Longer-Term Physiological and Metabolic Effects of Gastric Bypass Surgery

Cost-Effectiveness of Bariatric Surgery in Patients Living with Obesity and Type 2 Diabetes

Aims

The favourable effects of bariatric surgeries on body weight reduction and glucose control have been demonstrated in several studies. Additionally, the cost-effectiveness of bariatric surgeries has been confirmed in several analyses. The aim of the current analysis was to demonstrate the cost-effectiveness of bariatric surgeries in obese patients with type 2 diabetes in Hungary compared to conventional diabetes treatments based on economic modelling of published clinical trial results.

Materials and Methods

Patients entered the simulation model at the age of 45 with body mass index (BMI) ≥ 30 kg/m2 and type 2 diabetes. The model was performed from the public payer's perspective, comparing sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) procedures to conventional care of diabetes. The results were provided separately for three BMI categories.

Results

The base-case analysis demonstrated that both surgery types were dominant; i.e., they saved 17 064 to 24 384 Euro public payer expenditures and resulted in improved health outcomes (1.36 to 1.50 quality-adjusted life years gain (QALY)) in the three BMI categories. Bariatric surgeries extended the life expectancy and the disease-free survival times of all the investigated diabetes complications. All the scenario analyses confirmed the robustness of the base-case analysis, such that bariatric surgeries remained dominant compared to conventional diabetes treatments.

Conclusion

The results of this cost-effectiveness analysis highlight the importance of bariatric surgeries as alternatives to conventional diabetes treatments in the obese population. Therefore, it is strongly recommended that a wider population has access to these surgeries in Hungary.

Associations between diet composition, dietary pattern, and weight outcomes after bariatric surgery: a systematic review

INTRODUCTION

Literature describing the impact of dietary intake on weight outcomes after bariatric surgery has not been synthesized. This study aimed to synthesize the evidence regarding any association between diet composition and weight outcomes post-bariatric surgery.

METHODS

CINAHL, Cochrane, Embase, MEDLINE and Scopus were searched for adult studies up to June 2021 that assessed any association between dietary intakes (≥1-macronutrient, food group, or dietary pattern) and weight outcomes at 12-months or longer after bariatric surgery. Risk of bias and quality assessments were conducted using the Scottish Intercollegiate Guidelines Network checklists and the NHMRC's Level of Evidence and Grades for Recommendations. Study findings were presented according to the time of post-surgery dietary intake assessment (≤12months, between 12 and 24 months, ≥24months).

RESULTS

5923 articles were identified, 260 were retrieved for full text screening, and 36 were eligible for inclusion (9 interventional including five randomized-controlled trials, and 27 observational cohort studies; sample sizes: 20-1610; total sample: 5065; follow-up periods: 1 year-12 years; level of evidence: II to IV, risk of bias: low to high). Findings on the association between long-term weight outcomes and dietary composition up to 24-months were mixed. After 24-months, studies consistently suggested no significant associations between weight loss and macronutrient composition or core food group patterns, or between carbohydrate, protein or food group patterns and weight recurrence. A single cohort study reported a weak association between diet quality score and weight-recurrence after 24-months.

CONCLUSION

There was no strong evidence to support significant associations between diet composition and weight outcomes post-bariatric surgery. The heterogeneity in study design and quality may reduce generalizability to external populations. Individualized dietary recommendations may be useful to support long-term post-surgery weight outcomes. More studies are needed to define and measure diet quality in this patient cohort.

REGISTRATION

PROSPERO (CRD42021264120).

