Efficacy of 24-week monotherapy with acarbose, glibenclamide, or placebo in NIDDM patients. The Essen Study

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.

Reversal and Remission of T2DM - An Update for Practitioners

Over the past 50 years, many countries around the world have faced an unchecked pandemic of obesity and type 2 diabetes (T2DM). As best practice treatment of T2DM has done very little to check its growth, the pandemic of diabesity now threatens to make health-care systems economically more difficult for governments and individuals to manage within their budgets. The conventional view has been that T2DM is irreversible and progressive. However, in 2016, the World Health Organization (WHO) global report on diabetes added for the first time a section on diabetes reversal and acknowledged that it could be achieved through a number of therapeutic approaches. Many studies indicate that diabetes reversal, and possibly even long-term remission, is achievable, belying the conventional view. However, T2DM reversal is not yet a standardized area of practice and some questions remain about long-term outcomes. Diabetes reversal through diet is not articulated or discussed as a first-line target (or even goal) of treatment by any internationally recognized guidelines, which are mostly silent on the topic beyond encouraging lifestyle interventions in general. This review paper examines all the sustainable, practical, and scalable approaches to T2DM reversal, highlighting the evidence base, and serves as an interim update for practitioners looking to fill the practical knowledge gap on this topic in conventional diabetes guidelines.

A Practical Review of Diabetes Mellitus Type 2 Treatment in Primary Care

The treatment of diabetes mellitus type 2 (DM2) is becoming more complex as new medications are approved. Primary care providers must maintain their medical knowledge on emerging medications for best patient care. This review simplifies the non-insulin treatments of diabetes with an emphasis on the cardio-renal protectants, sodium-glucose cotransporter 2 (SGLT-2) inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1).

Efficacy and Safety of Mulberry Twig Alkaloids Tablet for the Treatment of Type 2 Diabetes: A Multicenter, Randomized, Double-Blind, Double-Dummy, and Parallel Controlled Clinical Trial

OBJECTIVE

This study aimed to evaluate the efficacy and safety of mulberry twig alkaloids (Sangzhi alkaloids [SZ-A]) in the treatment of type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

This was a multicenter, randomized, double-blind, double-dummy, and parallel controlled noninferiority clinical trial that was conducted for 24 weeks. A total of 600 patients were randomly allocated to the SZ-A group (n = 360) or acarbose group (n = 240). The primary efficacy end point was the change of glycosylated hemoglobin (HbA_1c) compared with baseline. In addition, adverse events (AEs), severe AEs (SAEs), treatment-related AEs (TAEs), and gastrointestinal disorders (GDs) were monitored.

RESULTS

After treatment for 24 weeks, the change in HbA_1c was -0.93% (95% CI -1.03 to -0.83) (-10.2 mmol/mol [-11.3 to -9.1]) and -0.87% (-0.99 to -0.76) (-9.5 mmol/mol [-10.8 to -8.3]) in the SZ-A and acarbose groups, respectively, and the least squares mean difference was -0.05% (95% CI -0.18 to 0.07) (-0.5 mmol/mol [-2.0 to 0.8]) between the two groups, with no significant difference on the basis of covariance analysis (P > 0.05). The incidence of TAEs and GDs was significantly lower in the SZ-A group than the acarbose group (P < 0.01), but no differences for AEs or SAEs between the two groups were observed (P > 0.05).

CONCLUSIONS

SZ-A exhibited equivalent hypoglycemic effects to acarbose in patients with T2D. Nevertheless, the incidence of TAEs and GDs was lower following SZ-A treatment than acarbose treatment, suggesting good safety.

Monitoring and management of hyperglycemia in patients with advanced diabetic kidney disease

Diabetes mellitus is the leading cause of end-stage renal disease, and uncontrolled hyperglycemia is directly related to the increased mortality in this setting. As kidney function decreases, it becomes more challenging to control blood glucose since the risk of hypoglycemia increases. Decreased appetite, changes in glycaemia homeostasis, along with reduced renal excretion of anti-hyperglycemic drugs tend to facilitate the occurrence of hypoglycemia, despite the paradoxical occurrence of insulin resistance in advanced kidney disease. Thus, in patients using insulin and/or oral anti-hyperglycemic agents, dynamic adjustments with drug dose reduction or drug switching are often necessary. Furthermore, in addition to consider these pharmacokinetics alterations, it is of utmost importance to choose drugs with proven cardio-renal benefits in this setting, such as sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide 1 receptor agonists. In this review, we summarize the indications and contraindications, titration of doses and side effects of the available anti-hyperglycemic agents in the presence of advanced diabetic kidney disease (DKD) and dialysis, highlighting the risks and benefits of the different agents. Additionally, basic renal function assessment and monitoring of glycemic control in DKD will be evaluated in order to guide the use of drugs and define the glycemic targets to be achieved.

