Evaluation of lorcaserin on progression of prediabetes to type 2 diabetes and reversion to euglycemia

Prediabetes: A Benign Intermediate Stage or a Risk Factor in Itself?

Prediabetes is a condition when the blood glucose levels are above the normal range but below the threshold for defining diabetes. Previously considered benign, it is now recognized to be associated with various macrovascular and microvascular complications, with increases in the risk of cardiovascular events, nephropathy neuropathy, and retinopathy. Early identification of prediabetics may help detect the risk for these future complications at an earlier stage. Moreover, therapeutic options for prediabetes are available, which can retard its progression to diabetes and the subsequent development of complications. Hence, we make a case for the early identification of prediabetes through screening methods and appropriate institution of management strategies.

Changes in Glucose Metabolism and Glycemic Status With Once-Weekly Subcutaneous Semaglutide 2.4 mg Among Participants With Prediabetes in the STEP Program

OBJECTIVE

This analysis of 3,375 adults with overweight/obesity across the Semaglutide Treatment Effect in People with obesity (STEP) 1, 3, and 4 trials evaluated whether more participants with prediabetes had normoglycemia after 68 weeks' treatment with once-weekly semaglutide 2.4 mg plus lifestyle intervention versus placebo and assessed changes in glucose metabolism in participants with prediabetes.

RESEARCH DESIGN AND METHODS

STEP 1, 3, and 4 were phase 3, 68-week, randomized, placebo-controlled, multinational trials; STEP 4 had a 20-week semaglutide run-in and 48-week randomized period. Analyses included changes (week 0-68; before the washout period) in glycemic status (prespecified: STEP 1 and 3; post hoc: STEP 4), and in HbA1c, fasting plasma glucose (FPG), and HOMA insulin resistance (HOMA-IR) among participants with prediabetes (post hoc).

RESULTS

Significantly more participants with baseline (week 0) prediabetes (n = 1,536) had normoglycemia at week 68 with semaglutide versus placebo (STEP 1, 84.1% vs. 47.8%; STEP 3, 89.5% vs. 55.0%; STEP 4, 89.8% vs. 70.4%; all P < 0.0001). Fewer participants with baseline normoglycemia had prediabetes at week 68 with semaglutide versus placebo (STEP 1, 2.9% vs. 10.9%; STEP 3, 3.2% vs. 5.8%; STEP 4, 1.1% vs. 5.0%). Semaglutide resulted in greater improvements in HbA1c, FPG, and HOMA-IR than placebo among participants with baseline prediabetes (all P < 0.01).

CONCLUSIONS

STEP 1, 3, and 4 collectively provide a robust assessment of the effects of semaglutide on glucose metabolism and prediabetes in a large cohort of adults with overweight/obesity while on treatment. Among participants with baseline prediabetes, 68 weeks' treatment with semaglutide versus placebo led to significant improvements in glucose metabolism and a higher likelihood of normoglycemia.

The serotonergic system dysfunction in diabetes mellitus

Most peripheral serotonin (5-HT) is synthesized in enterochromaffin cells, and most circulating 5-HT is stored in platelets. As a monoamine, 5-HT has several functions in various non-neuronal and neuronal systems. In the central nervous system, it functions as a neurotransmitter to modulate feeding behavior and mood. Numerous clinical trials have focused on increasing 5-HT activation in the central nervous system, including those involving anti-obesity drugs currently in the market, although severe side effects on peripheral system can lead to the withdrawal of certain drugs. Recent studies have revealed that both the peripheral and central serotonergic systems play a vital role in diabetes and its complications. This review summarizes the roles of the serotonergic system in blood glucose regulation, diabetic macroangiopathy, diabetic peripheral neuropathy, and diabetic encephalopathy, indicating its potential clinical significance as a therapeutic target for the treatment of diabetes and its complications.

