Comparison of metabolic profile and adiponectin level with pioglitazone versus voglibose in patients with type-2 diabetes mellitus associated with metabolic syndrome

Efficacy and Safety of Metformin Versus the Other Oral Antidiabetic Drugs in Japanese Type 2 Diabetes Patients: A Network Meta-analysis

Introduction

Although metformin is recommended as a first-line treatment for patients with type 2 diabetes (T2D) in Western countries, no specific treatment is recommended in Japan, and various agents are used. Metformin has long been used at low doses in Japan, and information regarding its effect at the maximum maintenance dose is lacking. Here, we compared the efficacy and safety of metformin at 1500 mg/day with those of the other oral anti-diabetic drugs (OADs) approved in Japan.

Methods

Randomized controlled trials comparing a change in hemoglobin A1c (HbA1c) from baseline at 12 weeks or later (ΔHbA1c) among OADs (including placebo) as a first-line treatment in adult patients with T2D were selected by systematic review with comprehensive searching of CENTRAL, MEDLINE, Ichushi Web, and EMBASE and manual searching of clinical trial registries. The ΔHbA1c and incidence of hypoglycemia were compared among OAD treatments using Bayesian network meta-analysis (NMA). The relative risk (RR) of the incidence of hypoglycemia was determined relative to that of placebo.

Results

Forty-six randomized controlled trials were identified in the systematic review, and 37 studies, comprising 38 different types of treatments, including placebos, were selected for the NMA of ΔHbA1c. Compared with metformin 1500 mg/day, 20 OAD treatments were significantly less effective in reducing HbA1c from baseline (differences from metformin 1500 mg/day: 0.40–0.96%). Two treatments (glimepiride 2 mg/day and pioglitazone 45 mg/day) showed greater mean reductions in HbA1c from baseline than metformin 1500 mg/day (− 0.38% and − 0.03%), although these differences were not significant. Regarding the incidence of hypoglycemia, only pioglitazone 30 mg/day among 31 treatments showed a lower RR (< − 0.01), whereas 23 treatments showed a significantly higher RR (1.02–66.71) than metformin 1500 mg/day.

Conclusion

The NMA suggested a preferable efficacy and safety profile of metformin 1500 mg/day compared with the other OADs approved in Japan.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01979-1.

Effects of sitagliptin on exercise capacity and hemodynamics in patients with type 2 diabetes mellitus and coronary artery disease

Sitagliptin attenuates left ventricular (LV) dysfunction and may improve oxygen uptake in animals. The effects of sitagliptin on oxygen uptake (VO₂) and exercise hemodynamics have been unclear in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD). Thirty patients with T2DM and CAD were randomized into a sitagliptin (50 mg/day) or voglibose (0.6 mg/day) group. Patients underwent maximal cardiopulmonary exercise testing. VO₂ and hemodynamics were evaluated at rest, anaerobic threshold and peak exercise. Resting LV diastolic function (E', peak early diastolic mitral annular velocity) and geometry were evaluated by echocardiography, and endothelial function by reactive hyperemia peripheral arterial tonometry. A total of 24 patients (69 ± 9 years) completed 6 months of intervention. Peak VO₂ in the sitagliptin and voglibose groups (25.3 ± 7.3 vs. 24.0 ± 7.4, 22.7 ± 4.8 vs. 22.1 ± 5.2 ml/kg/min) was slightly decreased after 6 months (time effect p = 0.051; group × time effect p = 0.49). No effects were observed on LV ejection fraction, E', or reactive hyperemia index in either group. Heart rate during exercise was unaffected in both groups. Systolic blood pressure was unchanged by sitagliptin at rest and during exercise, but slightly lowered by voglibose at anaerobic threshold and peak exercise. In patients with T2DM and CAD, sitagliptin had little effect on resting LV and arterial function, exercise capacity, or exercise hemodynamics. Further studies need to be conducted with more patients as the number of the patients in this study was limited.