Seaweed Extract Improves Carbohydrate Metabolism in Overweight and Obese Adults

Background:

Background: Obesity is characterized by chronic low-grade inflammation and associated with type 2 diabetes. Seaweed is one of the largest producers of biomass in the marine environment and is a rich arsenal of functional ingredients that may possess the potential to prevent type 2 diabetes.

Objective:

The aim was to investigate the effects of seaweed extract on glucose metabolism and markers of inflammation in overweight and obese individuals.

Methods:

Participants (N=76, ≥40 years, body mass index ≥25 kg/m2) who volunteered for this 10- week randomized, controlled, doubly blinded intervention study, were randomized into an intervention group (seaweed extract, 3 capsules=1200 mg/day) or a control group (placebo, 3 capsules/day). The extract derived from the brown seaweed bladder wrack (Fucus vesiculosus). At baseline and endpoint of the study, fasting samples were analysed for blood glucose, insulin, inflammation markers, liver enzymes and creatinine (renal function).

Results:

Drop out was 11.8% and not significantly different between groups. Fasting blood glucose and insulin were improved at the endpoint in the intervention group, but no changes were observed in the control group (corrected endpoint differences between groups: glucose=0.61 mmol/L, P=0.038; insulin=0.72 μU/L, P=0.038). Measures of inflammation, liver enzymes and renal function did not change significantly during the study.

Conclusion:

Ingestion of seaweed extract over 10 weeks improves glucose metabolism without affecting measures of inflammation, liver function or renal function.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Noninsulin Diabetes Therapies in Older Adults

Diabetes risk increases with age due to changes in β-cell function and increased insulin resistance and is one of the most common chronic medical conditions in the elderly. Diabetes management in this population requires a multidisciplinary, patient-centric approach due to wide heterogeneity in patients' health and functional capacities. Meticulous assessment of each patient before formulating a regimen and thorough patient education are keys to success in achieving glycemic goals, which should be individualized. Lifestyle modification is recommended for every patient.

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.

Diabetes: the place of new therapies

Until the discovery of insulin in 1921 there were no effective treatments for diabetes mellitus. After the advent of long-acting insulin, the first oral agents, sulfonylureas became available in the mid-1950s, quickly followed (outside of the United States) by metformin. It was then another three decades before newer agents became available, with alpha glucosidase inhibitors, thiazolidinediones and meglitinides following in the 1990s. Since the turn of the century, several new classes have also been launched. But how do these agents fit into the management of type 2 diabetes? How does one choose which drug class to use after metformin? This review looks at the agents launched since 2000 and how and when they can be used. It also deals with some of the controversies that have arisen and how decisions have changed as a result, in particular moving away from the use of HbA1c as the driver for decision, but rather the cardiovascular safety of these agents and their use in the prevention of premature cardiovascular morbidity and mortality. Now that some of these agents have shown cardiovascular benefit, will this lead to a change in the treatment paradigm?

Meta-analysis and critical review on the efficacy and safety of alpha-glucosidase inhibitors in Asian and non-Asian populations

AIMS/INTRODUCTION

To evaluate the efficacy and safety of alpha-glucosidase inhibitors (AGI) in Asian and non-Asian type 2 diabetes patients.

MATERIALS AND METHODS

Studies were identified through a literature search of MEDLINE, EMBASE and other databases until December 2016. All statistical analyses were carried out in Review Manager statistical software by computing the weighted mean difference or odds ratio and 95% confidence interval.

RESULTS

A total of 67 studies were included. AGI vs placebo: compared with the placebo, AGI treatment led to a greater decrease in hemoglobin A1c (HbA1c), fasting plasma glucose and postprandial plasma glucose. No significant difference was observed in HbA1c change, fasting plasma glucose change, postprandial plasma glucose change or incidence of hypoglycemia between Asian and non-Asian patients. AGI vs active controls: in Asian patients, AGI treatment showed a lower reduction in HbA1c compared with dipeptidyl peptidase-4 inhibitors and sulfonylurea. In non-Asian patients, AGI treatment showed a lower reduction in HbA1c compared with thiazolidinedione. No significant difference was observed in HbA1c change and bodyweight change when comparing AGI with other oral hypoglycemic agents between Asian and non-Asian patients.

CONCLUSIONS

The effects of AGI treatment on glycemic control and bodyweight reduction were superior to the placebo without an increased incidence of hypoglycemia, but with an increased incidence of gastrointestinal discomforts. The hypoglycemic effects of AGI were comparable between Asian and non-Asian patients.

