Efficacy and safety of acarbose in metformin-treated patients with type 2 diabetes

Fixed-Dose Combination Formulations in Solid Oral Drug Therapy: Advantages, Limitations, and Design Features

Whilst monotherapy is traditionally the preferred treatment starting point for chronic conditions such as hypertension and diabetes, other diseases require the use of multiple drugs (polytherapy) from the onset of treatment (e.g., human immunodeficiency virus acquired immunodeficiency syndrome, tuberculosis, and malaria). Successful treatment of these chronic conditions is sometimes hampered by patient non-adherence to polytherapy. The options available for polytherapy are either the sequential addition of individual drug products to deliver an effective multi-drug regimen or the use of a single fixed-dose combination (FDC) therapy product. This article intends to critically review the use of FDC drug therapy and provide an insight into FDC products which are already commercially available. Shortcomings of FDC formulations are discussed from multiple perspectives and research gaps are identified. Moreover, an overview of fundamental formulation considerations is provided to aid formulation scientists in the design and development of new FDC products.

Efficacy and safety of alogliptin versus acarbose in Chinese type 2 diabetes patients with high cardiovascular risk or coronary heart disease treated with aspirin and inadequately controlled with metformin monotherapy or drug-naive: A multicentre, randomized, open-label, prospective study (ACADEMIC)

AIMS

To demonstrate the noninferiority of alogliptin to acarbose, in terms of antidiabetic efficacy, in Chinese people with uncontrolled type 2 diabetes (T2D) and high cardiovascular risk.

MATERIALS AND METHODS

ACADEMIC (NCT03794336) was a randomized, open-label, phase IV study conducted at 46 sites in China. Antidiabetic treatment-naive or metformin-treated adults with uncontrolled T2D (glycated haemoglobin [HbA1c] 58.0-97.0 mmol/mol) were randomized 2:1 to alogliptin 25 mg once daily or acarbose 100 mg three times daily for 16 weeks. All participants had a documented history of coronary heart disease or high cardiovascular risk at screening and received aspirin (acetylsalicylic acid) 100 mg daily throughout the trial. The primary endpoints were change in HbA1c versus baseline, and the incidence of gastrointestinal adverse events (AEs). Safety and tolerability were also assessed.

RESULTS

A total of 1088 participants were randomized. Alogliptin was noninferior to acarbose for the change in Week-16 HbA1c (least-squares mean change [standard error] -11.9 [0.4] vs. -11.4 [0.5] mmol/mol, respectively; difference between arms -0.5 [0.7] mmol/mol; 95% confidence interval -1.9 to 0.8 mmol/mol), and was associated with a lower incidence of gastrointestinal AEs (8.9% vs. 33.6%, respectively; P < 0.0001). More alogliptin than acarbose recipients achieved HbA1c <53.0 mmol/mol without gastrointestinal AEs (48.0% vs. 32.7%; P < 0.0001). Discontinuations due to treatment-related AEs were less frequent with alogliptin than acarbose (0.3% vs. 2.5%).

CONCLUSIONS

Glycaemic control was comparable between alogliptin and acarbose, but the gastrointestinal tolerability of alogliptin was better. More patients achieved target HbA1c without gastrointestinal AEs with alogliptin, suggesting that this agent may be preferred in clinical practice.

Kefir Culture-Mediated Fermentation to Improve Phenolic-Linked Antioxidant, Anti-Hyperglycemic and Human Gut Health Benefits in Sprouted Food Barley

The bioprocessing strategy is an effective approach to improve bioavailability and stability of bioactive compounds for designing functional foods and ingredients. In this study, food barley was bio-transformed to improve functional bioactives by sprouting, coupled with beneficial lactic acid bacteria (LAB)-based fermentation. Dairy Kefir culture with mixed beneficial LAB strains was targeted to ferment aqueous slurries of sprouted hulless food barley flour (unpigmented, purple, and black barley) for 72 h, and modulation of phenolic-linked antioxidant and anti-hyperglycemic functionalities were evaluated using in vitro assay models. The biochemical parameters analyzed were total soluble phenolic (TSP) content, profile of phenolic compounds, total antioxidant activity, and anti-hyperglycemic property-relevant α-amylase and α-glucosidase enzyme inhibitory activities. Furthermore, human gut health benefits of relevant properties of fermented slurries of barley flour were also evaluated based on growth of Kefir culture and subsequent determination of anti-bacterial potential against pathogenic human ulcer causing bacteria Helicobacter pylori. Kefir culture-mediated fermentation of 48-h sprouted barley flours improved the TSP content and associated antioxidant and anti-hyperglycemic functionalities. Additionally, anti-bacterial potential against H. pylori and sustaining active growth of viable LAB cells above the minimum level required for probiotic activity were also observed in fermented food barley flour slurries.

Inhibition of α-glucosidases by tea polyphenols in rat intestinal extract and Caco-2 cells grown on Transwell

Inhibition of maltase, sucrase, isomaltase and glucoamylase activity by acarbose, epigallocatechin gallate, epicatechin gallate and four polyphenol-rich tea extract from white, green, oolong, black tea, were investigated by using rat intestinal enzymes and human Caco-2 cells. Regarding rat intestinal enzyme mixture, all four tea extracts were very effective in inhibiting maltase and glucoamylase activity, but only white tea extract inhibited sucrase and isomaltase activity and the inhibition was limited. Mixed-type inhibition on rat maltase activity was observed. Tea extracts in combination with acarbose, produced a synergistic inhibitory effect on rat maltase activity. Caco-2 cells experiments were conducted in Transwells. Green tea extract and epigallocatechin gallate show dose-dependent inhibition on human sucrase activity, but no inhibition on rat sucrase activity. The opposite was observed on maltase activity. The results highlighted the different response in the two investigated model systems and show that tea polyphenols are good inhibitors for α-glucosidase activity.

Comparison of Glycemic Excursion Using Flash Continuous Glucose Monitoring in Patients with Type 2 Diabetes Mellitus Before and After Treatment with Voglibose

Purpose: To determine the effect of Voglibose add-on therapy on daily glycemic excursions (using FreeStyle^® Libre Pro™, a Flash glucose monitoring system) in Indian patients with type 2 diabetes mellitus (T2DM) receiving a stable dose of metformin (Met) or metformin+sulfonylurea (Met+SU). Patients and Methods: T2DM patients with glycosylated hemoglobin (HbA1c) ≥7.0% and at least two postprandial excursions ≥140 mg/dL (within 2 h of meal) during the screening phase (visit 1/day -14 ± 2) were enrolled in this prospective, multicenter interventional study. The patients were randomized at visit 2 (day 0 ± 2) to receive Voglibose 0.2 or 0.3 mg tablets (BID/TID) as add-on therapy to Met and Met+SU. All the patients were followed at day 14 ± 2 (visit 3), month 3 ± 14 days (visit 4), 14 weeks (i.e., visit 4 + 14 days) ±2 days (visit 5), and month 6 ± 14 days (visit 6). Continuous glucose monitoring was performed to study glycemic excursions at visits 2, 3, and 5. The study outcomes were: change in average number of glycemic excursions per day, percent time spent in glucose fluctuations, mean Postprandial glucose (PPG), Fasting plasma glucose (FPG), day and night time mean glucose levels from baseline to day 14 and week 14; change in mean amplitude of glycemic excursion (MAGE) from baseline to 14 weeks; and mean HbA1c level at 3 and 6 months. Results: Out of 110 patients enrolled, 101 patients (91.8%) (Met+SU+Voglibose: 73 and Met+Voglibose: 28) completed the study. There was a significant decrease in average number of glycemic excursions per day from baseline to day 14 in the Met+Sul+Voglibose group and to week 14 in the Met+Voglibose group. There was also a significant reduction in percent time spent above target glucose range from baseline to day 14 in both treatment groups and to week 14 in the Met+SU+Voglibose group. A significant reduction in mean PPG area under the curve, day and night time mean glucose levels, and mean FPG levels from baseline to day 14 was reported in both treatment groups. A significant reduction in night time glucose, and average MAGE and HbA1c levels was reported from baseline to week 14 in the Met+Voglibose group and the Met+SU+Voglibose group, respectively. At 6 months, body weight, glucose levels, cholesterol, low-density lipoprotein-cholesterol, and HbA1c were significantly lower, especially in the Met+SU+Voglibose arm. Conclusion: Voglibose was useful in reducing glycemic variability and improving glycemic control in Asian Indian adults with T2DM. (CTRI/2018/04/013074).

