Surgical cure for type 2 diabetes by foregut or hindgut operations: a myth or reality? A systematic review. Surg Endosc. 2017;31:25-37. [PMID: 27194257 DOI: 10.1007/s00464-016-4952-4]

RYGB surgery has modest effects on intestinal morphology and gut hormone populations in the bypassed biliopancreatic limb but causes reciprocal changes in GLP-2 and PYY in the alimentary limb

Roux-en-Y gastric-bypass (RYGB) induced alterations in intestinal morphology and gut-cell hormone expression profile in the bypassed biliopancreatic-limb (BPL) versus the alimentary-limbs (AL) are poorly characterised. This pilot study has therefore explored effects following RYGB in high-fat-diet (HFD) and normal-diet (ND) rats. Female Wistar rats (4-week-old) were fed HFD or ND for 23-weeks prior to RYGB or sham surgeries. Immunohistochemical analysis of excised tissue was conducted three-weeks post-surgery. After RYGB, intestinal morphology of the BPL in both HFD and ND groups was unchanged with exception of a small decrease in villi width in the ND-RYGB and crypt depth in the HFD-RYGB group. However, in the AL, villi width was decreased in ND-RYGB rats but increased in the HFD-RYGB group. In addition, crypt depth decreased after RYGB in the AL of HFD rats. GIP positive cells in either limb of both groups of rats were unchanged by RYGB. Similarly, there was little change in GLP-1 positive cells, apart from a small decrease of numbers in the villi of the BPL in HFD rats. RYGB increased GLP-2 cell numbers in the AL of ND-RYGB rats, including in both crypts and villi. This was associated with decreased numbers of cells expressing PYY in the AL of ND-RYGB rats. The BPL appears to maintain normal morphology and unchanged enteroendocrine cell populations despite being bypassed in RYGB-surgery. In contrast, in the AL, villi area is generally enhanced post-RYGB in ND rats with increased numbers of GLP-2 positive cells and decreased expression of PYY.

Reversal and Remission of T2DM - An Update for Practitioners

Over the past 50 years, many countries around the world have faced an unchecked pandemic of obesity and type 2 diabetes (T2DM). As best practice treatment of T2DM has done very little to check its growth, the pandemic of diabesity now threatens to make health-care systems economically more difficult for governments and individuals to manage within their budgets. The conventional view has been that T2DM is irreversible and progressive. However, in 2016, the World Health Organization (WHO) global report on diabetes added for the first time a section on diabetes reversal and acknowledged that it could be achieved through a number of therapeutic approaches. Many studies indicate that diabetes reversal, and possibly even long-term remission, is achievable, belying the conventional view. However, T2DM reversal is not yet a standardized area of practice and some questions remain about long-term outcomes. Diabetes reversal through diet is not articulated or discussed as a first-line target (or even goal) of treatment by any internationally recognized guidelines, which are mostly silent on the topic beyond encouraging lifestyle interventions in general. This review paper examines all the sustainable, practical, and scalable approaches to T2DM reversal, highlighting the evidence base, and serves as an interim update for practitioners looking to fill the practical knowledge gap on this topic in conventional diabetes guidelines.

Revisiting the concept of incretin and enteroendocrine L-cells as type 2 diabetes mellitus treatment

The significant growth in type 2 diabetes mellitus (T2DM) prevalence strikes a common threat to the healthcare and economic systems globally. Despite the availability of several anti-hyperglycaemic agents in the market, none can offer T2DM remission. These agents include the prominent incretin-based therapy such as glucagon-like peptide-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 inhibitors that are designed primarily to promote GLP-1R activation. Recent interest in various therapeutically useful gastrointestinal hormones in T2DM and obesity has surged with the realisation that enteroendocrine L-cells modulate the different incretins secretion and glucose homeostasis, reflecting the original incretin definition. Targeting L-cells offers promising opportunities to mimic the benefits of bariatric surgery on glucose homeostasis, bodyweight management, and T2DM remission. Revising the fundamental incretin theory is an essential step for therapeutic development in this area. Therefore, the present review explores enteroendocrine L-cell hormone expression, the associated nutrient-sensing mechanisms, and other physiological characteristics. Subsequently, enteroendocrine L-cell line models and the latest L-cell targeted therapies are reviewed critically in this paper. Bariatric surgery, pharmacotherapy and new paradigm of L-cell targeted pharmaceutical formulation are discussed here, offering both clinician and scientist communities a new common interest to push the scientific boundary in T2DM therapy.

