Type 2 Diabetes Remission Rates After Laparoscopic Gastric Bypass and Gastric Banding: Results of the Longitudinal Assessment of Bariatric Surgery Study

Metabolic surgery for the treatment of type 2 diabetes in patients with BMI lower than 35 kg/m2 : Why caution is still needed

Bariatric surgery has shifted from being a risky procedure to an evidence-based one, with proven benefits on all-cause mortality, cardiovascular disease, cancer, and diabetes control. The procedure has an overall positive result on type 2 diabetes mellitus (T2DM), with a substantial number of patients achieving disease remission. This has resulted in several studies assessing possible weight-independent effects of bariatric surgery on glycemic improvement, in addition to recommendation of the procedure to patients with class 1 obesity and T2DM, for whom the procedure was classically not indicated, and adoption of a new term, "metabolic surgery," to highlight the overall metabolic benefit of the procedure beyond weight loss. Recently, the Diabetes Surgery Summit (DSS) has included metabolic surgery in its T2DM treatment algorithm. Although the discussion brought by this consensus is highly relevant, the recommendation of metabolic surgery for patients with uncontrolled T2DM and a body mass index of 30 to 35 kg/m² still lacks enough evidence. This article provides an overall view of the metabolic benefits of bariatric/metabolic surgery in patients with class 1 obesity, compares the procedure against clinical treatment, and presents our rationale for defending caution on recommending the procedure to less obese individuals.

Adjustable gastric band surgery or medical management in patients with type 2 diabetes and obesity: three-year results of a randomized trial

BACKGROUND

Few randomized trials have compared surgical versus lifestyle and pharmacologic approaches for type 2 diabetes (T2D) patients with mild to moderate obesity.

OBJECTIVES

This study examined resolution of hyperglycemia (A1C <6.5% and fasting glucose <126 mg/dL) 3 years after randomization to either a laparoscopic adjustable gastric band (LAGB) or 1-year diabetes and weight management (DWM) program.

SETTING

University medical center, United States.

METHODS

Forty T2D patients (mean ± SD: age, 51.3 ±10.0 yr; weight 109.5 ± 15.0 kg; body mass index [BMI] 36.5 ± 3.7 kg/m²; HBA1C 8.2% ± 1.2%) were randomized to LAGB (n = 18) or DWM (n = 22).

RESULTS

At 3 years, 13% of 16 patients in LAGB and 5% of 17 patients in DWM achieved resolution of hyperglycemia (P = .601), with a modestly greater reduction in antidiabetic medications in the surgical group (P = .054). Reductions from baseline in A1C were sustained at 3 years in LAGB (-.82% [95% CI: -1.62 to -.01], P = .046) compared with DWM (+.23% [95% CI: -.57 to 1.03], P = .567). The surgical group had greater weight loss (-12.0 kg [95% CI: -15.9 to -8.1] versus -4.8 [95% CI: -8.6 to -.9], P = .010). HDL-cholesterol increased more after surgery (P = .003), but changes in triglycerides, LDL-cholesterol, and blood pressure did not differ between treatments. Diabetes- and obesity-specific quality of life improved comparably with both therapies.

CONCLUSIONS

Achievement of American Diabetes Association targets for glucose, lipids, and blood pressure was similar with both treatment strategies. LAGB leads to greater sustained weight loss and higher HDL cholesterol compared with a DWM program. These findings may help guide patients with T2D and obesity when exploring options for diabetes and weight management.

Type 2 Diabetes Mellitus (T2DM) "Remission" in Non-bariatric Patients 65 Years and Older

Objective: To analyze the factors associated with type 2 diabetes mellitus (T2DM) “remission” in non-bariatric Medicare patients 65 years and older.

Research Design and Methods: A retrospective cohort analysis of a Medicare Advantage health plan was conducted using administrative data. An individual was identified as T2DM if the individual had: ≥ 2 medical claims for T2DM coded 250.xx excluding type 1 diabetes; or ≥ 2 pharmacy claims related to T2DM; or ≥ 2 combined medical claims, pharmacy claims for T2DM in 12 months. A T2DM individual was in “remission” if they had no T2DM related claims for more than 12 months continuously. This is different from the standard American Diabetes Association (ADA) definition of remission which includes HbA1c values and hence is represented in quotation (as “remission”). 10,059 T2DM individuals were evaluated over a period of 8 years from 2008 to 2015. Cox proportional hazards was used to identify significant variables associated with T2DM “remission.”

Results: 4.97% of patients studied met the definition of T2DM “remission” in the study cohort. After adjusting for covariates this study found a number of variables associated with T2DM “remission” that were not previously reported: no statin use; low diabetes complications severity index score; no hypertension; no neuropathy; no retinopathy; race (non-white and non-African American); presence of other chronic ischemic heart disease (IHD) and females (p < 0.05).

Conclusion: T2DM “remission” in Medicare patients 65 years and older is observed in a community setting in a small proportion of non-bariatric patients.

Reversing Type 2 Diabetes: A Narrative Review of the Evidence

BACKGROUND

Type 2 diabetes (T2D) has long been identified as an incurable chronic disease based on traditional means of treatment. Research now exists that suggests reversal is possible through other means that have only recently been embraced in the guidelines. This narrative review examines the evidence for T2D reversal using each of the three methods, including advantages and limitations for each.

METHODS

A literature search was performed, and a total of 99 original articles containing information pertaining to diabetes reversal or remission were included.

RESULTS

Evidence exists that T2D reversal is achievable using bariatric surgery, low-calorie diets (LCD), or carbohydrate restriction (LC). Bariatric surgery has been recommended for the treatment of T2D since 2016 by an international diabetes consensus group. Both the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) now recommend a LC eating pattern and support the short-term use of LCD for weight loss. However, only T2D treatment, not reversal, is discussed in their guidelines.

CONCLUSION

Given the state of evidence for T2D reversal, healthcare providers need to be educated on reversal options so they can actively engage in counseling patients who may desire this approach to their disease.

Surgical options for glycaemic control in Type 1 diabetes

In recent years, bariatric surgery, also referred to as metabolic surgery, has become the most successful treatment option in those with Type 2 diabetes and obesity. There are some similarities in the pathological pathways in Type 1 and Type 2 diabetes, but the use of surgery in Type 1 diabetes remains unestablished and controversial. The treatment and management of Type 1 diabetes can be very challenging but recent advances in surgical interventions and technology has the potential to expand and optimize treatment options. This review discusses the current status of some surgical options available to people with Type 1 diabetes. These include implantable continuous glucose monitoring systems, continuous intraperitoneal insulin infusion pumps, closed-loop insulin delivery systems (also known as the artificial pancreas system) utilizing the latter two modalities of glucose monitoring and insulin delivery, and bariatric or metabolic surgery. Whole pancreas and islet transplantation are beyond the scope of this review but are briefly discussed.