Considerations when using alpha-glucosidase inhibitors in the treatment of type 2 diabetes

Introduction: Alpha-glucosidase inhibitors (AGIs) - oral antihyperglycemic drugs, inhibit upper gastrointestinal enzymes that break down complex carbohydrates into glucose. As a result, the absorption of glucose is delayed, postprandial glucose reduced, and glycemic control improved.Areas covered: In this review, the authors describe the current recommendations on the use of the three major approved AGIs (acarbose, miglitol, voglibose). Efficacy and safety parameters together with ethnic considerations have been highlighted throughout the manuscript. The article also discusses potential diabetes prevention and cardiovascular effects of these medications.Expert opinion: The overall safety and efficacy of this class of drug appears to be high: AGIs do not increase the risk of hypoglycemia, do not cause weight gain; they also significantly improve postprandial hyperglycemia, have been associated with the reduction in risk factors for cardiovascular disease and may also delay the progression of prediabetes to T2DM. In general, we continue to believe that acarbose, miglitol, and voglibose should be used as third-line add on treatment options to other anti-hyperglycemic agents. However, this class can have earlier consideration in elderly and/or when metformin is contraindicated.

Inhibition of α-glucosidase activity by selected edible seaweeds and fucoxanthin

A 5 mg/mL solution of water, methanol and acetone extracts of seaweeds were used for α-glucosidase inhibition assay hyphenated with high performance liquid chromatography-mass spectrometry (HPLC-HRMS). The results showed acetone extracts of Undaria pinnatifida has the strongest inhibitory effect against α-glucosidase activity with IC50 0.08 ± 0.002 mg/mL. The active compound found in Undaria pinnatifida was identified as fucoxanthin. Analytical standard sample of fucoxanthin significantly inhibited α-glucosidase with IC50 value 0.047 ± 0.001 mg/mL. An inhibition kinetics study indicates that fucoxanthin is showing mixed-type inhibition. These results suggest that Undaria pinnatifida has a potential to inhibit α-glucosidase and may be used as a bioactive food ingredient for glycaemic control.

Programming of Multicomponent Temporal Release Profiles in 3D Printed Polypills via Core-Shell, Multilayer, and Gradient Concentration Profiles

Additive manufacturing (AM) appears poised to provide novel pharmaceutical technology and controlled release systems, yet understanding the effects of processing and post-processing operations on pill design, quality, and performance remains a significant barrier. This paper reports a study of the relationship between programmed concentration profile and resultant temporal release profile using a 3D printed polypill system consisting of a Food and Drug Administration (FDA) approved excipient (Pluronic F-127) and therapeutically relevant dosages of three commonly used oral agents for treatment of type 2 diabetes (300-500 mg per pill). A dual-extrusion hydrogel microextrusion process enables the programming of three unique concentration profiles, including core-shell, multilayer, and gradient structures. Experimental and computational studies of diffusive mass transfer processes reveal that programmed concentration profiles are dynamic throughout both pill 3D printing and solidification. Spectrophotometric assays show that the temporal release profiles could be selectively programmed to exhibit delayed, pulsed, or constant profiles over a 5 h release period by utilizing the core-shell, multilayer, and gradient distributions, respectively. Ultimately, this work provides new insights into the mass transfer processes that affect design, quality, and performance of spatially graded controlled release systems, as well as demonstrating the potential to create disease-specific polypill technology with programmable temporal release profiles.

Factors That Influence Pancreatic Beta Cell Function and Insulin Resistance in Newly Diagnosed Type 2 Diabetes Patients: A Sub-Analysis of the MARCH Trial

INTRODUCTION

The Metformin and Acarbose in Chinese as the initial Hypoglycemic treatment (MARCH) trial has demonstrated a similar efficacy in HbA1c reduction between acarbose and metformin treatments in newly diagnosed type 2 diabetes mellitus (T2DM) patients. The current sub-analysis of the MARCH trail aims to evaluate the baseline characteristics that may influence the improvement of pancreatic β-cell function and insulin resistance after acarbose therapy in Chinese patients with newly diagnosed T2DM.

METHODS

Of the 784 patients who entered the MARCH trail, 391 were assigned to the acarbose therapy group; 304 of these completed 48 weeks of follow-up of acarbose therapy. At 48 weeks, on the basis of the tertiles of change in homeostasis model assessment-beta cell function (∆HOMA-β) and homeostasis model assessment-insulin resistance (∆HOMA-IR), the subjects were divided into lowly, mediumly, and highly improved groups.

RESULTS

In the highly improved HOMA-β group, patients had higher systolic blood pressure (SBP), 2-h postprandial blood glucose (PBG), hemoglobin A1c (HbA1c), and lower high-density lipoprotein cholesterol (HDL-c), fasting serum insulin (FINS) concentration, and HOMA-IR in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between HbA1c, SBP, and highly improved ∆HOMA-β (p < 0.05), while an inverse correlation was evident between HDL-c and highly improved ∆HOMA-β (p < 0.05). The highly improved HOMA-IR group had a significantly higher body mass index (BMI), fasting blood glucose (FBG), FINS concentration, and HOMA-β in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between FBG, waist circumference, and highly improved HOMA-IR (p < 0.05).

CONCLUSION

Newly diagnosed T2DM Chinese patients with lower baseline HDL-c and higher HbA1c and SBP values are more likely to achieve improvement in beta cell function whereas baseline fasting blood glucose and waist circumference were the significant factors associated with improvement in insulin resistance with acarbose therapy.

TRIAL REGISTRATION

The clinical trial registry number was ChiCTR-TRC-08000231.

Network meta-analysis of lorcaserin and oral hypoglycaemics for patients with type 2 diabetes mellitus and obesity

In addition to weight loss, randomized controlled trials have shown improvement in glycaemic control in patients taking lorcaserin. The aim of this study aim was to compare adding lorcaserin or other glucose lowering medications to metformin on weight and glycaemic control. A systematic review and network meta-analysis of randomized controlled trials were conducted. Included studies (published 1990-2014) were of lorcaserin or glucose lowering medications in type 2 diabetic patients compared to placebo or different active treatments. Studies had to report ≥1 key outcome (change in weight or HbA1c, % HbA1c <7, hypoglycaemia). Direct meta-analysis was performed using DerSimonian and Laird random effects models, and network meta-analysis with Bayesian Markov-chain Monte Carlo random effects models; 6552 articles were screened and 41 included. Lorcaserin reduced weight significantly more than thiazolidinediones, glinides, sulphonylureas and dipeptidyl peptidase-4 inhibitors, some of which may have led to weight gain. There were no significant differences in weight change between lorcaserin and alpha-glucoside inhibitors, glucagon-like peptide-1 agonists and sodium/glucose cotransporter 2 inhibitors. Network meta-analysis showed lorcaserin was non-inferior to all other agents on HbA1c reduction and % achieving HbA1c of <7%. The risk of hypoglycaemia was not significantly different among studied agents except that sulphonylureas were associated with higher risk of hypoglycaemia than lorcaserin. Although additional studies are needed, this analysis suggests in a population of patients with a body mas index of ≥27 who do not achieve glycaemic control on a single agent, lorcaserin may be added as an alternative to an add-on glucose lowering medication.

Metformin combined with acarbose vs. single medicine in the treatment of type 2 diabetes: A meta-analysis

The present meta-analysis aimed to evaluate metformin combined with acarbose compared with monotherapy with either of the two drugs for type 2 diabetes (T2DM). Relevant trials were retrieved through searching PubMed, Embase, Cochrane library, China National Knowledge Infrastructure, Wanfang and Chongqing VIP information network databases. Heterogeneous and homogeneous data were statistically combined using a random- and fixed-effects model, respectively. For dichotomous and continuous data, the merged effect size was presented as the risk ratio (RR) and weighted mean differences (WMD), respectively, with 95% confidence interval (CI). All included studies were divided into subgroups. A Funnel plot was used to detect publication bias. Review Manager 5.2 software was applied to perform the statistical analyses. Meta-analysis revealed that compared with metformin monotherapy, combined therapy was significantly more efficacious regarding indexes including the total effective rate, fasting blood glucose (FBG), blood glucose levels at two post-prandial hours (2HPG) and hemoglobin A1C (HbA1c). Similarly, combined therapy showed advantages on indexes including FBG, 2HPG and HbA1c over acarbose therapy after 4 months of treatment. In conclusion, the findings of the present meta-analysis suggested that combined therapy of metformin and acarbose appears to be more efficacious than metformin or acarbose monotherapy.

