Thiazolidinediones improve beta-cell function in type 2 diabetic patients

Managing insulin resistance: the forgotten pathophysiological component of type 2 diabetes

Glucagon-like peptide-1 (GLP-1) receptor agonists have gained widespread use in the treatment of individuals with type 2 diabetes because of their potent weight loss promoting effect, ability to augment β-cell function, and cardiovascular protective effects. However, despite causing impressive weight loss, GLP-1 receptor agonists do not normalise insulin sensitivity in people with type 2 diabetes and obesity, and the long-term effects of this class of antidiabetic medication on muscle mass, frailty, and bone density have been poorly studied. Although GLP-1 receptor agonists improve insulin sensitivity secondary to weight loss, the only true direct insulin-sensitising drugs are thiazolidinediones. Because of side-effects associated with type 2 diabetes therapy, these drugs have not gained widespread use. In lieu of the important role of insulin resistance in the cause of type 2 diabetes and in the pathogenesis of atherosclerotic cardiovascular disease in type 2 diabetes, development of potent insulin-sensitising drugs that can be used in combination with GLP-1 receptor agonists remains a large unmet need in the management of individuals with type 2 diabetes.

Efficacy and Safety of Pioglitazone Add-on in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Metformin and Dapagliflozin: A Multicenter, Randomized, Double-blind, and Placebo-Controlled Study

PURPOSE

The purpose of this study was to determine the efficacy and safety profile of pioglitazone compared with placebo (PBO) in patients with type 2 diabetes (T2D) inadequately controlled with metformin and dapagliflozin.

METHODS

In this prospective, multicenter, randomized, double-blind, PBO-controlled trial, 366 patients with T2D who did not meet glycemic targets (7.0% ≤ glycosylated hemoglobin [HbA1c] ≤ 10.5%), despite treatment with metformin ≥1000 mg and dapagliflozin 10 mg, received either a PBO, 15 mg of pioglitazone daily (PIO15), or 30 mg of pioglitazone daily (PIO30). The primary end point was the mean change in HbA1c from baseline at 24 weeks across the groups.

FINDINGS

For the 366 participants (PBO, n = 124; PIO15, n = 118; PIO30, n = 124), the mean age was 55.6 years and mean duration of diabetes was 8.7 years, with a baseline HbA1c of 7.9%. After 24 weeks, HbA1c reduced significantly in the PIO15 and PIO30 groups from baseline, with intergroup differences of -0.38% and -0.83%, respectively, compared with the PBO group. The proportion of patients with HbA1c levels <7% was significantly higher in the PIO15 and PIO30 groups than in the PBO group. The adverse event rates did not significantly differ across the groups, indicating favorable safety profiles for triple combination therapy using metformin, dapagliflozin, and pioglitazone.

IMPLICATIONS

The addition of pioglitazone as a third oral antidiabetic medication is an appropriate option for patients with T2D inadequately controlled with metformin and dapagliflozin based on the resulting significant efficacy in glycemic control and favorable safety profile.

CLINICALTRIALS

gov identifier: NCT04885712.

Terpenoids as potential phytoconstituent in the treatment of diabetes: From preclinical to clinical advancement

BACKGROUND

Diabetes mellitus, a hyperglycemic condition associated with multitudinous organ dysfunction, is a hallmark of the metabolic disorder. This life-threatening condition affects millions of individuals globally, harming them financially, physically and psychologically in the course of therapy.

PURPOSES

The course therapy for illnesses has undergone ground-breaking transformations due to recent technical advances and insights. Alternatively, the administration of hyperglycemia-reducing agents results in several complications, including severe cardiovascular disease, kidney failure, hepatic problems, and several dermatological conditions. Consideration of alternate diabetic therapy having minimal side effects or no adverse reactions has been driven by such problems.

STUDY DESIGN

An extensive literature study was conducted in authoritative scientific databases such as PubMed, Scopus, and Web of Science to identify the studies elucidating the bioactivities of terpenoids in diabetic conditions.

METHODS

Keywords including 'terpenoids', 'monoterpenes', 'diterpenes', 'sesquiterpenes', 'diabetes', 'diabetes mellitus', 'clinical trials', 'preclinical studies', and 'increased blood glucose' were used to identify the relevant research articles. The exclusion criteria, such as English language, duplication, open access, abstract only, and studies not involving preclinical and clinical research, were set. Based on these criteria, 937 relevant articles were selected for further evaluation.

RESULTS

Triterpenes can serve as therapeutic agents for diabetic retinopathy, peripheral neuropathy, and kidney dysfunction by inhibiting several pathways linked to hyperglycemia and its complications. Therefore, it is essential to draw special attention to these compounds' therapeutic effectiveness and provide scientific professionals with novel data.

CONCLUSION

This study addressed recent progress in research focussing on mechanisms of terpenoid, its by-products, physiological actions, and therapeutic applications, particularly in diabetic and associated disorders.

Pancreatic beta-cell mass and function and therapeutic implications of using antidiabetic medications in type 2 diabetes

Nowadays, the focus of diabetes treatment has switched from lowering the glucose level to preserving glycemic homeostasis and slowing the disease progression. The main pathophysiology of both type 1 diabetes and long-standing type 2 diabetes is pancreatic β-cell mass loss and dysfunction. According to recent research, human pancreatic β-cells possess the ability to proliferate in response to elevated insulin demands. It has been demonstrated that in insulin-resistant conditions in humans, such as obesity or pregnancy, the β-cell mass increases. This ability could be helpful in developing novel treatment approaches to restore a functional β-cell mass. Treatment strategies aimed at boosting β-cell function and mass may be a useful tool for managing diabetes mellitus and stopping its progression. This review outlines the processes of β-cell failure and detail the many β-cell abnormalities that manifest in people with diabetes mellitus. We also go over standard techniques for determining the mass and function of β-cells. Lastly, we provide the therapeutic implications of utilizing antidiabetic drugs in controlling the mass and function of pancreatic β-cells.

Adipose tissue macrophages secrete small extracellular vesicles that mediate rosiglitazone-induced insulin sensitization

The obesity epidemic continues to worsen worldwide, driving metabolic and chronic inflammatory diseases. Thiazolidinediones, such as rosiglitazone (Rosi), are PPARγ agonists that promote 'M2-like' adipose tissue macrophage (ATM) polarization and cause insulin sensitization. As ATM-derived small extracellular vesicles (ATM-sEVs) from lean mice are known to increase insulin sensitivity, we assessed the metabolic effects of ATM-sEVs from Rosi-treated obese male mice (Rosi-ATM-sEVs). Here we show that Rosi leads to improved glucose and insulin tolerance, transcriptional repolarization of ATMs and increased sEV secretion. Administration of Rosi-ATM-sEVs rescues obesity-induced glucose intolerance and insulin sensitivity in vivo without the known thiazolidinedione-induced adverse effects of weight gain or haemodilution. Rosi-ATM-sEVs directly increase insulin sensitivity in adipocytes, myotubes and primary mouse and human hepatocytes. Additionally, we demonstrate that the miRNAs within Rosi-ATM-sEVs, primarily miR-690, are responsible for these beneficial metabolic effects. Thus, using ATM-sEVs with specific miRNAs may provide a therapeutic path to induce insulin sensitization.

Beta-cell function in type 2 diabetes (T2DM): Can it be preserved or enhanced?

Type 2 diabetes (T2DM) is a complex metabolic disorder manifested by hyperglycemia, insulin resistance, and deteriorating beta-cell function. A way to prevent progression of the disease might be to enhance beta-cell function and insulin secretion. However, most previous studies examined beta-cell function while patients were using glycemia-lowering agents without an adequate period off medications (washout). In the present review we focus on studies with a washout period. We performed a literature search (2010 to June 2021) using beta-cell function and enhancement. The evidence shows that beta-cell function can be enhanced. Bariatric surgery and very low calorie diets show improvement in beta-cell function in many individuals. In addition, use of glucagon-like peptide-1 receptor agonists for prolonged periods (3 years or more) can also lead to improvement of beta-cell function. Further research is needed to understand the mechanisms leading to improved beta-cell function and identify agents that could enhance beta-cell function in patients with T2DM.

