Metabolic surgery for type II diabetes: an update

Duodenal enteroendocrine cells and GIP as treatment targets for obesity and type 2 diabetes

The duodenum is an important source of endocrine and paracrine signals controlling digestion and nutrient disposition, notably including the main incretin hormone glucose-dependent insulinotropic polypeptide (GIP). Bariatric procedures that prevent nutrients from contact with the duodenal mucosa are particularly effective interventions to reduce body weight and improve glycaemic control in obesity and type 2 diabetes. These procedures take advantage of increased nutrient delivery to more distal regions of the intestine which enhances secretion of the other incretin hormone glucagon-like peptide-1 (GLP-1). Preclinical experiments have shown that either an increase or a decrease in the secretion or action of GIP can decrease body weight and blood glucose in obesity and non-insulin dependent hyperglycaemia, but clinical studies involving administration of GIP have been inconclusive. However, a synthetic dual agonist peptide (tirzepatide) that exerts agonism at receptors for GIP and GLP-1 has produced marked weight-lowering and glucose-lowering effects in people with obesity and type 2 diabetes. This appears to result from chronic biased agonism in which the novel conformation of the peptide triggers enhanced signalling by the GLP-1 receptor through reduced internalisation while reducing signalling by the GIP receptor directly or via functional antagonism through increased internalisation and degradation.

Metabolic Surgery in Korea

Metabolic surgery (MS) is a surgery that focuses on improving obesity-related comorbidities. It is often referred to as "diabetic surgery" because of its focus on treating type 2 diabetes. MS is distinguished from bariatric surgery (BS), in which weight loss is the primary goal. However, from a broader perspective, all surgeries for obese patients with diabetes can be considered MS. In Korea, metabolic and bariatric surgery (MBS) has been covered by the national health insurance since 2019. Patients with a body mass index (BMI) ≥35 or those with a BMI ≥30 and obesity-related comorbidities were eligible for MBS. Simultaneously, MS for patients with BMI values between 27.5 and 30 was partly reimbursed. The two major metabolic surgeries are Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). According to the registry of the Korean Society of Metabolic and Bariatric Surgery, 1,560 metabolic surgeries for obese patients with diabetes were performed between 2019 and 2021 in Korea, which was approximately 35.6% of all bariatric surgeries. SG was the most common, followed by RYGB and duodenal switch surgery. When dividing the patients with diabetes who underwent MBS into two groups, specifically those with BMI <35 and ≥35, we found that SG was performed most common procedure in both groups. However, there was a higher proportion of RYGB and duodenal switch operation in the former, indicating a difference in surgical methods between the two groups. MS is a promising tool for the management of poorly controlled diabetes. More data are needed to establish proper patient selection and choice of surgical type.

Delineating mouse β-cell identity during lifetime and in diabetes with a single cell atlas

Although multiple pancreatic islet single-cell RNA-sequencing (scRNA-seq) datasets have been generated, a consensus on pancreatic cell states in development, homeostasis and diabetes as well as the value of preclinical animal models is missing. Here, we present an scRNA-seq cross-condition mouse islet atlas (MIA), a curated resource for interactive exploration and computational querying. We integrate over 300,000 cells from nine scRNA-seq datasets consisting of 56 samples, varying in age, sex and diabetes models, including an autoimmune type 1 diabetes model (NOD), a glucotoxicity/lipotoxicity type 2 diabetes model (db/db) and a chemical streptozotocin β-cell ablation model. The β-cell landscape of MIA reveals new cell states during disease progression and cross-publication differences between previously suggested marker genes. We show that β-cells in the streptozotocin model transcriptionally correlate with those in human type 2 diabetes and mouse db/db models, but are less similar to human type 1 diabetes and mouse NOD β-cells. We also report pathways that are shared between β-cells in immature, aged and diabetes models. MIA enables a comprehensive analysis of β-cell responses to different stressors, providing a roadmap for the understanding of β-cell plasticity, compensation and demise.

The remission rate, metabolic changes, and quality of life assessment among patients with type 2 diabetes post-bariatric surgery in Riyadh, Saudi Arabia: A cross-sectional study

OBJECTIVES

To assess the remission rate, metabolic changes, and quality of life after bariatric surgery among Saudi patients with type 2 diabetes (T2DM).

METHODS

This cross-sectional study was conducted in 2 main centers in the Riyadh, Saudi Arabia. The study included patients with T2DM who underwent either laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB) surgery from 2014 to 2018. The remission rate was defined based on the American Diabetes Association (ADA) and the International Diabetes Federation (IDF) criteria. Quality of life was assessed using the World Health Organization Quality of Life (WHOQOL)-BREF.