Understanding and overcoming metformin gastrointestinal intolerance

Metformin is the most widely prescribed drug for patients with type 2 diabetes mellitus and the first-line pharmacological option as supported by multiple international guidelines, yet a rather large proportion of patients cannot tolerate metformin in adequate amounts because of its associated gastrointestinal (GI) adverse events (AEs). GI AEs typically encountered with metformin therapy include diarrhoea, nausea, flatulence, indigestion, vomiting and abdominal discomfort, with diarrhoea and nausea being the most common. Although starting at a low dose and titrating slowly may help prevent some GI AEs associated with metformin, some patients are unable to tolerate metformin at all and it may also be difficult to convince patients to start metformin again after a bout of GI AEs. Despite this clinical importance, the underlying mechanisms of the GI intolerance associated with metformin are poorly known. In the present review, we discuss: the epidemiology of metformin-associated GI intolerance and its underlying mechanisms; genotype variability and associated factors affecting metformin GI intolerance, such as comorbidities, co-medications and bariatric surgery; clinical consequences and therapeutic strategies to overcome metformin GI intolerance. These strategies include appropriate titration of immediate-release metformin, use of extended-release metformin, the promise of delayed-release metformin and gut microbiome modulators, as well as alternative pharmacological therapies when metformin cannot be tolerated at all. Given the available data, all efforts should be made to maintain metformin before considering a shift to another drug therapy.

Glycemic excursions are positively associated with HbA1c reduction from baseline after treatment with acarbose in patients with type 2 diabetes on metformin monotherapy

BACKGROUND

The aim of the present study was to examine the association between glycemic excursions before treatment and HbA1c reduction after treatment intensification with acarbose or glibenclamide in patients with type 2 diabetes (T2D).

METHODS

Patients receiving single or dual oral antidiabetic drug treatment with an HbA1c of 7.0-11.0 % (53-97 mmol/mol) were switched to metformin monotherapy (500 mg, t.i.d.) for 8 weeks, followed by randomization to either acarbose (100 mg, t.i.d.) or glibenclamide (5 mg, t.i.d.) as add-on treatment for 16 weeks. Glycemic excursions were assessed as mean amplitude of glycemic excursions (MAGE) with 72-h ambulatory continuous glucose monitoring. Treatment efficacy was evaluated as relative HbA1c reduction (%), calculated as (baseline HbA1c - post-treatment HbA1c)/baseline HbA1c × 100.

RESULTS

Fifty patients (mean [±SD] age 53.5 ± 8.2 years, 48 % men, mean baseline HbA1c 8.4 ± 1.2 %) were analyzed. Baseline MAGE was positively correlated with relative HbA1c reduction from baseline in patients treated with acarbose (r = 0.421, P = 0.029) but not glibenclamide (r = 0.052, P = 0.813). Linear regression analysis revealed that the association between baseline MAGE and relative HbA1c reduction from baseline (β = 0.125, P = 0.029) in patients treated with acarbose remained significant after adjustment for several confounders (P < 0.05 for all models).

CONCLUSIONS

In patients with T2D on metformin monotherapy, baseline MAGE was positively correlated with relative HbA1c reduction from baseline after treatment with acarbose, but not glibenclamide. These findings highlight the importance of glycemic excursions in individualized treatment for patients with T2D.

Effects of the addition of acarbose to insulin and non-insulin regimens in veterans with type 2 diabetes mellitus

OBJECTIVES

The primary objective of the study was to assess the mean change in hemoglobin A1c (HbA1c) when acarbose was added to insulin and non-insulin regimens in patients with type 2 diabetes mellitus (T2DM). Secondary objectives were to evaluate the discontinuation rate of acarbose, and to assess the number of patients who were placed on insulin despite the addition of acarbose.

METHODS

A retrospective chart review was conducted on veterans with T2DM initiated on acarbose between October 1, 2013 and December 31, 2013. To be included, patients must have had a refill history indicating at least 3 months of acarbose use and HbA1c readings within 6 months prior to initiation and after at least 3 months of use. Excluded patients were those with type 1 diabetes mellitus, serum creatinine ≥2 mg/dL at acarbose initiation, or a diagnosis based on ICD-9 codes for an existing gastrointestinal condition or liver cirrhosis. The two-tailed, paired t-test was used for analysis of the primary objective and descriptive statistics were used for all other outcomes.

RESULTS

Of the 146 patients screened, 102 patients were included in the study. Exclusions were primarily due to patients not being on acarbose for at least 3 months (n=43). The average HbA1c before and after acarbose initiation was 9.08% (SD=1.74) and 8.43% (SD=1.74) respectively, with an average HbA1c reduction of 0.65% (n=102, p=0.0005). Forty patients (39.2%) discontinued acarbose after at least 3 months of use. Of the 73 patients not on insulin at the time of acarbose initiation, 19 (26%) were started on insulin therapy despite addition of acarbose.

CONCLUSION

Acarbose can be considered in patients who may reach their HbA1c goal with minimal HbA1c reduction. However, adverse effects are a limitation to use. Potential risks and benefits should be assessed and discussed with the patient prior to prescribing acarbose.

Alpha-glucosidase inhibitors and hepatotoxicity in type 2 diabetes: a systematic review and meta-analysis

Alpha-glucosidase inhibitors (AGIs) was reported to be associated with several rare adverse hepatic events, but with inconsistent results. We aimed to investigate the risk of hepatotoxicity associated with the use of AGIs in patients with type 2 diabetes mellitus (T2DM), and performed a systematic review and meta-analysis. Fourteen studies (n = 2881) were eligible, all of which were RCTs. Meta-analysis of data regarding elevation of more than 3-fold the upper limit of normal (ULN) of AST and ALT showed statistically significant differences between AGIs treatment versus control (OR 6.86, 95% CI 2.50 to 18.80; OR 6.48, 95% CI 2.40 to 17.49). Subgroup analyses of elevation of more than 1.8-fold ULN of AST and ALT by dose of AGIs showed differential effects on AST and ALT (AST: OR 0.38 vs 7.31, interaction P = 0.003; ALT: OR 0.32 vs 4.55, interaction p = 0.02). Meta-analysis showed that AGIs might increase the risk of hepatotoxicity, and higher dose appeared to be associated with higher risk of hepatotoxicity. However, the evidence is limited with surrogate measures (i.e. ALT and AST), and no clinically important adverse events were observed.

Therapeutic potential of α-glucosidase inhibitors in type 2 diabetes mellitus: an evidence-based review

INTRODUCTION

Postprandial hyperglycemia (PPHG) contributes to micro- and macro-vascular complications more than fasting hyperglycemia in patients with type 2 diabetes mellitus. Due to the traditional carbohydrate-rich diet, Asians, particularly Indians and Chinese need agents to control the higher risk of uncontrolled PPHG. Targeting PPHG with α-glucosidase inhibitors (AGIs), either alone or in combination with other oral hypoglycemic agents and insulin, provide overall glycemic control with transient mild gastrointestinal disorders. Treatment with AGIs, especially acarbose, has also shown to provide beneficial effects on lipid levels, blood pressure, coagulation factors, carotid intima-media thickness and endothelial dysfunction. New insights of acarbose therapy obtained like increased activity of gut hormones and improved gut microbiota may explain the benefits on weight, whereas increased production of H2 may explains its cardiovascular benefits to some extent.

AREAS COVERED

A systematic search strategy was developed to identify randomized controlled trials in MEDLINE, PubMed, EMBASE and ongoing trials databases.

EXPERT OPINION

AGIs as a class and acarbose in particular, are most useful in combatting PPHG and glucose variability across the spectrum of diabetes therapy, particularly in Asian patients. Together with their effects on incretin hormones and gut-microbiota AGIs can be considered beyond glycemic control as 'cardio-protective agents.'

Dapagliflozin combination therapy in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a progressive disease, and most patients ultimately require two or more antidiabetes drugs in addition to lifestyle changes to achieve and maintain glycemic control. Current consensus statements and guidelines recommend metformin as first-line pharmacotherapy for the treatment of T2DM in most patients. When glycemic control cannot be maintained with metformin alone, the sequential, stepwise addition of other agents is recommended. Agents such as thiazolidinediones or sulfonylureas have typically been added to metformin therapy. Although effective in reducing glycated hemoglobin, these drugs are often associated with adverse effects, most notably weight gain, and in the case of sulfonylureas, hypoglycemia. Sodium-glucose cotransporter 2 inhibitors, such as dapagliflozin, are the newest class of antidiabetes drugs approved for the treatment of T2DM. Dapagliflozin effectively improves glycemic control by increasing the renal excretion of excess glucose. In clinical trials, dapagliflozin has been well tolerated and has additional benefits of weight loss, low risk of hypoglycemia and reduction in blood pressure. This review discusses the clinical evidence and rationale for the use of dapagliflozin as add-on therapy in T2DM. The results suggest that dapagliflozin add-on therapy is a promising new treatment option for a wide range of patients with T2DM. Results from an ongoing cardiovascular outcomes trial are needed to establish the long-term safety of dapagliflozin.