Chinese Sumac Fruits (Rhus chinesis Mill.) Alleviate Type 2 Diabetes in C57BL/6 Mice through Repairing Islet Cell Functions, Regulating IRS-1/PI3K/AKT Pathways and Promoting the Entry of Nrf2 into the Nucleus

This research aimed to probe the potential alleviative effects of ethanol extracts of Chinese sumac (Rhus chinesis Mill.) fruits against type 2 diabetes mellitus (T2DM) in C57BL/6 mice induced by high-fat/high-fructose diet (HFFD) and streptozotocin. The results showed that the ethanol extracts could significantly regulate blood glucose levels, glycosylated hemoglobin, blood lipids, insulin, and insulin resistance, while also restoring endogenous oxidative stress. Pathological and immunohistochemical analyses revealed that the extracts partially restored the physiological function of islet cells. Furthermore, Western blotting results suggested that the extracts could regulate the protein expression in IRS-1/PI3K/AKT signaling pathway, and immunofluorescence findings demonstrated their potential to promote the translocation of Nrf2 into the nucleus. This study elucidated a novel finding that ethanol extracts derived from Chinese sumac fruits have the potential to alleviate symptoms of T2DM in mice. Moreover, these findings could offer valuable scientific insights into the potential utilization of R. chinensis fruits as nutritional supplement and/or functional food to prevent or ameliorate diabetes.

Pre-Meal Whey Protein Alters Postprandial Insulinemia by Enhancing β-Cell Function and Reducing Insulin Clearance in T2D

CONTEXT

Treatments that reduce postprandial glycemia (PPG) independent of stimulating insulin secretion are appealing for the management of type 2 diabetes (T2D). Consuming pre-meal whey protein (WP) reduces PPG by delaying gastric emptying and increasing plasma insulin concentrations. However, its effects on β-cell function and insulin kinetics remains unclear.

OBJECTIVE

To examine the PPG-regulatory effects of pre-meal WP by modeling insulin secretion rates (ISR), insulin clearance, and β-cell function.

METHODS

This was a single-blind, randomized, placebo-controlled, crossover design study in 18 adults with T2D (HbA1c, 56.7 ± 8.8 mmol/mol) who underwent 2 240-minute mixed-meal tolerance tests. Participants consumed WP (15 g protein) or placebo (0 g protein) 10 minutes before a mixed-macronutrient breakfast meal. PPG, pancreatic islet, and incretin hormones were measured throughout. ISR was calculated by C-peptide deconvolution. Estimates of insulin clearance and β-cell function were modeled from glucose, insulin, and ISR. Changes in PPG incremental area under the curve (iAUC; prespecified) and insulin clearance (post hoc) were measured.

RESULTS

β-cell function was 40% greater after WP (P = .001) and was accompanied with a -22% reduction in postprandial insulin clearance vs placebo (P < .0001). Both the peak change and PPG iAUC were reduced by WP (-1.5 mmol/L and -16%, respectively; both P < .05). Pre-meal WP augmented a 5.9-fold increase in glucagon and glucagon-like peptide 1 iAUC (both P < .0001), and a 1.5-fold increase in insulin iAUC (P < .001). Although the plasma insulin response was greater following WP, ISR was unaffected (P = .133).

CONCLUSION

In adults with T2D, pre-meal WP reduced PPG by coordinating an enhancement in β-cell function with a reduction in insulin clearance. This enabled an efficient postprandial insulinemic profile to be achieved without requiring further β-cell stimulation.Trial registry ISRCTN ID: ISRCTN17563146 Website link: www.isrctn.com/ISRCTN17563146.

Type 2 diabetes subgroups and response to glucose-lowering therapy: Results from the EDICT and Qatar studies

AIM

To examine the efficacy of glucose-lowering medications in subgroups of patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Cluster analysis was performed in participants in the Efficacy and Durability of Initial Combination Therapy for Type 2 Diabetes (EDICT) study and the Qatar study using age, body mass index (BMI), glycated haemoglobin (HbA1c), and homeostatic model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β). Participants also underwent an oral glucose tolerance test with measurement of plasma glucose, insulin and C-peptide concentrations to derive independent measures of insulin secretion and insulin sensitivity. The response to glucose-lowering therapies (change in HbA1c) was measured in each participant cluster for 3 years.

RESULTS

Three distinct and comparable clusters/groups of T2DM patients were identified in both the EDICT and Qatar studies. Participants in Group 1 had the highest HbA1c and manifested severe insulin deficiency. Participants in Group 3 had comparable insulin sensitivity to those in Group 1 but better beta-cell function and better glucose control. Participants in Group 2 had the highest BMI with severe insulin resistance accompanied by marked hyperinsulinaemia, which was primarily attributable to decreased insulin clearance. Unexpectedly, participants in Group 1 had better response to combination therapy with pioglitazone plus exenatide than with insulin therapy or metformin sequentially followed by glipizide and basal insulin, while participants in Group 2 responded equally well to both therapies despite very severe insulin resistance.

CONCLUSION

Distinct metabolic phenotypes characterize different T2DM clusters and differential responses to glucose-lowering therapies. Participants with severe insulin deficiency respond better to agents that preserve beta-cell function, while, surprisingly, patients with severe insulin resistance did not respond favourably to insulin sensitizers.

FGF21 contributes to metabolic improvements elicited by combination therapy with exenatide and pioglitazone in patients with type 2 diabetes

Fibroblast growth factor 21 (FGF21) is increased acutely by carbohydrate ingestion and is elevated in patients with type 2 diabetes (T2D). However, the physiological significance of increased FGF21 in humans remains largely unknown. We examined whether FGF21 contributed to the metabolic improvements observed following treatment of patients with T2D with either triple (metformin/pioglitazone/exenatide) or conventional (metformin/insulin/glipizide) therapy for 3 yr. Forty-six patients with T2D were randomized to receive either triple or conventional therapy to maintain HbA1c < 6.5%. A 2-h 75-g oral glucose tolerance test (OGTT) was performed at baseline and following 3 years of treatment to assess glucose tolerance, insulin sensitivity, and β-cell function. Plasma total and bioactive FGF21 levels were quantitated before and during the OGTT at both visits. Patients in both treatment arms experienced significant improvements in glucose control, but insulin sensitivity and β-cell function were markedly increased after triple therapy. At baseline, FGF21 levels were regulated acutely during the OGTT in both groups. After treatment, fasting total and bioactive FGF21 levels were significantly reduced in patients receiving triple therapy, but there was a relative increase in the proportion of bioactive FGF21 compared with that observed in conventionally treated subjects. Relative to baseline studies, triple therapy treatment also significantly modified FGF21 levels in response to a glucose load. These changes in circulating FGF21 were correlated with markers of improved glucose control and insulin sensitivity. Alterations in the plasma FGF21 profile may contribute to the beneficial metabolic effects of pioglitazone and exenatide in human patients with T2D.NEW & NOTEWORTHY In patients with T2D treated with a combination of metformin/pioglitazone/exenatide (triple therapy), we observed reduced total and bioactive plasma FGF21 levels and a relative increase in the proportion of circulating bioactive FGF21 compared with that in patients treated with metformin and sequential addition of glipizide and basal insulin glargine (conventional therapy). These data suggest that FGF21 may contribute, at least in part, to the glycemic benefits observed following combination therapy in patients with T2D.

Efficacy of lower doses of pioglitazone after stroke or transient ischaemic attack in patients with insulin resistance

AIMS

Pioglitazone is a potent insulin-sensitizing drug with anti-atherosclerotic properties, but adverse effects have limited its use. We assessed the benefits and risks of lower versus higher doses of pioglitazone taken by participants in the Insulin Resistance Intervention in Stroke Trial.

MATERIALS AND METHODS

Efficacy [myocardial infarction (MI) or recurrent stroke] new-onset diabetes) and adverse outcomes (oedema, weight gain, heart failure and bone fracture) were examined for subjects assigned to pioglitazone or placebo within strata defined by mode dose of study drug taken (i.e. the dose taken on most days in the study).

RESULTS

Among the 1938 patients randomized to pioglitazone, the mode dose was <15 mg/day in 546 participants, 15 mg/day in 128, 30 mg/day in 89, and 45 mg/day in 1175. There was no significant effect on stroke/MI or new-onset diabetes with <15 mg/day. For 15 mg/30 mg/day pooled, the adjusted hazard ratios (95% CI) for stroke/MI were 0.48 (0.30, 0.76; p = .002) and 0.74 (0.69, 0.94) for 45 mg/day. For new-onset diabetes, the adjusted hazard ratios were 0.34 (0.15, 0.81; p = .001) and 0.31 (0.59, 0.94; p = .001) respectively. For oedema, weight gain and heart failure, the risk estimates for pioglitazone were lower for subjects taking <45 mg daily. For fractures, the increased risk with pioglitazone was similar across all dose strata.