Monotherapy in patients with type 2 diabetes mellitus

In order to improve the quality of life and to prevent chronic complications related to diabetes mellitus, intensive lifestyle modification and proper medication are needed from the early stage of diagnosis of type 2 diabetes mellitus (T2DM). When using the first medication for diabetic patients, the appropriate treatment should be selected considering the clinical characteristics of the patient, efficacy of the drug, side effects, and cost. In general, the use of metformin as the first treatment for oral hypoglycemic monotherapy is recommended because of its excellent blood glucose-lowering effect, relatively low side effects, long-term proven safety, low risk of hypoglycemia, and low weight gain. If metformin is difficult to use as a first-line treatment, other appropriate medications should be selected in view of the clinical situation. If the goal of achieving glycemic control is not achieved by monotherapy, a combination therapy with different mechanisms of action should be initiated promptly.

Monotherapy in Patients with Type 2 Diabetes Mellitus

In order to improve the quality of life and to prevent chronic complications related to diabetes mellitus, intensive lifestyle modification and proper medication are needed from the early stage of diagnosis of type 2 diabetes mellitus (T2DM). When using the first medication for diabetic patients, the appropriate treatment should be selected considering the clinical characteristics of the patient, efficacy of the drug, side effects, and cost. In general, the use of metformin as the first treatment for oral hypoglycemic monotherapy is recommended because of its excellent blood glucose-lowering effect, relatively low side effects, long-term proven safety, low risk of hypoglycemia, and low weight gain. If metformin is difficult to use as a first-line treatment, other appropriate medications should be selected in view of the clinical situation. If the goal of achieving glycemic control is not achieved by monotherapy, a combination therapy with different mechanisms of action should be initiated promptly.

Associations between changes in glucagon-like peptide-1 and bodyweight reduction in patients receiving acarbose or metformin treatment

BACKGROUND

The present post hoc analysis investigated whether changes in endogenous glucagon-like peptide-1 (∆GLP-1) levels are associated with weight loss in newly diagnosed diabetes patients.

METHODS

In all, 784 subjects from the Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment (MARCH) study were stratified according to ∆GLP-1. Changes in clinical and physiological parameters were evaluated across ∆GLP-1 subgroups (low, medium, and high) to assess correlations between ∆GLP-1 and weight loss in acarbose- versus metformin-treated groups.

RESULTS

After 24 weeks treatment, greater ∆GLP-1 was associated with significantly greater weight loss (-2 vs -1 kg in the medium/high vs low ∆GLP-1 groups, respectively) and reduction in body mass index (BMI; -0.88, -0.83, and -0.69 kg/m² in the high, medium, and low ∆GLP-1 groups, respectively). In the acarbose-treated group, there was a significant association between ∆GLP-1 and BMI reductions, and greater ∆GLP-1 across the high, medium, and low ∆GLP-1 groups was correlated with greater weight loss (-2.8, -2.1, and -1.9 kg, respectively) and reductions in fasting plasma glucose (-1.57, -1.28, and -1.02 mmol/L, respectively) at Week 24. No significant differences were found across ∆GLP-1 subgroups in metformin-treated patients (P > 0.05). Multivariate linear regression analysis revealed that gender, baseline BMI, and ∆GLP-1 at Week 24 were associated with weight loss. Baseline BMI and ∆GLP-1 in the acarbose-treated group and baseline BMI in the metformin-treated group predicted weight loss at Week 24.

CONCLUSION

Changes in GLP-1 levels are associated with weight loss in newly diagnosed Chinese diabetes patients receiving acarbose.

Reappraisal and perspectives of clinical drug-drug interaction potential of α-glucosidase inhibitors such as acarbose, voglibose and miglitol in the treatment of type 2 diabetes mellitus

1. Amidst the new strategies being developed for the management of type 2 diabetes mellitus (T2DM) with both established and newer therapies, alpha glucosidase inhibitors (AGIs) have found a place in several treatment protocols. 2. The objectives of the review were: (a) to compile and evaluate the various clinical pharmacokinetic drug interaction data for AGIs such as acarbose, miglitol and voglibose; (b) provide perspectives on the drug interaction data since it encompasses coadministered drugs in several key areas of comorbidity with T2DM. 3. Critical evaluation of the interaction data suggested that the absorption and bioavailability of many coadministered drugs were not meaningfully affected from a clinical perspective. Therefore, on the basis of the current appraisal, none of the AGIs showed an alarming and/or overwhelming trend of interaction potential with several coadministered drugs. Hence, dosage adjustment is not warranted in the use of AGIs in T2DM patients in situations of comorbidity. 4. The newly evolving fixed dose combination strategies with AGIs need to be carefully evaluated to ensure that the absorption and bioavailability of the added drug are not impaired due to concomitant food ingestion.

