric bypass, and hysterectomy) who developed perioperative complications in the first few weeks of COVID-19 outbreak in Tehran, Iran in the month of February 2020. COVID-19 can complicate the perioperative course with diagnostic challenge and a high potential fatality rate. In locations with widespread infections and limited resources, the risk of elective surgical procedures for index patient and community may outweigh the benefit.

Safety and Efficacy of Bariatric Surgery in Inflammatory Bowel Disease Patients: a Systematic Review and Meta-analysis

BACKGROUND

The safety and efficacy of bariatric surgery in inflammatory bowel disease (IBD) patients is poorly understood. We conducted a systematic review and meta-analysis studying safety and efficacy of bariatric surgery in IBD patients as well as the impact of bariatric surgery on IBD course.

METHODS

We conducted a comprehensive search of multiple databases (through September 2019) to identify studies that reported outcome of bariatric surgery in IBD patients. Outcomes assessed included the pooled rate of adverse events, change in medications after bariatric surgery, and 12-month excess weight loss (EWL) and body mass index (BMI) reduction after bariatric surgery.

RESULTS

A total of 10 studies were included in final analysis. The pooled rate of early and late adverse events was 15.9% (95% CI, 9.3-25.9) and 16.9% (95% CI, 12.1-23.1), respectively. The rate of adverse events in Roux-en-Y gastric bypass was 45.6% (95% CI, 21.9-71.4) compared with 21.6% (95% CI, 11.1-38) in sleeve gastrectomy (p = 0.11). The pooled rate of 12-month EWL and BMI reduction after surgery was 66.1% (95% CI, 59.8-72.3%) and 13.7 kg/m² (95% CI, 12.5-14.9), respectively. The pooled rate of decrease, increase, and no change of IBD medications were 45.6% (95% CI, 23.8-69.2), 11% (95% CI, 6.3-18.4), and 57.6% (95% CI, 39.2-74.1), respectively.

CONCLUSIONS

Bariatric surgery has acceptable safety and efficacy profile in IBD patients. Nearly half of patients had decrease in their IBD medications after bariatric surgery, and only 10% experienced therapeutic escalation following bariatric surgery. Sleeve gastrectomy may be the preferred procedure in this population.

0583 Obesity-Associated Sleep Hypoventilation Syndrome and Adverse Post-Operative Bariatric Surgery Outcomes

Introduction

Although obesity hypoventilation syndrome (OHS) is associated with right ventricular dysfunction and increased mortality, its contribution to post-bariatric surgery risk remains unclear due to non-systematic OHS assessments. We hypothesize that patients with obesity-associated sleep hypoventilation (OASH) have increased adverse post-bariatric surgery outcomes than those without.

Methods

Patients undergoing polysomnography (PSG) prior to bariatric surgery at the Cleveland Clinic from 2011-2018 were retrospectively examined. OASH was defined by body mass index (BMI) ≥30kg/m2 and either PSG-based end-tidal CO2 ≥45mmHg or serum bicarbonate ≥27mEq/L. The following were considered individually and as a composite outcome: ICU stay, re-intubation, tracheostomy, discharge disposition or 30-day readmission. All-cause mortality was also examined. Outcomes were compared using two-sample t-test or Wilcoxon rank sum test and Chi-square or Fisher exact test. A multivariable logistic regression model included age, sex, BMI, apnea hypopnea index(AHI) and diabetes to examine OAHS and the composite outcome. All-cause mortality was compared using Kaplan-Meier estimation and hazard ratios from Cox proportional hazards models. SAS software (version 9.4) was used with overall significance level of 0.05.

Results

The sample comprised 1665 patients: age 45.2±12 years, 20.4% male, BMI=48.7±9 kg/m2, and 63.6% Caucasian. OASH prevalence was 68.5%. OAHS patients were older and more likely to be male with higher BMI, AHI and HbA1c. Although some individual outcomes were higher in OASH vs. non-OASH, findings were not statistically significant: re-intubation (1.5%vs.1.3%, p=0.81) and 30-day readmission (13.8% vs.11.3%, p=0.16). The composite outcome remained significantly associated with OAHS in the multivariable model: OR=1.36, 95%CI:1.005,1.845. Mortality was 2% in OASH and not significantly higher than non-OAHS (HR=1.39, 95%CI:0.56,3.42).