IMPACT OF WEIGHT LOSS TRAJECTORY FOLLOWING RANDOMIZATION TO BARIATRIC SURGERY ON LONG-TERM DIABETES GLYCEMIC AND CARDIOMETABOLIC PARAMETERS

Objective: It is unclear whether acute weight loss or the chronic trajectory of weight loss after bariatric surgery is associated with long-term type 2 diabetes mellitus (T2DM) glycemic improvement. This ancillary study of the Surgical Treatment and Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) trial aimed to answer this question. Methods: In STAMPEDE, 150 patients with T2DM were randomized to bariatric surgery, and 96 had 5-year follow-up. Data post-Roux-en-Y gastric bypass (RYGB, n = 49) and sleeve gastrectomy (SG, n = 47) were analyzed. We defined percent weight loss in the first year as negative percent decrease from baseline weight to lowest weight in the first year. Percent weight regain was positive percent change from lowest weight in the first year to fifth year. Weight change was then correlated with cardiometabolic (CM) and glycemic outcomes at 5 years using Spearman rank correlations and multivariate analysis. Results: In both RYGB and SG, less weight loss in the first year positively correlated with higher 5-year glycated hemoglobin (HbA1c) (RYGB, β = +0.13; P<.001 and SG, β = 0.14; P<.001). In SG, greater weight regain from nadir positively correlated with higher HbA1c (β = 0.06; P = .02), but not in RYGB. Reduced first-year weight loss was also correlated with increased 5-year triglycerides (β = 1.81; P = .01), but not systolic blood pressure. Weight regain did not correlate with CM outcomes. Conclusion: Acute weight loss may be more important for T2DM glycemic control following both RYGB and SG as compared with weight regain. Clinicians should aim to assist patients with achieving maximal weight loss in the first year post-op to maximize long-term health of patients. Abbreviations: BMI = body mass index; HbA1c = glycated hemoglobin; RYGB = Roux-en-Y gastric bypass; SBP = systolic blood pressure; SG = sleeve gastrectomy; STAMPEDE = Surgical Treatment and Medications Potentially Eradicate Diabetes Efficiently; T2DM = type 2 diabetes mellitus; TG = triglyceride.

[Metabolic surgery]

In recent years the surgical treatment of metabolic diseases has become established as an effective alternative to conservative treatment. The new S3 guidelines address these changes and give clear indications for obesity surgery. One of the core points of the new guidelines is the differentiation between obesity surgery and metabolic surgery. In obesity surgery the primary aim of treatment is weight loss whereas for metabolic indications the aim is an improvement of comorbidities independent of the body mass index (BMI). With respect to the selection of procedures sleeve gastrectomy (SG) and the traditional Roux-en-Y gastric bypass (RYGB) can be used as safe and evidence-based operative procedures. The RYGB has better metabolic effects but higher complication and reintervention rates. More recent procedures, such as the one anastomosis gastric bypass (OAGB) and single anastomosis duodeno-ileal (SADI) bypass possibly have slightly stronger metabolic effects, however, the risk of malnutrition and vitamin deficiency is higher.

Serum biomarkers of inflammation and adiposity in the LABS cohort: associations with metabolic disease and surgical outcomes

BACKGROUND

The utility of serum biomarkers related to inflammation and adiposity as predictors of metabolic disease prevalence and outcomes after bariatric surgery are not well-defined.

METHODS

Associations between pre- and post-operative serum levels of four biomarkers (C-reactive protein (CRP), cystatin C (CC), leptin, and ghrelin) with baseline measures of adiposity and metabolic disease prevalence (asthma, diabetes, sleep apnea), and weight loss and metabolic disease remission after bariatric surgery were studied in the Longitudinal Assessment of Bariatric Surgery (LABS) cohort.

RESULTS

Baseline CRP levels were positively associated with the odds of asthma but not diabetes or sleep apnea; baseline CC levels were positively associated with asthma, diabetes, and sleep apnea; baseline leptin levels were positively associated with asthma and negatively associated with diabetes and sleep apnea; baseline ghrelin levels were negatively associated with diabetes and sleep apnea. Increased weight loss was associated with increased baseline levels of leptin and CRP and decreased baseline levels of CC. Remission of diabetes and asthma was not associated with baseline levels of any biomarker. A higher likelihood of asthma remission was associated with a greater decrease in leptin levels, and a higher likelihood of diabetes remission was predicted by a lesser decrease in CC. Bariatric surgery was associated with decreased post-operative CC, CRP, and leptin levels, and increased post-operative ghrelin levels.

CONCLUSION

This is the largest study to date of serum biomarkers of inflammation and adiposity in a bariatric surgery cohort. Biomarker levels correlate with metabolic disease prevalence prior to bariatric surgery, and with weight loss but not metabolic disease remission after surgery. Bariatric surgery regulates serum biomarker levels in a manner consistent with anti-inflammatory and compensatory orexigenic effects. These data contribute to our understanding of the mechanisms underlying the biologic effects of bariatric surgery.

Diet, Diabetes Status, and Personal Experiences of Individuals with Type 2 diabetes Who Self-Selected and Followed a Low Carbohydrate High Fat diet

BACKGROUND

Low carbohydrate high fat (LCHF) diets are increasing in popularity amongst patients with type 2 diabetes (T2D), however it is unclear what constitutes a sustainable LCHF diet in a real-world setting.

METHODS

This descriptive multi-method study characterized the diets, T2D status, and personal experiences of individuals with T2D who claimed to have followed an LCHF diet for at least 6 months. Participants completed a medications history, mixed-method dietary assessment, provided a blood sample, and were interviewed in-depth about their experiences with the diet (First-Assessment). Past medical records were obtained corresponding to T2D diagnosis and prior to starting their LCHF diets. Additionally, participants were followed up 15 months later to assess T2D remission (Follow-Up).