A Review of Current Trends with Type 2 Diabetes Epidemiology, Aetiology, Pathogenesis, Treatments and Future Perspectives

Type 2 diabetes (T2D), which has currently become a global pandemic, is a metabolic disease largely characterised by impaired insulin secretion and action. Significant progress has been made in understanding T2D aetiology and pathogenesis, which is discussed in this review. Extrapancreatic pathology is also summarised, which demonstrates the highly multifactorial nature of T2D. Glucagon-like peptide (GLP)-1 is an incretin hormone responsible for augmenting insulin secretion from pancreatic beta-cells during the postprandial period. Given that native GLP-1 has a very short half-life, GLP-1 mimetics with a much longer half-life have been developed, which are currently an effective treatment option for T2D by enhancing insulin secretion in patients. Interestingly, there is continual emerging evidence that these therapies alleviate some of the post-diagnosis complications of T2D. Additionally, these therapies have been shown to induce weight loss in patients, suggesting they could be an alternative to bariatric surgery, a procedure associated with numerous complications. Current GLP-1-based therapies all act as orthosteric agonists for the GLP-1 receptor (GLP-1R). Interestingly, it has emerged that GLP-1R also has allosteric binding sites and agonists have been developed for these sites to test their therapeutic potential. Recent studies have also demonstrated the potential of bi- and tri-agonists, which target multiple hormonal receptors including GLP-1R, to more effectively treat T2D. Improved understanding of T2D aetiology/pathogenesis, coupled with the further elucidation of both GLP-1 activity/targets and GLP-1R mechanisms of activation via different agonists, will likely provide better insight into the therapeutic potential of GLP-1-based therapies to treat T2D.

Higher HbA1c levels associate with lower hippocampal serotonin transporter availability in non-diabetic adults with obesity

The current study aimed to investigate whether the in vivo availability of central serotonin reuptake transporters (5-HTT) is associated with plasma levels of glycosylated hemoglobin (HbA1c) in non-diabetic humans with obesity. 5-HTT availability was measured by using positron emission tomography (PET) imaging with the 5-HTT selective radiotracer [¹¹C]DASB in 23 non-diabetic individuals with obesity and 14 healthy, non-obesity controls. Parametric images of binding potential BP_ND were generated from the PET data and analyzed together with HbA1c levels by using volume of interest analysis for brain areas relevant to appetite control. Voxel-based morphometry (VBM) of individual magnetic resonance imaging data was further performed to correlate grey matter density (GMD) maps with HbA1c. We found significant negative correlations between HbA1c levels and BP_ND in right and left hippocampus in obesity (r = − 0.717, p < 0.001, and r = − 0.557, p = 0.006, respectively). VBM analyses revealed that higher HbA1c levels were associated with GMD in the right para-hippocampal area. Our results indicate that chronically high blood glucose levels may evoke changes in hippocampal 5-HTT levels that are in part tied to local microstructure.

Pharmacotherapeutic options for prediabetes

INTRODUCTION

'Prediabetes' is a condition of elevated glucose not attaining the established criteria for a diagnosis of diabetes. The United States Diabetes Prevention Program (DPP) began in 1996 and was the iconic study of prediabetes. In that study, after 3 years, the risk of reaching the numerical criteria of diabetes was reduced by 58% by intensive emphasis on diet and exercise whereas treatment with metformin achieved a lesser reduction of 31%. The DPP was widely heralded as suggesting that lifestyle change was superior to pharmacologic therapy in the prediabetes population. This conclusion may be overreaching in terms of the long-term results of that study.

AREAS COVERED

The author reviews the subsequent pharmacologic efforts to prevent diabetes in this population. He reviews the existing literature for pharmacologic treatment of prediabetes using Pubmed.gov using the keywords of prediabetes, impaired fasting glucose and impaired glucose tolerance.

EXPERT OPINION

Prediabetes is primarily related to being overweight. Obesity has health consequences going beyond glucose elevation. The approach to prediabetes should be primarily by pursuing weight loss with therapeutic agents such as GLP-1 receptor agonists and SGLT2 inhibitors.

Regression from prediabetes to normal glucose levels is more frequent than progression towards diabetes: The CRONICAS Cohort Study

AIMS

This study aimed to (1) estimate the prevalence of prediabetes according to different definitions, (2) evaluate regression to normal glucose levels and progression towards T2DM, and (3) determine factors associated with regression and progression across four diverse geographical settings in a Latin American country.

METHODS

The CRONICAS Cohort Study was conducted in four different areas in Peru. Enrollment started in September 2010 and follow-up was conducted in 2013. Prediabetes, T2DM and normal glucose levels were determined according to definitions from the World Health Organization (WHO), American Diabetes Association (ADA), and National Institute for Health and Care Excellence (NICE). The main outcomes were regression to normal glucose levels and incidence of T2DM. Prevalence estimates and 95% confidence intervals (95% CI) were calculated. Crude and adjusted models using Poisson regression were performed and relative risk ratios (RRR) and 95% CI were calculated.

