Metabolic effect of repaglinide or acarbose when added to a double oral antidiabetic treatment with sulphonylureas and metformin: a double-blind, cross-over, clinical trial

A systematic review, meta-analysis, dose-response, and meta-regression of the effects of acarbose intake on glycemic markers in adults

Purpose

Prior research has yielded mixed results regarding the impact of acarbose intake on glycemic markers. To provide a more comprehensive analysis, a systematic review and meta-analysis was performed to compile data from various randomized controlled trials (RCTs) examining the effects of acarbose intake on fasting blood sugar (FBS), insulin, hemoglobin A1C (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR) in adults.

Methods

To identify relevant literature up to April 2023, a comprehensive search was conducted on various scholarly databases, including PubMed, Web of Science, and Scopus databases. The effect size of the studies was evaluated using a random-effects model to calculate the weighted mean differences (WMD) and 95% confidence intervals (CI). Heterogeneity between studies was assessed using Cochran's Q test and I2.

Results

This systematic review and meta-analysis included a total of 101 RCTs with a total of 107 effect sizes. The effect sizes for FBS in milligrams per deciliter (mg/dl), insulin in picomoles per liter (pmol/l), hemoglobin A1C (HbA1c) in percentage (%), and homeostasis model assessment of insulin resistance (HOMA-IR) were 92, 46, 80, and 22, respectively. The pooled analysis indicated that acarbose intake resulted in significant decreases in FBS (p = 0.018), insulin (p < 0.001), HbA1c (p < 0.001), and HOMA-IR (p < 0.001).

Conclusion

The findings of this systematic review and meta-analysis suggest that acarbose intake can potentially lead to significant improvements in glycemic parameters by decreasing the levels of FBS, HbA1c, and insulin. However, larger and more rigorously designed studies are still needed to further evaluate and strengthen this association.

The effect of acarbose on lipid profiles in adults: a systematic review and meta-analysis of randomized clinical trials

PURPOSE

Dyslipidemia, characterized by elevated levels of triglycerides (TG), low-density lipoprotein (LDL), total cholesterol (TC), and reduced levels of high-density lipoprotein (HDL), is a major risk factor for cardiovascular diseases (CVD). Several studies have shown the potential of acarbose in improving serum lipid markers. However, there have been conflicting results on the topic in adults. Therefore, a comprehensive systematic review and meta-analysis was conducted to assess the impact of acarbose on lipid profiles.

METHODS

The random-effects approach was used to combine the data, and the results were provided as weighted mean difference (WMD) with 95% confidence intervals (CI).

RESULTS

Our meta-analysis included a total of 74 studies with a combined sample size of 7046 participants. The results of the analysis showed that acarbose resulted in a reduction in levels of TG (WMD = - 13.43 mg/dl, 95% CI: - 19.20, - 7.67; P < 0.001) and TC (WMD = - 1.93 mg/dl, 95% CI: - 3.71, - 0.15; P = 0.033), but did not affect other lipid markers. When conducting a nonlinear dose-response analysis, we found that acarbose was associated with an increase in levels of HDL (coefficients = 0.50, P = 0.012), with the highest increase observed at a dosage of 400 mg/d. Furthermore, our findings suggested a non-linear relationship between the duration of the intervention and TC (coefficients = - 18.00, P = 0.032), with a decline observed after 50 weeks of treatment.

CONCLUSION

The findings of this study suggest that acarbose can reduce serum levels of TG and TC. However, no significant effects were observed on LDL or HDL levels.