Conclusion

In this largest sample to date of systematically phenotyped OASH in patients undergoing bariatric surgery, we identify increased post-operative morbidity in those with OASH. Further study is needed to identify whether peri-operative treatment of OASH improves surgical outcomes.

Support

 

Gastric Bypass Surgery Improves the Skeletal Muscle Ceramide/S1P Ratio and Upregulates the AMPK/ SIRT1/ PGC-1α Pathway in Zucker Diabetic Fatty Rats

PURPOSE

Roux-en-Y gastric bypass (RYGB) is associated with remission of type 2 diabetes. However, the cellular and molecular mechanisms remain unknown. We hypothesized that RYGB would increase peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), sirtuin-1 (SIRT1), AMPK/pAMPK, and citrate synthase (CS) protein expression and decrease insulin resistance and these changes would be mediated by sphingolipids, including ceramides and the sphingolipid metabolite sphingosine-1 phosphate (S1P).

MATERIALS AND METHODS

Male ZDF rats were randomized to RYGB (n = 7) or sham surgery (n = 7) and harvested after 28 days. Total tissue ceramide, ceramide subspecies (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1), and S1P were quantified in the white gastrocnemius muscle using LC-ESI-MS/MS after separation with HPLC. Total SIRT1, AMPK, PGC-1α, and CS protein expression were measured by Western blot.

RESULTS

Body weight, fasting glucose, insulin, and HOMA-IR decreased significantly after RYGB compared with sham control. These changes were paralleled by lower total ceramide (483.7 ± 32.3 vs. 280.1 ± 38.8 nmol/g wwt), C18:0 ceramide subspecies (P < 0.05), higher S1P (0.83 ± 0.05 vs. 1.54 ± 0.21 nmol/g wwt, P < 0.05), and a lower ceramide/S1P ratio (P < 0.05) in the RYGB versus sham group. AMPK, pAMPK, SIRT1, PGC-1α, and CS protein expression was also higher after RYGB (P < 0.05). The ceramide/S1P ratio correlated with weight loss (r = 0.48, P = 0.08), insulin resistance (r = 0.61, P = 0.02), PGC-1α (r = - 0.51, P < 0.06), CS (r = - 0.63, P = 0.01), and SIRT1 (r = - 0.54, P < 0.04).

CONCLUSION

Our data demonstrate that sphingolipid balance, and increased AMPK, SIRT1, PGC-1α, and CS protein expression are part of the mechanism that contributes to the remission of diabetes after RYGB surgery.

Bariatric Surgery Improves HDL Function Examined by ApoA1 Exchange Rate and Cholesterol Efflux Capacity in Patients with Obesity and Type 2 Diabetes

Bariatric surgery improves glycemic control better than medical therapy; however, the effect of bariatric surgery on HDL function is not well characterized. Serum samples were available at baseline, 1-, and 5-years post procedures, for 90 patients with obesity and type 2 diabetes who were randomized to intensive medical therapy (n = 20), Roux-en-Y gastric bypass (RYGB, n = 37), or sleeve gastrectomy (SG, n = 33) as part of the STAMPEDE clinical trial. We examined serum HDL function by two independent assays, apolipoprotein A-1 exchange rate (AER) and cholesterol efflux capacity (CEC). Compared with baseline, AER was significantly higher at 5 years for participants in all treatment groups, but only increased significantly at 1 year in the RYGB and SG groups. CEC was divided into ABCA1-dependent and independent fractions, and the later was correlated with AER. ABCA1-independent CEC increased significantly only at 5 years in both surgical groups, but did not significantly change in the medical therapy group. There was no significant change in ABCA1-dependent CEC in any group. The increase in AER, but not ABCA1-independent CEC, was correlated with the reduction in body mass index and glycated hemoglobin levels among all subjects at 5 years, indicating that AER as a measure of HDL function would be a better reflection of therapy versus CEC.

Predicting 10-Year Risk of End-Organ Complications of Type 2 Diabetes With and Without Metabolic Surgery: A Machine Learning Approach

OBJECTIVE

To construct and internally validate prediction models to estimate the risk of long-term end-organ complications and mortality in patients with type 2 diabetes and obesity that can be used to inform treatment decisions for patients and practitioners who are considering metabolic surgery.