RESULTS

A total of 232 patients were included with a mean age of 44.3 ± 10.3 years. 93.4% of the patients had LSG, while only 6.6% had RYGB surgery. Among patients who underwent either LSG or RYGB surgery, there was a significant improvement in metabolic and glycemic markers compared to the baseline. According to the ADA criteria, 48.5% of the patients had complete remission, while 18.9% had partial remission. Overall, 7% of the patients met the IDF optimization criteria, while 5.7% met the IDF improvement criteria. The mean score for all the QOL domains exceeded 63 ± 13, with the environmental and physical health domains having the highest scores.

CONCLUSION

Among Saudi patients, bariatric surgery was associated with high remission rates and a better quality of life.

Safety and Efficacy of Laparoscopic Vertical Clip Gastroplasty: Early Results of an Italian Multicenter Study

PURPOSE

Sleeve gastrectomy, the most commonly performed bariatric surgery procedure, carries limitations both short term including postoperative complications such as hemorrhage and gastric fistula and long term such as weight regain and gastroesophageal reflux. A new procedure has been proposed to overcome many of these limitations: laparoscopic vertical clip gastroplasty (LVCG) with BariClip.

MATERIALS AND METHODS

Fifty patients were offered LVCG and enrolled for a feasibility study in two referral bariatric centers. Indication was given as for sleeve gastrectomy, after a multidisciplinary path evaluating age, gender, BMI, comorbidities, eating behaviors, and gastroesophageal reflux. The primary outcome was major postoperative complications. Secondary outcomes included weight loss, incidence of de-novo GERD, and comorbidity resolution.

RESULTS

Patients had a mean age of 44 years and mean BMI of 37 kg/m² ± 6.2. All procedures were performed successfully in laparoscopy, with no conversion or intraoperative adverse events. The overall major postoperative complication rate was 6%. Re-operation was required in three patients for slippage. No mortality occurred. Excess weight loss, excess BMI loss, and total weight loss at 6 months were 36%, 57%, and 22%, respectively. There was no instance of de-novo GERD. Resolution of hypertension occurred in 50% of cases, OSAS in 65% of cases, and DMII in 80% of cases.

CONCLUSION

The safety of LVCG procedure has been reproduced in a multicentric, multi-surgeon study. Weight loss outcomes appear promising. A randomized trial is needed to fully assess the benefits of LVCG.

Investigating the change in gene expression profile of blood mononuclear cells post-laparoscopic sleeve gastrectomy in Chinese obese patients

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is a sustainable technique that effectively treats morbid obesity. However, the molecular mechanisms underlying the improvement of metabolic health following this process warrants more investigation. This study investigates LSG-related molecules and uses bulk RNA-sequencing high-throughput analysis to unravel their regulatory mechanisms.

METHODS

Peripheral blood mononuclear cells (PBMC) were collected from ten obese patients with BMI ≥ 32.5 kg/m² in the Department of General Surgery of Kunming First People's Hospital. After LSG, patients were followed up for one month, and blood samples were retaken. Blood samples from ten patients before and after LSG and bulk RNA-Seq data were analyzed in this study. LSG-associated gene expression was detected by weighted gene coexpression network analysis (WGCNA) and differential analysis. Subsequently, essential signature genes were identified using logistic least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) algorithms. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and single-sample gene set enrichment analysis (ssGSEA) were utilized to reveal the potential functions of the target genes. Furthermore, the Pearson correlation of signature genes with leptin and lipocalin was also explored. Finally, we constructed a robust endogenous RNA (ceRNA) network based on miRWalk and starBase databases.

RESULTS

We identified 18 overlapping genes from 91 hub genes, and 165 differentially expressed mRNAs (DE-mRNA), which were revealed to be significantly associated with immune cells, immune response, inflammatory response, lipid storage, and localization upon functional enrichment analysis. Three signature genes, IRF1, NFKBIA, and YRDC, were identified from the 18 overlapping genes by LASSO and SVM-REF algorithms. The logistic regression model based on the three signature genes highlighted how robustly they discriminated between samples. ssGSEA indicated these genes to be involved in lipid metabolism and degradation pathways. Moreover, leptin levels were significantly reduced in patients undergoing LSG, and NFKBIA significantly negatively correlated with leptin. Finally, we identified how the long non-coding RNA (lncRNA) ATP2B1-AS1 regulated the expression of the signature genes by competitively binding to six microRNAs (miRNAs), which were hsa-miR-6509-5p, hsa-miR-330-5P, hsa-miR-154-5P, hsa-miR-145-5P, hsa-miR4726-5P and hsa-miR-134-5P.

CONCLUSION

This study identified three critical regulatory genes significantly differentiated between patients before and after LSG treatment and highlighted their potentially crucial role after bariatric surgery. This provides novel insights to increase our understanding of the underlying mechanisms of weight loss and associated metabolic improvement after bariatric surgery.