Factors Associated with Dietary Habit Changes in Korean Stomach Cancer Survivors after Cancer Treatment

The current nutritional guidelines for stomach cancer survivors (SCSs) mainly focus on the influence of the surgical resection of the stomach, with limited guidance regarding a wider range of food options. We aimed to investigate the factors associated with healthier dietary changes in Korean adult SCSs. This cross-sectional study assessed dietary pattern changes after cancer treatment for 11 food categories, using a self-administered questionnaire. A 'healthier dietary change' was operationally defined as a reduced consumption of red and processed meat, grains, salt, and burnt food, and an increased consumption of poultry, fish, vegetables, fruits, legumes, and dairy products. Among a total of 624 SCSs, approximately 60% of participants reported dietary changes in a healthier direction in three or more food categories, while 9.1% reported no changes. There was no significant difference in dietary habit changes between surgery types. Multivariable adjusted analysis showed that elderly and long-term survivors were inversely associated with a healthier dietary change. SCSs with a higher level of educational achievement and income were more likely to make healthier changes in their intake of processed meat, vegetables, fruits, burnt food, or salt. SCSs with higher levels of fear of cancer recurrence, anxiety, or depression were more likely to follow healthier dietary changes regarding fish, meat, fruits, grains, or burnt food. Change in dietary pattern varied across different food items, and was associated with various characteristics of SCSs. It is crucial to repeatedly provide SCSs with information about healthier dietary patterns, considering their sociodemographic, clinical, and psychological characteristics.

Meal Patterns and Food Choices of Female Rats Fed a Cafeteria-Style Diet Are Altered by Gastric Bypass Surgery

After Roux-en-Y gastric bypass surgery (RYGB), rats tend to reduce consumption of high-sugar and/or high-fat foods over time. Here, we sought to investigate the behavioral mechanisms underlying these intake outcomes. Adult female rats were provided a cafeteria diet comprised of five palatable foodstuffs varying in sugar and fat content and intake was monitored continuously. Rats were then assigned to either RYGB, or one of two control (CTL) groups: sham surgery or a nonsurgical control group receiving the same prophylactic iron treatments as RYGB rats. Post-sur-gically, all rats consumed a large first meal of the cafeteria diet. After the first meal, RYGB rats reduced intake primarily by decreasing the meal sizes relative to CTL rats, ate meals more slowly, and displayed altered nycthemeral timing of intake yielding more daytime meals and fewer nighttime meals. Collectively, these meal patterns indicate that despite being motivated to consume a cafeteria diet after RYGB, rats rapidly learn to modify eating behaviors to consume foods more slowly across the entire day. RYGB rats also altered food preferences, but more slowly than the changes in meal patterns, and ate proportionally more energy from complex carbohydrates and protein and proportionally less fat. Overall, the pattern of results suggests that after RYGB rats quickly learn to adjust their size, eating rate, and distribution of meals without altering meal number and to shift their macronutrient intake away from fat; these changes appear to be more related to postingestive events than to a fundamental decline in the palatability of food choices.

Bariatric Surgery Impacts Levels of Serum Lipids during Pregnancy

INTRODUCTION

Bariatric surgery confers a high risk for nutritional deficiencies that could affect physiologic adaptation of lipids during pregnancy. We aimed to evaluate differences in serum lipids in pregnant women after bariatric surgery compared to obese and lean mothers.

METHODS

25 women with a history of Roux-en-Y gastric bypass (RYGB), 19 obese and 19 normal-weight controls were included at the 24th-28th gestational week for determination of fasting lipids with follow-up in a subgroup after delivery. Data on neonatal biometry were additionally assessed.

RESULTS

Women after RYGB showed lower total-cholesterol (TC), low-density lipoprotein C (LDL-C), non-high-density lipoprotein C (non-HDL-C) and triglycerides (TG) compared to obese mothers. Despite their higher BMI, women after RYGB showed lower TC, LDL-C and non-HDL-C than normal-weight mothers. Ultrasensitive C-reactive protein was lower in RYGB mothers than in obese ones, reaching values of lean controls. Differences remained unchanged in BMI-matched comparison. Birth weight percentiles of RYGB offspring were associated with maternal TC (r = 0.59, p = 0.021), LDL-C (r = 0.71, p = 0.003), non-HDL (r = 0.59, p = 0.021) but not HDL-C or TG. After delivery, lipids decreased in all women; however, TC and LDL-C showed more attenuated decline in mothers after RYGB than control women.

