Review of multimodal treatment for type 2 diabetes: combining metabolic surgery and pharmacotherapy

Determining the role of novel metabolic pathways in driving intracranial pressure reduction after weight loss

Idiopathic intracranial hypertension, a disease classically occurring in women with obesity, is characterized by raised intracranial pressure. Weight loss leads to the reduction in intracranial pressure. Additionally, pharmacological glucagon-like peptide-1 agonism reduces cerebrospinal fluid secretion and intracranial pressure. The potential mechanisms by which weight loss reduces intracranial pressure are unknown and were the focus of this study. Meal stimulation tests (fasted plasma sample, then samples at 15, 30, 60, 90 and 120 min following a standardized meal) were conducted pre- and post-bariatric surgery [early (2 weeks) and late (12 months)] in patients with active idiopathic intracranial hypertension. Dynamic changes in gut neuropeptides (glucagon-like peptide-1, gastric inhibitory polypeptide and ghrelin) and metabolites (untargeted ultra-high performance liquid chromatography-mass spectrometry) were evaluated. We determined the relationship between gut neuropeptides, metabolites and intracranial pressure. Eighteen idiopathic intracranial hypertension patients were included [Roux-en-Y gastric bypass (RYGB) n = 7, gastric banding n = 6 or sleeve gastrectomy n = 5]. At 2 weeks post-bariatric surgery, despite similar weight loss, RYGB had a 2-fold (50%) greater reduction in intracranial pressure compared to sleeve. Increased meal-stimulated glucagon-like peptide-1 secretion was observed after RYGB (+600%) compared to sleeve (+319%). There was no change in gastric inhibitory polypeptide and ghrelin. Dynamic changes in meal-stimulated metabolites after bariatric surgery consistently identified changes in lipid metabolites, predominantly ceramides, glycerophospholipids and lysoglycerophospholipids, which correlated with intracranial pressure. A greater number of differential lipid metabolites were observed in the RYGB cohort at 2 weeks, and these also correlated with intracranial pressure. In idiopathic intracranial hypertension, we identified novel changes in lipid metabolites and meal-stimulated glucagon-like peptide-1 levels following bariatric surgery which were associated with changes in intracranial pressure. RYGB was most effective at reducing intracranial pressure despite analogous weight loss to gastric sleeve at 2 weeks post-surgery and was associated with more pronounced changes in these metabolite pathways. We suggest that these novel perturbations in lipid metabolism and glucagon-like peptide-1 secretion are mechanistically important in driving a reduction in intracranial pressure following weight loss in patients with idiopathic intracranial hypertension. Therapeutic targeting of these pathways, for example with glucagon-like peptide-1 agonist infusion, could represent a therapeutic strategy.

Use of SGLT2 inhibitors after bariatric/metabolic surgery: Risk/benefit balance

Bariatric/metabolic surgery and sodium-glucose cotransporter 2 inhibitors (SGLT2is) are becoming increasingly popular for the management of overweight/obese patients with type 2 diabetes mellitus (T2DM). Consequently, the chance that a patient undergoing bariatric/metabolic surgery is also treated with an SGLT2i would be rather common in clinical practice. Both risks and benefits have been reported. On the one hand, several cases of euglycemic diabetic ketoacidosis have been reported within the few days/weeks after bariatric/metabolic surgery. The causes are diverse but a drastic reduction in caloric (carbohydrate) intake most probably plays a crucial role. Thus, SGLT2is should be stopped a few days (and even more if a pre-operative restricted diet is prescribed to reduce liver volume) before the intervention and reintroduced only when the caloric (carbohydrate) intake is sufficient. On the other hand, SGLT2is may exert a favorable effect to reduce the risk of postprandial hypoglycemia, a complication reported among patients who have been treated with bariatric/metabolic surgery. An increased hepatic glucose production and a reduced production of interleukin-1β have been proposed as possible underlying mechanisms for this protective effect. Finally, whether SGLT2is could prolong diabetes remission following surgery and improve the prognosis of patients with T2DM who benefit from bariatric/metabolic surgery remains to be investigated.