CONCLUSIONS

Lower doses of pioglitazone appear to confer much of the benefit with less adverse effects than the full dose. Further study is needed to confirm these findings so that clinicians may optimize dosing of this secondary prevention strategy in patients with stroke.

An overview of alogliptin + pioglitazone for the treatment of type 2 diabetes

INTRODUCTION

Type 2 diabetes (T2D) is a progressive condition, and sequential additions of therapy are usually required to maintain glycemic control. The options for glucose lowering therapies have increased considerably in recent years. Fixed-dose combinations such as alogliptin with pioglitazone provide a convenient choice which can improve medication adherence.

AREAS COVERED

The authors performed a literature search to identify publications describing the efficacy and safety of alogliptin and pioglitazone when used separately and in combinations.

EXPERT OPINION

Pioglitazone activates peroxisome proliferator-activated receptor-gamma which improves insulin sensitivity and helps to preserve β-cell function with a durable improvement in glycemic control. Pioglitazone can retard the progression of atherosclerosis and reduce cardiovascular events, but it is associated with adverse events including weight gain, fluid retention, and increased risk of fractures. Alogliptin improves glycemic control and appears neutral in terms of cardiovascular events. It does not appear to increase the adverse events associated with pioglitazone and use of the combination may permit the use of lower doses of pioglitazone with reduced adverse effects. There are no cardiovascular outcome studies with the combination but the cardiovascular benefits of pioglitazone and additional glucose lowering effects of alogliptin provide a useful combination with convenient once daily dosing.

Emerging Treatment Strategies for Diabetes Mellitus and Associated Complications: An Update

The occurrence of diabetes mellitus (DM) is increasing rapidly at an accelerating rate worldwide. The status of diabetes has changed over the last three generations; whereas before it was deemed a minor disease of older people but currently it is now one of the leading causes of morbidity and mortality among middle-aged and young people. High blood glucose-mediated functional loss, insulin sensitivity, and insulin deficiency lead to chronic disorders such as Type 1 and Type 2 DM. Traditional treatments of DM, such as insulin sensitization and insulin secretion cause undesirable side effects, leading to patient incompliance and lack of treatment. Nanotechnology in diabetes studies has encouraged the development of new modalities for measuring glucose and supplying insulin that hold the potential to improve the quality of life of diabetics. Other therapies, such as β-cells regeneration and gene therapy, in addition to insulin and oral hypoglycemic drugs, are currently used to control diabetes. The present review highlights the nanocarrier-based drug delivery systems and emerging treatment strategies of DM.

The Regulatory Roles of PPARs in Skeletal Muscle Fuel Metabolism and Inflammation: Impact of PPAR Agonism on Muscle in Chronic Disease, Contraction and Sepsis

The peroxisome proliferator-activated receptor (PPAR) family of transcription factors has been demonstrated to play critical roles in regulating fuel selection, energy expenditure and inflammation in skeletal muscle and other tissues. Activation of PPARs, through endogenous fatty acids and fatty acid metabolites or synthetic compounds, has been demonstrated to have lipid-lowering and anti-diabetic actions. This review will aim to provide a comprehensive overview of the functions of PPARs in energy homeostasis, with a focus on the impacts of PPAR agonism on muscle metabolism and function. The dysregulation of energy homeostasis in skeletal muscle is a frequent underlying characteristic of inflammation-related conditions such as sepsis. However, the potential benefits of PPAR agonism on skeletal muscle protein and fuel metabolism under these conditions remains under-investigated and is an area of research opportunity. Thus, the effects of PPARγ agonism on muscle inflammation and protein and carbohydrate metabolism will be highlighted, particularly with its potential relevance in sepsis-related metabolic dysfunction. The impact of PPARδ agonism on muscle mitochondrial function, substrate metabolism and contractile function will also be described.

Vitamin D Combined with Pioglitazone Mitigates Type-2 Diabetes-induced Hepatic Injury Through Targeting Inflammation, Apoptosis, and Oxidative Stress

Inflammation is a major pathophysiological factor in development of type-2 diabetes mellitus (T2DM). Vitamin D (VITD) plays an imperative role in modulation of several inflammatory responses. The current study aimed to investigate the possible beneficial effects of coadministration of VITD with pioglitazone (PIO), a PPAR-γ agonist, in fructose/streptozotocin (F/STZ) T2DM model in male Wistar rats. T2DM was induced by maintaining rats on 10% (w/v) fructose in drinking water for 9 weeks with an intraperitoneal injection of sub-diabetogenic dose of STZ (35 mg/kg) by the end of the fourth week. One week after STZ injection, PIO (10 mg/kg/day) alone or with VITD (500 IU/kg/day) was administered orally to diabetic rats till the end of the experiment. Blood samples were collected, livers were homogenized to determine biochemical parameters, and samples of livers were fixed in 10% formalin in saline for histological examination. Administration of PIO alone improved diabetes-induced inflammatory and oxidative states besides controlling hyperglycemia and decreasing apoptosis. Coadministration of VIT D with PIO promoted additional improvement in glycemic and lipid profiles, provided further control on diabetic-induced hepatic inflammation evident by downregulating TLR2, TLR4, and IKK-β while upregulating IκB-α expression and reducing inflammatory cytokines namely; NF-κB, TNF-α, IL-6, and IL-1β, decreasing apoptosis and oxidative stress by hampering caspase-3 and MDA contents, respectively, and improved liver histology than PIO alone. These beneficial effects of VIT D may expand its use by diabetics combined with antidiabetic drugs due to its anti-inflammatory, antioxidant, and antiapoptotic properties.

Efficacy Evaluation Study for Microburst Insulin Infusion: A Novel Model of Care

Objectives: This study aims to evaluate the impact of Microburst Insulin Infusion (MII) treatment on Type 1 and 2 diabetic patients' HbA1c, lipids, peripheral neuropathy, and patient-reported health status.

Methods: We reviewed clinical charts, including lab results, for more than 80 diabetic and pre-diabetic patients treated at one U.S. outpatient clinic in St. Louis, Missouri between February 2017 and December 2019. Data included patient demographics, treatment data, lab and neuropathy tests, and self-reported patient health status questions.

The explanatory variable was number of months of MII treatment. Treatments are 3–4 h in length, with two intensive infusions the first week and one treatment each week thereafter, usually for 12 weeks total. Lab tests were at 12-week intervals.

Generalized linear modeling and t-tests assessed the significance of differences between patients' baseline lab values, neuropathy measures, and health status before treatment vs. after final treatment.

Results: Number of MII treatments per patient ranged from 1 to 262, over 1–24 months. Time in MII treatment was significantly associated with reductions in HbA1c by nearly 0.04 points per month, and triglycerides declined 3 points per month. Neuropathy measures of large toe vibratory sensation (clanging tuning fork) improved significantly, as did patient-reported health and feelings of improvement since beginning treatment.

Discussion: The MII therapy appears to be efficacious in treating diabetic patients, particularly those with complications like neuropathy. Our findings affirmed several other studies. We uniquely incorporated patient health questionnaires, and empirically studied MII treatment efficacy for diabetes in a population large enough to permit statistically valid inferences. With multiple waves of data for over 80 patients, this is one of the most extensive quantitative studies of microburst insulin infusion therapy conducted to date, with protocols more uniformly implemented and survey instruments more consistently administered by the same clinical team. Given the advances in insulin infusion therapy brought by MII, and early indications of its efficacy, the time is right for more in-depth studies of the outcomes patients can achieve, the physiological mechanisms by which they occur, MII's comparative effectiveness vis-à-vis traditional treatments, and cost-effectiveness.

Personalized approach for type 2 diabetes pharmacotherapy: where are we and where do we need to be?

INTRODUCTION

Cluster analysis has identified distinct groups of type 2 diabetes (T2D) subjects with distinct metabolic characteristics. Thus, personalizing pharmacologic therapy to individual phenotypic and pathophysiologic characteristics has potential to improve metabolic control and reduce risk of microvascular and macrovascular complications.