Goals of cure: Perspectives on the concept of cure in type 2 diabetes

RATIONALE, AIMS AND OBJECTIVES: Type 2 diabetes (T2D) is an archetypical chronic condition of significant prevalence. Yet the concept of cure in the context of T2D reveals an interplay between the medical imagination and clinical realities that can shift the course of a patient's care. There are two domains in which cure is sociologically constructed: the professional domain occupied by clinicians treating people with T2D, and the lay domain occupied by T2D patients. Lay epistemologies of cure tend to be focused on modifying the experience of having T2D, while professional epistemologies tend to focus on modifying the disease through medical treatment. The objective of this study is to explore the role of the concept of cure in the context of type 2 diabetes, a model for chronic disease.

METHODS

Through surveys and interviews of T2D patients, providers and researchers at an urban academic medical centre, I explore the perspectives and attitudes each group have towards the concept of cure in T2D. Semi-structured interviews of T2D professionals and patient surveys consisting of free response questions and Likert scale items were thematically analysed for perspectives on cure in T2D.

RESULTS

Sixteen T2D patients met inclusion criteria and consented to the survey and ten T2D professionals were interviewed. Cure is conceived of heterogeneously both within and between epistemologies. Patients carry hopes of cure predicated on eliminating the unpleasant experiences of T2D and its treatments, while T2D professionals tend to avoid invoking the concept of cure, at least to patients, on grounds of clinical uncertainty. However, the concept of cure is a significant motivator of treatment in both lay and professional epistemologies.

CONCLUSION

Different viewpoints on cure in T2D present an opportunity for shared meaning and decision making between patients and their providers that can frame the best possible outcome for patient care.

Comparison of the Outcomes of Single Anastomosis Duodeno-Ileostomy with Sleeve Gastrectomy (SADI-S), Single Anastomosis Sleeve Ileal (SASI) Bypass with Sleeve Gastrectomy, and Sleeve Gastrectomy Using a Rodent Model with Diabetes

OBJECTIVE

Single anastomosis duodeno-ileostomy with sleeve gastrectomy (SADI-S) is a powerful form of bariatric surgery; however, it has a high risk of malnutrition. Single anastomosis sleeve ileal (SASI) bypass with sleeve gastrectomy may be used as an alternative procedure to avoid malnutrition associated with SADI-S; however, no comparison between the two procedures has been performed.

METHODS

Sprague-Dawley rats with diabetes (n = 32) were divided into four groups: SADI-S (n = 8), SASI (n = 8), SG (n = 8), and SHAM (n = 8). Body weight, food intake, and fasting blood glucose were measured, and the oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed before and after surgery. Blood samples were collected before and after the surgery to assess the levels of glucagon-like peptide-1 (GLP-1), hemoglobin, albumin, vitamin B12, calcium, and iron.

RESULTS

The SADI-S and SASI groups showed significantly greater weight loss and better glucose control than the SG group postoperatively. The SADI-S and SASI groups showed similar improvements in glucose control throughout the study. The SADI-S and SASI groups had significantly higher GLP-1 levels than the SG group at 6 months. The SADI-S and SASI groups presented with various degrees of deficiencies, with the SADI-S group showing a higher risk for hypoalbuminemia and iron deficiency than the SASI group.

CONCLUSIONS

The SASI procedure may be a better alternative as it has excellent bariatric and metabolic results with lower risk for hypoalbuminemia and can be easily converted into either SADI-S or SG procedures. Nevertheless, further clinical results are needed.