Future therapies for obesity

Obesity is a chronic disease associated with increased morbidity and mortality. Bariatric surgery can lead to sustained long-term weight loss (WL) and improvement in multiple obesity-related complications, but it is not scalable at the population level. Over the past few years, gut hormone-based pharmacotherapies for obesity and type 2 diabetes mellitus (T2DM) have rapidly evolved, and combinations of glucagon-like peptide 1 (GLP1) with other gut hormones (glucose-dependent insulinotropic polypeptide (GIP), glucagon, and amylin) as dual or triple agonists are under investigation to enhance and complement the effects of GLP1 on WL and obesity-related complications. Tirzepatide, a dual agonist of GLP1 and GIP receptors, marks a new era in obesity pharmacotherapy in which a combination of gut hormones could approach the WL achieved with bariatric surgery. In this review, we discuss emerging obesity treatments with a focus on gut hormone combinations and the concept of a multimodal approach for obesity management.

Critical Appraisal of Current Acute LBP Management and the Role of a Multimodal Analgesia: A Narrative Review

Acute low back pain (LBP) stands as a leading cause of activity limitation and work absenteeism, and its associated healthcare expenditures are expected to become substantial when acute LBP develops into a chronic and even refractory condition. Therefore, early intervention is crucial to prevent progression to chronic pain, for which the management is particularly challenging and the most effective pharmacological therapy is still controversial. Current guideline treatment recommendations vary and are mostly driven by expertise with opinion differing across different interventions. Thus, it is difficult to formulate evidence-based guidance when the relatively few randomized clinical trials have explored the diagnosis and management of LBP while employing different selection criteria, statistical analyses, and outcome measurements. This narrative review aims to provide a critical appraisal of current acute LBP management by discussing the unmet needs and areas of improvement from bench-to-bedside, and proposes multimodal analgesia as the way forward to attain an effective and prolonged pain relief and functional recovery in patients with acute LBP.

The Metabolomic Effects of Tripeptide Gut Hormone Infusion Compared to Roux-en-Y Gastric Bypass and Caloric Restriction

CONTEXT

The gut-derived peptide hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY) are regulators of energy intake and glucose homeostasis and are thought to contribute to the glucose-lowering effects of bariatric surgery.

OBJECTIVE

To establish the metabolomic effects of a combined infusion of GLP-1, OXM, and PYY (tripeptide GOP) in comparison to a placebo infusion, Roux-en-Y gastric bypass (RYGB) surgery, and a very low-calorie diet (VLCD).

DESIGN AND SETTING

Subanalysis of a single-blind, randomized, placebo-controlled study of GOP infusion (ClinicalTrials.gov NCT01945840), including VLCD and RYGB comparator groups.

PATIENTS AND INTERVENTIONS

Twenty-five obese patients with type 2 diabetes or prediabetes were randomly allocated to receive a 4-week subcutaneous infusion of GOP (n = 14) or 0.9% saline control (n = 11). An additional 22 patients followed a VLCD, and 21 underwent RYGB surgery.

MAIN OUTCOME MEASURES

Plasma and urine samples collected at baseline and 4 weeks into each intervention were subjected to cross-platform metabolomic analysis, followed by unsupervised and supervised modeling approaches to identify similarities and differences between the effects of each intervention.

RESULTS

Aside from glucose, very few metabolites were affected by GOP, contrasting with major metabolomic changes seen with VLCD and RYGB.

CONCLUSIONS

Treatment with GOP provides a powerful glucose-lowering effect but does not replicate the broader metabolomic changes seen with VLCD and RYGB. The contribution of these metabolomic changes to the clinical benefits of RYGB remains to be elucidated.

Metabolic recovery after weight loss surgery is reflected in serum microRNAs

INTRODUCTION

Bariatric surgery offers the most effective treatment for obesity, ameliorating or even reverting associated metabolic disorders, such as type 2 diabetes. We sought to determine the effects of bariatric surgery on circulating microRNAs (miRNAs) that have been implicated in the metabolic cross talk between the liver and adipose tissue.

RESEARCH DESIGN AND METHODS

We measured 30 miRNAs in 155 morbidly obese patients and 47 controls and defined associations between miRNAs and metabolic parameters. Patients were followed up for 12 months after bariatric surgery. Key findings were replicated in a separate cohort of bariatric surgery patients with up to 18 months of follow-up.