AREAS COVERED

The authors review the classification of T2D, genetic markers, pathophysiology and natural history of T2D, the ABCDE approach to therapy, the ADA/EASD stepwise approach to therapy, available antidiabetic agents, and provide a more rational therapeutic approach based upon pathophysiology and cardiovascular and renal outcome trials.

EXPERT OPINION

Although insulin resistance is the earliest detectable abnormality, overt T2D does not occur in the absence of progressive beta cell failure. Because of the complex etiology of T2D (Ominous Octet), initiation of therapy with combined agents that (i) target both insulin resistance and beta cell dysfunction and (ii) prevent macrovascular, as well as microvascular, complications will be required. The ratio of C-peptide at 120 minutes (OGTT) to baseline C-peptide predicts with high sensitivity who will respond to metformin, the response to glucose-lowering agents and provides a useful tool to guide optimal glucose lowering therapy.

Prediabetes: how pathophysiology drives potential intervention on a subclinical disease with feared clinical consequences

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder whose rising incidence suggests the epidemic proportions of the disease. Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT) - alone or combined - represent two intermediate metabolic condition between Normal Glucose Tolerance (NGT) and overt T2DM. Several studies have demonstrated that insulin resistance and beta-cell impairment can be identified even in normoglycemic prediabetic individuals. Worsening of these two conditions may lead to progression of IGT and/or IFG status to overt diabetes. Starting from these assumptions, it seems logical to suppose that interventions aimed at improving metabolic conditions, even in prediabetes, could represent an effective target to halt transition from IGT/IFG to manifest T2DM. Starting from pathophysiological knowledge, in this review we evaluate two possible interventions (lifestyle modifications and pharmacological agents) eligible as prediabetes therapy since they have been demonstrated to improve insulin resistance and beta-cell impairment. Detecting high-risk people and treating them could represent an effective strategy to slow down progression to overt diabetes, normalize glucose tolerance, and even prevent micro- and macrovascular complications.

Durability of Triple Combination Therapy Versus Stepwise Addition Therapy in Patients With New-Onset T2DM: 3-Year Follow-up of EDICT

OBJECTIVE

To compare the long-term efficacy of initiating therapy with metformin/pioglitazone/exenatide in patients with new-onset type 2 diabetes mellitus (T2DM) versus sequential addition of metformin followed by glipizide and insulin.

RESEARCH DESIGN AND METHODS

Drug-naive patients (N = 318) with new-onset T2DM were randomly assigned to receive for 3 years either 1) combination therapy with metformin, pioglitazone, and exenatide (triple therapy) or 2) sequential addition of metformin followed by glipizide and insulin (conventional therapy) to maintain HbA_1c at <6.5% (48 mmol/mol). Insulin sensitivity and β-cell function were measured at baseline and 3 years. The primary outcome was the difference in HbA_1c between the groups at 3 years.

RESULTS

Baseline HbA_1c ± SEM values were 9.0% ± 0.2% and 8.9% ± 0.2% in the triple therapy and conventional therapy groups, respectively. The decrease in HbA_1c resulting from triple therapy was greater at 6 months than that produced by conventional therapy (0.30% [95% CI 0.21-0.39]; P = 0.001), and the HbA_1c reduction was maintained at 3 years in patients receiving triple therapy compared with conventional therapy (6.4% ± 0.1% and 6.9% ± 0.1%, respectively), despite intensification of antihyperglycemic therapy in the latter. Thus, the difference in HbA_1c between the two treatment groups at 3 years was 0.50% (95% CI 0.39-0.61; P < 0.0001). Triple therapy produced a threefold increase in insulin sensitivity and 30-fold increase in β-cell function. In conventional therapy, insulin sensitivity did not change and β-cell function increased by only 34% (both P < 0.0001 vs. triple therapy).

CONCLUSIONS

Triple therapy with agents that improve insulin sensitivity and β-cell function in patients with new-onset T2DM produces greater, more durable HbA_1c reduction than agents that lower glucose levels without correcting the underlying metabolic defects.

Type 2 diabetes subgroups and potential medication strategies in relation to effects on insulin resistance and beta-cell function: A step toward personalised diabetes treatment?

Background

Type 2 diabetes is a syndrome defined by hyperglycaemia that is the result of various degrees of pancreatic β-cell failure and reduced insulin sensitivity. Although diabetes can be caused by multiple metabolic dysfunctions, most patients are defined as having either type 1 or type 2 diabetes. Recently, Ahlqvist and colleagues proposed a new method of classifying patients with adult-onset diabetes, considering the heterogenous metabolic phenotype of the disease. This new classification system could be useful for more personalised treatment based on the underlying metabolic disruption of the disease, although to date no prospective intervention studies have generated data to support such a claim.

Scope of Review

In this review, we first provide a short overview of the phenotype and pathogenesis of type 2 diabetes and discuss the current and new classification systems. We then review the effects of different anti-diabetic medication classes on insulin sensitivity and β-cell function and discuss future treatment strategies based on the subgroups proposed by Ahlqvist et al.

Major Conclusions

The proposed novel type 2 diabetes subgroups provide an interesting concept that could lead to a better understanding of the pathophysiology of the broad group of type 2 diabetes, paving the way for personalised treatment choices based on understanding the root cause of the disease. We conclude that the novel subgroups of adult-onset diabetes would benefit from anti-diabetic medications that take into account the main pathophysiology of the disease and thereby prevent end-organ damage. However, we are only beginning to address the personalised treatment of type 2 diabetes, and studies investigating the effects of current and novel drugs in subgroups with different metabolic phenotypes are needed to develop personalised treatment of the syndrome

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Novel subgroups of type 2 diabetes provide a concept that could lead to a better understanding of its pathophysiology.

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Treatment strategies would benefit from anti-diabetic medications that influence the main pathophysiology of diabetes.

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Here, we review different anti-diabetic medications classes affecting insulin sensitivity and β-cell function.

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We suggest that future treatment strategies could benefit by taking into account subgroups provided by Ahlqvist et al.

Age, sex, disease severity, and disease duration difference in placebo response: implications from a meta-analysis of diabetes mellitus

BACKGROUND

The placebo response in patients with diabetes mellitus is very common. A systematic evaluation needs to be updated with the current evidence about the placebo response in diabetes mellitus and the associated factors in clinical trials of anti-diabetic medicine.

METHODS

Literature research was conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies published between the date of inception and June 2019. Randomized placebo-controlled trials conducted in type 1and type 2 diabetes mellitus (T1DM/T2DM) were included. Random-effects model and meta-regression analysis were accordingly used. This meta-analysis was registered in PROSPERO as CRD42014009373.

RESULTS

Significantly weight elevation (effect size (ES) = 0.33 kg, 95% CI, 0.03 to 0.61 kg) was observed in patients with placebo treatments in T1DM subgroup while significantly HbA1c reduction (ES = - 0.12%, 95% CI, - 0.16 to - 0.07%) and weight reduction (ES = - 0.40 kg, 95% CI, - 0.50 to - 0.29 kg) were observed in patients with placebo treatments in T2DM subgroup. Greater HbA1c reduction was observed in patients with injectable placebo treatments (ES = - 0.22%, 95% CI, - 0.32 to - 0.11%) versus oral types (ES = - 0.09%, 95% CI, - 0.14 to - 0.04%) in T2DM (P = 0.03). Older age (β = - 0.01, 95% CI, - 0.02 to - 0.01, P < 0.01) and longer diabetes duration (β = - 0.02, 95% CI, - 0.03 to - 0.21 × 10^-2, P = 0.03) was significantly associated with more HbA1c reduction by placebo in T1DM. However, younger age (β = 0.02, 95% CI, 0.01 to 0.03, P = 0.01), lower male percentage (β = 0.01, 95% CI, 0.22 × 10^-2, 0.01, P < 0.01), higher baseline BMI (β = - 0.02, 95% CI, - 0.04 to - 0.26 × 10^-2, P = 0.02), and higher baseline HbA1c (β = - 0.09, 95% CI, - 0.16 to - 0.01, P = 0.02) were significantly associated with more HbA1c reduction by placebo in T2DM. Shorter diabetes duration (β = 0.06, 95% CI, 0.06 to 0.10, P < 0.01) was significantly associated with more weight reduction by placebo in T2DM. However, the associations between baseline BMI, baseline HbA1c, and placebo response were insignificant after the adjusted analyses.