Oral Antidiabetic Agents: A Comparative Review

Type 2 diabetes mellitus is a chronic disease characterized by insulin resistance, impaired insulin secretion, and/or increased hepatic glucose production. The mainstays of drug treatment are the oral antidiabetic agents. Insulin is usually reserved for patients who do not achieve fasting plasma glucose or A1C goals with or cannot tolerate the oral antidiabetic agents. There are 5 classes of oral antidiabetic agents available in the United States: sulfonylureas, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, and nonsulfonylurea secretagogues. They have differences and similarities with respect to their pharmacology and role in diabetes. This article reviews the pharmacology, efficacy, safety, and selection of the oral agents used to treat type 2 diabetes mellitus.

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.'

WITHDRAWN: Sulphonylurea monotherapy for patients with type 2 diabetes mellitus

The Cochrane Metabolic and Endocrine Disorders Group withdrew this review as of Issue 7, 2015 because of the involvement of one author (SS Lund) being employed in a pharmaceutical company. The authors of the review and the Cochrane Metabolic and Endocrine Disorders Group did not find that this was a breach of the rules of the Cochrane Collaboration at the time when it was published. However, after the publication of the review, the Cochrane Collaboration requested withdrawal of the review due to the employment of the author. A new protocol for a review to cover this topic will be published. This will have a new title and a markedly improved protocol fulfilling new and important developments and standards within the Cochrane Collaboration as well as an improved inclusion and search strategy making it necessary to embark on a completely new review project.

The editorial group responsible for this previously published document have withdrawn it from publication.

Acarbose monotherapy and weight loss in Eastern and Western populations with hyperglycaemia: an ethnicity-specific meta-analysis

OBJECTIVE

To demonstrate if weight loss achieved with acarbose in individuals with hyperglycaemia differs between Eastern and Western populations.

METHODS

Databases and reference lists of clinical trials on acarbose were searched. Eligible studies were randomised controlled trials of acarbose monotherapy in populations with hyperglycaemia of more than 12-week duration that provided data on body weight (BW) or body mass index (BMI).

RESULTS

A total of 34 trials (6082 participants) were included. The effect of acarbose on BW was superior to that of placebo [weighted mean difference (WMD) = -0.52, 95% confidence interval (CI) -0.78 to -0.25], nateglinide (WMD = -1.33, 95% CI -1.51 to -0.75) and metformin (WMD = -0.67, 95% CI -1.14 to -0.20). Compared with placebo, there was a significantly greater weight loss of 0.92 kg (p < 0.05, I(2)  = 88.8%) with acarbose in Eastern populations (WMD = -1.20, 95% CI -1.51 to -0.75) than that in Western populations (WMD = -0.28, 95% CI -0.59 to 0.03). Across all studies, the acarbose group achieved a significantly larger absolute weight loss of (change from baseline) 1.35 kg (p < 0.05, I(2)  = 94.3%) in Eastern populations (WMD = -2.26, 95% CI -2.70 to -1.81) than in Western populations (WMD = -0.91, 95% CI -1.36 to -0.47). Nevertheless, the possible risk of bias in Eastern studies may influence the results.

CONCLUSION

The effect of acarbose on weight loss seems to be more pronounced in Eastern than in Western populations with hyperglycaemia, and is superior to that of placebo, nateglinide and metformin across both ethnicities.

Comparison of acarbose and voglibose in diabetes patients who are inadequately controlled with basal insulin treatment: randomized, parallel, open-label, active-controlled study

We studied the efficacy and safety of acarbose in comparison with voglibose in type 2 diabetes patients whose blood glucose levels were inadequately controlled with basal insulin alone or in combination with metformin (or a sulfonylurea). This study was a 24-week prospective, open-label, randomized, active-controlled multi-center study. Participants were randomized to receive either acarbose (n=59, 300 mg/day) or voglibose (n=62, 0.9 mg/day). The mean HbA1c at week 24 was significantly decreased approximately 0.7% from baseline in both acarbose (from 8.43% ± 0.71% to 7.71% ± 0.93%) and voglibose groups (from 8.38% ± 0.73% to 7.68% ± 0.94%). The mean fasting plasma glucose level and self-monitoring of blood glucose data from 1 hr before and after each meal were significantly decreased at week 24 in comparison to baseline in both groups. The levels 1 hr after dinner at week 24 were significantly decreased in the acarbose group (from 233.54 ± 69.38 to 176.80 ± 46.63 mg/dL) compared with the voglibose group (from 224.18 ± 70.07 to 193.01 ± 55.39 mg/dL). In conclusion, both acarbose and voglibose are efficacious and safe in patients with type 2 diabetes who are inadequately controlled with basal insulin. (ClinicalTrials.gov number, NCT00970528).

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.

Cardiovascular safety of sulfonylureas: a meta-analysis of randomized clinical trials

AIM

Cardiovascular safety of sulfonylurea has been questioned by some authors. This article aims at collecting all available data on this issue from randomized trials.