The effects of acarbose treatment on cardiovascular risk factors in impaired glucose tolerance and diabetic patients: a systematic review and dose-response meta-analysis of randomized clinical trials

Acarbose (ACB) seems to be an effective drug in the management of cardiovascular risk factors. However, no previous meta-analysis of randomized controlled trials (RCTs) has been done to evaluate the effects of ACB on cardiovascular risk factors on impaired glucose tolerance (IGT), type 2 diabetes mellitus (T2D), and type 1 diabetes mellitus (T1D). We comprehensively searched electronic databases including Scopus, Web of Science, and PubMed for RCTs for related keywords up to September 2022. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence interval (CI). The pooled analysis demonstrated that ACB treatment had a significant effect on fasting blood glucose (FBG) (WMD = -3.55 mg/dL; 95%CI: -6.29, -0.81; p = 0.011), fasting insulin (WMD = -6.73 pmoL/L; 95%CI: -10.37, -3.10; p < 0.001), HbA1c [WMD = -0.32%; 95%CI: -0.45, -0.20; p < 0.001], body weight (WMD = -1.25 kg; 95%CI: -1.79, -0.75; p < 0.001), body mass index (BMI) (WMD = -0.64 kg/m2; 95%CI: -0.92, -0.37; p < 0.001), tumor necrosis factor-alpha (TNF-α) (WMD = -2.70 pg/mL, 95%CI: -5.25, -0.16; p = 0.037), leptin (WMD = -1.58 ng/mL; 95%CI: -2.82, -0.35; p = 0.012), alanine transaminase (ALT) (WMD = 0.71 U/L; 95%CI: -0.31, 1.85; p = 0.164), triglyceride (TG) (WMD = -13.89 mg/dL; 95%CI: -20.69, -7.09; p < 0.001), total cholesterol (TC) (WMD = -2.26 mg/dL; 95%CI: -4.18, -0.34; p = 0.021), systolic blood pressure (SBP) (WMD = -1.29 mmHg; 95%CI: -2.44, -0.15; p = 0.027), and diastolic blood pressure (DBP) (WMD = 0.02 mmHg; 95%CI: -0.41, 0.45; p = 0.925) in an intervention group, compared with a placebo group. The non-linear dose-response analysis showed that ACB reduces the TC in trial duration by >50 weeks, and 180 mg/day is more effective for the decrement of CRP. ACB can improve lipid profiles, glycemic indices, anthropometric indices, and inflammatory markers in T2D, T1D, and IGT patients.

The role of Recent Pharmacotherapeutic Options on the Management of Treatment Resistant Type 2 Diabetes

INTRODUCTION

Type 2 diabetes mellitus is a complex progressive disease leading to chronic hyperglycemia due to insulin resistance and pancreatic beta-cell failure. Intensification of treatment regimens is often necessary due to the overall decline in insulin secretion. Unfortunately, many patients are unable to achieve optimal glycemic control despite the standard of care and thus may be classified as 'treatment resistant'.

AREAS COVERED

Newer pharmacotherapeutic agents, either injectable or oral, such as Glucagon-like-peptide-1 receptor agonists (GLP-1RA) and Sodium-glucose Cotransporter-2 (SGLT2) inhibitors are, herein, described. These agents can be used as single agents or fixed combinations that reduce glycemia while lessening the risk for hypoglycemia and renal and cardiovascular diseases.

EXPERT OPINION

If individualized target HbA1c is not obtained despite diet, lifestyle, and metformin therapy, then additional oral and injectable therapies should be considered. This may include newer agents such as GLP-1RA and SGLT2 inhibitors alone or in combination that provide renal protection and reduce cardiovascular and hypoglycemic risks. These newer agents have substantial potential for lowering HbA1c through differing but complementary mechanisms. Use of new insulin analogs with GLP-1RA preparations either alone or in fixed-ratio combinations, such as glargine/lixisenatide and degludec/liraglutide, can also reduce the multiple drug adherence burden while improving glycemic control.

A time to revisit the two oldest prandial anti-diabetes agents: acarbose and repaglinide

PURPOSE

Compared with newer prandial anti-diabetes agents, repaglinide and acarbose are unique in being globally available in generic versions, being oral, and being the cheapest of all. The aim of this study was to compare their efficacy when used alone or in combination.