CONCLUSION

The placebo response in diabetes mellitus was systematically outlined. Age, sex, disease severity (indirectly reflected by baseline BMI and baseline HbA1c), and disease duration were associated with placebo response in diabetes mellitus. The association between baseline BMI, baseline HbA1c, and placebo response may be the result of regression to the mean.

Insulin Resistance the Link between T2DM and CVD: Basic Mechanisms and Clinical Implications

Insulin resistance (IR) is a cardinal feature of type 2 diabetes mellitus (T2DM). It also is associated with multiple metabolic abnormalities which are known cardiovascular disease (CVD) risk factors. Thus, IR not only contributes to the development of hyperglycemia in T2DM patients, but also to the elevated CVD risk. Improving insulin sensitivity is anticipated to both lower the plasma glucose concentration and decrease CVD risk in T2DM patients, independent of glucose control. We review the molecular mechanisms and metabolic consequences of IR in T2DM patients and discuss the importance of addressing IR in the management of T2DM.

Efficacy and Safety of Pioglitazone versus Glimepiride after Metformin and Alogliptin Combination Therapy: A Randomized, Open-Label, Multicenter, Parallel-Controlled Study

BACKGROUND

There is limited information regarding the optimal third-line therapy for managing type 2 diabetes mellitus (T2DM) that is inadequately controlled using dual combination therapy. This study assessed the efficacy and safety of pioglitazone or glimepiride when added to metformin plus alogliptin treatment for T2DM.

METHODS

This multicenter, randomized, active-controlled trial (ClinicalTrials.gov: NCT02426294) recruited 135 Korean patients with T2DM that was inadequately controlled using metformin plus alogliptin. The patients were then randomized to also receive pioglitazone (15 mg/day) or glimepiride (2 mg/day) for a 26-week period, with dose titration was permitted based on the investigator's judgement.

RESULTS

Glycosylated hemoglobin levels exhibited similar significant decreases in both groups during the treatment period (pioglitazone: -0.81%, P<0.001; glimepiride: -1.05%, P<0.001). However, the pioglitazone-treated group exhibited significantly higher high density lipoprotein cholesterol levels (P<0.001) and significantly lower homeostatic model assessment of insulin resistance values (P<0.001). Relative to pioglitazone, adding glimepiride to metformin plus alogliptin markedly increased the risk of hypoglycemia (pioglitazone: 1/69 cases [1.45%], glimepiride: 14/66 cases [21.21%]; P<0.001).

CONCLUSION

Among patients with T2DM inadequately controlled using metformin plus alogliptin, the addition of pioglitazone provided comparable glycemic control and various benefits (improvements in lipid profiles, insulin resistance, and hypoglycemia risk) relative to the addition of glimepiride.

Insulin Resistance and Atherosclerosis: Implications for Insulin-Sensitizing Agents

Patients with type 2 diabetes mellitus (T2DM) are at high risk for macrovascular complications, which represent the major cause of mortality. Despite effective treatment of established cardiovascular (CV) risk factors (dyslipidemia, hypertension, procoagulant state), there remains a significant amount of unexplained CV risk. Insulin resistance is associated with a cluster of cardiometabolic risk factors known collectively as the insulin resistance (metabolic) syndrome (IRS). Considerable evidence, reviewed herein, suggests that insulin resistance and the IRS contribute to this unexplained CV risk in patients with T2DM. Accordingly, CV outcome trials with pioglitazone have demonstrated that this insulin-sensitizing thiazolidinedione reduces CV events in high-risk patients with T2DM. In this review the roles of insulin resistance and the IRS in the development of atherosclerotic CV disease and the impact of the insulin-sensitizing agents and of other antihyperglycemic medications on CV outcomes are discussed.

Effects of Periodic Intensive Insulin Therapy: An Updated Review

Background

Traditional insulin treatment for diabetes mellitus with insulin administered subcutaneously yields nonpulsatile plasma insulin concentrations that represent a fraction of normal portal vein levels. Oral hypoglycemic medications result in the same lack of pulsatile insulin response to blood glucose levels. Intensive treatments of significant complications of diabetes are not recommended due to complicated multidrug regimens, significant weight gain, and the high risk of hypoglycemic complications. Consequently, advanced complications of diabetes do not have an effective treatment option because conventional therapy is not sufficient. Intensive insulin therapy (IIT) simulates normal pancreatic function by closely matching the periodicity and amplitude of insulin secretion in healthy subjects; however, the mechanisms involved with the observed improvement are not clearly understood.

Objective

The current review aims to analyze the pathophysiology of insulin secretion, discuss current therapies for the management of diabetes, provides an updates on the recent advancements of IIT, and proposes its mechanism of action.

Methods

A literature search on PubMed, MEDLINE, Embase, and CrossRef databases was performed on multiple key words regarding the history and current variations of pulsatile and IIT for diabetes treatment. Articles reporting the physiology of insulin secretion, advantages of pulsatile insulin delivery in patients with diabetes patients, efficacy and adverse effects of current conventional insulin therapies for the management of diabetes, benefits and shortcomings of pancreas and islet transplantation, or clinical trials on patients with diabetes treated with pulsed insulin therapy or advanced IIT were included for a qualitative analysis and categorized into the following topics: mechanism of insulin secretion in normal subjects and patients with diabetes and current therapies for the management of diabetes, including oral hypoglycemic agents, insulin therapy, pancreas and islet transplantation, pulsed insulin therapy, and advances in IIT.

Results

Our review of the literature shows that IIT improves the resolution of diabetic ulcers, neuropathy, and nephropathy, and reduces emergency room visits. The likely mechanism responsible for this improvement is increased insulin sensitivity from adipocytes, as well as increased insulin receptor expression.

Conclusions

Recent advancements show that IIT is an effective option for both type 1 diabetes mellitus and type 2 diabetes mellitus patient populations. This treatment resembles normal pancreatic function so closely that it has significantly reduced the effects of relatively common complications of diabetes in comparison to standard treatments. Thus, this new treatment is a promising advancement in the management of diabetes. (Curr Ther Res Clin Exp. 2019; 80:XXX–XXX).

Pioglitazone: The forgotten, cost-effective cardioprotective drug for type 2 diabetes

Type 2 diabetes individuals are at high risk for macrovascular complications: myocardial infarction, stroke and cardiovascular mortality. Recent cardiovascular outcome trials have demonstrated that agents in two antidiabetic classes (SGLT2 inhibitors and GLP-1 receptor agonists) reduce major adverse cardiovascular events. However, there is strong evidence that an older and now generically available medication, the thiazolidinedione, pioglitazone, can retard the atherosclerotic process (PERISCOPE and Chicago) and reduce cardiovascular events in large randomized prospective cardiovascular outcome trials (IRIS and PROactive). Pioglitazone is a potent insulin sensitizer, preserves beta-cell function, causes durable reduction in HbA1c, corrects multiple components of metabolic syndrome and improves nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Adverse effects (weight gain, fluid retention, fractures) must be considered, but are diminished with lower doses and are arguably outweighed by these multiple benefits. With healthcare expenses attributable to diabetes increasing rapidly, this cost-effective drug requires reconsideration in the therapeutic armamentarium for the disease.

Therapeutic medications against diabetes: What we have and what we expect

Diabetes has become one of the largest global health and economic burdens, with its increased prevalence and high complication ratio. Stable and satisfactory blood glucose control are vital to reduce diabetes-related complications. Therefore, continuous attempts have been made in antidiabetic drugs, treatment routes, and traditional Chinese medicine to achieve better disease control. New antidiabetic drugs and appropriate combinations of these drugs have increased diabetes control significantly. Besides, novel treatment routes including oral antidiabetic peptide delivery, nanocarrier delivery system, implantable drug delivery system are also pivotal for diabetes control, with its greater efficiency, increased bioavailability, decreased toxicity and reduced dosing frequency. Among these new routes, nanotechnology, artificial pancreas and islet cell implantation have shown great potential in diabetes therapy. Traditional Chinese medicine also offer new options for diabetes treatment. Our paper aim to overview these therapeutic methods for diabetes therapy. Proper combinations of these existing anti-diabetic medications and searching for novel routes are both necessary for better diabetes control.