Comparative efficacy and safety of antidiabetic drug regimens added to metformin monotherapy in patients with type 2 diabetes: a network meta-analysis

Introduction

When first line therapy with metformin is insufficient for patients with type 2 diabetes (T2D), the optimal adjunctive therapy is unclear. We assessed the efficacy and safety of adjunctive antidiabetic agents in patients with inadequately controlled T2D on metformin alone.

Materials and Methods

A search of MEDLINE and CENTRAL, clinicaltrials.gov, regulatory websites was performed. We included randomized controlled trials of 3–12 months duration, evaluating Food and Drug Administration or European Union approved agents (noninsulin and long acting, once daily basal insulins) in patients experiencing inadequate glycemic control with metformin monotherapy (≥1500 mg daily or maximally tolerated dose for ≥4 weeks). Random-effects network meta-analyses were used to compare the weighted mean difference for changes from baseline in HbA1c, body weight (BW) and systolic blood pressure (SBP), and the risk of developing hypoglycemia, urinary (UTI) and genital tract infection (GTI).

Results

Sixty-two trials evaluating 25 agents were included. All agents significantly reduced HbA1c vs. placebo; albeit not to the same extent (range, 0.43% for miglitol to 1.29% for glibenclamide). Glargine, sulfonylureas (SUs) and nateglinide were associated with increased hypoglycemia risk vs. placebo (range, 4.00–11.67). Sodium glucose cotransporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 analogs, miglitol and empagliflozin/linagliptin significantly reduced BW (range, 1.15–2.26kg) whereas SUs, thiazolindinediones, glargine and alogliptin/pioglitazone caused weight gain (range, 1.19–2.44kg). SGLT2 inhibitors, empagliflozin/linagliptin, liraglutide and sitagliptin decreased SBP (range, 1.88–5.43mmHg). No therapy increased UTI risk vs. placebo; however, SGLT2 inhibitors were associated with an increased risk of GTI (range, 2.16–8.03).

Conclusions

Adding different AHAs to metformin was associated with varying effects on HbA1c, BW, SBP, hypoglycemia, UTI and GTI which should impact clinician choice when selecting adjunctive therapy.

Inhibitory effect of black tea and its combination with acarbose on small intestinal α-glucosidase activity

ETHNOPHARMACOLOGICAL RELEVANCE

It is said that black tea is effective against type 2 diabetes mellitus because it can help modulate postprandial hyperglycemia. However, the mechanism underlying its therapeutic and preventive effects on type 2 diabetes mellitus is unclear. In this study, we focused on the effect of black tea on the carbohydrate digestion and absorption process in the gastrointestinal tract. We examined whether black tea can modulate postprandial hyperglycemia.

MATERIALS AND METHODS

The freeze-dried powder of the aqueous extract of black tea leaves (JAT) was used for in vitro studies of α-amylase activity, α-glucosidase activity, and glucose uptake by glucose transporters in Caco-2 cells; ex vivo studies of small intestinal α-glucosidase activity; and in vivo studies of oral sugar tolerance in GK rats, an animal model of nonobese type 2 diabetes mellitus.

RESULTS

Half maximal inhibitory concentration values indicated that JAT significantly reduced α-glucosidase activity, but weakly reduced α-amylase activity. Kinetic studies of rat small intestinal α-glucosidase activity revealed that the combination of JAT and the α-glucosidase inhibitor, acarbose, showed a mixed-type inhibition. JAT had no effect on the uptake of 2'-deoxy-d-glucose by glucose transporter 2 (GLUT2) and the uptake of α-methyl-d-glucose by sodium-dependent glucose transporter 1 (SGLT1). In the oral sucrose tolerance test in GK rats, JAT reduced plasma glucose levels in a dose-dependent manner compared with the control group. The hypoglycemic action of JAT was also confirmed: JAT, in combination with acarbose, produced a synergistic inhibitory effect on plasma glucose levels in vivo. In contrast to the oral sucrose tolerance test, JAT showed no effect in the oral glucose tolerance test.

CONCLUSIONS

JAT was demonstrated to inhibit the degradation of disaccharides into monosaccharides by α-glucosidase in the small intestine. Thereby indirectly preventing the absorption of the dietary source of glucose mediated by SGLT1 and GLUT2 transporters localized at the apical side of enterocytes in the small intestine. The results indicate that black tea could be useful as a functional food in the dietary therapy for borderline type 2 diabetes mellitus that could modulate postprandial hyperglycemia.

Pharmacologic treatment of type 2 diabetes: oral medications

OBJECTIVE

To review the oral and injectable pharmacologic treatment options for type 2 diabetes.

DATA SOURCES

A literature search was conducted using PubMed electronic database for studies published in English between 1993 and September 2014. Search terms included diabetes mellitus, type 2 diabetes, and the individual name for each antidiabetic medication reviewed. In addition, manual searches were performed for cross-references from publications. Package inserts, United States Food and Drug Administration (FDA) Web site, Institute for Safe Medication Practices Web site, American Diabetes Association Web site and scientific session poster presentations, and individual drug company Web pages were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

This review focused on information elucidated over the past 10 years to assist prescribers in choosing optimal therapy based on individual patient characteristics. Studies leading to the approval of or raising safety concerns for the antidiabetic medications reviewed in this article were included.

DATA SYNTHESIS

In the past 10 years, there have been 4 novel oral antidiabetic medication classes and 9 new injectable agents and insulin products approved by the FDA for the treatment of type 2 diabetes as well as new information regarding the safety and use of several older antidiabetic medication classes. The distinctions were reviewed for each individual agent, and a comparison was completed if there was more than one agent in a particular therapeutic class. Using current information available, select investigational agents in phase III trials or those with a pending new drug application were highlighted.

CONCLUSION

There are now 9 distinct oral pharmacologic classes and a variety of insulin and noninsulin injectable medications available for the treatment of type 2 diabetes. Metformin remains the first-line treatment option for most patients. When considering options for alternative or additional treatment, prescribers must weigh the benefits and risks using individual patient characteristics.

Efficacy of acarbose in different geographical regions of the world: analysis of a real-life database

BACKGROUND

Alpha-glucosidase inhibitors are recommended in some international guidelines as first-line, second-line and third-line treatment options but are not used worldwide due to perceived greater effectiveness in Asians than Caucasians.

METHODS

Data from ten post-marketing non-interventional studies using acarbose, the most widely used alpha-glucosidase inhibitor, from 21 countries, provinces and country groups were pooled. Effects on glycated hemoglobin (HbA1c ) were analysed for four major ethnicity/region groups (European Caucasians and Asians from East, Southeast and South Asia) to identify differences in the response to acarbose.

RESULTS

The safety and efficacy populations included 67 682 and 62 905 patients, respectively. Mean HbA1c in the total population decreased by 1.12 ± 1.31% at the 3-month visit from 8.4% at baseline (p < 0.0001). Reductions in HbA1c , fasting plasma glucose and post-prandial plasma glucose were greater in patients with higher baseline values. Acarbose was well tolerated, with few episodes of hypoglycemia (0.03%) and gastrointestinal adverse events (2.76%). Data from 30 730 Caucasians from Europe and Asians from three major regions of Asia with non-missing gender/age information and baseline/3-month HbA1c data were analysed by multivariable analyses of covariance. After adjustment for relevant baseline confounding factors, Southeast and East Asians had slightly better responses to acarbose than South Asians and European Caucasians; however, the differences were small.

CONCLUSIONS

Acarbose was effective in both European Caucasians and Asians; however, after adjustment for baseline confounding factors, significant small differences in response favoured Southeast and East Asians.

Effectiveness and safety of fixed dose combination of acarbose/metformin in Indian Type 2 diabetes patients: Results from observational GLOBE Study

Primary objective - evaluate effectiveness and safety of acarbose/metformin fixed dose FDC on glycemic control in Indian T2DM patients in real life clinical setting. Secondary objective - evaluate safety and satisfaction of treatment.

MATERIALS AND METHODS

Open-label, prospective, multicentre, single-arm, non-interventional study. Patients included were aged ≥18 years with T2DM on Acarbose (25/50 mg) and Metformin (500 mg) FDC. Glycemic parameters were recorded during observation.