Anti-inflammatory properties of antidiabetic agents

The reciprocal relationship between hyperglycemia and inflammation in the setting of diabetes mellitus has been the subject of extensive research. Insulin resistance, the hallmark of diabetic metabolic dysregulation, has been linked to the inflammatory cascade occurring mainly in adipose tissue. The main pathophysiologic processes facilitating the aforementioned interplay, is a phenotype switch of macrophages to the M1 class following gluco- and lipotoxicity and gut microbial remodeling. Given the correlation between inflammation and metabolic abnormalities, the elucidation of the exact mechanisms linking the two along with exploring the possible role of modulation of one in order to alter the other, could open up the possibility of novel therapeutic approaches for diabetes mellitus and its complications. Therefore, the aim of this review is to summarize the growing body of evidence concerning the molecular basis and results of pro-inflammatory processes in diabetic subjects along with the effect of current antidiabetic treatment options on tissue inflammation.

Pleiotropic effects of sitagliptin versus voglibose in patients with type 2 diabetes inadequately controlled via diet and/or a single oral antihyperglycemic agent: a multicenter, randomized trial

PURPOSE

A step-up strategy for diet therapy and/or single oral antihyperglycemic agent (OHA) regimens has not yet been established. The aim of this study was to evaluate hemoglobin A1c (HbA1c) as a primary end point, and the pleiotropic effects on metabolic and cardiovascular parameters as secondary end points, of sitagliptin versus voglibose in patients with type 2 diabetes with inadequate glycemic control while on diet therapy and/or treatment with a single OHA.

METHODS

In this multicenter, randomized, open-label, parallel-group trial, a total of 260 patients with inadequately controlled type 2 diabetes (HbA1c levels >6.9%) were randomly assigned to receive either sitagliptin (50 mg, once daily) or voglibose (0.6 mg, thrice daily) for 12 weeks. The primary end point was HbA1c levels.

RESULTS

Patients receiving sitagliptin showed a significantly greater decrease in HbA1c levels (-0.78±0.69%) compared with those receiving voglibose (-0.30±0.78%). Sitagliptin treatment also lowered serum alkaline phosphatase levels and increased serum creatinine, uric acid, cystatin-C and homeostasis model assessment-β values. Voglibose increased low-density lipoprotein-cholesterol levels and altered serum levels of several fatty acids, and increased Δ-5 desaturase activity. Both drugs increased serum adiponectin. The incidence of adverse events (AEs) was significantly lower in the sitagliptin group, due to the decreased incidence of gastrointestinal AEs.

CONCLUSIONS

Sitagliptin shows superior antihyperglycemic effects compared with voglibose as a first-line or second-line therapy. However, both agents possess unique pleiotropic effects that lead to reduced cardiovascular risk in Japanese people with type 2 diabetes.

TRIAL REGISTRATION NUMBER

UMIN 000003503.

Hypoglycemic agents and potential anti-inflammatory activity

Current literature shows an association of diabetes and secondary complications with chronic inflammation. Evidence of these immunological changes include altered levels of cytokines and chemokines, changes in the numbers and activation states of various leukocyte populations, apoptosis, and fibrosis during diabetes. Therefore, treatment of diabetes and its complications may include pharmacological strategies to reduce inflammation. Apart from anti-inflammatory drugs, various hypoglycemic agents have also been found to reduce inflammation that could contribute to improved outcomes. Extensive studies have been carried out with thiazolidinediones (peroxisome proliferator-activated receptor-γ agonist), dipeptidyl peptidase-4 inhibitors, and metformin (AMP-activated protein kinase activator) with each of these classes of compounds showing moderate-to-strong anti-inflammatory action. Sulfonylureas and alpha glucosidase inhibitors appeared to exert modest effects, while the injectable agents, insulin and glucagon-like peptide-1 receptor agonists, may improve secondary complications due to their anti-inflammatory potential. Currently, there is a lack of clinical data on anti-inflammatory effects of sodium–glucose cotransporter type 2 inhibitors. Nevertheless, for all these glucose-lowering agents, it is essential to distinguish between anti-inflammatory effects resulting from better glucose control and effects related to intrinsic anti-inflammatory actions of the pharmacological class of compounds.