CONCLUSION

Pregnancies after RYGB show alterations of physiologic patterns in lipid profile. Further studies are required to evaluate whether imbalances in maternal lipids constitute a risk for abnormal fetal growth in this special cohort.

Gastric Emptying and Distal Gastrectomy Independently Enhance Postprandial Glucagon-Like Peptide-1 Release After a Mixed Meal and Improve Glycemic Control in Subjects Having Undergone Pancreaticoduodenectomy

OBJECTIVES

New-onset diabetes frequently resolves after pancreaticoduodenectomy (PD). Glucagon-like peptide-1 (GLP-1) conceivably is involved as its release is enhanced by rapid gastric emptying and distal bowel exposure to nutrients. We aimed at studying factors associated with GLP-1 release after PD.

METHODS

Fifteen PD subjects with distal gastrectomy (Whipple) and 15 with pylorus preservation were evaluated. A test meal containing 1 g paracetamol to measure gastric emptying was ingested. Blood for the measurement of paracetamol, glucose, insulin, and GLP-1 was drawn at baseline and 10, 20, 30, 60, 90, 120, 150, and 180 minutes thereafter. The Matsuda index of insulin sensitivity was calculated.

RESULTS

In univariate analysis, gastric emptying correlated with GLP-1. Glucagon-like peptide-1 responses to the modes of operation did not differ. Multiple regression analysis confirmed gastric emptying and Whipple versus pylorus-preserving pancreaticoduodenectomy as independent predictors of GLP-1 release. The Matsuda index of insulin sensitivity correlated with GLP-1 concentrations and inversely with body mass index. Patients after Whipple procedure revealed lower glycated hemoglobin as compared with pylorus-preserving pancreaticoduodenectomy.

CONCLUSIONS

Following PD, the postprandial GLP-1 release seems to be enhanced by rapid gastric emptying and to improve insulin sensitivity. Partial gastrectomy versus pylorus preservation enhanced the release of GLP-1, conceivably because of greater distal bowel exposure to undigested nutrients.

Glucagon-like peptide 1 (GLP-1) drives postprandial hyperinsulinemic hypoglycemia in pregnant women with a history of Roux-en-Y gastric bypass operation

BACKGROUND

The influential role of incretin hormones on glucose metabolism in patients with a history of Roux-en-Y gastric bypass (RYGB) has been investigated thoroughly, but there has been little examination of the effect of incretins and ectopic lipids on altered glucose profiles, especially severe hypoglycemia in pregnant women with RYGB.

METHODS

In this prospective clinical study, an oral glucose tolerance test (OGTT), an intravenous glucose tolerance test (IVGTT), and continuous glucose monitoring (CGM) were conducted in 25 women with RYGB during pregnancy, 19 of normal weight (NW) and 19 with obesity (OB) between the 24th and the 28th weeks of pregnancy, and 3 to 6 months post-partum. Post-partum, the ectopic lipid content in the liver, heart, and skeletal muscle was analyzed using ¹H-magnetic resonance spectroscopy (¹H-MRS).

RESULTS

RYGB patients presented with major fluctuations in glucose profiles, including a high occurrence of postprandial hyperglycemic spikes and hypoglycemic events during the day, as well as a high risk of hypoglycemic periods during the night (2.9 ± 1.1% vs. 0.1 ± 0.2% in the OB and vs. 0.8 ± 0.6% in the NW groups, p < 0.001). During the extended OGTT, RYGB patients presented with exaggerated expression of GLP-1, which was the main driver of the exaggerated risk of postprandial hypoglycemia in a time-lagged correlation analysis. Basal and dynamic GLP-1 levels were not related to insulin sensitivity, insulin secretion, or beta cell function and did not differ between pregnant women with and without GDM. A lower amount of liver fat (2.34 ± 5.22% vs.5.68 ± 4.42%, p = 0.015), which was positively related to insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR: rho = 0.61, p = 0.002) and beta-cell function (insulinogenic index: rho = 0.65, p = 0.001), was observed in the RYGB group after delivery in comparison to the OB group.