METHODS

In a randomized, double-blind, prospective study, 358 recently diagnosed type 2 diabetes (T2D) patients, who on a combined therapy with metformin and insulin glargine had a fasting plasma glucose (FGP) of <7.2 mmol/L but a 2-h postprandial plasma glucose (2hPPG) >10 mmol/L, were assigned to three groups of additional treatment with either repaglinide, acarbose, or repaglinide-plus-acarbose for 4 months.

RESULTS

With intention-to-treat analysis, 63% of repaglinide group, 45.4 percent of acarbose group, and 75.7% of repaglinide-plus-acarbose group reached the primary endpoint of 2hPPG < 10 mmol/L while maintaining FPG < 7.2 mmol/L. Treatment adherence rate was 75.6% with repaglinide, 61.4% with acarbose, and 81.3% with repaglinide-plus-acarbose (p = 0.001). Among the groups, weight was significantly lower in acarbose group (p < 0.05). Twenty-one percent of repaglinide patients, 4.9% of acarbose subjects, and 10.3% of repaglinide-plus-acarbose cases reported at least one episode of hypoglycemia (p < 0.005). HbA1C and basal insulin requirement were significantly lower in repaglinide group (p = 0.004, p = 0.0002). Triglycerides were lowest in acarbose group (p = 0.005).

CONCLUSIONS

Both acarbose and repaglinide were vastly effective in lowering postprandial hyperglycemia of recently diagnosed T2D. When combined, they were even more efficacious and the disease had a better outcome. Compared with newer peers, these two are particularly useful where and when cost consideration in diabetes treatment is a prime concern.

Acarbose-metformin is more effective in glycemic variability control than repaglinide-metformin in T2DM patients inadequately controlled with metformin: a retrospective cohort study

Background

Acarbose and repaglinide are widely used either by themselves or in combination with other medications. However, their efficacy in diabetes control has not been compared when used in combination with metformin.

Methods

The present study aimed to compare their effects on glycemic variability (GV) control when taken with metformin for type 2 diabetes mellitus (T2DM) inadequately controlled with metformin alone. In this retrospective cohort study, T2DM patients who were treated with either acarbose-metformin or repaglinide-metformin combination were recruited. Either acarbose 100 mg or repaglinide 2 mg triple daily was taken for the subsequent 12 weeks in combination with metformin. Demographic data, biochemical data and 7-point glycemic self-monitoring conducted with capillary blood (SMBG) data were reviewed after one week and 12 weeks. The primary outcome including glucose control and changes in GV as well as other factors affecting GV and the incidence of hypoglycemia were also analyzed.

Results

Of the 305 T2DM patients enrolled, data from 273 subjects, 136 in the acarbose-metformin group (M+A) and 137 in the repaglinide-metformin group (M+R) were analyzed. Both regimens improved glycemic control at 12 weeks post commencement of new medications. GV, expressed as the mean amplitude of plasma glycemic excursions (MAGE, 5.0 ± 2.6 vs. 2.8 ± 1.6 mmol/L, p < 0.001 in M+A; 5.1 ± 2.5 vs. 2.9 ± 1.3 mmol/L, p < 0.001 in M+R), standard deviation of blood glucose (SDBG, 3.6 ± 1.3 vs. 2.0 ± 0.9 mmol/L, p < 0.001 in M+A; 3.7 ± 1.3 vs. 2.4 ± 1.3 p < 0.001 in M+R), coefficient of variation of blood glucose (CVBG, (0.30 ± 0.09 vs. 0.21 ± 0.1, p < 0.001 in M+A; 0.31 ± 0.09 vs. 0.24 ± 0.12, p < 0.001 in M+R), postprandial amplitude of glycemic excursions (PPGE, 5.2 ± 2.6 vs. 2.8 ± 1.6 mmol/L, p < 0.001 in M+A; 5.3 ± 2.5 vs. 2.9 ± 1.3 mmol/L, p < 0.001 in M+R) or largest amplitude of glycemic excursions (LAGE, 9.8 ± 3.6 vs. 5.4 ± 2.4 mmol/L, p < 0.001 in M+A; 10.1 ± 3.4 vs. 6.3 ± 3.2 mmol/L, p < 0.001 in M+R) decreased significantly after the addition of acarbose or repaglinide (p < 0.05 respectively). Compared with repaglinide-metformin, acarbose-metformin was more effective in GV control at 12 weeks post commencement of new medications (p < 0.05). This study indicates that both acarbose-metformin and repaglinide-metformin combinations could effectively reduce GV and the acarbose-metformin combination seems to be more effective than the repaglinide-metformin combination. However, this conclusion should be confirmed by future large-scaled and more comprehensive studies due to the limitations of the present study.