METHODS

A meta-analysis was performed including all trials with a duration of at least 6 months, comparing a sulfonylurea with a non-sulfonylurea agent in type 2 diabetes. Major cardiovascular events (MACE) and mortality were retrieved and combined to calculate Mantel-Haenzel odds ratio (MH-OR).

RESULTS

Of the 115 selected trials, 62 reported information on MACE, and 30 reported at least one event. MH-OR for sulfonylurea was 1.08 [0.86-1.36], p = 0.52 (1.85 [1.20-2.87], p = 0.005, in the five trials vs. DPP4 inhibitors, no significant differences vs. other comparators). The MH-OR for myocardial infarction and stroke was 0.88 [0.75-1.04], p = 0.13 and 1.28 [1.03-1.60], p = 0.026, respectively. Mortality was significantly increased with sulfonylureas (MH-OR: 1.22 [1.01-1.49], p = 0.047).

CONCLUSIONS

In type 2 diabetes, the use of sulfonylureas is associated with increased mortality and a higher risk of stroke, whereas the overall incidence of MACE appears to be unaffected. Significant differences in cardiovascular risk could be present in direct comparisons with specific classes of glucose-lowering agents, such as DPP4 inhibitors, but this hypothesis needs to be confirmed in long-term cardiovascular outcomes trials. The results of this meta-analysis need to be interpreted with caution, mainly because of limitations in trial quality and under-reporting of information on cardiovascular events and mortality. However, the cardiovascular safety of sulfonylureas cannot be considered established unless it is evaluated in long-term cardiovascular outcomes trials.

Improved post-prandial ghrelin response by nateglinide or acarbose therapy contributes to glucose stability in Type 2 diabetic patients

BACKGROUND

Recent studies highlight an important role of ghrelin in glucose homeostasis, while the association between ghrelin regulation and glucose fluctuation is unclear.

AIM

We compared the effects of two postprandial hypoglycemic agents on ghrelin response and determined the contribution of ghrelin response to glucose stability in Type 2 diabetic (T2DM) patients.

SUBJECTS AND METHODS

Forty newly- diagnosed T2DM patients were randomly allocated to receive nateglinide or acarbose for 4 weeks, with twenty body mass index (BMI)-matched normoglycemic subjects as controls. Mean glucose values and daily average glucose excursion were assessed using continuous glucose monitoring system. Serum ghrelin levels were determined by enzyme-linked immunosorbent assay.

RESULTS

T2DM patients had similar fasting ghrelin levels (p=0.546), while their postprandial ghrelin suppressions at 30 min and 120 min were reduced as compared to BMI-matched normoglycemic controls (p<0.01). Both nateglinide and acarbose increased post-prandial ghrelin suppression at 120 min and reduced ghrelin area under the curve (AUCGHRL) (p<0.05), while only nateglinide increased postprandial ghrelin suppression at 30 min (p<0.01), which was positively correlated with the increased early-phase insulin secretion by 4 weeks of nateglinide therapy (r=0.48, p=0.05). The decrease in AUCGHRL was positively correlated with the decrease in daily average glucose excursion and mean glucose values either by 4 weeks of nateglinide or acarbose therapy (p<0.05).

CONCLUSIONS

Both nateglinide and acarbose increase post-prandial ghrelin suppression. Improved ghrelin regulation is most likely to play a role in glucose stability in T2DM patients with nateglinide or acarbose therapy.

Sulphonylurea monotherapy for patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a growing health problem worldwide. Whether sulphonylureas show better, equal or worse therapeutic effects in comparison with other antidiabetic interventions for patients with T2DM remains controversial.

OBJECTIVES

To assess the effects of sulphonylurea monotherapy versus placebo, no intervention or other antidiabetic interventions for patients with T2DM.

SEARCH METHODS

We searched publications in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS and CINAHL (all until August 2011) to obtain trials fulfilling the inclusion criteria for our review.

SELECTION CRITERIA

We included clinical trials that randomised patients 18 years old or more with T2DM to sulphonylurea monotherapy with a duration of 24 weeks or more.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias. The primary outcomes were all-cause and cardiovascular mortality. Secondary outcomes were other patient-important outcomes and metabolic variables. Where possible, we used risk ratios (RR) with 95% confidence intervals (95% CI) to analyse the treatment effect of dichotomous outcomes. We used mean differences with 95% CI to analyse the treatment effect of continuous outcomes. We evaluated the risk of bias. We conducted trial sequential analyses to assess whether firm evidence could be established for a 10% relative risk reduction (RRR) between intervention groups.