RESULTS

Higher circulating levels of liver-related miRNAs, such as miR-122, miR-885-5 p or miR-192 were observed in morbidly obese patients. The levels of these miRNAs were positively correlated with body mass index, percentage fat mass, blood glucose levels and liver transaminases. Elevated levels of circulating liver-derived miRNAs were reversed to levels of non-obese controls within 3 months after bariatric surgery. In contrast, putative adipose tissue-derived miRNAs remained unchanged (miR-99b) or increased (miR-221, miR-222) after bariatric surgery, suggesting a minor contribution of white adipose tissue to circulating miRNA levels. Circulating levels of liver-derived miRNAs normalized along with the endocrine and metabolic recovery of bariatric surgery, independent of the fat percentage reduction.

CONCLUSIONS

Since liver miRNAs play a crucial role in the regulation of hepatic biochemical processes, future studies are warranted to assess whether they may serve as determinants or mediators of metabolic risk in morbidly obese patients.

From the Knife to the Endoscope-a History of Bariatric Surgery

PURPOSE OF REVIEW

Current bariatric surgical practice has developed from early procedures, some of which are no longer routinely performed. This review highlights how surgical practice in this area has developed over time.

RECENT FINDINGS

This review outlines early procedures including jejuno-colic and jejuno-ileal bypass, initial experience with gastric bypass, vertical banded gastroplasty and biliopancreatic diversion with or without duodenal switch. The role laparoscopy has played in the widespread utilization of surgery for treatment of obesity will be described, as will the development of procedures which form the mainstay of current bariatric surgical practice including gastric bypass, sleeve gastrectomy and adjustable gastric banding. Endoscopic therapies for the treatment of obesity will be described. By outlining how bariatric surgical practice has developed over time, this review will help practicing surgeons understand how individual procedures have evolved and also provide insight into potential future developments in this field.

Insulin resistance in bariatric surgery

PURPOSE OF REVIEW

To give an updated review on the underlying mechanisms and clinical effects of improved glucose control after bariatric surgery.

RECENT FINDINGS

The basic principles of the mechanism for the metabolic effects of bariatric surgery can be categorized into calorie restriction, deviation of nutrients, and reduced amounts of adipose tissue. Recent findings suggest the importance of early changes following deviation of nutrients to more distal parts of the small bowel resulting in altered release of gastrointestinal hormones, altered gut microbiota, and weight-reduction. In the long-term, loss of adipose tissue results in reduced inflammation and improved insulin sensitivity. From a clinical perspective these changes are associated with remission of diabetes in patients with morbid obesity and type 2 diabetes, prevention of diabetes in patients with insulin resistance without overt type 2 diabetes and prevention of both microvascular and macrovascular complications for all patients with morbid obesity.

SUMMARY

At present, bariatric surgery remains the most effective treatment option to improve glucose control and long-term complications associated with hyperglycemia in patients with obesity.Although the mechanisms behind these metabolic effects remain only partially understood, further knowledge on these complex mechanisms may help identifying durable treatment options for morbid obesity and important metabolic comorbidities.

The Mitigating Effect of Phentermine and Topiramate on Weight Regain After Roux-en-Y Gastric Bypass Surgery

OBJECTIVE

Weight regain (WR) after Roux-en-Y gastric bypass surgery (RYGB) starts to occur 2 years after surgery, ultimately affecting at least 25% of patients. A limited number of studies have evaluated the impact of antiobesity medications (AOMs) on this phenomenon.

METHODS

This study reviewed the electronic medical records of 1,196 patients who underwent RYGB between 2004 and 2015. WR was evaluated by comparing each patient's weight during subsequent postoperative office visits to nadir weight (lowest weight after RYGB, n = 760), taking into consideration the interval during which WR occurred. Patients who were prescribed AOMs and came to follow-up visits were classified as adherent users, whereas those who missed their follow-up visits were considered nonadherent. This study used a linear mixed model, Cox regression, and generalized equation estimator to determine the impact of AOMs on WR trajectory, hazard ratio for time to event, and odds ratio for repeated event occurrence, respectively.

RESULTS

Despite the lack of a unified protocol for using AOMs, the three statistical models converged to show that phentermine and topiramate, used individually or in combination, can significantly reduce WR after RYGB.

CONCLUSIONS

Phentermine and topiramate are effective in mitigating WR after RYGB. Further studies are needed to help ascertain optimal use of AOMs after bariatric surgery.