Type 1 and 2 diabetes mellitus: A review on current treatment approach and gene therapy as potential intervention

Type 1 and type 2 diabetes mellitus is a serious and lifelong condition commonly characterised by abnormally elevated blood glucose levels due to a failure in insulin production or a decrease in insulin sensitivity and function. Over the years, prevalence of diabetes has increased globally and it is classified as one of the leading cause of high mortality and morbidity rate. Furthermore, diabetes confers a huge economic burden due to its management costs as well as its complications are skyrocketing. The conventional medications in diabetes treatment focusing on insulin secretion and insulin sensitisation cause unwanted side effects to patients and lead to incompliance as well as treatment failure. Besides insulin and oral hypoglycaemic agents, other treatments such as gene therapy and induced β-cells regeneration have not been widely introduced to manage diabetes. Therefore, this review aims to deliver an overview of the current conventional medications in diabetes, discovery of newer pharmacological drugs and gene therapy as a potential intervention of diabetes in the future.

Whole-Organism Chemical Screening Identifies Modulators of Pancreatic β-Cell Function

β-Cell loss and dysfunction play a critical role in the progression of type 1 and type 2 diabetes. Identifying new molecules and/or molecular pathways that improve β-cell function and/or increase β-cell mass should significantly contribute to the development of new therapies for diabetes. Using the zebrafish model, we screened 4,640 small molecules to identify modulators of β-cell function. This in vivo strategy identified 84 stimulators of insulin expression, which simultaneously reduced glucose levels. The insulin promoter activation kinetics for 32 of these stimulators were consistent with a direct mode of action. A subset of insulin stimulators, including the antidiabetic drug pioglitazone, induced the coordinated upregulation of gluconeogenic pck1 expression, suggesting functional response to increased insulin action in peripheral tissues. Notably, Kv1.3 inhibitors increased β-cell mass in larval zebrafish and stimulated β-cell function in adult zebrafish and in the streptozotocin-induced hyperglycemic mouse model. In addition, our data indicate that cytoplasmic Kv1.3 regulates β-cell function. Thus, using whole-organism screening, we have identified new small-molecule modulators of β-cell function and glucose metabolism.

Successful treatment of prediabetes in clinical practice using physiological assessment (STOP DIABETES)

BACKGROUND

Of the 84 million American adults with prediabetes, over 5 to 7 years, about 28 million progress to type 2 diabetes. We aimed to assess whether a real-world, pathophysiology-based, therapeutic approach could prevent development of type 2 diabetes in high-risk individuals.

METHODS

We did a retrospective observational study of people at increased risk of type 2 diabetes from a community practice in southern California, USA. Participants had an oral glucose tolerance test and were assigned a risk stratification on the basis of presence and severity of insulin resistance, impaired β-cell function, and glycaemia (ie, 1-h plasma glucose concentration of more than 8·6 mmol/L during an oral glucose tolerance test). Treatment was recommended on the basis of risk: metformin, pioglitazone, glucagon-like peptide-1 (GLP-1) receptor agonist, and lifestyle therapy for participants at high risk of diabetes, and metformin, pioglitazone, and lifestyle therapy for those at intermediate risk. Individuals who refused pharmacological therapy were assigned to lifestyle therapy only. Participants were followed up every 6 months and oral glucose tolerance tests were repeated at 6 months and subsequently every 2 years or sooner. The primary outcome of our analysis was incidence of type 2 diabetes according to the American Diabetes Association criteria, within the study period (2009-16). This study is registered with ClinicalTrials.gov, number NCT03308773.

FINDINGS

Between Jan 1, 2009 and Dec 31, 2016, we assessed 1769 people at increased risk of diabetes, of which 747 (42%) were identified at high or intermediate risk and were recommended pharmacological treatment. Of 422 participants analysed, 28 (7%) progressed to type 2 diabetes (seven [5%] of 141 participants who received metformin, pioglitazone, and lifestyle therapy, none [0%] of 81 who received metformin, pioglitazone, GLP-1 receptor agonist, and lifestyle therapy, and 21 [11%] of 200 who received lifestyle therapy only) after mean follow-up of 32·09 months (SEM 1·24). Compared with participants who received lifestyle therapy only, the adjusted hazard ratio for progression to type 2 diabetes was 0·29 (95% CI 0·11-0·78, p=0·0009) in participants who received metformin and pioglitazone, and 0·12 (95% CI 0·02-0·94, p=0·04) in participants who received metformin, pioglitazone, and GLP-1 receptor agonist. Improved β-cell function was the strongest predictor of type 2 diabetes prevention.

INTERPRETATION

Progression to type 2 diabetes in people at high risk of diabetes can be markedly reduced with interventions designed to correct underlying pathophysiological disturbances (ie, impaired insulin secretion and resistance) in a real-world setting.

FUNDING

None.

Vildagliptin/pioglitazone combination improved the overall glycemic control in type I diabetic rats

Type I diabetes (TID) is generally assumed to be caused by an immune associated, if not directly immune-mediated, destruction of pancreatic β-cells. In patients with long-term diabetes, the pancreas lacks insulin-producing cells and the residual β-cells are unable to regenerate. Patients with TID are subjected to a lifelong insulin therapy which shows risks of hypoglycemia, suboptimal control and ketosis. In this study, we investigated the potential role of vildagliptin (Vilda) alone or in combination with pioglitazone (Pio), as treatment regimens for TID using streptozotocin (STZ)-induced TID model in rats. Daily oral administration of Vilda (5 mg/kg) alone or in combination with Pio (20 mg/kg) for 7 weeks significantly reduced blood glucose levels and HbA1c. It increased serum insulin levels and decreased serum glucagon. It also showed a strong antioxidant activity. Immunohistochemical analysis showed a marked improvement in β-cells in treated groups when compared with the diabetic group, which appeared in the normal cellular and architecture restoration of β-cells in the islets of Langerhans. Vilda alone or in combination with Pio has the ability to improve the overall glycemic control in type I diabetic rats and may be considered a hopeful and effective remedy for TID.

Pioglitazone Improved Insulin Sensitivity and First Phase Insulin Secretion Among Obese and Lean People with Diabetes: A Multicenter Clamp Study

INTRODUCTION

To investigate the effects of pioglitazone (PIO) on insulin resistance and first phase insulin secretion among obese and lean Chinese people with type 2 diabetes mellitus (T2DM).

METHODS

Sixty-eight drug-naïve patients with T2DM were treated with PIO for 16 weeks. Before and after the treatment, insulin sensitivity was evaluated by the euglycemic hyperinsulinemic clamp test. Plasma insulin levels at 0, 3, 5, 7, and 10 min during intravenous glucose tolerance test were determined to calculate the first phase insulin secretion and pancreatic β-cell function. Circulating adiponectin levels were quantified.

RESULTS

In both the lean and the obese patients with T2DM, the reduction of HbA_1c following the PIO treatment was more than 1% (P < 0.001) and glucose infusion rate, acute insulin response, glucose disposal index, and β-cell glucose sensitivity increased significantly (P < 0.001). A multiple linear regression analysis showed that the improvements of first phase insulin secretion and insulin sensitivity were independently associated with the changes of HbA_1c, but the change of first phase insulin secretion exhibited a higher correlation coefficient (R² = 0.20, P = 0.001) than the change of insulin sensitivity did (R² = 0.07, P = 0.040). The PIO treatment led to a significant increase in adiponectin levels only in the obese group (P < 0.05).

CONCLUSION

A 16-week treatment of PIO significantly increased insulin sensitivity and β-cell function in the lean group as well as in the obese group among Chinese T2DM patients, demonstrating that both lean and obese diabetic adults would profit from PIO.

TRIAL REGISTRATION

The ChiCTR registry number is ChiCTR-OPC-17011571.

FUNDING

Takeda Pharmaceutical Co. Ltd. and Pfizer Pharmaceutical Co. Ltd.

Empagliflozin Treatment Is Associated With Improved β-Cell Function in Type 2 Diabetes Mellitus

OBJECTIVE

To examine whether lowering plasma glucose concentration with the sodium-glucose transporter-2 inhibitor empagliflozin improves β-cell function in patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients with T2DM (N = 15) received empagliflozin (25 mg/d) for 2 weeks. β-Cell function was measured with a nine-step hyperglycemic clamp (each step, 40 mg/dL) before and at 48 hours and at 14 days after initiating empagliflozin.