RESULTS

Total 9364 patients were enrolled in the study (mean age, 50.7 years and 60.1% were male). Mean (SD) FBG and PPG was significantly reduced by 42.4 (32.6) mg/dl (P < 0.0001) and 80.2 (49.7) mg/dl (P < 0.0001) respectively at the end of observation. Mean (SD) HbA1c reduced by -1.0% (0.8) to 7.3% (0.7) at the last follow-up visit (P <0.0001). Majority of patients (97.5%) and physicians (98.42%) were satisfied with acarbose/metformin FDC treatment. Also, significant reduction in body weight by -1.7 (2.2) kg was observed (P < 0.0001). Patients with known T2DM and newly diagnosed showed a similar glycemic control (P < 0.0001). Drug-related adverse events were reported by only 1.4% patients mostly gastrointestinal.

CONCLUSIONS

Acarbose/metformin FDC was efficacious, safe well accepted in routine clinical practice. It was well-tolerated without significant risk of hypoglycemia and can be used in early T2DM management.

Investigation of bioequivalence of a new fixed-dose combination of acarbose and metformin with the corresponding loose combination as well as the drug-drug interaction potential between both drugs in healthy adult male subjects

WHAT IS KNOWN AND OBJECTIVE

Both metformin and acarbose are recommended monotherapy and add-on therapy in type 2 diabetes mellitus (T2DM). A fixed-dose combination (FDC) of acarbose and metformin has been developed to reduce pill burden and potentially improve compliance. The current study investigated the bioequivalence of the acarbose/metformin FDC compared with the individual agents administered simultaneously (loose combination). Secondary endpoints were the safety and tolerability of the FDC and the potential for drug-drug interactions between acarbose and metformin.

METHODS

A single-centre, randomized, open-label, four-period crossover study was conducted in healthy male Korean subjects aged 18-45 years. Following one-period balanced Williams design, participants were randomized to receive four single oral treatments on different study days separated by ≥7 days' washout. Treatments were as follows: (i) acarbose/metformin 50/500 mg FDC (test); (ii) acarbose 50 mg and metformin 500 mg as loose combination (reference); (iii) acarbose 50 mg; and (iv) metformin 500 mg. Serial blood samples were taken for glucose and insulin levels for 4 h after a sucrose load on the day before and day of study drug administration. Additionally, serial blood samples were taken for analysis of metformin levels for 24 h after each drug containing metformin. The area under the curve for 4 h post-test (AUC0-4 h ) and the maximal serum concentration (Cmax ) of plasma glucose and serum insulin were primary pharmacodynamic (PD) parameters, and Cmax , AUC0-last and AUC for metformin levels were primary pharmacokinetic (PK) parameters. The bioequivalence of the FDC to the loose combination was considered established if the 90% confidence intervals (CIs) of the baseline-adjusted PD parameter ratios (test vs. reference) for plasma glucose and the PK parameter ratios for metformin fell completely within current acceptance limits (0·8-1·25).

RESULTS AND DISCUSSION

Thirty-three of 40 randomized subjects completed the study; five withdrew consent and two discontinued because of adverse events (AEs). The 24-h plasma concentration-time curves of metformin and the 4-h plasma glucose-time curves after acarbose/metformin FDC (test) and acarbose + metformin loose combination (reference) were almost superimposable. The geometric least squares (LS) mean of the RatioAUC and RatioCmax for plasma glucose after the FDC vs. loose combination, and the LS mean of the ratios in metformin AUC, AUC0-last and Cmax were close to unity, and the 90% CI of all these parameters fell within the predefined equivalence range of 0·8-1·25, confirming bioequivalence. The metformin AUC was reduced by 26% and Cmax by 34% after acarbose + metformin compared with metformin alone. Eight subjects (20·0%) reported AEs, but all were mild, and most were gastrointestinal, as expected for these agents. The incidence of AEs was not higher with the combinations vs. monotherapy.

WHAT IS NEW AND CONCLUSION

These data demonstrate that the acarbose/metformin FDC is bioequivalent to the loose combination of these agents. Although acarbose slightly reduced the bioavailability of metformin, the accumulated evidence of the efficacy of this combination implies that this is clinically irrelevant. The observed AE profile was consistent with the established knowledge on the safety of the two drugs.

Comparisons of the efficacy of alpha glucosidase inhibitors on type 2 diabetes patients between Asian and Caucasian

Background

To compare the efficacy of glycemic control and insulin secretion of alpha glucosidase inhibitors (AGI) on type 2 diabetes patients between Asian and Caucasian.

Methodology/Principal Findings

The MEDLINE®, EMBASE®, CENTRAL were searched and qualified studies in Asian and Caucasian population comparing AGI treatment with placebo or other oral anti-diabetic drugs in type 2 diabetic patients were included. Totally 58 qualified studies were included. When AGI treatment was compared with placebo, a significant difference in HbA1c decline from baseline favoring AGI treatment was found in Asian (weighted mean difference (WMD), −0.50%; 95% CI, −0.66% to −0.34%) and in Caucasian a significant difference in HbA1c decline favoring AGI treatment was also found (WMD, −0.68%; 95% CI, −0.76% to −0.60%). In Asian, fasting plasma glucose was reduced with AGI treatment compared with placebo (WMD, −0.53 mmol/L; 95% CI, −0.91 to −0.14 mmol/L) and in Caucasian there was also a significant difference in FPG changes favoring AGI therapy (WMD, −0.88 mmol/L; 95% CI, −1.00 to −0.77 mmol/L). Studies in Asian showed a significant difference in fasting insulin changes favoring AGI treatment (WMD, −0.78 uU/ml; 95% CI, −0.96 to −0.59 uU/ml). While in Caucasian fasting insulin was decreased without significance with AGI treatment (WMD-1.24 uU/ml; 95% CI, −2.51 to 0.04 uU/ml). Body weight was decreased with AGI treatment in Asian (WMD, −1.00 kg; 95% CI, −1.69 to −0.31 kg) and was also decreased with AGI treatment in Caucasian (WMD, −0.73 kg; 95% CI, −1.13 to −0.33 kg).

Conclusions/Significance

According to results from this meta-analysis, the efficacy in glucose lowering, body weight reduction and insulin secretion decreasing of AGI treatment in Asian were comparable with those in Caucasian.

Acarbose plus metformin fixed-dose combination outperforms acarbose monotherapy for type 2 diabetes

AIM

To compare the efficacy and safety of acarbose plus metformin fixed-dose combination (FDC) versus acarbose monotherapy for type 2 diabetes (T2D).

METHODS

Eligible T2D patients undergoing treatment with diet control only or oral antidiabetic medications were run-in on acarbose 50mg thrice-daily for 4 weeks, then randomised either to continue this monotherapy, or to acarbose 50mg plus metformin hydrochloride 500mg FDC (acarbose/metformin FDC), each thrice-daily for 16 weeks.

RESULTS

Acarbose/metformin FDC therapy significantly reduced HbA1c, fasting plasma glucose (FPG), and postprandial plasma glucose (PPG) from baseline (all p<0.0001) with superior efficacy compared with acarbose monotherapy (between-group differences; HbA1c -1.35%; FPG -29.5mg/dl; PPG -41.6mg/dl; all p<0.0001). Proportionally more patients treated with acarbose/metformin FDC achieved HbA1c <7.0% (47.8% vs. 10.7%, p<0.0001). Both treatments reduced bodyweight (p<0.0001), with a significant between-group difference (-0.6kg, p<0.01) favouring acarbose/metformin FDC. Hypoglycaemia was not reported with either treatment, and the incidence of other adverse events did not differ significantly between the groups.

CONCLUSIONS

Compared with acarbose monotherapy, acarbose/metformin FDC has superior antihyperglycaemic efficacy, brings proportionally more T2D patients to HbA1c goal, and further reduces bodyweight. Acarbose/metformin FDC is well-tolerated without significant risk of hypoglycaemia and is a potentially advantageous therapy for T2D.

Antioxidant and antidiabetic activities of black mung bean (Vigna radiata L.)

Interest in mung bean as a functional food is growing. The objective of this study was to characterize the phenolic compounds, antioxidant activities, and antidiabetic activities of black mung beans. Five black mung beans were selected, and one green mung bean was included for comparison. The free phenolic acid and bound phenolic acid contents ranged from 16.68 to 255.51 μg/g and from 2284.53 to 5363.75 μg/g, respectively, whereas the total anthocyanin contents ranged from 0 to 810.55 μg/g with cyanidin-3-glucoside as the most dominant form, respectively. Among the mung beans tested, black mug bean Xiaoqu 7110 had the highest content of bound phenolic acids and exhibited the strongest antioxidant capacities (1,1-diphenyl-2-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and oxygen radical absorbance capacity) as compared to the other tested mung beans. Jiheilv 27-3 exhibited higher antidiabetic activities (inhibition of α-glucosidase and advanced glycation end products).