Outcomes of Diabetic Retinopathy Post-Bariatric Surgery in Patients with Type 2 Diabetes Mellitus

Bariatric surgery is an emerging therapeutic approach for obese type 2 diabetes mellitus (T2DM) patients, with proven benefits for achieving target glucose control and even remission of diabetes. However, the effect of bariatric surgery upon diabetic retinopathy is still a subject of debate as some studies show a positive effect while others raise concerns about potential early worsening effects. We performed a systematic review, on PubMed, Science Direct, and Web of Science databases regarding the onset and progression of diabetic retinopathy in obese T2DM patients who underwent weight-loss surgical procedures. A total of 6375 T2DM patients were analyzed. Most cases remained stable after bariatric surgery (89.6%). New onset of diabetic retinopathy (DR) was documented in 290 out of 5972 patients (4.8%). In cases with DR at baseline, progression was documented in 50 out of 403 (12.4%) and regression in 90 (22.3%). Preoperative careful preparation of hemoglobin A1c (HbA1c), blood pressure, and lipidemia should be provided to minimize the expectation of DR worsening. Ophthalmologic follow-up should be continued regularly in the postoperative period even in the case of diabetic remission. Further randomized trials are needed to better understand the organ-specific risk factors for progression and provide personalized counseling for T2DM patients planned for bariatric surgery.

Effect of Roux-en-Y Gastric Bypass with Different Lengths of Biliopancreatic and Alimentary Limbs for Patients with Type 2 Diabetes Mellitus and a BMI < 35 kg/m2: 5-Year Outcomes in Chinese Patients

PURPOSE

There have been no definite conclusions about the biliopancreatic limb (BPL) and alimentary limb (AL) lengths in Roux-en-Y gastric bypass (RYGB) operations for different populations and BMIs. Western scholars have performed many studies on the lengths of the BPL and AL in patients with a BMI ≥ 35 kg/m². However, for diabetic Chinese patients with BMI < 35 kg/m², few people have compared the effects of different BPL and AL lengths on patient prognosis.

PATIENTS AND METHODS

Clinical data were collected prospectively and analyzed retrospectively for 87 patients with type 2 diabetes (T2DM) who underwent RYGB with a BPL of 50 cm and an AL of 50 cm (BPL50/AL50) or with a BPL of 100 cm and an AL of 100 cm (BPL100/AL100) and who were followed up for 5 years.

RESULTS

The cohort included 42 patients in the BPL50/AL50 group and 45 patients in the BPL100/AL100 group. At 5 years, there were significant differences in BMI, total weight loss (TWL%), glycosylated hemoglobin, and homeostasis model assessment insulin resistance between BPL50/AL50 and BPL100/AL100 (P < 0.05). Diabetes remission rate of the BPL100/AL100 group was significantly higher than that of the BPL50/AL50 group. Diabetes remission at 1 year after surgery correlated with the length limb (BPL + AL), duration of diabetes and TWL%. There was no difference in complications between BPL50/AL50 and BPL100/AL100.

CONCLUSIONS

RYGB with BPL100/AL100 is a safe and effective treatment for diabetic patients with a BMI < 35 kg/m² and offers significant improvement in weight loss and glycemic control.

Revisional large gastric pouch with Roux-en-Y gastric bypass for patients with type 2 diabetes and a body mass index less than 35 kg/m2: a cause and effect analysis

PURPOSE

To evaluate the long-term efficacy of large gastric pouch surgery and revisional surgery in patients with a body mass index (BMI) < 35 kg/m² and type 2 diabetes mellitus (T2DM).

METHODS

We conducted a retrospective review of patients who underwent laparoscopic Roux-en-Y gastrojejunostomy with a large gastric pouch in our hospital. The clinical pre- and post-surgery data, including BMI, waist circumference, fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), lipid metabolism-related indicators, homoeostatic model assessment of insulin resistance (HOMA-IR), and major complications, were recorded and analyzed.

RESULTS

Twenty-four patients were included in the analysis, 12 of whom underwent revisional surgery. At their 5-year-follow-up after the primary surgery, the BMI and waist circumference of the patients with T2DM were lower than their baseline values. The BMI, HbA1c, HOMA-IR, FPG and waist circumference also decreased after the revisional surgery. The rates of remission of diabetes after the primary vs. after the revisional surgery were 4.17% vs. 41.70%, respectively (P < 0.05).

CONCLUSION

Roux-en-Y gastrojejunostomy with a large gastric pouch is not effective in the long term and, therefore, is unsuitable for Chinese patients with T2DM and a BMI < 35 kg/m². Conversely, revisional surgery has a definite effect on these patients.