RESULTS

Glucosuria was recorded on days 1 and 14 [mean ± standard error of the mean (SEM), 101 ± 10 g and 117 ± 11 g, respectively] after initiating empagliflozin, as were reductions in fasting plasma glucose levels (25 ± 6 mg/dL and 38 ± 8 mg/dL, respectively; both P < 0.05). After initiating empagliflozin and during the stepped hyperglycemic clamp, the incremental area under the plasma C-peptide concentration curve increased by 48% ± 12% at 48 hours and 61% ± 10% at 14 days (both P < 0.01); glucose infusion rate increased by 15% on day 3 and 16% on day 14, compared with baseline (both P < 0.05); and β-cell function, measured with the insulin secretion/insulin resistance index, increased by 73% ± 21% at 48 hours and 112% ± 20% at 14 days (both P < 0.01). β-cell glucose sensitivity during the hyperglycemic clamp was enhanced by 42% at 14 hours and 54% at 14 days after initiating empagliflozin (both P < 0.01).

CONCLUSION

Lowering the plasma glucose concentration with empagliflozin in patients with T2DM augmented β-cell glucose sensitivity and improved β-cell function.

Insulin secretion predicts the response to therapy with exenatide plus pioglitazone, but not to basal/bolus insulin in poorly controlled T2DM patients: Results from the Qatar study

The present study aims to identify predictors for response to combination therapy with pioglitazone plus exenatide vs basal/bolus insulin therapy in T2DM patients who are poorly controlled with maximum/near-maximum doses of metformin plus a sulfonylurea. Participants in the Qatar study received a 75-g OGTT with measurement of plasma glucose, insulin and C-peptide concentration at baseline and were then randomized to receive either treatment with pioglitazone plus exenatide or basal/bolus insulin therapy for one year. Insulin secretion measured with plasma C-peptide concentration during the OGTT was the strongest predictor of response to combination therapy (HbA1c ≤ 7.0%) with pioglitazone plus exenatide. A 54% increase in 2-hour plasma C-peptide concentration above the fasting level identified subjects who achieved the glycaemic goal (HbA1c < 7.0%) with 82% sensitivity and 79% specificity. Only baseline HbA1c was a predictor of response to basal/bolus insulin therapy. Thus, the increment in 2-hour plasma C-peptide concentration above the fasting level provides a useful tool to identify poorly controlled T2DM patients who can achieve glycaemic control without insulin therapy, and thereby, can be used to individualize antihyperglycaemic therapy in poorly controlled T2DM patients.

Initiating therapy in patients newly diagnosed with type 2 diabetes: Combination therapy vs a stepwise approach

There is clear evidence that achieving glycaemic targets reduces the risk of developing complications as a result of type 2 diabetes (T2D). Many patients, however, continue to have suboptimal glycaemic control because of issues that include unclear advice on how to achieve these targets as well as clinical inertia. The two management approaches recommended for patients newly diagnosed with T2D are stepwise and combination therapy, each of which has advantages and disadvantages. Stepwise therapy may result in good patient adherence and allow greater individualization of therapy, and minimization of side effects and cost, and so may be appropriate for patients who are closer to goal. Stepwise therapy, however, may also lead to frequent delays in achieving glycaemic goals and longer exposure to hyperglycaemia. Combination therapy, which is now emerging as an important therapy option, has a number of potential advantages over stepwise therapy, including reduction in clinical inertia and earlier and more frequent achievement of glycated haemoglobin goals by targeting multiple pathogenic mechanisms simultaneously, which may more effectively delay disease progression. Compared with stepwise therapy, the disadvantages of combination therapy include reduced patient adherence resulting from complex, multi-drug regimens, difficulty determining the cause of poor efficacy and/or side effects, patient refusal to accept disease, and higher cost. Fixed-dose and fixed-ratio combinations are novel therapeutic approaches which may help address several issues of treatment complexity and patient burden associated with combination therapy comprising individual drugs. The choice of which drugs to administer and the decision to use stepwise vs combination therapy, however, should always be made on an individualized basis.

Add on DPP-4 inhibitor alogliptin alone or in combination with pioglitazone improved β-cell function and insulin sensitivity in metformin treated PCOS

PURPOSE

Impaired β-cell function remains unaddressed in PCOS. The aim of the study was to evaluate whether dipeptidyl peptidase-4 (DPP-4) inhibitor alogliptin (ALO) alone or in combination with pioglitazone (PIO) improves β-cell function along with insulin resistance (IR) in metformin (MET) treated obese women with PCOS with persistent IR.

MATERIALS AND METHODS

In 12-week randomized study, ALO 25 mg QD (n=15) or ALO 25 mg QD and PIO 30 mg QD (n=15) was added to MET 1000 mg BID in PCOS women (aged 34.4 ± 6.5 years, BMI 39.0 ± 4.9 kg/m², HOMA-IR 4.82 ± 2.52, mean ± SD). Model derived parameters of glucose homeostasis from the meal tolerance test (MTT) were determined. The ability of the β-cell function was assessed by the adaptation index (AI).

RESULTS

MET-ALO and MET-ALO-PIO resulted in a significant decrease of HOMA-IR (by 1.6±2.3 (p=0.039) and 2.9±3.3 (p=0.001), respectively) and an increase in insulin sensitivity (IS) after meal ingestion (oral glucose IS) by 31.4±97.5 ml·min^-1·m^-2 (p=0.007) vs 39.0±58.1 ml·min^-1·m^-2 (p=0.039), respectively. AI across the entire group was significantly improved from 329.6±200.6 to 442.5±303.9 (p=0.048).

CONCLUSIONS

ALO alone and in combination with PIO improved IR along with dynamic IS and meal related β-cell function when added to MET treated PCOS.

Combination therapy with GLP-1 receptor agonist and SGLT2 inhibitor

The SGLT2 inhibitors (SGLTi) and glucagon-like-1 receptor agonists (GLP-1 RAs) effectively reduce HbA1c, but via very different mechanisms, making them an effective duet for combination therapy. Recently, drugs in both of these antidiabetic classes have been shown to reduce cardiovascular events, most probably by different mechanisms. SGLT2i appear to exert their CV protective actions by haemodynamic effects, while GLP-1 RAs work via anti-atherogenic/anti-inflammatory mechanisms, raising the possibility that combined therapy with these 2 classes may produce additive CV benefits. The SGLT2i and GLP-1 RAs also reduced macroalbuminuria, decreased the time for doubling of serum creatinine, and slowed the time to end-stage renal disease. In this perspective, we review the potential benefit of combination SGLT2i/GLP-1 RA therapy on metabolic-cardiovascular-renal disease in patients with type 2 diabetes mellitus.

Cardiovascular Disease and Type 2 Diabetes: Has the Dawn of a New Era Arrived?

Hyperglycemia is the major risk factor for microvascular complications in patients with type 2 diabetes (T2D). However, cardiovascular disease (CVD) is the principal cause of death, and lowering HbA1c has only a modest effect on reducing CVD risk and mortality. The recently published LEADER and SUSTAIN-6 trials demonstrate that, in T2D patients with high CVD risk, the glucagon-like peptide 1 receptor agonists liraglutide and semaglutide reduce the primary major adverse cardiac events (MACE) end point (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke) by 13% and 24%, respectively. The EMPA-REG OUTCOME, IRIS (subjects without diabetes), and PROactive (second principal end point) studies also demonstrated a significant reduction in cardiovascular events in T2D patients treated with empagliflozin and pioglitazone. However, the benefit of these four antidiabetes agents (liraglutide, semaglutide, empagliflozin, and pioglitazone) on the three individual MACE end points differed, suggesting that different underlying mechanisms were responsible for the reduction in cardiovascular events. Since liraglutide, semaglutide, pioglitazone, and empagliflozin similarly lower the plasma glucose concentration but appear to reduce CVD risk by different mechanisms, there emerges the intriguing possibility that, if used in combination, the effects of these antidiabetes agents may be additive or even multiplicative with regard to cardiovascular benefit.

Efficacy of Exenatide Plus Pioglitazone Vs Basal/Bolus Insulin in T2DM Patients With Very High HbA1c

OBJECTIVE

To examine the efficacy and safety of combination therapy with exenatide plus pioglitazone vs basal/bolus insulin in patients with poorly controlled type 2 diabetes mellitus (T2DM) with very high hemoglobin A1c (HbA1c) (>10%) receiving sulfonylurea plus metformin and with a long duration of disease.

DESIGN AND PARTICIPANTS

Participants (n = 101) in the Qatar Study with very poor glycemic control (HbA1c >10%) and a long duration of diabetes (10.9 years) receiving maximum/near-maximum doses of sulfonylurea plus metformin were randomly assigned to receive pioglitazone plus weekly exenatide (combination therapy), or basal plus prandial insulin (insulin therapy), to maintain HbA1c <7.0%.