Metformin: an old but still the best treatment for type 2 diabetes

The management of T2DM requires aggressive treatment to achieve glycemic and cardiovascular risk factor goals. In this setting, metformin, an old and widely accepted first line agent, stands out not only for its antihyperglycemic properties but also for its effects beyond glycemic control such as improvements in endothelial dysfunction, hemostasis and oxidative stress, insulin resistance, lipid profiles, and fat redistribution. These properties may have contributed to the decrease of adverse cardiovascular outcomes otherwise not attributable to metformin's mere antihyperglycemic effects. Several other classes of oral antidiabetic agents have been recently launched, introducing the need to evaluate the role of metformin as initial therapy and in combination with these newer drugs. There is increasing evidence from in vivo and in vitro studies supporting its anti-proliferative role in cancer and possibly a neuroprotective effect. Metformin's negligible risk of hypoglycemia in monotherapy and few drug interactions of clinical relevance give this drug a high safety profile. The tolerability of metformin may be improved by using an appropiate dose titration, starting with low doses, so that side-effects can be minimized or by switching to an extended release form. We reviewed the role of metformin in the treatment of patients with type 2 diabetes and describe the additional benefits beyond its glycemic effect. We also discuss its potential role for a variety of insulin resistant and pre-diabetic states, obesity, metabolic abnormalities associated with HIV disease, gestational diabetes, cancer, and neuroprotection.

A review of the efficacy and safety of oral antidiabetic drugs

INTRODUCTION

Additional oral antidiabetic agents to metformin, sulfonylureas (SU) and thiazolidinediones (TZD) are approved for the treatment of type 2 diabetes.

AREAS COVERED

The efficacy and safety of metformin, SUs, TZDs, dipeptidyl peptidase-IV (DPP-4) inhibitors, meglitinide analogs, α-glucosidase inhibitors (AGIs), bile-acid sequestrants (BAS) and bromocriptine will be reviewed.

EXPERT OPINION

Several new oral agents have been approved for type 2 diabetes management in recent years. It is important to understand the efficacy and safety of these medications in addition to the older agents to best maximize oral drug therapy for diabetes. Of the recently introduced oral hypoglycemic/antihyperglycemic agents, the DPP-4 inhibitors are moderately efficacious compared with mainstay treatment with metformin with a low side-effect profile and have good efficacy in combination with other oral agents and insulin. They are a recommended alternative when metformin use is limited by gastrointestinal (GI) side effects or when SU treatment results in significant hypoglycemia or weight gain. Meglitinide analogs are limited by their frequent dosing, expense and hypoglycemia (repaglinide > nateglinide), while AGIs are also limited by their dosing schedule and GI side-effect profile. BAS and bromocriptine have the lowest efficacy with regard to HbA(1c) reduction, also are plagued by GI adverse reactions, but have a low risk of hypoglycemia.

Effect of antidiabetic agents added to metformin on glycaemic control, hypoglycaemia and weight change in patients with type 2 diabetes: a network meta-analysis

AIM

Most guidelines recommend metformin as first-line therapy in patients with type 2 diabetes. However, the choice of a second-line drug lacks consistent consensus. We aimed to assess available information of antidiabetic drugs added to metformin on the change in glycated haemoglobin A1c (A1C), risk of hypoglycaemia and change in body weight.

METHODS

PubMed and Cochrane Central Register of Controlled Trials were searched for randomized controlled trials (RCTs) written in English through December 2011. We analysed direct and indirect comparisons of different treatments using Bayesian network meta-analysis.

RESULTS

Thirty-nine RCTs involving 17 860 individuals were included. Glucagon-like peptide-1 (GLP-1) analogues resulted in greater decrease in A1C compared with sulfonylureas, glinides, thiazolidinediones, α-glucosidase inhibitors and DPP-4 inhibitors [-0.20% (95% CI -0.34 to -0.04%), -0.31% (95% CI -0.61 to -0.02%), -0.20% (95% CI -0.38 to -0.00), -0.36% (95% CI -0.64 to -0.07%), -0.32% (95% CI -0.47 to -0.17%), respectively] and was comparable with basal insulin and biphasic insulin. A1C decrease was greater for sulfonylureas compared with DPP-4 inhibitors [-0.12% (-0.23 to -0.03%)], and for biphasic insulin compared with glinides (-0.36%; 95% CI -0.82 to -0.11%). Compared with placebo, the risk of hypoglycaemia was increased in the sulfonylureas, glinides, basal insulin and biphasic insulin. Weight increase was seen with sulfonylureas, glinides, thiazolidinediones, basal insulin and biphasic insulin, and weight loss was seen with α-glucosidase inhibitors and GLP-1 analogues.

CONCLUSIONS

Biphasic insulin, GLP-1 analogues and basal insulin were ranked the top three drugs in terms of A1C reduction. GLP-1 analogues did not increase the risk of hypoglycaemia and resulted in a significant decrease in body weight. Most oral antidiabetic drugs had similar effects on A1C, but some agents had a lower risk of hypoglycaemia and body weight gain.

Acarbose revisited for efficacy, safety and cardiovascular benefits: a key role for controlling glycemic variability

There is a growing body of evidence to illustrate the effect of postprandial hyperglycemia (PPHG) in cardiovascular disease development and as a key component of diurnal hyperglycemia. Agents such as acarbose, which has been shown to reduce 24-h glycemia and glycated hemoglobin (mainly via its effects on PPHG), may have the potential to reduce the risk of adverse cardiovascular outcomes as indicated in secondary analyses of the STOP-NIDDM trial. Although the results of the NAVIGATOR trial showed no effect of PPHG reduction on cardiovascular outcomes, acarbose has a different mode of action to nateglinide. This could lead to marked cardiovascular differences, and it is important to fully investigate this. The ongoing ACE trial will determine the effect of acarbose on a composite primary end point of cardiovascular outcomes.

Consensus report: the current role of self-monitoring of blood glucose in non-insulin-treated type 2 diabetes

The Coalition for Clinical Research--Self-Monitoring of Blood Glucose Scientific Board convened a meeting in San Francisco, CA, July 20-21, 2011, to discuss the current practice of self-monitoring of blood glucose (SMBG) in non-insulin-treated (NIT) type 2 diabetes mellitus (T2DM). Twelve physician panel members from academia, practice, and government attended this meeting. These experts came from the United States, Brazil, Canada, France, Germany, Italy, and the United Kingdom. In addition, three consultants from Australia, Germany, and the United States contributed to the group's final report. This coalition was organized by Diabetes Technology Society. Self-monitoring of blood glucose was studied from eight perspectives related to patients with NIT T2DM: (1) epidemiological studies; (2) randomized controlled trials (RCT)s and meta-analyses; (3) targets, timing, and frequency of SMBG use; (4) incidence and role of SMBG in preventing hypoglycemia with single-drug regimens and combination regimens consisting of antihyperglycemic agents other than secretagogues and insulin; (5) comparison of SMBG with continuous glucose monitoring; (6) technological capabilities and limitations of SMBG; (7) barriers to appropriate use of SMBG; and (8) methods and end points for appropriate future clinical trials. The panel emphasized recent studies, which reflect the current approach for applying this intervention. Among the participants there was consensus that: SMBG is an established practice for patients with NIT T2DM, and to be most effective, it should be performed in a structured format where information obtained from this measurement is used to guide treatment; New, high-quality efficacy data from RCTs have demonstrated efficacy of SMBG in NIT T2DM in trials reported since 2008; Both patients and health care professionals require education on how to respond to the data for SMBG to be effective; and Additional well-defined studies are needed to assess the benefits and costs of SMBG with end points not limited to hemoglobin A1c.