Blood glucose and pressure controls in diabetic kidney disease: Narrative review of adherence, barriers and evidence of achievement

AIMS

To review the epidemiology and the clinical evidence regarding achieving blood pressure (BP) and blood glucose control in patients with chronic kidney disease (CKD) and diabetes mellitus (DM), with emphasis on adherence and barriers within the context of Australian clinical guidelines. This article then considers Australian services aimed at BP, DM, and CKD, guideline adherence and control.

METHODS

Evidence from PubMed-listed articles published between 1994 and 2016 is considered, including original research, focusing on randomised controlled trials and prospective studies, review articles, meta- analyses, expert and professional bodies' guidelines as well as our experience.

RESULTS

There have been no Australian studies that consider adherence to BP control in DM and CKD patients. This is a major limitation in preventing DM and renal disease progression. It is possible that Australian clinicians are not adhering to DM, hypertension (HT), and glucose recommendations, thus resulting in reduced patient outcomes.

CONCLUSIONS

It is hoped that future studies ascertain the extent to which the required BP and glucose control in patients is achieved, and the potential barriers to adherence. The significance of this is immense since the impact of failure to control blood glucose levels and BP leads to renal damage.

Services aimed at achieving desirable clinical outcomes in patients with chronic kidney disease and diabetes mellitus: A narrative review

There is a large number of patients with chronic kidney disease (CKD), diabetes mellitus (DM), and hypertension (HT) but whether the targets on blood pressure (BP) control in patients with DM and/or CKD are met is not clear. This narrative review therefore investigated evidence on services aimed at achieving desirable clinical results in patients with CKD and DM, and HT in Australia. Literature pertaining to pathology diagnosis and management of these patients as well as the complexities in management were considered. This involved evidence from PubMed-listed articles published between 1993 and 2016 including original research studies, focusing on randomised controlled trials and prospective studies where possible, systematic and other review articles, meta- analyses, expert consensus documents and specialist society guidelines, such as those from the National Heart Foundation of Australia, American Diabetes Association, the Department of Health, The Royal College of Pathologists of Australasia, and The Australasian College of Emergency Medicine. Based on the literature reviewed, it is yet unknown as to how effective programs, such as diabetes inpatient services, endocrine out-patient services, and cardiac rehabilitation services, are at achieving guideline recommendations. It is also not clear how or whether clinicians are encumbered by complexities in their efforts of adhering to DM, HT, and glucose control recommendations, and the potential reasons for clinical inertia. Future studies are needed to ascertain the extent to which required BP and glucose control in patients is achieved, and whether clinical inertia is a barrier.