Efficacy of voglibose in type 2 diabetes

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is currently at epidemic proportions and the forecast is for a continued sharp increase in global prevalence. An even larger proportion of the population has prediabetes (impaired glucose tolerance [IGT]) underscoring the urgent need for preventive strategies. Even in the presence of adequate glycosylated hemoglobin (HbA1c) levels, postprandial hyperglycemia can occur and is known to have a stronger association with cardiovascular morbidity than fasting glucose. The α-glucosidase inhibitor voglibose is widely used in Japan to improve postprandial hyperglycemia.

AREAS COVERED

This review examines the literature for the pharmacology, pharmacokinetics, clinical efficacy and safety of voglibose in patients with T2DM. Particular focus is on its efficacy in preventing T2DM in individuals with IGT and its efficacy as add-on therapy or in combination with other oral antidiabetic agents in patients with T2DM.

EXPERT OPINION

As the relationship between glucose levels and cardiovascular risk extends below the diabetic threshold, postprandial hyperglycemia is recognized as a key therapeutic target in the treatment of T2DM. Strategies to prevent the progression of IGT to overt T2DM have enormous potential to reduce the individual and societal burden of disease. Voglibose is the first oral antidiabetic agent to gain approval in Japan for this indication.

Voglibose: an alpha glucosidase inhibitor

Diabetes Mellitus (DM) is a morbid disease worldwide, with increasing incidence as time passes. It has macro-vascular and micro-vascular complications. The main cause of these complications is poorly controlled postprandial hyperglycaemia. Alpha glucosidase inhibitors, namely acarbose, voglibose and miglitol, are available for therapy. Voglibose is well tolerated and effective in comparable doses among these drugs. This article highlights the important features of voglibose.

α-Glucosidase inhibitors and their use in clinical practice

Post-prandial hyperglycemia still remains a problem in the management of type 2 diabetes mellitus. Of all available anti-diabetic drugs, α-glucosidase inhibitors seem to be the most effective in reducing post-prandial hyperglycemia. We conducted a review analyzing the clinical efficacy and safety of α-glucosidase inhibitors, both alone and in combination with other anti-diabetic drugs, with respect to glycemic control, inflammation and atherosclerosis. α-Glucosidase inhibitors proved to be effective and safe both in monotherapy and as an add-on to other anti-diabetic drugs. Compared to miglitol and voglibose, acarbose seems to have some additive effects such as stabling carotid plaques, and reducing inflammation. Acarbose also proved to reverse impaired glucose tolerance to normal glucose tolerance.

Secondary prevention of stroke: Pleiotropic effects of optimal oral pharmacotherapy

Stroke is a major cause of mortality and disability worldwide. During the past three decades, major advances have occurred in secondary prevention, which have demonstrated the broader potential for the prevention of stroke. Risk factors for stroke include previous stroke or transient ischemic attack, hypertension, high blood cholesterol and diabetes. Proven secondary prevention strategies are anti-platelet agents, antihypertensive drugs, statins and glycemic control. In the present review, we evaluated the secondary prevention of stroke in light of clinical studies and discuss new pleiotropic effects beyond the original effects and emerging clinical evidence, with a focus on the effect of optimal oral pharmacotherapy.

Clinical neuroprotective drugs for treatment and prevention of stroke

Stroke is an enormous public health problem with an imperative need for more effective therapies. In therapies for ischemic stroke, tissue plasminogen activators, antiplatelet agents and anticoagulants are used mainly for their antithrombotic effects. However, free radical scavengers, minocycline and growth factors have shown neuroprotective effects in the treatment of stroke, while antihypertensive drugs, lipid-lowering drugs and hypoglycemic drugs have shown beneficial effects for the prevention of stroke. In the present review, we evaluate the treatment and prevention of stroke in light of clinical studies and discuss new anti-stroke effects other than the main effects of drugs, focusing on optimal pharmacotherapy.