RESEARCH DESIGN AND METHODS

A total of 2,287 patients with type 2 diabetes who underwent metabolic surgery between 1998 and 2017 in the Cleveland Clinic Health System were propensity-matched 1:5 to 11,435 nonsurgical patients with BMI ≥30 kg/m2 and type 2 diabetes who received usual care with follow-up through December 2018. Multivariable time-to-event regression and random forest machine learning models were built and internally validated using fivefold cross-validation to predict the 10-year risk for four outcomes of interest. The prediction models were programmed to construct user-friendly web-based and smartphone applications of Individualized Diabetes Complications (IDC) Risk Scores for clinical use.

RESULTS

The prediction tools demonstrated the following discrimination ability based on the area under the receiver operating characteristic curve (1 = perfect discrimination and 0.5 = chance) at 10 years in the surgical and nonsurgical groups, respectively: all-cause mortality (0.79 and 0.81), coronary artery events (0.66 and 0.67), heart failure (0.73 and 0.75), and nephropathy (0.73 and 0.76). When a patient's data are entered into the IDC application, it estimates the individualized 10-year morbidity and mortality risks with and without undergoing metabolic surgery.

CONCLUSIONS

The IDC Risk Scores can provide personalized evidence-based risk information for patients with type 2 diabetes and obesity about future cardiovascular outcomes and mortality with and without metabolic surgery based on their current status of obesity, diabetes, and related cardiometabolic conditions.

Double-blinded, randomized, and controlled study on the effects of canagliflozin after bariatric surgery: A pilot study

Setting

Bariatric surgery is indicated for patients diagnosed with obesity and type 2 diabetes. Many patients achieve type 2 diabetes remission soon after bariatric surgery. Even though most maintain good glycemic control, remission is not maintained in all patients, and as a result, some patients may relapse. Type 2 diabetes relapse is common in patients who regain weight; weight regain is prevalent 1 to 2 years after surgery. Additional pharmacotherapy may be required to aid bariatric surgery in fostering weight loss and reducing blood glucose levels.

Objectives

The purpose of this clinical trial was to determine the effects of canagliflozin in participants who initially achieved type 2 diabetes remission but subsequently relapsed.

Methods

The double‐blinded, randomized, and prospective study recruited participants (n = 16) roughly 3 years after bariatric surgery. The participants were followed for 6 months.

Results

Body mass index (−1.24 kg/m²) and body weight (−3.7 kg) were significantly reduced with canagliflozin therapy versus placebo. There were improvements in body fat composition as denoted by reductions in android (−3.00%) and truncal (−2.67%) fat. Also, there were differences in blood glucose and hemoglobin A1C at 6 months.

Conclusion

After bariatric surgery, canagliflozin improved weight loss and glycemic outcomes in participants with type 2 diabetes. Canagliflozin also facilitated improvements in body fat composition.

Late Relapse of Diabetes After Bariatric Surgery: Not Rare, but Not a Failure

OBJECTIVE

To characterize the status of cardiometabolic risk factors after late relapse of type 2 diabetes mellitus (T2DM) and to identify factors predicting relapse after initial diabetes remission following bariatric surgery to construct prediction models for clinical practice.

RESEARCH DESIGN AND METHODS

Outcomes of 736 patients with T2DM who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at an academic center (2004-2012) and had ≥5 years' glycemic follow-up were assessed. Of 736 patients, 425 (58%) experienced diabetes remission (HbA_1c <6.5% [48 mmol/mol] with patients off medications) in the 1st year after surgery. These 425 patients were followed for a median of 8 years (range 5-14) to characterize late relapse of diabetes.

RESULTS

In 136 (32%) patients who experienced late relapse, a statistically significant improvement in glycemic control, number of diabetes medications including insulin use, blood pressure, and lipid profile was still observed at long-term. Independent baseline predictors of late relapse were preoperative number of diabetes medications, duration of T2DM before surgery, and SG versus RYGB. Furthermore, patients who relapsed lost less weight during the 1st year after surgery and regained more weight afterward. Prediction models were constructed and externally validated.

CONCLUSIONS

While late relapse of T2DM is a real phenomenon (one-third of our cohort), it should not be considered a failure, as the trajectory of the disease and its related cardiometabolic risk factors is changed favorably after bariatric surgery. Earlier surgical intervention, RYGB (compared with SG) and more weight loss (less late weight regain) are associated with less diabetes relapse in the long-term.