Carbohydrate restriction with postmeal walking effectively mitigates postprandial hyperglycemia and improves endothelial function in type 2 diabetes

Postprandial hyperglycemia has deleterious effects on endothelial function. Restricting carbohydrate intake and postmeal walking have each been shown to reduce postprandial hyperglycemia, but their combination and subsequent effects on endothelial function have not been investigated. Here, we sought to examine the effect of blunting postprandial hyperglycemia by following a low-carbohydrate diet, with or without postmeal walking exercise, on markers of vascular health in type 2 diabetes (T2D). In a randomized crossover design, individuals with T2D ( n = 11) completed three 4-day controlled diet interventions consisting of 1) low-carbohydrate diet alone (LC), 2) low-carbohydrate diet with 15-min postmeal walks (LC + Ex), and 3) low-fat control diet (CON). Fasting blood samples and brachial artery flow-mediated dilation (%FMD) were measured before and after each intervention. Total circulating microparticles (MPs), endothelial MPs, platelet MPs, monocyte-platelet aggregates, and adhesion molecules were assessed as biomarkers of vascular health. There was a significant condition × time interaction for %FMD ( P = 0.01), with post hoc tests revealing improved %FMD after LC + Ex (+0.8 ± 1.0%, P = 0.02), with no change after LC or CON. Endothelial MPs were significantly reduced with the LC diet by ~45% (from 99 ± 60 to 44 ± 31 MPs/μl, P = 0.02), with no change after LC + Ex or CON (interaction: P = 0.04). Total MPs were lower (main effect time: P = 0.02), whereas monocyte-platelet aggregates were higher (main effect time: P < 0.01) after all interventions. Plasma adhesion molecules and C-reactive protein were unaltered. Attenuating postprandial hyperglycemic excursions using a low-carbohydrate diet combined with postmeal walking appears to be an effective strategy to improve endothelial function in individuals with T2D. NEW & NOTEWORTHY Carbohydrate restriction and postmeal walking lower postprandial hyperglycemia in individuals with type 2 diabetes. Here, we show that the combination significantly improved endothelial function and that carbohydrate restriction alone reduced circulating endothelial microparticles in individuals with type 2 diabetes. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/low-carb-diet-and-exercise-improve-endothelial-health/ .

Pharmacotherapy of 'treatment resistant' type 2 diabetes

INTRODUCTION

Despite type 2 diabetes (T2D) management offers a variety of pharmacological interventions targeting different defects, numerous patients remain with persistent hyperglycaemia responsible for severe complications. Unlike resistant hypertension, treatment resistant T2D is not a classical concept although it is a rather common observation in clinical practice. Areas covered: This article proposes a definition for 'treatment resistant diabetes', analyses the causes of poor glucose control despite standard therapy, briefly considers the alternative approaches to glucose-lowering pharmacotherapy and finally describes how to overcome poor glycaemic control, using innovative oral or injectable combination therapies. Expert opinion: Before considering intensifying the pharmacotherapy of a patient with poorly controlled T2D, it is important to verify treatment adherence, target obesity and consider various non pharmacological improvement quality interventions. If treatment resistant diabetes is defined as not achieving glycated haemoglobin target despite oral triple therapy with a third glucose-lowering agent added to metformin-sulfonylurea dual treatment, the combination of a dipeptidyl peptidase-4 (DPP-4) inhibitor and a sodium glucose cotransporter type 2 (SGLT2) inhibitor may offer new opportunities before considering injectable therapies. Insulin basal therapy (± metformin) may be optimized by the addition of a SGLT2 inhibitor or a glucagon-like peptide-1 (GLP-1) receptor agonist.

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.'

A new blood glucose management algorithm for type 2 diabetes: a position statement of the Australian Diabetes Society

Lowering blood glucose levels in people with type 2 diabetes has clear benefits for preventing microvascular complications and potential benefits for reducing macrovascular complications and death. Treatment needs to be individualised for each person with diabetes. This should start with selecting appropriate glucose and glycated haemoglobin targets, taking into account life expectancy and the patient's wishes. For most people, early use of glucose-lowering therapies is warranted. A range of recently available therapies has added to the options for lowering glucose levels, but this has made the clinical pathway for treating diabetes more complicated. This position statement from the Australian Diabetes Society outlines the risks, benefits and costs of the available therapies and suggests a treatment algorithm incorporating the older and newer agents.