Impact of Weight Loss on the Severity of Albuminuria in Obese Diabetic Patients Undergoing Laparoscopic Sleeve Gastrectomy and One-Anastomosis Gastric Bypass

Aim

To examine the effect of weight-loss induced bariatric procedures on albuminuria levels among diabetic patients suffering from obesity.

Methods

Adults patients who suffer from morbid obesity and type 2 diabetes mellitus (T2DM) were included in a prospective cohort study. Subjects were scheduled to undergo laparoscopic sleeve gastrectomy (LSG) or one-anastomosis gastric bypass (OAGB). The albumin-to-creatinine ratio (ACR) was adopted to assess the degree of albuminuria. Microalbuminuria was determined as a ratio of >2.5-30 mg/mmol and >3.5-30 mg/mmol for males and females, respectively, while macroalbuminuria was diagnosed when the ACR exceeded >30 mg/mmol.

Results

The mean uACR decreased significantly from 20.95±16.89 to 9.92±12.69mg/mmol in LSG cohort (p <0.001), and from 19.52±16.65 to 9.34±11.77mg/mmol in the OAGB cohort, with no statistically considerable differences between both cohorts at the end of follow-up (p = 0.78). Twelve months after the procedures, the percentages of cases with microalbuminuria decreased significantly to 23.8% and 23.9%, respectively (p < 0.001); likewise, the percentages of cases with macroalbuminuria significantly decreased to 7.9% and 7.5% in the LSG and OAGB groups, respectively (p < 0.001). There were no statistically considerable differences between LSG and OAGB regarding the percentages of patients with micro or macroalbuminuria at the end of follow-up. Besides, there were no significant associations between the degree of weight loss and improvement (p = 0.959) or remission (p = 0.73) of microalbuminuria.

Conclusion

Bariatric surgery significantly reduced the severity of albuminuria 1-year after the procedure, with no preference for one procedure over the other.

Biliopancreatic Diversion (BPD), Long Common Limb Revisional Biliopancreatic Diversion (BPD + LCL-R), Roux-en-Y Gastric Bypass [RYGB] and Sleeve Gastrectomy (SG) mediate differential quantitative changes in body weight and qualitative modifications in body composition: a 5-year study

AIMS

Bariatric surgeries induce profound weight loss (decrease in body mass index, BMI), through a decrease in fat mass (FM) and to a much lesser degree of fat-free mass (FFM). Some reports indicate that the weight which is lost after gastric bypass (RYGB) and sleeve gastrectomy (SG) is at least partially regained 2 years after surgery. Here we compare changes in BMI and body composition induced by four bariatric procedures in a 5 years follow-up study.

METHODS

We analyzed retrospectively modifications in BMI, FM and FFM obtained through Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), biliopancreatic diversion (BPD) and a long common limb revisional biliopancreatic diversion (reduction of the gastric pouch and long common limb; BPD + LCL-R). Patients were evaluated at baseline and yearly for 5 years. Of the whole cohort of 565 patients, a subset of 180 patients had all yearly evaluations, while the remaining had incomplete evaluations. Setting University Hospital.

RESULTS

In a total of 180 patients evaluated yearly for 5 years, decrease in BMI and FM up to 2 years was more rapid with RYGB and SG than BPD and BPD + LCL-R; with RYGB and SG both BMI and FM slightly increased in the years 3-5. At 5 years, the differences were not significant. When analysing the differences between 2 and 5 years, BPD + LCL-R showed a somewhat greater effect on BMI and FM than RYGB, BPD and SG. Superimposable results were obtained when the whole cohort of 565 patients with incomplete evaluation was considered.

CONCLUSIONS

All surgeries were highly effective in reducing BMI and fat mass at around 2 years; with RYGB and SG both BMI and FM slightly increased in the years 3-5, while BPD and BPD + LCL-R showed a slight further decreases in the same time interval.

The Gut Microbiome: Connecting Diet, Glucose Homeostasis, and Disease

Type 2 diabetes rates continue to rise unabated, underscoring the need to better understand the etiology and potential therapeutic options available for this disease. The gut microbiome plays a role in glucose homeostasis, and diabetes is associated with alterations in the gut microbiome. Given that consumption of a Western diet is associated with increased metabolic disease, and that a Western diet alters the gut microbiome, it is plausible that changes in the gut microbiota mediate the dysregulation in glucose homeostasis. In this review, we highlight a few of the most significant mechanisms by which the gut microbiome can influence glucose regulation, including changes in gut permeability, gut-brain signaling, and production of bacteria-derived metabolites like short-chain fatty acids and bile acids. A better understanding of these pathways could lead to the development of novel therapeutics to target the gut microbiome in order to restore glucose homeostasis in metabolic disease. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.