RESULTS

Twenty-eight participants completed First-Assessment and 24 completed Follow-Up. Habitual carbohydrate intake was 20 to 50 g/d for 10 participants and 50 to 115 g/d for 17 participants. Commonly reported foods were full-fat dairy, non-starchy vegetables, coconut oil, eggs, nuts, olives and avocados, olive oil, and red meat and poultry with fat. Median (interquartile range) for HbA1c was 7.5 (6.5-9.5) % prior to starting their diets, 5.8 (5.4-6.2) % at First-Assessment and 5.9 (5.3-6.6) % at Follow-Up. Reported body weight and glucose-lowering medication requirements were considerably lower at both assessments than when starting the diet. At Follow-Up, 24 participants had been following their LCHF diets for 35 (26-53) months, the majority of which were in full or partial T2D remission. Participants perceived reduced hunger and cravings as one of the most important aspects of their diets. Of concern, many participants felt unsupported by their doctors.

CONCLUSION

This study described the foods and characteristics of an LCHF "lifestyle" that was sustainable and effective for certain T2D patients in a real-world setting.

DiaRem2: Incorporating duration of diabetes to improve prediction of diabetes remission after metabolic surgery

BACKGROUND

DiaRem is a validated tool for predicting the likelihood of type 2 diabetes (T2D) remission after Roux-en-Y gastric bypass (RYGB) surgery.

OBJECTIVES

The objective of this study was to determine if the addition of duration of T2D to DiaRem improves its ability to discriminate between patients with or without T2D remission and/or to reclassify presurgery patients into accurate risk groups.

SETTING

Academic Medical Center.

METHODS

This study included patients consented into a prospective registry of Roux-en-Y gastric bypass between July 2009 and November 2015 with known duration of T2D (n = 307). Electronic health record-derived duration of T2D was compared with patient reported duration of T2D in a subset of patients (n = 48). DiaRem2 was created using clinical variables from DiaRem and duration of T2D. Area under the curve and the net reclassification index were used to assess increased performance of DiaRem2.

RESULTS

Self-reported duration of T2D was highly concordant with electronic health record-derived T2D duration (96% agreement). Early T2D remission occurred in 44% of patients. DiaRem2 included age, hemoglobin A1C, insulin medication use, and duration of T2D. DiaRem2 had a higher area under the curve than DiaRem (.876 versus .850, P = .026), reduced the number of remission risk groups from 5 down to 3, and reclassified patients from intermediate to either high or low remission groups (net reclassification index, P < .0001).

CONCLUSIONS

DiaRem2 simplifies and improves the accuracy of assessing probability of T2M remission after Roux-en-Y gastric bypass. Self-reported duration of T2D is an acceptable surrogate for T2D duration derived from clinical data.

Reduction in Comorbid Conditions Over 5 Years Following Bariatric Surgery in Medicaid and Commercially Insured Patients

OBJECTIVE

This study sought to determine changes in the prevalence of comorbid disease following bariatric surgery in Medicaid patients compared with commercially insured patients.

METHODS

Data were obtained from the Longitudinal Assessment of Bariatric Surgery, an observational cohort study of adults undergoing bariatric surgery at one of six geographically diverse centers in the United States. A total of 1,201 patients who underwent Roux-en-Y gastric bypass with 5 years of follow-up were identified. Poisson mixed models were used to estimate relative risks (RRs) and compare changes in common comorbidities between insurance groups within 0-1 and 1-5 years post surgery. Propensity scores were used to achieve balance in the baseline comorbidity burden between Medicaid and commercial patients.

RESULTS

In the first year, risk of all six comorbidities decreased substantially over time in both groups, ranging from a 32% to a 69% decrease from baseline. After 1 year post surgery, the risk of disease was stable in both groups (RRs ranged from 1.0 to 1.1). After propensity score weighting, the RRs in the first year were more similar in magnitude, while the RRs in the 1- to 5-year period were unchanged.

CONCLUSIONS

These results suggest that Medicaid patients experience a medium-term reduction in comorbid disease after bariatric surgery.

Trends in procedure type, patient characteristics, and outcomes among persons with knee osteoarthritis undergoing bariatric surgery, 2005-2014

OBJECTIVE

To evaluate trends in the utilization, clinical characteristics, and inpatient outcomes among persons with knee osteoarthritis undergoing bariatric surgery.

METHOD

We used the National Inpatient Sample (NIS) to examine trends of bariatric surgeries performed on adults with clinically documented knee osteoarthritis between 2005 and 2014. We abstracted hospital setting, procedure, demographic and clinical characteristics, and inpatient surgical outcomes from each discharge. We examined temporal trends using linear regression and Cochran-Armitage test for trend.

RESULTS

The utilization of bariatric surgery among persons with knee osteoarthritis from 2005 to 2014 remained consistent, with an annual total of about 3,300 procedures performed nationally. The most common procedure type changed from laparoscopic Roux-en-Y (65%) in 2005-2006 to laparoscopic sleeve gastrectomy (58%) in 2013-2014. The median age, proportion on Medicare, and age- and sex-adjusted prevalence of diabetes increased from 46 to 51 years, 7-23%, and 28-32%, respectively. From 2005 to 2014, the median adjusted costs, in 2017 USD, for laparoscopic and open Roux-en-Y surgeries decreased from $15,100 to $13,300 (p < 0.01) and $14,100 to $10,100 (p = 0.0001), respectively, whereas the costs of laparoscopic sleeve gastrectomy and laparoscopic banding did not change significantly. In-hospital mortality remained at 0.0-0.1% from 2005 to 2014.

CONCLUSION

Although growing evidence suggests that bariatric surgery is associated with improvements in osteoarthritis pain and functional status, the utilization of bariatric surgery among morbidly obese persons with knee osteoarthritis remained consistent from 2005 to 2014. Bariatric surgery in persons with knee osteoarthritis is generally safe, as inpatient complication and mortality rates remained low despite an increase in age and number of comorbidities.

Multicentre cohort study of antihypertensive and lipid-lowering therapy cessation after bariatric surgery

Background

Few studies have assessed changes in antihypertensive and lipid-lowering therapy after bariatric surgery. The aim of this study was to assess the 6-year rates of continuation, discontinuation or initiation of antihypertensive and lipid-lowering therapy after bariatric surgery compared with those in a matched control group of obese patients.

Methods

This nationwide observational population-based cohort study used data extracted from the French national health insurance database. All patients undergoing gastric bypass or sleeve gastrectomy in France in 2009 were matched with control patients. Mixed-effect logistic regression models were used to analyse factors that influenced discontinuation or initiation of treatment over a 6-year interval.