CONCLUSION

GLP-1 is mainly involved in the regulation of postprandial glucose metabolism and therefore especially in the development of postprandial hypoglycemia in pregnant RYGB patients, who are characterized by major alterations in glucose profiles, and thus in long-term regulation, multiple organ-related mechanisms, such as the lipid content in the liver, must be involved.

Deactivation of the NLRP3 inflammasome in infiltrating macrophages by duodenal-jejunal bypass surgery mediates improvement of beta cell function in type 2 diabetes

OBJECTIVE

Bariatric surgery could improve pancreatic beta cell function, thereby leading to the remission of the type 2 diabetes mellitus (T2DM). However, the specific mechanism underlying this phenomenon is yet to be revealed. The aim of this study is to test the hypothesis that Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in infiltrating macrophages plays an important role in the modulation of beta cell function after duodenal-jejunal bypass (DJB) surgery.

METHODS

DJB and sham surgery were performed in diabetic Sprague-Dawley (SD) rats induced by high-fat diet (HFD) and streptozotocin (STZ). Body weight, food intake, and glucose tolerance test (GTT) were measured at indicated time points. Apoptosis of the beta cells was measured by Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling (TUNEL) assay. We also assessed the macrophage content and NLRP3 expression in the rat model. Furthermore, macrophage reconstitution was performed after DJB surgery. Beta cell function and NLRP3 inflammasome pathway were re-evaluated in wild-type macrophage reconstitution group and NLRP3-knockdown macrophage reconstitution group.

RESULTS

DJB surgery group rats displayed rapid and sustained improvement in glucose tolerance. Decreased apoptosis and improved secretion function of the beta cells were observed in DJB surgery group. NLRP3 inflammasome pathway in infiltrating macrophages was also suppressed after DJB surgery. Moreover, diabetic remission acquired by DJB sustained in NLRP3-knockdown macrophage reconstitution group, while extinguished in group reconstituted with wild-type macrophage.

CONCLUSIONS

NLRP3 inflammasome deactivation in infiltrating macrophages is involved in marked beta cell function improvement after DJB surgery.

Esophagus-duodenum Gastric Bypass Surgery Improves Glucose and Lipid Metabolism in Mice

Background

Despite of its significant therapeutic effects on obesity and metabolic diseases, Roux-en-Y gastric bypass (RYGB) has limited clinical application because of considerable impacts on the gastrointestinal structure and postoperative complications. This study aims to develop a simplified surgical approach with less damage and complication but efficient metabolic benefit.

Methods

The effects of Esophagus-Duodenum gastric bypass (EDGB) on body weight, food intake, glucose and lipid metabolism were compared to RYGB in mice.

Findings

EDGB is simple, has higher survival rate and less complication. Relative to RYGB, EDGB demonstrated modest body weight control, identical improvement of glucose and lipid metabolism in obese mice. Blood glucose increased significantly 15 and 30 min after oral glucose administration, then markedly decreased in both EDGB and RYGB groups relative to the sham surgery, indicating a quicker absorption of oral glucose and improvement in glucose uptake by insulin targeted tissues. Insulin sensitivity was identically improved. EDGB significantly decreased plasma and hepatic triglyceride levels, while increased browning in visceral and subcutaneous white adipose tissue to the extent identical to RYGB. Levels of ghrelin and nesfatin-1 increased significantly after EDGB and RYGB.

Interpretation

EDGB is a valuable model to study the metabolic benefit of bariatric surgery in mice.

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Esophagus-Duodenum gastric bypass surgery is easier and safer to perform in mice.

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Esophagus-Duodenum gastric bypass can produce a metabolic benefit as efficient as Roux-en-Y gastric bypass.