MAIN RESULTS

We included 72 randomised controlled trials (RCTs) with 22,589 participants; 9707 participants randomised to sulphonylureas versus 12,805 participants randomised to control interventions. The duration of the interventions varied from 24 weeks to 10.7 years. We judged none of the included trials as low risk of bias for all bias domains. Patient-important outcomes were seldom reported.First-generation sulphonylureas (FGS) versus placebo or insulin did not show statistical significance for all-cause mortality (versus placebo: RR 1.46, 95% CI 0.87 to 2.45; P = 0.15; 2 trials; 553 participants; high risk of bias (HRB); versus insulin: RR 1.18, 95% CI 0.88 to 1.59; P = 0.26; 2 trials; 1944 participants; HRB). FGS versus placebo showed statistical significance for cardiovascular mortality in favour of placebo (RR 2.63, 95% CI 1.32 to 5.22; P = 0.006; 2 trials; 553 participants; HRB). FGS versus insulin did not show statistical significance for cardiovascular mortality (RR 1.36, 95% CI 0.68 to 2.71; P = 0.39; 2 trials; 1944 participants; HRB). FGS versus alpha-glucosidase inhibitors showed statistical significance in favour of FGS for adverse events (RR 0.63, 95% CI 0.52 to 0.76; P = 0.01; 2 trials; 246 participants; HRB) and for drop-outs due to adverse events (RR 0.28, 95% CI 0.12 to 0.67; P = 0.004; 2 trials; 246 participants; HRB).Second-generation sulphonylureas (SGS) versus metformin (RR 0.98, 95% CI 0.61 to 1.58; P = 0.68; 6 trials; 3528 participants; HRB), thiazolidinediones (RR 0.92, 95% CI 0.60 to 1.41; P = 0.70; 7 trials; 4955 participants; HRB), insulin (RR 0.96, 95% CI 0.79 to 1.18; P = 0.72; 4 trials; 1642 participants; HRB), meglitinides (RR 1.44, 95% CI 0.47 to 4.42; P = 0.52; 7 trials; 2038 participants; HRB), or incretin-based interventions (RR 1.39, 95% CI 0.52 to 3.68; P = 0.51; 2 trials; 1503 participants; HRB) showed no statistically significant effects regarding all-cause mortality in a random-effects model. SGS versus metformin (RR 1.47; 95% CI 0.54 to 4.01; P = 0.45; 6 trials; 3528 participants; HRB), thiazolidinediones (RR 1.30, 95% CI 0.55 to 3.07; P = 0.55; 7 trials; 4955 participants; HRB), insulin (RR 0.96, 95% CI 0.73 to 1.28; P = 0.80; 4 trials; 1642 participants; HRB) or meglitinide (RR 0.97, 95% CI 0.27 to 3.53; P = 0.97; 7 trials, 2038 participants, HRB) showed no statistically significant effects regarding cardiovascular mortality. Mortality data for the SGS versus placebo were sparse. SGS versus thiazolidinediones and meglitinides did not show statistically significant differences for a composite of non-fatal macrovascular outcomes. SGS versus metformin showed statistical significance in favour of SGS for a composite of non-fatal macrovascular outcomes (RR 0.67, 95% CI 0.48 to 0.93; P = 0.02; 3018 participants; 3 trials; HRB). The definition of non-fatal macrovascular outcomes varied among the trials. SGS versus metformin, thiazolidinediones and meglitinides showed no statistical significance for non-fatal myocardial infarction. No meta-analyses could be performed for microvascular outcomes. SGS versus placebo, metformin, thiazolidinediones, alpha-glucosidase inhibitors or meglitinides showed no statistical significance for adverse events. SGS versus alpha-glucosidase inhibitors showed statistical significance in favour of SGS for drop-outs due to adverse events (RR 0.48, 95% CI 0.24 to 0.96; P = 0.04; 9 trials; 870 participants; HRB). SGS versus meglitinides showed no statistical significance for the risk of severe hypoglycaemia. SGS versus metformin and thiazolidinediones showed statistical significance in favour of metformin (RR 5.64, 95% CI 1.22 to 26.00; P = 0.03; 4 trials; 3637 participants; HRB) and thiazolidinediones (RR 6.11, 95% CI 1.57 to 23.79; P = 0.009; 6 trials; 5660 participants; HRB) for severe hypoglycaemia.Third-generation sulphonylureas (TGS) could not be included in any meta-analysis of all-cause mortality, cardiovascular mortality or non-fatal macro- or microvascular outcomes. TGS versus thiazolidinediones showed statistical significance regarding adverse events in favour of TGS (RR 0.88, 95% CI 0.78 to 0.99; P = 0.03; 3 trials; 510 participants; HRB). TGS versus thiazolidinediones did not show any statistical significance for drop-outs due to adverse events. TGS versus other comparators could not be performed due to lack of data.For the comparison of SGS versus FGS no meta-analyses of all-cause mortality, cardiovascular mortality, non-fatal macro- or microvascular outcomes, or adverse events could be performed.Health-related quality of life and costs of intervention could not be meta-analysed due to lack of data.In trial sequential analysis, none of the analyses of mortality outcomes, vascular outcomes or severe hypoglycaemia met the criteria for firm evidence of a RRR of 10% between interventions.