Results

In 2009, 8199 patients underwent primary gastric bypass (55·2 per cent) or sleeve gastrectomy (44·8 per cent). After 6 years, the proportion of patients receiving antihypertensive and lipid-lowering therapy had decreased more in the bariatric group than in the control group (antihypertensives: –40·7 versus –11·7 per cent respectively; lipid-lowering therapy: –53·6 versus –20·2 per cent; both P &lt; 0·001). Gastric bypass was the main predictive factor for discontinuation of therapy for hypertension (odds ratio (OR) 9·07, 95 per cent c.i. 7·72 to 10·65) and hyperlipidaemia (OR 11·91, 9·65 to 14·71). The proportion of patients not receiving treatment at baseline who were subsequently started on medication was lower after bariatric surgery than in controls for hypertension (5·6 versus 15·8 per cent respectively; P &lt; 0·001) and hyperlipidaemia (2·2 versus 9·1 per cent; P &lt; 0·001). Gastric bypass was the main protective factor for antihypertensives (OR 0·22, 0·18 to 0·26) and lipid-lowering medication (OR 0·12, 0·09 to 0·15).

Conclusion

Bariatric surgery is associated with a good discontinuation of antihypertensive and lipid-lowering therapy, with gastric bypass being more effective than sleeve gastrectomy.

Obesity and type 2 diabetes: Also linked in therapeutic options

The prevalence of obesity has increased worldwide over the past decades. Obesity is associated with multiple comorbidities, such as type 2 diabetes, that generates a great impact on health and economy. Weight loss in these patients leads to glycemic control so it is a target to achieve. Lifestyle changes are not effective enough and recently other treatments have been developed such as bariatric/metabolic surgery, as well as drugs for type 2 diabetes and antiobesity drugs. The aim of this review is to compare the results in weight reduction and glycemic control of the different kinds of drugs with bariatric / metabolic surgery's results in type 2 diabetes.

Weight-Independent Mechanisms of Glucose Control After Roux-en-Y Gastric Bypass

Roux-en-Y gastric bypass results in large and sustained weight loss and resolution of type 2 diabetes in 60% of cases at 1-2 years. In addition to calorie restriction and weight loss, various gastro-intestinal mediated mechanisms, independent of weight loss, also contribute to glucose control. The anatomical re-arrangement of the small intestine after gastric bypass results in accelerated nutrient transit, enhances the release of post-prandial gut hormones incretins and of insulin, alters the metabolism and the entero-hepatic cycle of bile acids, modifies intestinal glucose uptake and metabolism, and alters the composition and function of the microbiome. The amelioration of beta cell function after gastric bypass in individuals with type 2 diabetes requires enteric stimulation. However, beta cell function in response to intravenous glucose stimulus remains severely impaired, even in individuals in full clinical diabetes remission. The permanent impairment of the beta cell may explain diabetes relapse years after surgery.

Impact of bariatric surgery on cardiovascular and renal complications of diabetes: a focus on clinical outcomes and putative mechanisms

INTRODUCTION

Cardiovascular and renal disease accounts for a substantial proportion of the morbidity and mortality associated with obesity and type 2 diabetes mellitus (T2DM). Bariatric surgery is associated with improved long-term cardiovascular and renal outcomes.

AREAS COVERED

All major case-control, cohort, and randomized controlled trial studies of bariatric surgery in adults with T2DM were screened and data on prespecified cardiovascular and renal outcomes collated. Bariatric surgery reduces all-cause mortality and risk of cardiovascular disease, albuminuria and progressive chronic kidney disease. Patients with poorer glycemic control and established microvascular disease preoperatively may stand to benefit the most from the surgical approach. Reduced sympathetic drive, remission of glomerular hypertension, enhanced natriuresis, gut microbiota shifts, reduced systemic and renal inflammation, improved lipoprotein profiles, and reductions in chronic cardiac remodeling may all be implicated.

EXPERT COMMENTARY

Ongoing RCTs of bariatric surgery selectively recruiting patients with class 1 obesity and established microvascular complications of diabetes will help to better characterize which subgroups of patients benefit most from this effective therapy.

MANAGEMENT OF ENDOCRINE DISEASE: Which metabolic procedure? Comparing outcomes in sleeve gastrectomy and Roux-en Y gastric bypass

Obesity and its associated comorbidities have become one of the largest challenges for health care in the near future. Conservative therapy for obesity and related comorbidities has a very high failure rate and poor long-term results. Similarly, the conservative and medical management of the majority of metabolic diseases such as type 2 diabetes mellitus are only able to slow down disease progression but have no causal effect on the disease process. Obesity surgery has evolved as a highly effective therapy for severe obesity achieving long-lasting weight loss. Furthermore, several studies have demonstrated the beneficial effects of obesity surgery on reduction of overall mortality, reduction of cardiovascular events and superior control of obesity-related diseases such as type 2 diabetes mellitus, dyslipidemia and also the non-alcoholic steatohepatitis compared to medical therapy. Based on these findings, the term 'metabolic surgery' with the focus on treating metabolic diseases independent of body weight has been coined. Of great interest are recent studies that show that even existing complications of metabolic diseases such as diabetic nephropathy or the non-alcoholic steatohepatitis can be reversed by metabolic surgery. Although metabolic surgery has proven to be a safe and effective treatment for obesity, resolution of comorbidities and enhancing quality of life, it is still uncertain and unclear, which surgical procedure is the most effective to achieve these metabolic effects. The aim of this review is to compare the effects of the two currently most widely used metabolic operations, the Roux-en-Y gastric bypass and the sleeve gastrectomy in the treatment of obesity and its related comorbidities.

Insurance status differences in weight loss and regain over 5 years following bariatric surgery

BACKGROUND

The effectiveness of bariatric surgery among Medicaid beneficiaries, a population with a disproportionately high burden of obesity, remains unclear. We sought to determine if weight loss and regain following bariatric surgery differed in Medicaid patients compared to commercial insurance.

SUBJECTS/METHODS

Data from the Longitudinal Assessment of Bariatric Surgery, a ten-site observational cohort of adults undergoing bariatric surgery (2006-2009) were examined for patients who underwent Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Adjustable Band (LAGB), or Sleeve Gastrectomy (SG). Using piecewise spline linear mixed-effect models, weight change over 5 years was modeled as a function of insurance type (Medicaid, N = 190; commercially insured, N = 1448), time, procedure type, and sociodemographic characteristics; additionally, interactions between all time, insurance, and procedure type indicators allowed time- and procedure-specific associations with insurance type. For each time-spline, mean (kg) difference in weight change in commercially insured versus Medicaid patients was calculated.