Cultivar evaluation and effect of fermentation on antioxidant capacity and in vitro inhibition of α-amylase and α-glucosidase by highbush blueberry (Vaccinium corombosum)

The berry fruits of highbush blueberry (Vaccinium corymbosum) contain bioactive compounds with potential health benefits. The objective was to evaluate blueberries grown in southern Illinois as well as the effect of fermentation, at two different temperatures, on chemical and physical parameters. Fruits from fifteen blueberry cultivars were analyzed. Fruit diameter ranged from 12.8 mm to 18.7 mm, pH from 2.6 to 3.7, reducing sugars from 6.4% to 15.2%, total sugars from 13.9% to 21.6%, total polyphenols from 0.39 to 1.00 mg gallic acid equivalents (GAE)/g blueberry and antioxidant capacity from 5.8 to 10.9 μM Trolox equivalents (TE)/g. In vitro α-amylase and α-glucosidase inhibitory capacity relative to the positive control acarbose, a known anti-diabetic drug, showed a range from 91.8 to 103.3% for α-amylase and from 103.2% to 190.8% for α-glucosidase. Wines prepared from several of these blueberry cultivars were analyzed throughout fermentation and compared at room temperature and cold temperature fermentation for pH (3.5 to 6.3), °Brix (13.6 to 29.7), total polyphenols (375.4 to 657.1 μg GAE/mL wine), and antioxidant capacity (4.5 to 25.1 mM TE). The wines were also tested for their in vitro capacity to inhibit α-amylase and α-glucosidase and maintained similar inhibitory action as the berries. Highbush blueberry cultivars and their fermented beverages are good natural sources of antioxidants and starch-degrading enzyme inhibitors important for type 2 diabetes management.

Second-line therapy in patients with type 2 diabetes inadequately controlled with metformin monotherapy: a systematic review and mixed-treatment comparison meta-analysis

BACKGROUND

Although there is general agreement that metformin should be used as first-line pharmacotherapy in patients with type 2 diabetes, uncertainty remains regarding the choice of second-line therapy once metformin is no longer effective. We conducted a systematic review and meta-analysis to assess the comparative safety and efficacy of all available classes of antihyperglycemic therapies in patients with type 2 diabetes inadequately controlled on metformin monotherapy.

METHODS

MEDLINE, EMBASE, BIOSIS Previews, PubMed and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials published in English from 1980 to October 2009. Additional citations were obtained from grey literature and conference proceedings and through stakeholder feedback. Two reviewers independently selected studies, extracted data and assessed risk of bias. Key outcomes of interest were hemoglobin A1c, body weight, hypoglycemia, quality of life, long-term diabetes-related complications, serious adverse drug events and mortality. Mixed-treatment comparison and pairwise meta-analyses were conducted to pool trial results, when appropriate.

RESULTS

We identified 49 active and non-active controlled randomized trials that compared 2 or more of the following classes of antihyperglycemic agents and weight-loss agents: sulfonylureas, meglitinides, thiazolidinediones (TZDs), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues, insulins, alpha-glucosidase inhibitors, sibutramine and orlistat. All classes of second-line antihyperglycemic therapies achieved clinically meaningful reductions in hemoglobin A1c (0.6% to 1.0%). No significant differences were found between classes. Insulins and insulin secretagogues were associated with significantly more events of overall hypoglycemia than the other agents, but severe hypoglycemia was rarely observed. An increase in body weight was observed with the majority of second-line therapies (1.8 to 3.0 kg), the exceptions being DPP-4 inhibitors, alpha-glucosidase inhibitors and GLP-1 analogues (0.6 to -1.8 kg). There were insufficient data available for diabetes complications, mortality or quality of life.

INTERPRETATION

DPP-4 inhibitors and GLP-1 analogues achieved improvements in glycemic control similar to those of other second-line therapies, although they may have modest benefits in terms of weight gain and overall hypoglycemia. Further long-term trials of adequate power are required to determine whether newer drug classes differ from older agents in terms of clinically meaningful outcomes.

Updated review: improved glycemic control with repaglinide-metformin in fixed combination for patients with type 2 diabetes

As the prevalence of type 2 diabetes continues to rise, new drug therapies will need to be explored to prevent morbidity and mortality associated with diabetes as well as growing health care costs. Type 2 diabetes is characterized by decreased insulin secretion and sensitivity. Numerous oral medications are currently approved for the treatment of type 2 diabetes. A treat-to-failure approach has traditionally been adopted with step-wise additions of oral medications; however, a growing frequency of treatment failures with monotherapy has led to the use of combination therapies earlier in the treatment of type 2 diabetes. One such combination regimen is repaglinide (a prandial glucose optimizer that increases insulin release) plus metformin (an insulin sensitizer that inhibits hepatic glucose output and increases peripheral glucose uptake while minimizing weight gain). Findings from several clinical trials have shown repaglinide plus metformin combination therapy to be superior to either monotherapy with significant reductions in hemoglobin A1C and fasting glucose values. Repaglinide used in combination also has shown less incidence of hypoglycemia compared with other combination therapies such as sulphonylureas plus metformin. Repaglinide plus metformin combination therapy appears to be a valuable therapeutic option for type 2 diabetic patients seeking a less complex drug regimen while potentially achieving better glucose control if currently inadequately controlled on monotherapy.

Comparative evaluation of incretin-based antidiabetic medications and alternative therapies to be added to metformin in the case of monotherapy failure

Aims/Introduction:  To compare clinical consequences of using inretin-based medications versus conventional antidiabetic agents as add-on to metformin in case of monotherapy failure in patients with type 2 diabetes.

MATERIALS AND METHODS

  The medical literature including recent abstracts from international diabetes conferences was searched for reports from clinical trials with incretin mimetics (GLP-1 receptor agonists), inhibitors of dipeptidyl peptidase-4 (DPP-4, incretin enhancers) and conventional antidiabtic drugs coadministered with metformin after monotherapy failure. A scoring system is suggested to compare the clinical utility of using incretin-based versus conventional antidiabetic agents in this situation.

RESULTS

  Incretin mimetics and DPP-4 inhibitors on top of metformin treatment help achieve glycaemic control comparable to other efficient antidiabetic drugs, both if separate or head-to-head trials were considered. Incretin-based antidiabetic drugs did not cause hypoglycaemia (different from sulfonylureas, meglitinides and insulin) and weight gain (different from sulfonylureas, meglitinides, thiazolidinediones, and insulin). DPP-4 inhibitors were weight neutral, incretin mimetics lead to weight loss. The clinical profile of incretin-based medications received the highest scores, followed by α-glucosidase inhibitors, with far lower scores assigned to insulin, glitazones, and sulfonyureas (in this order).

CONCLUSIONS

  Based on the results from clinical trials, incretin-based medications have been shown to be efficacious antidiabetic drugs with a favourable adverse event and tolerability profile. This leads to high scores using a novel system paying attention to multiple facets contributing to the selection of antidiabetic drugs for general recommendation and individual treatment choices.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Oral antidiabetic drug metabolism: pharmacogenomics and drug interactions

BACKGROUND

Type 2 diabetes is progressive in nature and so to control cardiovascular risk, most patients need combinations of oral antidiabetic drugs (OADs) plus or minus insulin. Thus, drug-drug interactions may substantially contribute to harmful effects of intensive glucose lowering therapy.

METHODS

A PubMed literature search was performed to select the most recent and relevant publications examining OAD metabolism and the effects of concomitant use of OADs.

RESULTS/CONCLUSION

Considering the individual sensitivity to OADs, pharmacogenetic factors could be of critical importance. The therapeutic range and efficacy as well as adverse effects of OADs may be significantly affected by genetic polymorphisms of cytochrome P450 drug metabolising enzymes, organic cation transporters or organic anion transporting polypeptides. Although current data suggest that modest pharmacokinetics interferences among some OAD combinations exist, they do not seem to have substantial clinical consequences. As long-term adherence to multi-drug treatment is poor in diabetic patients, the future will show a strong move towards earlier treatment with combination therapies. As metformin is cardiovascular protective and is not metabolised through the hepatic cytochrome P450 system, it is a key compound for any OAD combination. There is an overwhelming amount of small-sized in vitro studies and investigations mostly including healthy volunteers dealing with short-term effects and surrogate parameters of concomitant OAD use. Further evidence from large-scale studies including typical subjects with type 2 diabetes, in particular multimorbid and geriatric patients with polypharmacy, is needed. Postmarketing surveillance using large patients' registries could be helpful to improve the early detection of clinically relevant drug-drug interactions.