AUTHORS' CONCLUSIONS

There is insufficient evidence from RCTs to support the decision as to whether to initiate sulphonylurea monotherapy. Data on patient-important outcomes are lacking. Therefore, large-scale and long-term randomised clinical trials with low risk of bias, focusing on patient-important outcomes are required.

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.

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.

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.

Evaluation of efficacy of acarbose on glucose fluctuation and postprandial glucose using continuous glucose monitoring in type 2 diabetes mellitus

BACKGROUND

The objective of this study was to evaluate the effects of the α-glucosidase inhibitor acarbose on glucose fluctuations in patients with type 2 diabetes using continuous glucose monitoring (CGM).

METHODS

CGM was performed for 4 days (72 h), and acarbose at 300 mg/day was administered on two of these days but not on the other two days. The effects on blood glucose fluctuations were evaluated.

RESULTS

We recruited a total of 10 patients (five men and five women) with a mean ± SD age of 63.1 ± 12.1 years, body mass index of 22.6 ± 5.4 kg/m(2), and glycohemoglobin of 9.9 ± 1.9%. During treatment with acarbose, significant decreases in median (range) SD of 24-h mean blood glucose (22.48 [6.39-47.22] mg/dL vs. 32.78 [18.83-58.93] mg/dL, P = 0.004), 24-h blood glucose fluctuations (453.27 [128.51-903.94] mg·h/dL vs. 677.05 [358.03-1,234.57] mg·h/dL, P = 0.002), and mean amplitude of glycemic excursions (65.00 [18.17-117.50] vs. 97.09 [53.00-166.67], P = 0.010) occurred compared with no treatment.

CONCLUSIONS

Acarbose reduced excessive blood glucose fluctuations.

Glucose supply and insulin demand dynamics of antidiabetic agents

BACKGROUND

For microvascular outcomes, there is compelling historical and contemporary evidence for intensive blood glucose reduction in patients with either type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). There is also strong evidence to support macrovascular benefit with intensive blood glucose reduction in T1DM. Similar evidence remains elusive for T2DM. Because cardiovascular outcome trials utilizing conventional algorithms to attain intensive blood glucose reduction have not demonstrated superiority to less aggressive blood glucose reduction (Action to Control Cardiovascular Risk in Diabetes; Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation; and Veterans Affairs Diabetes Trial), it should be considered that the means by which the blood glucose is reduced may be as important as the actual blood glucose.

METHODS

By identifying quantitative differences between antidiabetic agents on carbohydrate exposure (CE), hepatic glucose uptake (HGU), hepatic gluconeogenesis (GNG), insulin resistance (IR), peripheral glucose uptake (PGU), and peripheral insulin exposure (PIE), we created a pharmacokinetic/pharmacodynamic model to characterize the effect of the agents on the glucose supply and insulin demand dynamic. Glucose supply was defined as the cumulative percentage decrease in CE, increase in HGU, decrease in GNG, and decrease in IR, while insulin demand was defined as the cumulative percentage increase in PIE and PGU. With the glucose supply and insulin demand effects of each antidiabetic agent summated, the glucose supply (numerator) was divided by the insulin demand (denominator) to create a value representative of the glucose supply and insulin demand dynamic (SD ratio).

RESULTS

Alpha-glucosidase inhibitors (1.25), metformin (2.20), and thiazolidinediones (TZDs; 1.25-1.32) demonstrate a greater effect on glucose supply (SD ratio >1), while secretagogues (0.69-0.81), basal insulins (0.77-0.79), and bolus insulins (0.62-0.67) demonstrate a greater effect on insulin demand (SD ratio <1).

CONCLUSION

Alpha-glucosidase inhibitors, metformin, and TZDs demonstrate a greater effect on glucose supply, while secretagogues, basal insulin, and bolus insulin demonstrate a greater effect on insulin demand. Because T2DM cardiovascular outcome trials have not demonstrated macrovascular benefit with more aggressive blood glucose reduction when using conventional algorithms that predominantly focus on insulin demand, it would appear logical to consider a model that incorporates both the extent of blood glucose lowering (hemoglobin A1c) and the means by which the blood glucose was reduced (SD ratio) when considering macrovascular outcomes.