RESULTS

Medicaid patients had higher mean weight at baseline (138.3 kg vs. 131.2 kg). From 0 to 1 year post-operatively, Medicaid patients lost similar amounts of weight to commercial patients following all procedure types (mean weight Δ difference [95% CI]: RYGB: -0.9 [-3.2, 1.4]; LAGB: -1.5 [-6.7, 3.8]; SG: 5.1 [-4.0, 14.2]). From 1 to 3 years post-operatively Medicaid and commercial patients continued to experience minimal weight loss or began to slowly regain weight (mean weight Δ difference [95% CI]: RYGB: 0.9 [0.0, 2.0]; LAGB: -2.1 [-4.2, 0.1]; SG: 0.7 [-3.0, 4.3]). From 3 to 5 years post-operatively, the rate of regain tended to be faster among commercial patients compared to Medicaid patients (mean weight Δ difference [95% CI]: RYGB: 1.1 [0.1, 2.0]; LAGB: 1.5 [-0.5, 3.5]; SG: 1.0 [-2.5, 4.5]).

CONCLUSIONS

Although Medicaid patients had a higher baseline weight, they achieved similar amounts of weight loss and tended to regain weight at a slower rate than commercial patients.

From diabetes remedy to diabetes remission; could single-anastomosis gastric bypass be a safe bridge to reach target in non-obese patients?

BACKGROUND/AIMS

Type 2 diabetes mellitus (T2DM) is considered a chronic progressive incurable metabolic disease. Single-anastomosis gastric bypass (SAGB) has proved to be effective in obese patients, yet its impact on non-obese diabetics is not extensively studied. The aim is to determine the anthropometric and glycemic outcomes of SAGB as a proposed line of treatment for T2DM patients with body mass index (BMI) 25-30 kg/m².

METHODS

From November 2013 to March 2016, a prospective study has been conducted at Ain-Shams University Hospitals on 17 consecutive patients who have undergone SAGB. The demographic and anthropometric data, as well as the relevant laboratory results, were reported. Complete T2DM remission is considered if glycosylated hemoglobin (HbA1c) <6 % for at least 1 year without medication, whereas partial remission is considered if HbA1c<6.5%.

RESULTS

The mean age was 42.6 ±13.8 years, mean BMI was 26.7 ± 2.3 kg/m² and mean duration of DM was 6.3 ± 2.7 years. The mean baseline values of HbA1c, FPG (fasting plasma glucose), and 2-hours postprandial glucose (2-H PPG) were 9.9%, 176.3 mg/dl, and 310.3 mg/dl respectively. These values significantly dropped at the 18^th month to reach 5.8%, 93.4 mg/dl, and 156.2 mg/dl, with 13/17 patients became off-treatment (complete remission rate 76.4%).

CONCLUSION

T2DM patients with BMI 25-30 kg/m² are considered the most controversial group. SAGB is an efficient metabolic procedure and could be integrated into the treatment algorithm of T2DM. Such line of treatment opens new horizons to change the concept of treatment from diabetes remedy to diabetes remission.

Intestinal and Gastric Origins for Diabetes Resolution After Bariatric Surgery

PURPOSE OF REVIEW

This paper will review the intestinal and gastric origins for diabetes resolution after bariatric surgery.

RECENT FINDINGS

In addition to the known metabolic effects of changes in the gut hormonal milieu, more recent studies investigating the role of the microbiome and bile acids and changes in nutrient sensing mechanisms have been shown to have glycemic effects in human and animal models. Independent of weight loss, there are multiple mechanisms that may lead to amelioration or resolution of diabetes following bariatric surgery. There is abundant evidence pointing to changes in gut hormones, bile acids, gut microbiome, and intestinal nutrient sensing; more research is needed to clearly delineate their role in regulating energy and glucose homeostasis after bariatric surgery.

Altered glucose metabolism after bariatric surgery: What's GLP-1 got to do with it?

Bariatric surgery is an effective treatment for obesity. The two widely performed weight-loss procedures, Roux-en-Y gastric bypass (GB) and sleeve gastrectomy (SG), alter postprandial glucose pattern and enhance gut hormone secretion immediately after surgery before significant weight loss. This weight-loss independent glycemic effects of GB has been attributed to an accelerated nutrient transit from stomach pouch to the gut and enhanced secretion of insulinotropic gut factors; in particular, glucagon-like peptide-1 (GLP-1). Meal-induced GLP-1 secretion is as much as tenfold higher in patients after GB compared to non-surgical individuals and inhibition of GLP-1 action during meals reduces postprandial hyperinsulinemia after GB two to three times more than that in persons without surgery. Moreover, in a subgroup of patients with the late complication of postprandial hyperinsulinemic hypoglycemia after GB, GLP1R blockade reverses hypoglycemia by reducing meal stimulated insulin secretion. The role of enteroinsular axis activity after SG, an increasingly popular alternative to GB, is less understood but, similar to GB, SG accelerates nutrient delivery to the intestine, improves glucose tolerance, and increases postprandial GLP-1 secretion. This review will focus on the current evidence for and against the role of GLP-1 on glycemic effects of GB and will also highlight differences between GB and SG.

Prospective evaluation of insulin and incretin dynamics in obese adults with and without diabetes for 2 years after Roux-en-Y gastric bypass

AIMS/HYPOTHESIS

In this prospective case-control study we tested the hypothesis that, while long-term improvements in insulin sensitivity (S_I) accompanying weight loss after Roux-en-Y gastric bypass (RYGB) would be similar in obese individuals with and without type 2 diabetes mellitus, stimulated-islet-cell insulin responses would differ, increasing (recovering) in those with diabetes but decreasing in those without. We investigated whether these changes would occur in conjunction with favourable alterations in meal-related gut hormone secretion and insulin processing.

METHODS

Forty participants with type 2 diabetes and 22 participants without diabetes from the Longitudinal Assessment of Bariatric Surgery (LABS-2) study were enrolled in a separate, longitudinal cohort (LABS-3 Diabetes) to examine the mechanisms of postsurgical diabetes improvement. Study procedures included measures of S_I, islet secretory response and gastrointestinal hormone secretion after both intravenous glucose (frequently-sampled IVGTT [FSIVGTT]) and a mixed meal (MM) prior to and up to 24 months after RYGB.

RESULTS

Postoperatively, weight loss and S_I-_FSIVGTT improvement was similar in both groups, whereas the acute insulin response to glucose (AIRglu) decreased in the non-diabetic participants and increased in the participants with type 2 diabetes. The resulting disposition indices (DI_FSIVGTT) increased by three- to ninefold in both groups. In contrast, during the MM, total insulin responsiveness did not significantly change in either group despite durable increases of up to eightfold in postprandial glucagon-like peptide 1 levels, and S_I-MM and DI_MM increased only in the diabetes group. Peak postprandial glucagon levels increased in both groups.