RESULTS

At baseline, the prevalence of prediabetes varied markedly by definition used: 6.5%(95% CI 5.6-7.6%), 53.6% (95% CI 51.6-55.6%), and 24.6% (95% CI 22.8-26.4%) according to WHO, ADA and NICE criteria, respectively. After 2.2  years of follow-up, in those with prediabetes, the cumulative incidence of regression to euglycemia ranged between 31.4% and 68.9%, whereas the incidence of T2DM varied from 5.5% to 28.8%. Factors associated with regression to normal glucose levels and progression to diabetes were age, body mass index, and insulin resistance.

CONCLUSIONS

Regression from pre-diabetes back to euglycemia was much more common than progression to diabetes.

Energy Balance and Weight Loss for Diabetes Remission

Diabetes remission-the occurrence of durable normoglycemia without antidiabetic medications-has been demonstrated in some patients with type 2 diabetes who have achieved and sustained weight loss through lifestyle intervention or metabolic and bariatric surgery. Although this pursuit would represent a paradigm shift in our diabetes chronic care model, could diabetes remission become a routine treatment strategy in patients with type 2 diabetes? This article reviews the mechanisms by which weight loss can drive improvements in insulin sensitivity and β-cell function sufficient to normalize glycemia, treatment approaches that provide evidence for diabetes remission, and avenues for developing the research and discovery that will be required to make diabetes remission possible as part of the routine medical management of type 2 diabetes.

Lorcaserin vs. Phentermine among non-surgical and surgical obese patients: Anthropometric, glycemic, lipid, safety and cost outcomes

Background

To evaluate effectiveness, safety, and costs of Lorcaserin vs. phentermine among obese non–surgical and surgical patients (post bariatric surgery).

Methods

This retrospective study retrieved charts of all patients (January 2013–June 2016) who received Lorcaserin or phentermine for 3 months. The study assessed anthropometric, glycemic, and lipid changes, as well as side effects and cost of medications among overweight and obese non-surgical (n = 83) and surgical patients (n = 46). These two patient groups were compared using Chi-square (χ2) and unpaired‘t’ test for qualitative and quantitative variables respectively.

Results

At 3 months, among the non-surgical group, Phentermine patients had greater percentage of total weight loss (TWL%) (7.65 ± 8.26 vs. 2.99 ± 3.72%, P = 0.003), and greater BMI reduction (−3.16 ± 3.63 vs. −1.15 ± 1.53 kg/m², P = 0.003) than Lorcaserin. Within the surgical group, Lorcaserin patients had significantly smaller TWL% (1.86 ± 5.06 vs. 7.62 ± 9.80%, P = 0.012), and smaller BMI reduction (−0.74 ± 1.80 vs. −3.06 ± 4.08 kg/m², P = 0.012) than Phentermine. Lorcaserin exhibited significant total cholesterol and LDL improvements only among surgical patients with significant weight reduction (≥5% TW). Both medications were not associated with glycemic improvements among non-surgical and surgical groups. Phentermine had slightly more side effects but was less expensive.

Conclusions

Among both patient groups, phentermine was more effective in achieving weight loss. Lorcaserin showed dyslipidemia improvements only among surgical patients who achieved significant weight reduction. Anti-obesity medications as part of weight management programs can result in weight loss among non-surgical and surgical patients, or halt weight regain among surgical patients. This is the first study to evaluate the effectiveness and safety of two anti-obesity medications (lorcaserin vs. phentermine) among two distinct obese patient groups, non-surgical and surgical patients.

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First study to evaluate effectiveness and safety of lorcaserin vs. phentermine in obese non-surgical and surgical patients.

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Among both patient groups, phentermine was more effective in achieving weight loss than lorcaserin.

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Dyslipidemia improvements was only achieved in surgical patients who achieved significant weight reduction with lorcaserin.

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Both medications were not associated with glycemic improvements among non-surgical and surgical groups.

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Phentermine had slightly more side effects but was less expensive.