RESULTS

Baseline HbA1c was 11.5% ± 0.2% and 11.2% ± 0.2% (P = not significant) in combination therapy and insulin therapy groups, respectively. At 6 months, combination therapy caused a robust decrease in HbA1c to 6.7% ± 0.1% (∆ = -4.8%) compared with 7.4% ± 0.1% (∆ = -3.8%) in subjects receiving insulin therapy. Combination therapy was effective in lowering the HbA1c independent of sex, ethnicity, or body mass index. Subjects in the insulin therapy group experienced significantly greater weight gain and a 2.5-fold higher rate of hypoglycemia compared with patients receiving combination therapy.

CONCLUSION

Exenatide/pioglitazone combination therapy is an effective and safe therapeutic option in patients with poorly controlled T2DM receiving metformin plus sulfonylurea with very high HbA1c (>10%).

Combination Therapy With Exenatide Plus Pioglitazone Versus Basal/Bolus Insulin in Patients With Poorly Controlled Type 2 Diabetes on Sulfonylurea Plus Metformin: The Qatar Study

OBJECTIVE

The Qatar Study was designed to examine the efficacy of combination therapy with exenatide plus pioglitazone versus basal/bolus insulin in patients with long-standing poorly controlled type 2 diabetes mellitus (T2DM) on metformin plus a sulfonylurea.

RESEARCH DESIGN AND METHODS

The study randomized 231 patients with poorly controlled (HbA_1c >7.5%, 58 mmol/mol) T2DM on a sulfonylurea plus metformin to receive 1) pioglitazone plus weekly exenatide (combination therapy) or 2) basal plus prandial insulin (insulin therapy) to maintain HbA_1c <7.0% (53 mmol/mol).

RESULTS

After a mean follow-up of 12 months, combination therapy caused a robust decrease in HbA_1c from 10.0 ± 0.6% (86 ± 5.2 mmol/mol) at baseline to 6.1 ± 0.1% (43 ± 0.7 mmol/mol) compared with 7.1 ± 0.1% (54 ± 0.8 mmol/mol) in subjects receiving insulin therapy. Combination therapy was effective in lowering the HbA_1c independent of sex, ethnicity, BMI, or baseline HbA_1c. Subjects in the insulin therapy group experienced significantly greater weight gain and a threefold higher rate of hypoglycemia than patients in the combination therapy group.

CONCLUSIONS

Combination exenatide/pioglitazone therapy is a very effective and safe therapeutic option in patients with long-standing poorly controlled T2DM on metformin plus a sulfonylurea.

Peroxisome Proliferator-activated Receptor-γ Activation Augments the β-Cell Unfolded Protein Response and Rescues Early Glycemic Deterioration and β Cell Death in Non-obese Diabetic Mice

Type 1 diabetes is an autoimmune disorder that is characterized by a failure of the unfolded protein response in islet β cells with subsequent endoplasmic reticulum stress and cellular death. Thiazolidinediones are insulin sensitizers that activate the nuclear receptor PPAR-γ and have been shown to partially ameliorate autoimmune type 1 diabetes in humans and non-obese diabetic (NOD) mice. We hypothesized that thiazolidinediones reduce β cell stress and death independently of insulin sensitivity. To test this hypothesis, female NOD mice were administered pioglitazone during the pre-diabetic phase and assessed for insulin sensitivity and β cell function relative to controls. Pioglitazone-treated mice showed identical weight gain, body fat distribution, and insulin sensitivity compared with controls. However, treated mice showed significantly improved glucose tolerance with enhanced serum insulin levels, reduced β cell death, and increased β cell mass. The effect of pioglitazone was independent of actions on T cells, as pancreatic lymph node T cell populations were unaltered and T cell proliferation was unaffected by pioglitazone. Isolated islets of treated mice showed a more robust unfolded protein response, with increases in Bip and ATF4 and reductions in spliced Xbp1 mRNA. The effect of pioglitazone appears to be a direct action on β cells, as islets from mice treated with pioglitazone showed reductions in PPAR-γ (Ser-273) phosphorylation. Our results demonstrate that PPAR-γ activation directly improves β cell function and survival in NOD mice by enhancing the unfolded protein response and suggest that blockade of PPAR-γ (Ser-273) phosphorylation may prevent type 1 diabetes.

Impact of the use of anti-diabetic drugs on survival of diabetic dialysis patients: a 5-year retrospective cohort study in Taiwan

BACKGROUND

Type 2 diabetes mellitus (DM) and associated complications are common in patients with chronic kidney disease (CKD) and can increase morbidity and mortality. A longitudinal 5-year observational study was conducted to investigate whether the use of anti-diabetic medications or not affected survival rates of diabetic dialysis patients.

METHODS

Using a data sample of a million patients from Taiwan's National Health Insurance Database, a retrospective cohort study surveyed patients with type 2 DM who began dialysis between 2002 and 2007. The study population was classified into groups using or not using anti-diabetic drugs. The group using anti-diabetic drugs was then categorized into 3 subgroups, including use of only oral hypoglycemic agents (OHAs), only insulin, and OHAs-combined insulin groups. Subjects of these four groups were followed 5 years or to date of death. Three major areas were analyzed: (1) demographic data and medical history; (2) survival prognosis and causes of death; and (3) effects on survival prognosis of different classes of OHAs.

RESULTS

A total of 912 patients fitting inclusion criteria were enrolled and followed-up for 5 years or to date of death. A total 465 patients died, and those not using anti-diabetic drugs (67.34 %) had a higher mortality rate than those using anti-diabetic drugs (46.42 %). After the multivariate analysis, group of OHAs-combined insulin had the lowest risk of death (HR 0.36, 95 % CI 0.27-0.47), followed by OHAs alone (HR 0.49, 95 % CI 0.38-0.63) and then insulin alone (HR 0.67, 95 % CI 0.51-0.88). To clarify four classes of OHAs (sulfonylurea, α-glucosidase inhibitors, meglitinide, and thiazolidinedione) are used in Taiwan for uremia patient with type 2 DM, and in our study, there were no significant differences in survival prognosis for the four drugs. Finally, the most common cause of death was infectious disease and there were no significant differences among the four groups.

CONCLUSION

This 5-year observational study results suggested that diabetic dialysis patients with anti-diabetic drugs had a lower risk of death compared with those without anti-diabetic drugs. Despite insulin therapy, appropriate OHAs should play an important role in treating these patients.

Current Therapies for the Medical Management of Diabetes

Diabetes affects a large and diverse number of individuals who share in common its risks for complications but who differ greatly from one another in age, health, and a number of circumstances influential to successful treatment. Because type 2 diabetes comprises the majority of diabetes cases, a number of agents have been developed for its treatment. Their unique properties offer opportunities to overcome some of the treatment limitations of older medicines and enable a more individualized and flexible approach to glucose-lowering. At the same time, new medications are accompanied by greater costs and uncertainties about their long-term benefits or safety, and thus the present state of care for type 2 diabetes places focus on a process of shared decision-making between the clinician and patient as to which treatments can optimize health while minimizing harms. We review the major classes of diabetes agents and provide some guidance for how one might approach decision-making in choosing among them.

Revitalization of pioglitazone: the optimum agent to be combined with a sodium-glucose co-transporter-2 inhibitor

The recently completed EMPA-REG study showed that empagliflozin significantly decreased the major adverse cardiac events (MACE) endpoint, which comprised cardiovascular death, non-fatal myocardial infarction (MI) and stroke, in patients with high-risk type 2 diabetes (T2DM), primarily through a reduction in cardiovascular death, without a significant decrease in either MI or stroke. In the PROactive study, pioglitazone decreased the MACE endpoint by a similar degree to that observed in the EMPA-REG study, through a marked reduction in both recurrent MI and stroke and a modest reduction in cardiovascular death. These observations suggest that pioglitazone might be an ideal agent to combine with empagliflozin to further reduce cardiovascular events in patients with high-risk diabetes as empagliflozin also promotes salt/water loss and would be expected to offset any fluid retention associated with pioglitazone therapy. In the present paper, we provide an overview of the potential benefits of combined pioglitazone/empagliflozin therapy to prevent cardiovascular events in patients with T2DM.