CONCLUSIONS/INTERPRETATION

For up to 2 years following RYGB, obese participants without diabetes showed improvements in DI that approach population norms. Those with type 2 diabetes recovered islet-cell insulin secretion response yet continued to manifest abnormal insulin processing, with DI values that remained well below population norms. These data suggest that, rather than waiting for lifestyle or medical failure, RYGB is ideally considered before, or as soon as possible after, onset of type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00433810.

Clinical and Patient-Centered Outcomes in Obese Patients With Type 2 Diabetes 3 Years After Randomization to Roux-en-Y Gastric Bypass Surgery Versus Intensive Lifestyle Management: The SLIMM-T2D Study

OBJECTIVE

To compare the effect of Roux-en-Y gastric bypass (RYGB) surgery versus intensive medical diabetes and weight management (IMWM) on clinical and patient-reported outcomes in obese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We prospectively randomized 38 obese patients with type 2 diabetes (15 male and 23 female, with mean ± SD weight 104 ± 16 kg, BMI 36.3 ± 3.4 kg/m², age 52 ± 6 years, and HbA_1c 8.5 ± 1.3% [69 ± 14 mmol/mol]) to laparoscopic RYGB (n = 19) or IMWM (n = 19). Changes in weight, HbA_1c, cardiovascular risk factors (UKPDS risk engine), and self-reported health status (the 36-Item Short-Form [SF-36] survey, Impact of Weight on Quality of Life [IWQOL] instrument, and Problem Areas in Diabetes Survey [PAID]) were assessed.

RESULTS

After 3 years, the RYGB group had greater weight loss (mean -24.9 kg [95% CI -29.5, -20.4] vs. -5.2 [-10.3, -0.2]; P < 0.001) and lowering of HbA_1c (-1.79% [-2.38, -1.20] vs. -0.39% [-1.06, 0.28] [-19.6 mmol/mol {95% CI -26.0, -13.1} vs. -4.3 {-11.6, 3.1}]; P < 0.001) compared with the IMWM group. Changes in cardiometabolic risk for coronary heart disease and stroke were all more favorable in RYGB versus IMWM (P < 0.05 to P < 0.01). IWQOL improved more after RYGB (P < 0.001), primarily due to subscales of physical function, self-esteem, and work performance. SF-36 and PAID scores improved in both groups, with no difference between treatments. A structural equation model demonstrated that improvement in overall quality of life was more strongly associated with weight loss than with improved HbA_1c and was manifest by greater improvements in IWQOL than with either SF-36 or PAID.

CONCLUSIONS

Three years after randomization to RYGB versus IMWM, surgery produced greater weight loss, lower HbA_1c, reduced cardiovascular risk, and improvements in obesity-related quality of life in obese patients with type 2 diabetes.

The Science of Obesity Management: An Endocrine Society Scientific Statement

The prevalence of obesity, measured by body mass index, has risen to unacceptable levels in both men and women in the United States and worldwide with resultant hazardous health implications. Genetic, environmental, and behavioral factors influence the development of obesity, and both the general public and health professionals stigmatize those who suffer from the disease. Obesity is associated with and contributes to a shortened life span, type 2 diabetes mellitus, cardiovascular disease, some cancers, kidney disease, obstructive sleep apnea, gout, osteoarthritis, and hepatobiliary disease, among others. Weight loss reduces all of these diseases in a dose-related manner-the more weight lost, the better the outcome. The phenotype of "medically healthy obesity" appears to be a transient state that progresses over time to an unhealthy phenotype, especially in children and adolescents. Weight loss is best achieved by reducing energy intake and increasing energy expenditure. Programs that are effective for weight loss include peer-reviewed and approved lifestyle modification programs, diets, commercial weight-loss programs, exercise programs, medications, and surgery. Over-the-counter herbal preparations that some patients use to treat obesity have limited, if any, data documenting their efficacy or safety, and there are few regulatory requirements. Weight regain is expected in all patients, especially when treatment is discontinued. When making treatment decisions, clinicians should consider body fat distribution and individual health risks in addition to body mass index.

Lifestyle Intervention and Medical Management With vs Without Roux-en-Y Gastric Bypass and Control of Hemoglobin A1c, LDL Cholesterol, and Systolic Blood Pressure at 5 Years in the Diabetes Surgery Study

IMPORTANCE

The Roux-en-Y gastric bypass is effective in achieving established diabetes treatment targets, but durability is unknown.

OBJECTIVE

To compare durability of Roux-en-Y gastric bypass added to intensive lifestyle and medical management in achieving diabetes control targets.

DESIGN, SETTING, AND PARTICIPANTS

Observational follow-up of a randomized clinical trial at 4 sites in the United States and Taiwan, involving 120 participants who had a hemoglobin A1c (HbA1c) level of 8.0% or higher and a body mass index between 30.0 and 39.9 (enrolled between April 2008 and December 2011) were followed up for 5 years, ending in November 2016.

INTERVENTIONS

Lifestyle-intensive medical management intervention based on the Diabetes Prevention Program and LookAHEAD trials for 2 years, with and without (60 participants each) Roux-en-Y gastric bypass surgery followed by observation to year 5.

MAIN OUTCOMES AND MEASURES

The American Diabetes Association composite triple end point of hemoglobin A1c less than 7.0%, low-density lipoprotein cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg at 5 years.

RESULTS

Of 120 participants who were initially randomized (mean age, 49 years [SD, 8 years], 72 women [60%]), 98 (82%) completed 5 years of follow-up. Baseline characteristics were similar between groups: mean (SD) body mass index 34.4 (3.2) for the lifestyle-medical management group and 34.9 (3.0) for the gastric bypass group and had hemoglobin A1c levels of 9.6% (1.2) and 9.6% (1.0), respectively. At 5 years, 13 participants (23%) in the gastric bypass group and 2 (4%) in the lifestyle-intensive medical management group had achieved the composite triple end point (difference, 19%; 95% CI, 4%-34%; P = .01). In the fifth year, 31 patients (55%) in the gastric bypass group vs 8 (14%) in the lifestyle-medical management group achieved an HbA1c level of less than 7.0% (difference, 41%; 95% CI, 19%-63%; P = .002). Gastric bypass had more serious adverse events than did the lifestyle-medical management intervention, 66 events vs 38 events, most frequently gastrointestinal events and surgical complications such as strictures, small bowel obstructions, and leaks. Gastric bypass had more parathyroid hormone elevation but no difference in B12 deficiency.