From Entero-Endocrine Cell Biology to Surgical Interventional Therapies for Type 2 Diabetes

The physiological roles of the enteroendocrine system in relation to energy and glucose homeostasis regulation have been extensively studied in the past few decades. Considerable advances were made that enabled to disclose the potential use of gastro-intestinal (GI) hormones to target obesity and type 2 diabetes (T2D). The recognition of the clinical relevance of these discoveries has led the pharmaceutical industry to design several hormone analogues to either to mitigate physiological defects or target pharmacologically T2D.Amongst several advances, a major breakthrough in the field was the unexpected observation that enteroendocrine system modulation to T2D target could be achieved by surgically induced anatomical rearrangement of the GI tract. These findings resulted from the widespread use of bariatric surgery procedures for obesity treatment, which despite initially devised to induce weight loss by limiting the systemic availably of nutrients, are now well recognized to influence GI hormone dynamics in a manner that is highly dependent on the type of anatomical rearrangement produced.This chapter will focus on enteroendocrine system related mechanisms leading to improved glycemic control in T2D after bariatric surgery interventions.

In-and-Out Molecular Changes Linked to the Type 2 Diabetes Remission after Bariatric Surgery: An Influence of Gut Microbes on Mitochondria Metabolism

Different kinds of gastrointestinal tract modulations known as “bariatric surgery” are actually the most effective treatment for obesity and associated co-morbidities, such as type 2 diabetes (T2DM). The potential causes of those effects have yet to be explained. In our study, we focused on molecular changes evoked by laparoscopic sleeve gastrectomy leading to T2DM remission. Two complementary metabolomics techniques, namely, liquid chromatography coupled with mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS), were used to study those effects in a group of 20 obese patients with T2DM selected from a cohort of 372 obese individuals who underwent bariatric surgery and did not receive anti-diabetic treatment afterward. Modified levels of carnitines, lipids, amino acids (including BCAA) and α- and β-hydroxybutyric acids were detected. Presented alterations suggest a major role of mitochondria activity in T2DM remission process. Moreover, some of the observed metabolites suggest that changes in gut microbiota composition may also correlate with the tempo of diabetes recovery. Additional analyses confirmed a relationship between biochemical and clinical parameters and the aforementioned metabolites, thereby, highlighting a role of mitochondria and microbes. Our data suggests that there is a previously undescribed relationship between mitochondria and gut microbiota, which changes after the bariatric surgery. More investigations are needed to confirm and explore the observed findings.

Impact of gastric emptying and small intestinal transit on blood glucose, intestinal hormones, glucose absorption in the morbidly obese

This study evaluated gastric emptying (GE) and small intestinal (SI) transit in people with morbid obesity and their relationships to glycaemia, incretin hormones, and glucose absorption METHODS: GE and caecal arrival time (CAT) of a mixed meal were assessed in 22 morbidly obese (50.2 ± 2.5 years; 13 F:9 M; BMI: 48.6 ± 1.8 kg/m2) and 10 lean (38.6 ± 8.4 years; 5 F:5 M; BMI: 23.9 ± 0.7 kg/m2) subjects, using scintigraphy. Blood glucose, plasma 3-O-methylglucose, insulin, glucagon, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were measured. Insulin sensitivity and resistance were also quantified RESULTS: When compared with lean subjects, GE (t50: 60.7 ± 6.5 vs. 41.1 ± 7.3 min; P  = 0.04) and CAT (221.5 ± 9.8 vs. 148.0 ± 7.1 min; P =  0.001) of solids were prolonged in morbid obesity. Postprandial rises in GIP (P = 0.001), insulin (P  = 0.02), glucose (P = 0.03) and 3-O-methylglucose (P = 0.001) were less. Whereas GLP-1 increased at 45 mins post-prandially in lean subjects, there was no increase in the obese (P  = 0.04). Both fasting (P = 0.045) and postprandial (P = 0.012) plasma glucagon concentrations were higher in the obese CONCLUSIONS: GE and SI transit are slower in the morbidly obese, and associated with reductions in postprandial glucose absorption, and glycaemic excursions, as well as plasma GIP and GLP-1.

Reversibility of diabetes mellitus: Narrative review of the evidence

The global disease burden of diabetes mellitus is high. It is well-established that prediabetes is reversible but it is unclear whether diabetes is reversible once it has been diagnosed. The objective of this narrative review is to review the evidence of reversibility of diabetes mellitus and stimulate interest in prolonged remission as a treatment target. The current evidence for bariatric surgery is stronger than intensive medical management and the evidence is stronger for type 2 diabetes patients compared with type 1 diabetes patients. It is also unclear whether non obese diabetes patients would benefit from such interventions and the duration of diabetes before diabetes become irreversible. Further research is needed in this area especially with regards to the subgroup of diabetes patient who will benefit from these interventions and the long term safety and efficacy remains unknown especially with intensive medical management.