Gastrointestinal Peptides as Therapeutic Targets to Mitigate Obesity and Metabolic Syndrome

PURPOSE OF REVIEW

Obesity affects over than 600 million adults worldwide resulting in multi-organ complications and major socioeconomic impact. The purpose of this review is to summarise the physiological effects as well as the therapeutic implications of the gut hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin, peptide YY (PYY), and glucose-dependent insulinotropic peptide (GIP) in the treatment of obesity and type 2 diabetes.

RECENT FINDINGS

Clinical trials have proven that the widely used GLP-1 analogues have pleotropic effects beyond those on weight and glucose metabolism and appear to confer favourable cardiovascular and renal outcomes. However, GLP-1 analogues alone do not deliver sufficient efficacy for the treatment of obesity, being limited by their dose-dependent gastrointestinal side effects. Novel dual agonists for GLP-1/glucagon and GLP-1/GIP are being developed by the pharmaceutical industry and have demonstrated some promising results for weight loss and improvement in glycaemia over and above GLP-1 analogues. Triagonists (for example GLP-1/GIP/glucagon) are currently in pre-clinical or early clinical development. Gastrointestinal hormones possess complementary effects on appetite, energy expenditure, and glucose metabolism. We highlight the idea that combinations of these hormones may represent the way forward in obesity and diabetes therapeutics.

Long-term outcomes of bariatric surgery in patients with diabetes

Introduction: Initially seen as a weight-loss operation, bariatric surgery is now recognized as a metabolic procedure with a critical role in the management of type 2 diabetes mellitus (T2DM). Early improvement in glucose metabolism is a remarkable effect of surgery; however, what deserves equal thought are implications for long-term diabetes control and relapse. Evidence suggests the metabolic effects of surgery fatigue and a proportion of patients will experience relapse of T2DM, with or without weight regain. Herein, we discuss the evidence examining the durability of these effects and approaches to improve long-term control.Areas covered: PubMed, Embase, CENTRAL, and Medline were searched for trials looking at outcomes for patients with obesity and T2DM undergoing bariatric surgery between January 2000 andDecember 2019. Additional studies were found by searching publications from related journals and references.Export opinion: Bariatric surgery is a safe and effective treatment for T2DM and obesity however the response to surgery, like any other treatment is variable. Some patients will experience a relapse of diabetes in the long term. Recent developments in pharmacotherapy present an opportunity to augment or sustain what can be achieved with surgery. Combinational treatment may dramatically change the way both diseases are managed.

Activation of α7nAChR via vagus nerve prevents obesity-induced insulin resistance via suppressing endoplasmic reticulum stress-induced inflammation in Kupffer cells

Obesity is a major risk factor for type 2 diabetes mellitus and insulin resistance (IR). In the state of obesity, excess fat accumulates in the liver, a key organ in systemic metabolism, altering the inflammatory and metabolic signals contributing substantially to the development of hepatic IR. Current therapies for these metabolic disorders have not been able to reverse their rapidly rising prevalence. One of the reasons is that the effects of existing drugs are predominantly non-lasting [1,2]. The vagus nerve (VN) is known to play an essential role in maintaining metabolic homeostasis while decreased VN activity has been suggested to contribute to obesity associated metabolic syndrome [3,4]. Several studies have reported that activation of α7 nicotinic acetylcholine receptor (α7nAChR) cholinergic signaling with or without VN intervention has protective effects against obesity-related inflammation and other metabolic complications [5]. However, the molecular mechanisms are still not elucidated. Exaggerated endoplasmic reticulum (ER) stress and consequent dysregulated inflammation has been implicated in the development of lipid accumulation and IR [6]. Whether targeting α7nAChR can regulate IR through these pathways is rarely reported. Accordingly, the present proposal posits that activation of the α7nAChR by VNS attenuates ER stress induced inflammation, thus ameliorating hepatic IR in Kupffer cell. We will focus on the specific interaction between vagal cholinergic activity and the modulation of ER stress induced inflammation via the α7nAChR associated pathway during IR development. Recently, the Endocrine Society has emphasized the absence of specific evidence from basic science, clinical, and epidemiological literature to assess current knowledge regarding underlying mechanisms of obesity [7]. In this proposal, we assign a significant role to α7nAChR in obesity-induced hepatic IR, and suggest a possible therapeutic strategy with VNS intervention.