CONCLUSIONS AND RELEVANCE

In extended follow-up of obese adults with type 2 diabetes randomized to adding gastric bypass compared with lifestyle and intensive medical management alone, there remained a significantly better composite triple end point in the surgical group at 5 years. However, because the effect size diminished over 5 years, further follow-up is needed to understand the durability of the improvement.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00641251.

The Interface of Pancreatic Cancer With Diabetes, Obesity, and Inflammation: Research Gaps and Opportunities: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

A workshop on "The Interface of Pancreatic Cancer with Diabetes, Obesity, and Inflammation: Research Gaps and Opportunities" was held by the National Institute of Diabetes and Digestive and Kidney Diseases on October 12, 2017. The purpose of the workshop was to explore the relationship and possible mechanisms of the increased risk of pancreatic ductal adenocarcinoma (PDAC) related to diabetes, the role of altered intracellular energy metabolism in PDAC, the mechanisms and biomarkers of diabetes caused by PDAC, the mechanisms of the increased risk of PDAC associated with obesity, and the role of inflammatory events and mediators as contributing causes of the development of PDAC. Workshop faculty reviewed the state of the current knowledge in these areas and made recommendations for future research efforts. Further knowledge is needed to elucidate the basic mechanisms contributing to the role of hyperinsulinemia, hyperglycemia, adipokines, and acute and chronic inflammatory events on the development of PDAC.

Weight and Metabolic Outcomes 12 Years after Gastric Bypass

BACKGROUND

Few long-term or controlled studies of bariatric surgery have been conducted to date. We report the 12-year follow-up results of an observational, prospective study of Roux-en-Y gastric bypass that was conducted in the United States.

METHODS

A total of 1156 patients with severe obesity comprised three groups: 418 patients who sought and underwent Roux-en-Y gastric bypass (surgery group), 417 patients who sought but did not undergo surgery (primarily for insurance reasons) (nonsurgery group 1), and 321 patients who did not seek surgery (nonsurgery group 2). We performed clinical examinations at baseline and at 2 years, 6 years, and 12 years to ascertain the presence of type 2 diabetes, hypertension, and dyslipidemia.

RESULTS

The follow-up rate exceeded 90% at 12 years. The adjusted mean change from baseline in body weight in the surgery group was -45.0 kg (95% confidence interval [CI], -47.2 to -42.9; mean percent change, -35.0) at 2 years, -36.3 kg (95% CI, -39.0 to -33.5; mean percent change, -28.0) at 6 years, and -35.0 kg (95% CI, -38.4 to -31.7; mean percent change, -26.9) at 12 years; the mean change at 12 years in nonsurgery group 1 was -2.9 kg (95% CI, -6.9 to 1.0; mean percent change, -2.0), and the mean change at 12 years in nonsurgery group 2 was 0 kg (95% CI, -3.5 to 3.5; mean percent change, -0.9). Among the patients in the surgery group who had type 2 diabetes at baseline, type 2 diabetes remitted in 66 of 88 patients (75%) at 2 years, in 54 of 87 patients (62%) at 6 years, and in 43 of 84 patients (51%) at 12 years. The odds ratio for the incidence of type 2 diabetes at 12 years was 0.08 (95% CI, 0.03 to 0.24) for the surgery group versus nonsurgery group 1 and 0.09 (95% CI, 0.03 to 0.29) for the surgery group versus nonsurgery group 2 (P<0.001 for both comparisons). The surgery group had higher remission rates and lower incidence rates of hypertension and dyslipidemia than did nonsurgery group 1 (P<0.05 for all comparisons).

CONCLUSIONS

This study showed long-term durability of weight loss and effective remission and prevention of type 2 diabetes, hypertension, and dyslipidemia after Roux-en-Y gastric bypass. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.).

Weight Management in Patients with Type 1 Diabetes and Obesity

PURPOSE OF REVIEW

Patients with type 1 diabetes (T1D) are typically viewed as lean individuals. However, recent reports showed that their obesity rate surpassed that of the general population. Patients with T1D who show clinical signs of type 2 diabetes such as obesity and insulin resistance are considered to have "double diabetes." This review explains the mechanisms of weight gain in patients with T1D and how to manage it.

RECENT FINDINGS

Weight management in T1D can be successfully achieved in real-world clinical practice. Nutrition therapy includes reducing energy intake and providing a structured nutrition plan that is lower in carbohydrates and glycemic index and higher in fiber and lean protein. The exercise plan should include combination stretching as well as aerobic and resistance exercises to maintain muscle mass. Dynamic adjustment of insulin doses is necessary during weight management. Addition of anti-obesity medications may be considered. If medical weight reduction is not achieved, bariatric surgery may also be considered.

Long-Term Effects of Pregnancy Complications on Maternal Health: A Review

Background: Most pregnancy-related medical complications appear to resolve at delivery or shortly thereafter. Common examples are preterm labor, placental abruption, preeclampsia, and gestational diabetes. Women who developed such complications are known to be at increased risk of developing similar complications in future pregnancies. It has recently become evident that these women are at an increased risk of long term medical complications. Methods: A search through scientific publications in English regarding the association of obstetric complications and long-term maternal illness. Results: There is a clear association between various obstetric complications and long-term effects on maternal health. Conclusions: Women with a history of adverse pregnancy outcomes are at increased risk of cardiovascular and metabolic diseases later in life. Data increasingly links maternal vascular, metabolic, and inflammatory complications of pregnancy with an increased risk of vascular disease in later life.

Using genetics to inform new therapeutics for diabetes

The genetic architecture of diabetes has been extensively studied. Numerous genetic markers for diabetes have been reported. However, the translation of such knowledge into clinical interventions has been inadequate. Areas covered: We performed a literature search on various frontiers in diabetes treatment that could be improved using genetic information: (1) understanding the mechanisms of existing antidiabetic drugs, (2) repurposing existing drugs for the treatment of diabetes, (3) complementing clinical trial findings; (4) finding novel treatment approaches; (5) better estimation of the efficacy of metabolic surgery. Expert commentary: The translation of genetic information to clinical intervention requires further study, including the development of an appropriate genetic risk score algorithm for type 2 diabetes. Genomic studies provide empirical explanations for clinical trial findings. Moreover, the mechanisms of antidiabetic drugs should be thoroughly investigated to enable clinical trials and pharmacogenomics studies of these drugs. As metabolic surgery becomes more prevalent for the treatment of diabetes, genetic approaches may improve patient prioritization.