Achieving glycemic control in elderly patients with type 2 diabetes: a critical comparison of current options

The prevalence of type 2 diabetes mellitus (T2DM) is increasing in the elderly. Because of the unique characteristics of elderly people with T2DM, therapeutic strategy and focus should be tailored to suit this population. This article reviews the guidelines and studies related to older people with T2DM worldwide. A few important themes are generalized: 1) the functional and cognitive status is critical for older people with T2DM considering their life expectancy compared to younger counterparts; 2) both severe hypoglycemia and persistent hyperglycemia are deleterious to older adults with T2DM, and both conditions should be avoided when determining therapeutic goals; 3) recently developed guidelines emphasize the avoidance of hypoglycemic episodes in older people, even in the absence of symptoms. In addition, we raise the concern of glycemic variability, and discuss the rationale for the selection of current options in managing this patient population.

The role of nateglinide and repaglinide, derivatives of meglitinide, in the treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases worldwide, presenting a great challenge to the public health systems due to high morbidity and mortality, because of frequent micro-/macro-vascular complications. Many treatment options are now available, with different efficacy as well as mechanisms of action to improve deranged glucose metabolism. We review some of the available data on derivatives of meglitinide, namely nateglinide and repaglinide. These two compounds increase insulin secretion by a mechanism similar to the one of sulfonylureas, but with a shorter half-life. Nateglinide and repaglinide, derivatives of meglitinides, have characteristic pharmacodynamic and pharmacokinetic properties that, together with their proposed mechanism of action, make them useful for type 2 diabetes mellitus, especially when used in combination therapy.

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.

A comparison between sitagliptin or glibenclamide in addition to metformin + pioglitazone on glycaemic control and β-cell function: the triple oral therapy

AIMS

To evaluate which triple oral therapy between metformin + pioglitazone + sitagliptin and metformin + pioglitazone + glibenclamide can be more useful in improving glycaemic control and should be preferred in clinical practice.

METHODS

During the 2-year run-in period, patients were instructed to take metformin monotherapy for the first year, then a combination of metformin and pioglitazone for the second year, then patients were randomized to add glibenclamide or sitagliptin to the dual combination of metformin and pioglitazone for another year.

RESULTS

Body weight reached with sitagliptin at 36 months was lower than that reached with glibenclamide. Fasting plasma insulin and homeostasis model assessment of insulin resistance were significantly increased by triple therapy with glibenclamide and decreased by that with sitagliptin. While sitagliptin did not change homeostasis model assessment of β-cell function, this value was significantly increased by glibenclamide. Fasting plasma proinsulin was not influenced by triple oral therapy including glibenclamide, while it was decreased by the therapy including sitagliptin compared to glibenclamide. Triple oral therapy with sitagliptin better improved β-cell function measures compared with the glibenclamide therapy.

CONCLUSIONS

Sitagliptin should be preferred to glibenclamide as an addition to the metformin + pioglitazone combination for its better protection of β-cell secretion and its neutral effect on body weight.

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.

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.

Choice of therapy in patients with type 2 diabetes inadequately controlled with metformin and a sulphonylurea: a systematic review and mixed-treatment comparison meta-analysis

BACKGROUND

Metformin and a sulphonylurea are often used in combination for the treatment of type 2 diabetes mellitus. We conducted a systematic review and meta-analysis to evaluate the comparative safety and efficacy of all available classes of antihyperglycemic therapies in patients with type 2 diabetes inadequately controlled with metformin and sulphonylurea combination therapy.

METHODS

MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, BIOSIS Previews, PubMed and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials published in English from 1980 to November 2009. Additional citations were obtained from the grey literature and conference proceedings and through stakeholder feedback. Two reviewers independently selected the studies, extracted the data and assessed risk of bias. Key outcomes of interest were hemoglobin A1c, body weight, hypoglycemia, patients' satisfaction with treatment, quality of life, long-term diabetes-related complications, withdrawals due to adverse events, serious adverse events and mortality. Mixed-treatment comparison meta-analyses were conducted to calculate mean differences between drug classes for changes in hemoglobin A1c and body weight. When appropriate, pairwise meta-analyses were used to estimate differences for other outcomes.