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EDGB may serve as an alternative model to study the weight-loss-independent mechanisms for glycemic control.

A valuable bariatric surgery designated as esophagus-duodenum gastric bypass surgery is easier and safer to perform. Post-operative complications are rare and survival rate is higher. The benefits to reduce bodyweight and improve blood glucose are identical to the commonly used bariatric surgery named Roux-en-Y gastric bypass surgery. In addition, esophagus-duodenum gastric bypass surgery improves lipid profile in the extent identical to Roux-en-Y gastric bypass surgery. Our study indicates that esophagus-duodenum gastric bypass surgery may provide an alternative approach for the intervention of obesity, and its associated metabolic dysfunctions such as diabetes and fatty liver.

Systems Signatures Reveal Unique Remission-path of Type 2 Diabetes Following Roux-en-Y Gastric Bypass Surgery

Roux-en-Y Gastric bypass surgery (RYGB) is emerging as a powerful tool for treatment of obesity and may also cause remission of type 2 diabetes. However, the molecular mechanism of RYGB leading to diabetes remission independent of weight loss remains elusive. In this study, we profiled plasma metabolites and proteins of 10 normal glucose-tolerant obese (NO) and 9 diabetic obese (DO) patients before and 1-week, 3-months, 1-year after RYGB. 146 proteins and 128 metabolites from both NO and DO groups at all four stages were selected for further analysis. By analyzing a set of bi-molecular associations among the corresponding network of the subjects with our newly developed computational method, we defined the represented physiological states (called the edge-states that reflect the interactions among the bio-molecules), and the related molecular networks of NO and DO patients, respectively. The principal component analyses (PCA) revealed that the edge states of the post-RYGB NO subjects were significantly different from those of the post-RYGB DO patients. Particularly, the time-dependent changes of the molecular hub-networks differed between DO and NO groups after RYGB. In conclusion, by developing molecular network-based systems signatures, we for the first time reveal that RYGB generates a unique path for diabetes remission independent of weight loss.

Assessment of glucose regulation in pregnancy after gastric bypass surgery

AIMS/HYPOTHESIS

Roux-en-Y gastric bypass (RYGB) surgery is characterised by glycaemic variability. Prospective studies of glucose metabolism in pregnancy after RYGB are not available, therefore this study aimed to evaluate physiological alterations in glucose metabolism in pregnancy following RYGB.

METHODS

Sixty-three pregnant women (25 who underwent RYGB, 19 non-operated obese control women and 19 normal weight control women) were included. Frequently sampled 3 h OGTTs and 1 h IVGTTs were performed between 24 and 28 weeks of gestation and, in a subgroup, were repeated at 3-6 months after delivery.

RESULTS

We observed major alterations in glucose kinetics during the OGTT, including an early increase in plasma glucose followed by hypoglycaemia in 90% of women who had previously undergone RYGB. The higher degree of glycaemic variability in this group was accompanied by increased insulin, C-peptide and glucagon concentrations after oral glucose load, whereas no differences in insulin response were observed after parenteral glucose administration (RYGB vs normal weight). IVGTT data suggested improved insulin sensitivity (mean difference 0.226 × 10^-4 min^-1 [pmol/l]^-1 [95% CI 0.104, 0.348]; p < 0.001) and disposition index in pregnancies after RYGB when compared with obese control women. However, subtle alterations in insulin action and beta cell function were still observed when comparing women who had undergone RYGB with the normal-weight control group. Moreover, we observed that fetal growth was associated with maternal glucose nadir levels and insulin secretion in offspring of those who had previously undergone RYGB.

CONCLUSIONS/INTERPRETATION

Pregnancies after RYGB are affected by altered postprandial glucose, insulin and C-peptide dynamics. Insulin sensitivity is improved by RYGB, although subtle alterations in beta cell function are observed. Longitudinal studies are needed to assess potential consequences for fetal development and pregnancy outcomes.

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.