Appetite, Glycemia, and Entero-Insular Hormone Responses Differ Between Oral, Gastric-Remnant, and Duodenal Administration of a Mixed-Meal Test After Roux-en-Y Gastric Bypass

OBJECTIVE

To examine the effect of different feeding routes on appetite and metabolic responses after Roux-en-Y gastric bypass (RYGB).

RESEARCH DESIGN AND METHODS

A standard liquid meal was administered either orally, into the gastric remnant, or intraduodenally 6 months after RYGB. Changes in plasma glucose, insulin, glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY), and appetite were measured pre- and postprandially.

RESULTS

Postprandial GLP-1 and PYY responses were similar, whereas glucose, insulin, and GIP levels differed markedly after oral versus intraduodenal feeding. Intraduodenal feeding prompted an intermediate appetite response (i.e., between oral and intragastric). For postprandial glucose, insulin, and GIP levels, the intraduodenal route was more similar to the intragastric than the oral route. Intragastric administration did not evoke changes in appetite, glucose, or insulin; however, it slightly increased GLP-1 and PYY and moderately increased GIP.

CONCLUSIONS

Appetite and metabolic responses after RYGB depend on the route by which nutrients enter the gastrointestinal tract.

Duodenal long noncoding RNAs are associated with glycemic control after bariatric surgery in high-fat diet-induced diabetic mice

BACKGROUND

The duodenum plays a role in the mechanism of type 2 diabetes remission after bariatric surgery. Roux-en-Y gastric bypass (RYGB) may change gene expression in the duodenum and metabolism. Long noncoding RNAs (lncRNAs) constitute a novel class of RNAs that regulate gene expression. Little is known about how duodenal lncRNAs respond to RYGB. Logically, studies on the changes of duodenal lncRNAs potentially can lead to an understanding of the mechanisms of bariatric surgery, as well as discovery of antidiabetic drug targets and biomarkers predicting postoperative outcome.

OBJECTIVES

To investigate the expression signature of duodenal lncRNAs associated with glycemic improvement by duodenal-jejunal bypass (DJB), a component of RYGB, on a genome-wide scale in high-fat diet-induced diabetic mice.

SETTING

University medical center.

METHODS

High fat diet-induced diabetic mice were randomized into 2 groups receiving either the DJB or a sham procedure. Microarray was applied to screen the differentially expressed lncRNAs and messenger RNAs (mRNAs) in the duodenum between the DJB and sham groups, and the result was validated by quantitative real-time polymerase chain reaction in another cohort of animals. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the potential lncRNA functions. Based on Pearson correlation analysis, the lncRNA-mRNA and lncRNA-transcription factor (TF) interaction networks were constructed to identify and rank core regulatory lncRNAs and transcription factors.

RESULTS

A total of 301 lncRNAs, including 232 that were upregulated and 69 downregulated (fold change≥2.0), were differentially expressed in the duodenum between the DJB and sham groups. GO enrichment indicated that these lncRNA-coexpressed mRNAs were correlated with biological processes including cell proliferation, digestion, and catabolic and biosynthetic processes. KEGG pathway analysis revealed that in addition to the digestion and absorption signaling pathways, pancreatic secretion- and inflammatory process-related signaling pathways were mostly enriched in the DJB group. In addition, the lncRNA-mRNA interaction network combined with GO and KEGG pathway analysis suggested that as a top-ranked gene, NONMMUG021726 may play an important role in the mechanism of type 2 diabetes remission after DJB.

CONCLUSION

DJB leads to drastic changes in lncRNA and mRNA expressions in the duodenum. The majority of top-ranked lncRNAs and mRNAs have roles in pancreatic secretion and inflammatory processes, implying that bypass of the duodenum may initiate insulin secretion and attenuate inflammation. In addition, modulators of such lncRNAs, most likely NONMMUG021726, have potential to become therapeutic targets or biomarkers for prediction of the outcomes of bariatric surgery.