Metabolic and Bariatric Surgery for Obesity

Metabolic and bariatric surgery (MBS) leads to weight loss in obese individuals and reduces comorbidities such as type 2 diabetes. MBS is superior to medical therapy in reducing hyperglycemia in persons with type 2 diabetes, and has been associated with reduced mortality and incidences of cardiovascular events and cancer in obese individuals. New guidelines have been proposed for the use of MBS in persons with type 2 diabetes. We review the use of MBS as a treatment for obesity and obesity-related conditions and, based on recent evidence, propose that health care systems make the appropriate changes to increase accessibility for eligible patients.

What Bariatric Surgery Can Teach Us About Endoluminal Treatment of Obesity and Metabolic Disorders

Bariatric surgical procedures, including gastric bypass, vertical sleeve gastrectomy, and biliopancreatic diversion, are the most effective and durable treatments for obesity. In addition, These operations induce metabolic changes that provide weight-independent improvement in type 2 diabetes, fatty liver disease and other metabolic disorders. Initially thought to work by mechanical restriction of food intake or malabsorption of ingested nutrients, these procedures are now known to work through complex changes in neuroendocrine and immune signals emanating from the gut, including peptide hormones, bile acids, vagal nerve activity, and metabolites generated by the gut microbiota, all collaborating to reregulate appetite, food preference, and energy expenditure. Development of less invasive means of achieving these benefits would allow much greater dissemination of effective, gastrointestinal (GI)-targeted therapies for obesity and metabolic disorders. To reproduce the benefits of bariatric surgery, however, these endoscopic procedures and devices will need to mimic the physiological rather than the mechanical effects of these operations.

Impact of Fibroblast Growth Factors 19 and 21 in Bariatric Metabolism

BACKGROUND

Bariatric surgery is a popular and effective therapeutic intervention for obesity, which is an abnormal health condition that is prevalent worldwide. Metabolic improvements that precede weight loss after bariatric surgery may be mediated, in part, through the fibroblast growth factor (FGF) 15/19 and FGF21 signaling pathways. Both FGF15/19 and FGF21 are hormone-like members of the FGF family and exert their metabolic effects in an endocrine manner. Enhanced bile acid recycling after bariatric surgery leads to increased circulating levels of FGF15/19 in the distal small intestine. Synthesis of FGF21 is upregulated predominately in the fasting state through peroxisome proliferator-activated receptor pathways and to a lesser extent by FGF15/19. Key Messages: The biological functions of FGF15/19 and FGF21 are diverse and complicated. The tissue targeted effects of FGF15/19 and FGF21 of importance after bariatric surgery include the regulation of hepatic bile acid biosynthesis and ketogenesis as well as thermogenesis in adipose tissue, respectively. Furthermore, FGF15/19 and FGF21 function to regulate carbohydrate and lipid metabolism.

CONCLUSION

The long-term effects of bariatric surgery on weight loss are undisputable. However, the mechanism for improvements in glucose and lipid homeostasis observed shortly after bariatric surgery is less understood. This review article attempts to describe the known metabolic effects of FGF15/19 and FGF21 that may potentiate these improvements after bariatric surgery.

Glucose Metabolism After Gastric Banding and Gastric Bypass in Individuals With Type 2 Diabetes: Weight Loss Effect

OBJECTIVE

The superior effect of Roux-en-Y gastric bypass (RYGB) on glucose control compared with laparoscopic adjustable gastric banding (LAGB) is confounded by the greater weight loss after RYGB. We therefore examined the effect of these two surgeries on metabolic parameters matched on small and large amounts of weight loss.

RESEARCH DESIGN AND METHODS

Severely obese individuals with type 2 diabetes were tested for glucose metabolism, β-cell function, and insulin sensitivity after oral and intravenous glucose stimuli, before and 1 year after RYGB and LAGB, and at 10% and 20% weight loss after each surgery.

RESULTS

RYGB resulted in greater glucagon-like peptide 1 release and incretin effect, compared with LAGB, at any level of weight loss. RYGB decreased glucose levels (120 min and area under the curve for glucose) more than LAGB at 10% weight loss. However, the improvement in glucose metabolism, the rate of diabetes remission and use of diabetes medications, insulin sensitivity, and β-cell function were similar after the two types of surgery after 20% equivalent weight loss.

CONCLUSIONS

Although RYGB retained its unique effect on incretins, the superiority of the effect of RYGB over that of LAGB on glucose metabolism, which is apparent after 10% weight loss, was attenuated after larger weight loss.

Changes in risk factors and their contribution to reduction of mortality risk following gastric bypass surgery among obese individuals with type 2 diabetes: a nationwide, matched, observational cohort study

OBJECTIVE

We recently showed that Roux-en-Y gastric bypass (RYGB) reduces risks of mortality, cardiovascular death and myocardial infarction in obese individuals compared with matched patients with diabetes mellitus (DM). We have examined changes in risk factors after RYGB, with the aim of explaining these effects.

RESEARCH DESIGN AND METHODS

We matched (1:1) 6132 RYGB patients with DM reported to the Scandinavian Obesity Surgery Register with patients who had not undergone RYGB, based on sex, age, body mass index (BMI) and time, and assessed effects 2007-2014. We used causal mediation analysis to study effects mediated through changes to BMI and risk factors at 1 year based on Cox proportional hazards models.

RESULTS

Baseline BMI was 42 kg/m². Following RYGB, the lowest BMI was observed after 2 years (mean 31.9 kg/m²), and hemoglobin A1c (HbA1c) after 1 year (mean 6.32% (45.6 mmol/mol)). Maximum high-density lipoprotein (HDL) cholesterol was observed after 3-5 years (mean 1.46 mmol/L). Differences in BMI, HbA1c and HDL between the groups were statistically significant up to 6 years, and 2-3 years for low-density lipoprotein (LDL) and blood pressure, despite fewer glucose-lowering, hypertensive and lipid-lowering treatments. The causal mediation analysis suggested that RYGB has a positive effect on mortality risk, mainly by means of weight reduction (as opposed to changes to the risk factors analyzed).

CONCLUSIONS

Improvements in risk factors might contribute to the reduction of mortality risk after RYGB in obese individuals with type 2 diabetes, but the main effect seems to be mediated through a decrease in BMI, which could serve as a proxy for several mechanisms.