RESULTS

We identified 33 randomized controlled trials meeting the inclusion criteria. The methodologic quality of the studies was generally poor. Insulins (basal, biphasic, bolus), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues and thiazolidinediones (TZDs) all produced statistically significant reductions in hemoglobin A1c in combination with metformin and a sulphonylurea (-0.89% to -1.17%), whereas meglitinides and alpha-glucosidase inhibitors did not. Biphasic insulin, bolus insulin, and TZDs were associated with weight gain (1.85-5.00 kg), whereas DPP-4 inhibitors and alpha-glucosidase inhibitors were weight-neutral, and GLP-1 analogues were associated with modest weight loss. Treatment regimens containing insulin were associated with increased hypoglycemia relative to comparators, but severe hypoglycemia was rare across all treatments.

INTERPRETATION

Third-line agents for the treatment of type 2 diabetes are similar in terms of glycemic control but differ in their propensity to cause weight gain and hypoglycemia. Longer-term studies with larger sample sizes are required to determine if any of the drug classes are superior with regard to reducing diabetes-related complications.

Efficacy and safety profile evaluation of acarbose alone and in association with other antidiabetic drugs: a systematic review

BACKGROUND

Epidemiologic studies have revealed that postprandial hyperglycemia significantly contributes to high glycated hemoglobin concentrations and could be linked to the development of chronic diabetic complications.

OBJECTIVE

The purpose of our review was to evaluate the clinical efficacy and safety profile of treatment with acarbose alone and combined with other antidiabetic drugs.

METHODS

A systematic search strategy was developed to identify randomized controlled trials included in MEDLINE and the Cochrane Register of Controlled Trials. The terms acarbose, α-glucosidase inhibitors, type 2 diabetes, adverse events, combination therapy, and postprandial glucose were incorporated into an electronic search strategy that included the Dickersin filter for randomized controlled trials. To qualify for inclusion, clinical trials had to be randomized trials comparing treatment with acarbose at any dosage with any other antidiabetic drug in patients with type 2 diabetes mellitus or impaired glucose tolerance. Eligible trials had to present results on glycemic control or adverse events. Trial participants needed to be affected by type 2 diabetes mellitus or have impaired glucose tolerance, and the intervention had to include acarbose at any dosage as monotherapy or combined with other antidiabetic drugs. A validated 3-item scale was used to evaluate the overall reporting quality of the trials selected for inclusion in the present review. Nineteen trials were included.

RESULTS

Treatment with acarbose significantly reduced glycated hemoglobin levels when given as monotherapy and as an add-on to other antidiabetic drug treatment (P < 0.0001). Acarbose treatment was effective in patients with uncontrolled type 2 diabetes and in patients with apparently good metabolic control owing to its positive effect on postprandial hyperglycemia (P < 0.0001). Treatment with acarbose seemed to improve the lipid profile (P < 0.05), reduce circulating levels of cell adhesion molecules (P < 0.05), reduce intima-media thickness progression (P = 0.01), and reverse impaired glucose tolerance to normal glucose tolerance (P < 0.0001).

CONCLUSIONS

When current therapy is not adequate to obtain glycemic control, acarbose could be an option as monotherapy and as an add-on to other antidiabetic drug treatment, especially when postprandial hyperglycemia is the main concern. Long-term studies are needed to determine whether the effects observed with acarbose use are maintained over the years.

RETRACTED: Acarbose on insulin resistance after an oral fat load: a double-blind, placebo controlled study

AIM

We evaluated the effects of acarbose on insulin resistance parameters in diabetic patients before and after a standardized oral fat load (OFL).