Pharmacotherapy of Obesity: Limits and Perspectives

Obesity is a severe worldwide epidemic. Obesity comorbidities, such as type 2 diabetes mellitus, hypertension, and atherosclerosis, are costly for patients and governments. The treatment of obesity involves several facets, including lifestyle changes, bariatric surgery, and pharmacotherapy. As changes in lifestyle require considerable patient commitment that is sometimes unachievable, and surgery is expensive and invasive, pharmacotherapy is the primary option for most patients. This review describes the pharmacotherapy currently available in the USA, Europe, and Brazil, focusing on its limitations. We then analyze the results from clinical trials of new drug candidates. Most drugs cause weight loss of < 4 kg compared with controls, and severe adverse effects have caused a number of drugs to be withdrawn from the market in several countries. Drugs under development have not shown more significant weight loss or reduced adverse effects. We conclude that a significant portion of obese patients have few treatment options because of the adverse effects and minimal weight loss associated with current pharmacotherapy. However, drugs currently under development appear unable to change this scenario in the near future. Thus, it is essential that new compounds are developed and new molecular targets studied so obesity can be efficiently treated in all patients in the future.

Lorcaserin for prevention and remission of type 2 diabetes mellitus in people with overweight or obesity: protocol for a systematic review and meta-analysis

INTRODUCTION

High body mass index (BMI) is associated with risk of diabetes. Lorcaserin is a selective 5-hydroxytryptamine 2C agonist which exerts robust benefits on long-term weight loss by suppressing appetite among adults with overweight or obesity. The magnitude of efficacy of lorcaserin for preventing and remitting type 2 diabetes mellitus (T2DM) among those people remains undefined. Therefore, we plan to conduct this systematic review and meta-analysis to aggregate data from all published studies with regard to the issue to acquire reliable evidence.

METHODS AND ANALYSIS

We will search various databases for relevant trials published up to June 2019. Randomised controlled trials investigating the efficacy of lorcaserin for preventing and remitting T2DM among overweight and obese population will be included. A standardised data form will be used to complete data search and extraction in duplicate. All discrepancies will be resolved by consensus. The primary outcome will be incidence of T2DM in patients with pre-diabetes. Secondary outcomes will include achievement of normoglycaemia in people with pre-diabetes, remission of hyperglycaemia in patients with diabetes, the proportion of patients with weight loss of at least 5% or 10% and hypoglycaemia incident. Data synthesis and statistical analysis will be performed for each outcome with Stata V.14.0.

ETHICS AND DISSEMINATION

Ethics approval is not required. Results of our study will be submitted to a peer-review journal.

PROSPERO REGISTRATION NUMBER

CRD42019119136.

Prediabetes: Why Should We Care?

A clear link between cardiovascular disease and prediabetes has emerged over the past few years. Recent studies have shown that patients with prediabetes can suffer from coronary artery disease and diastolic heart failure even before progressing to overt diabetes. With this knowledge, physicians must identify prediabetes and take appropriate measures to optimize glycemic control. The pathophysiological defect seen in prediabetes can be managed with lifestyle modifications; thus, it is essential that physicians have a clear understanding of the current recommendations regarding diet and exercise. This review outlines the complications associated with prediabetes, presents an overview of the available pharmacological and surgical therapies that are effective in treating it, and provides a stepwise, multipronged approach for management.

GOALS FOR MEDICAL TREATMENT IN OBESITY AND PREDIABETES: IMPROVING OUTCOMES FOR BOTH

OBJECTIVE

The purpose of this review is to expose the surprising prevalence of diabetes-related complications in people with persistent prediabetes, and hence, to expand the paradigm of diabetes prevention to include the prevention of complications related to both hyperglycemia and obesity.

METHODS

Published literature was reviewed.

RESULTS

Approximately 84 million Americans have prediabetes, 85% of whom are overweight or obese. Although the incidence of diabetes-related complications is lower in people with prediabetes versus those with type 2 diabetes, the overall prevalence is virtually identical. Furthermore, many people with prediabetes not only suffer from the complications related to hyperglycemia, they also experience complications of obesity. Treating obesity as a disease has the potential to prevent complications of both hyperglycemia and obesity. Emerging data reveal the untapped potential for clinicians to enhance the effectiveness of anti-obesity medications through a mindful health care delivery style. This involves an understanding and ethical utilization of the placebo effect in conjunction with active medical therapy. This approach is not intended to mislead patients but rather to activate neurocircuitry that synergizes with the central action of the approved anti-obesity medications to potentiate weight loss.

CONCLUSION

Mindful administration of anti-obesity medications has the potential for widespread health benefits in people with obesity and prediabetes.

ABBREVIATIONS

ADA = American Diabetes Association; DPP = Diabetes Prevention Program; CVD = cardiovascular disease.