Oral combination therapy: repaglinide plus metformin for treatment of type 2 diabetes

Type 2 diabetes is characterized by decreases in insulin secretion and insulin sensitivity. Several classes of oral antidiabetic medications are currently approved for the treatment of type 2 diabetes. A stepwise treatment approach from monotherapy to combination therapy is traditionally used; however, the frequency of treatment failure with monotherapy has resulted in a move towards earlier treatment with combination therapies that target the two principal defects in glycaemic control. One such combination regimen is repaglinide (a prandial glucose regulator that increases insulin release) plus metformin (an insulin sensitizer that inhibits hepatic glucose output, increases peripheral glucose uptake and utilization and minimizes weight gain). Findings from several clinical trials have shown that combination therapy with repaglinide plus metformin is well tolerated and results in greater reductions of haemoglobin A(1c) and fasting plasma glucose values compared with either monotherapy. Repaglinide may also provide a more suitable alternative to combination therapy with sulphonylureas and metformin because of its reduced propensity for hypoglycaemia. The combination regimen of repaglinide plus metformin should therefore be considered as a valuable option in the management of patients with type 2 diabetes when monotherapy is no longer adequate.

Comparison of different drugs as add-on treatments to metformin in type 2 diabetes: a meta-analysis

BACKGROUND

Metformin is recommended as first-line treatment in type 2 diabetic patients. Several agents can be used as add-on treatments in metformin monotherapy failure. Most available clinical trials on the hypoglycemic efficacy of different drugs were performed either in monotherapy or in combination with agents other than metformin. Aim of the present meta-analysis is to collect available information on the efficacy of different hypoglycemic drugs, in combination with metformin, in patients failing to metformin, or to other oral monotherapies.

METHODS

An extensive Medline search, together with manual search of references from retrieved articles, was performed to identify randomized clinical trials comparing the efficacy on HbA1c of different agents, compared with placebo or with other active drugs, in combination with metformin, in patients failing to oral hypoglycemic therapy. HbA1c reduction at 16-36 months was considered for meta-analysis.

RESULTS

A total of 27 clinical trials were retrieved. Combining the results of different placebo-controlled trials, sulphonylureas, alpha-glucosidase inhibitors and thiazolidinediones induced a reduction [95%CI] of HbA1c of 0.85 [0.78; 0.94], 0.61 [0.55; 0.67], 0.42 [0.40; 0.44]%, respectively. In direct comparisons, sulphonylureas induced a greater reduction of HbA1c (of 0.17 [0.16; 0.18]%) than thiazolidinediones, and had a similar effect as insulin.

CONCLUSIONS

When combined with metformin, sulphonylureas and alpha-glucosidase inhibitors show a similar efficacy on HbA1c. The effects of drugs used as add-on to metformin monotherapy could be different from those observed in monotherapy.

Drug interactions of clinical importance with antihyperglycaemic agents: an update

Because management of type 2 diabetes mellitus usually involves combined pharmacological therapy to obtain adequate glucose control and treatment of concurrent pathologies (especially dyslipidaemia and arterial hypertension), drug-drug interactions must be carefully considered with antihyperglycaemic drugs. Additive glucose-lowering effects have been extensively reported when combining sulphonylureas (or the new insulin secretagogues, meglitinide derivatives, i.e. nateglinide and repaglinide) with metformin, sulphonylureas (or meglitinide derivatives) with thiazolidinediones (also called glitazones) and the biguanide compound metformin with thiazolidinediones. Interest in combining alpha-glucosidase inhibitors with either sulphonylureas (or meglitinide derivatives), metformin or thiazolidinediones has also been demonstrated. These combinations result in lower glycosylated haemoglobin (HbA(1c)), fasting glucose and postprandial glucose levels than with either monotherapy. Even if modest pharmacokinetic interferences have been reported with some combinations, they do not appear to have important clinical consequences. No significant adverse effects, except a higher risk of hypoglycaemic episodes that may be attributed to better glycaemic control, occur with any combination. Challenging the classical dual therapy with sulphonylurea plus metformin, there is a recent trend to use alternative dual combinations (sulphonylurea plus thiazolidinedione or metformin plus thiazolidinedione). In addition, triple therapy with the addition of a thiazolidinedione to the metformin-sulphonylurea combination has been recently evaluated and allows glucose targets to be reached before insulin therapy is considered. This triple therapy appears to be safe, with no deleterious drug-drug interactions being reported so far.Potential interferences may also occur between glucose-lowering agents and other drugs, and such drug-drug interactions may have important clinical implications. Relevant pharmacological agents are those that are widely coadministered in diabetic patients (e.g. lipid-lowering agents, antihypertensive agents); those that have a narrow efficacy/toxicity ratio (e.g. digoxin, warfarin); or those that are known to induce (rifampicin [rifampin]) or inhibit (fluconazole) the cytochrome P450 (CYP) system. Metformin is currently a key compound in the pharmacological management of type 2 diabetes, used either alone or in combination with other antihyperglycaemics. There are no clinically relevant metabolic interactions with metformin, because this compound is not metabolised and does not inhibit the metabolism of other drugs. In contrast, sulphonylureas, meglitinide derivatives and thiazolidinediones are extensively metabolised in the liver via the CYP system and thus, may be subject to drug-drug metabolic interactions. Many HMG-CoA reductase inhibitors (statins) are also metabolised via the CYP system. Even if modest pharmacokinetic interactions may occur, it is not clear whether drug-drug interactions between oral antihyperglycaemic agents and statins may have clinical consequences regarding both efficacy and safety. In contrast, a marked pharmacokinetic interference has been reported between gemfibrozil and repaglinide and, to a lesser extent, between gemfibrozil and rosiglitazone. This leads to a drastic increase in plasma concentrations of each antihyperglycaemic agent when they are coadministered with the fibric acid derivative, and an increased risk of adverse effects. Some antihypertensive agents may favour hypoglycaemic episodes when co-prescribed with sulphonylureas or meglitinide derivatives, especially ACE inhibitors, but this effect seems to result from a pharmacodynamic drug-drug interaction rather than from a pharmacokinetic drug-drug interaction. No, or only modest, interferences have been described with glucose-lowering agents and other pharmacological compounds such as digoxin or warfarin. The effects of inducers or inhibitors of CYP isoenzymes on the metabolism and pharmacokinetics of the glucose-lowering agents of each pharmacological class has been tested. Significantly increased (with CYP inhibitors) or decreased (with CYP inducers) plasma levels of sulphonylureas, meglitinide derivatives and thiazolidinediones have been reported in healthy volunteers, and these pharmacokinetic changes may lead to enhanced or reduced glucose-lowering action, and thus hypoglycaemia or worsening of metabolic control, respectively. In addition, some case reports have evidenced potential drug-drug interactions with various antihyperglycaemic agents that are usually associated with a higher risk of hypoglycaemia.

Glimepiride versus pioglitazone combination therapy in subjects with type 2 diabetes inadequately controlled on metformin monotherapy: results of a randomized clinical trial

OBJECTIVE

To compare the effect of add-on glimepiride or pioglitazone in subjects with type 2 diabetes inadequately controlled on metformin monotherapy.

RESEARCH DESIGN AND METHODS

Multicenter, randomized, parallel-group, open-label, forcedtitration study involving 203 adults with poorly controlled type 2 diabetes (A1C 7.5-10%) on metformin monotherapy. Subjects were randomized to receive glimepiride or pioglitazone, titrated to the maximum dose for 26 weeks. Subjects were evaluated for A1C changes, fasting plasma glucose (FPG), insulin, C-peptide, and lipid levels. Safety outcomes and diabetes-related healthcare resource utilization were also evaluated.

RESULTS

Both treatment groups achieved similar and significant mean decreases from baseline to endpoint (week 26) in A1C (p = 0.0001) and FPG (p < 0.05). Glimepiride therapy, however, resulted in a more rapid decline in A1C levels at weeks 6, 12, and 20 vs. pioglitazone (p < 0.05). A mean A1C < or = 7% was reached faster in the glimepiride group (median, 80-90 days vs. 140-150 days [p = 0.024]). Total and LDL cholesterol were significantly higher with pioglitazone treatment than with glimepiride at endpoint (p < 0.05). Glimepiride treatment was associated with an increased risk of hypoglycemia and pioglitazone with higher rate of peripheral edema. Healthcare resource utilization was similar between groups, but total healthcare costs were significantly lower for glimepiride versus pioglitazone over the course of the study, driven largely by drug costs. The use of fasting C-peptide concentration > or = 0.27 nmol/L in the inclusion criteria was a potential limitation as it may have included those patients with an improved probability for glimepiride or pioglitazone response. In addition, a larger patient population would have provided a greater degree of data applicability.

CONCLUSIONS

In patients with type 2 diabetes inadequately controlled on metformin monotherapy, add-on glimepiride or pioglitazone results in similar overall improvements in glycemic control. Compared with pioglitazone, glimepiride is associated with faster glycemic control, lower total and LDL cholesterol levels and reduced short-term healthcare costs.