MATERIALS AND METHODS

Patients were assigned to take acarbose 50 mg three times a day or placebo; after the first month, acarbose was titrated to 100 mg three times a day. We evaluated body mass index, glycemic control, fasting plasma insulin (FPI), post-prandial plasma insulin (PPI), homeostasis model assessment insulin resistance index (HOMA-IR), blood pressure, lipid profile, retinol binding protein-4 (RBP-4), adiponectin (ADN), tumor necrosis factor-α and resistin (r). Furthermore, at the baseline and at the end of the study, all patients underwent an OFL and an euglycemic hyperinsulinemic clamp.

RESULTS

We observed that acarbose was better than placebo in improving glycemic control and HOMA-IR and that it was also more effective in improving lipid profile, RBP-4 and ADN. Regarding FPI, PPI and r, we did not obtain any significant differences between the two groups. During the second OFL, performed after 7 months of therapy with acarbose, we observed a significant decrease of blood glucose, lipid profile and all insulin resistance parameters peaks compared with the OFL administered at baseline with acarbose, but not with placebo.

CONCLUSION

Acarbose was more effective than placebo in improving glycemic and lipid profile and in reducing the post-OFL peaks of the various parameters including the insulin resistance biomarkers.

Acarbose actions on insulin resistance and inflammatory parameters during an oral fat load

The aim of this study was to evaluate the effects of acarbose on inflammatory biomarkers and insulin resistance in diabetic patients before and after a standardized oral fat load (OFL). Ninety six patients were assigned to take acarbose 50mg three times a day and 92 to take placebo; after the first month acarbose was titrated to 100mg three times a day. We evaluated the following parameters at the baseline, and after 1, 2 and 7months: body mass index (BMI), glycemic control, fasting plasma insulin, post-prandial plasma insulin, homeostasis model assessment insulin resistance index (HOMA-IR), blood pressure, lipid profile, soluble intercellular adhesion molecule-1 (sICAM-1), interleukin-6 (IL-6), high-sensitivity C reactive protein (Hs-CRP), soluble vascular cell adhesion molecule-1 (sVCAM-1), and soluble E-selectin (sE-selectin). Furthermore, at the baseline and at the end of the study all patients underwent OFL, and an euglycemic hyperinsulinemic clamp to evaluate M value and total glucose requirement. Acarbose was better than placebo in improving glycemic and lipid profile, and HOMA-IR. Furthermore, acarbose gave a decrease of fasting plasma insulin, post-prandial insulin, s-ICAM-1, sVCAM-1, IL-6, and Hs-CRP, not observed with placebo, even if no significant differences between the two groups were observed. During the second OFL performed after the therapy with acarbose, we observed a significant decrease of all inflammatory parameters' peaks compared to the OFL administered at baseline. Acarbose was more effective than acarbose in reducing the post-OFL peaks of the various parameters included the inflammatory markers, after 7months of therapy.

Combination therapy for patients with Type 2 diabetes: repaglinide in combination with metformin

In patients with Type 2 diabetes mellitus (T2DM), adequate glycemic control is a critical factor in reducing long-term micro- and macro-vascular complications. Traditionally, the approach is to initiate monotherapy first, followed by combination therapy that targets two main defects in T2DM. Repaglinide, a rapidly acting insulin secretagog, stimulates insulin secretion via closure of ATP-dependent potassium channels on the cell membrane of β-cells. Repaglinide is ideally used at mealtime to reduce postprandial glucose levels, thus lowering the 24-h blood glucose profile and improving HbA1c levels. Metformin is an insulin sensitizer that effectively acts against insulin resistance, one of the predominant metabolic defects in T2DM. A combination of repaglinide and metformin is indicated as an adjunct to diet and exercise to improve glycemic control in adults with T2DM. When monotherapy with oral antidiabetic agents fails, combination therapy with repaglinide plus metformin has been demonstrated to be safe and effective in the treatment of T2DM.