Centrally Acting Agents for Obesity: Past, Present, and Future

For many years, obesity was believed to be a condition of overeating that could be resolved through counseling and short-term drug treatment. Obesity was not recognized as a chronic disease until 1985 by the scientific community, and 2013 by the medical community. Pharmacotherapy for obesity has advanced remarkably since the first class of drugs, amphetamines, were approved for short-term use. Most amphetamines were removed from the obesity market due to adverse events and potential for addiction, and it became apparent that obesity pharmacotherapies were needed that could safely be administered over the long term. This review of central nervous system (CNS) acting anti-obesity drugs evaluates current therapies such as phentermine/topiramate, which act through multiple neurotransmitter pathways to reduce appetite. In the synergistic mechanism of bupropion/naltrexone, naltrexone blocks the feed-back inhibitory circuit of bupropion to give greater weight loss. Lorcaserin, a selective agonist of a serotonin receptor that regulates food intake, and the glucagon-like-peptide-1 (GLP-1) receptor agonist liraglutide are reviewed. Future drugs include tesofensine, a potent triple reuptake inhibitor in Phase III trials for obesity, and semaglutide, an oral GLP-1 analog approved for diabetes and currently in trials for obesity. Another potential new pharmacotherapy, setmelanotide, is a melanocortin-4 receptor agonist, which is still in an early stage of development. As our understanding of the communication between the CNS, gut, adipose tissue, and other organs evolves, it is anticipated that obesity drug development will move toward new centrally acting combinations and then to drugs acting on peripheral target tissues.

Lifestyle and Pharmacotherapy for Weight Loss in Preventing or Delaying Diabetes

Preventing or delaying the conversion of prediabetes to overt diabetes can reduce mortality and morbidity rates, improve health-related quality of life, and reduce other comorbid complications associated with diabetes. Studies have shown that a modest weight loss is one strategy for preventing or delaying diabetes diagnosis. First-line therapy in preventing progression of prediabetes to overt diabetes is weight loss through lifestyle modifications; however, pharmacotherapy for weight loss may be initiated if lifestyle alone is ineffective. The purpose of this article is to describe the pharmacotherapeuptic options for weight loss that can be used in conjunction with lifestyle in the prevention or delay of diabetes in patients with prediabetes.

Lorcaserin improves glycemic control via a melanocortin neurocircuit

Objective

The increasing prevalence of type 2 diabetes (T2D) and associated morbidity and mortality emphasizes the need for a more complete understanding of the mechanisms mediating glucose homeostasis to accelerate the identification of new medications. Recent reports indicate that the obesity medication lorcaserin, a 5-hydroxytryptamine (5-HT, serotonin) 2C receptor (5-HT_2CR) agonist, improves glycemic control in association with weight loss in obese patients with T2D. Here we evaluate whether lorcaserin has an effect on glycemia without body weight loss and how this effect is achieved.

Methods

Murine models of common and genetic T2D were utilized to probe the direct effect of lorcaserin on glycemic control.

Results

Lorcaserin dose-dependently improves glycemic control in mouse models of T2D in the absence of reductions in food intake or body weight. Examining the mechanism of this effect, we reveal a necessary and sufficient neurochemical mediator of lorcaserin's glucoregulatory effects, brain pro-opiomelanocortin (POMC) peptides. To clarify further lorcaserin's therapeutic brain circuit, we examined the receptor target of POMC peptides. We demonstrate that lorcaserin requires functional melanocortin4 receptors on cholinergic preganglionic neurons (MC4R^ChAT) to exert its effects on glucose homeostasis. In contrast, MC4R^ChAT signaling did not impact lorcaserin's effects on feeding, indicating a divergence in the neurocircuitry underpinning lorcaserin's therapeutic glycemic and anorectic effects. Hyperinsulinemic-euglycemic clamp studies reveal that lorcaserin reduces hepatic glucose production, increases glucose disposal and improves insulin sensitivity.

Conclusions

These data suggest that lorcaserin's action within the brain represents a mechanistically novel treatment for T2D: findings of significance to a prevalent global disease.

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Obesity medication lorcaserin directly improves glycemic control without altering energy balance or body weight.

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Unlike current frontline type 2 diabetes medications, lorcaserin acts within the brain to improve glycemic control.

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Brain Pro-opiomelanocortin (POMC) peptides are a neurochemical mediator of lorcaserin's glucoregulatory effects.

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Lorcaserin increases insulin sensitivity, reduces hepatic glucose production and increases glucose disposal.