Diabetes medications and body weight

Tight diabetes control sometimes comes with a price: weight gain and hypoglycemia. Two of the three major recent trials that looked at the relationship between intensive diabetes control and cardiovascular events reported significant weight gain among the intensively treated groups. There is a growing concern that the weight gain induced by most diabetes medications diminishes their clinical benefits. On the other hand, there is a claim that treating diabetes with medications that are weight neutral or induces weight loss or less weight gain while minimizing those that increase body weight may emerge as the future direction for treating overweight and obese patients with diabetes. This review clarifies the weight effect of each of the currently available diabetes medications, and explains the mechanism of action behind this effect. Despite the great variability among reviewed clinical trials, the currently available evidence is quite sufficient to demonstrate the change in body weight in association with most of the currently available medications. This review also provides some guidelines on using diabetes medications during weight management programs.

Glucose homeostasis and the gastrointestinal tract: insights into the treatment of diabetes

The gastrointestinal tract is increasingly viewed as a critical organ in glucose metabolism because of its role in delivering glucose to the circulation and in secreting multiple glucoregulatory hormones that, in concert with insulin and glucagon, regulate glucose homeostasis. Under normal conditions, a complex interplay of these hormones acts to maintain plasma glucose within a narrow range despite large variations in the availability of glucose, particularly during transition from the fasting to fed state. In the fed state, the rate at which nutrients are passed from the stomach to the duodenum, termed gastric emptying rate, is a key determinant of postprandial glucose flux. In patients with diabetes, the regulation of glucose metabolism is disrupted resulting in fasting and postprandial hyperglycaemia. Elucidation of the role of the gastrointestinal tract, gut-derived glucoregulatory peptides and gastric emptying rate offers a new perspective on glucose homeostasis and the respective importance of these factors in the diabetes state. This review will highlight the importance of the gastrointestinal tract in playing a key role in glucose homeostasis, particularly in the postprandial period, and the role of established or new therapies that either leverage or modify gastrointestinal function to improve glycaemic state.

Orlistat in the prevention of diabetes in the obese patient

There has been an increase in the concern about preventing type 2 diabetes mellitus (T2DM), a disease with great and increasing prevalence. The prevalence of obesity, physical inactivity, Western processed diet, important risk factors for the development of T2DM, are also rising. Free fatty acids are increased in obesity and reduce insulin clearance and increase hepatic glucose production. Implementation of a healthy lifestyle has been show to slow the progression of impaired glucose tolerance to T2DM. Orlistat is an inhibitor of lipase activity, with proved efficacy in body weight reduction and long-term management of obesity and more favorable effects on carbohydrate metabolism and it was prospectively shown in XENDOS study that orlistat promoted long-term weight loss and prevented T2DM onset in obese individuals with normal and impaired glucose tolerance at baseline over four years. This benefit could be associated to the weight loss itself, to the limited absorption of lipids and reduction of plasma free fatty acids, to increased production of incretins or to modulation of secretion of cytokines by adipocytes, all effects secondary to orlistat treatment. A proposed strategy is to identify subjects at highest risk to receive a drug intervention, using lifestyle interventions alone at the community level.

Who should benefit from the use of alpha-glucosidase inhibitors?

Although most commonly used drugs such as biguanides, sulfonylureas, and more recently, thiazolidinediones, are effective in controlling fasting hyperglycemia, a high percentage of patients have sustained elevated hemoglobin A(1c) because of persistent elevation of postprandial plasma glucose (PPPG). alpha-Glucosidase inhibitors (AGIs) specifically target PPPG. AGIs have been shown in several randomized controlled trials to be effective in controlling blood glucose, whether they are used as monotherapy or in combination with other antidiabetic medications. Among the AGIs, acarbose has also been shown to decrease the risk of progressing to diabetes in subjects with impaired glucose tolerance (IGT). Studies have also suggested that acarbose could decrease the risk of cardiovascular disease, both in IGT and in diabetes. Furthermore, AGIs are very safe and are nontoxic drugs. Their only side effects are gastrointestinal, such as flatulence and diarrhea; however, these can be minimized by the "start low, go slow" approach. AGIs should be considered whenever postprandial hyperglycemia is the dominant metabolic abnormality.

Cardiovascular benefits and safety profile of acarbose therapy in prediabetes and established type 2 diabetes

Dysglycaemic disease is one of the most important health issues facing the world in the 21^st century. Patients with type 2 diabetes and individuals with prediabetes are at risk of developing macrovascular and microvascular complications. Long-term management strategies are therefore required that are effective at controlling dysglycaemia, well tolerated and, ideally, offer additional cardiovascular disease (CVD) risk-reduction benefits. The efficacy, safety and tolerability of the α-glucosidase inhibitor acarbose have been well-established in a wide range of patient populations in both clinical and community trials. In addition, acarbose has been shown to reduce cardiovascular complications in type 2 diabetes and prevent hypertension and CVD in individuals with impaired glucose tolerance (IGT). Acarbose has a very good safety profile and, owing to its straightforward, non-systemic mode of action, avoids most adverse events. The most common side-effects of acarbose are mild-to-moderate gastrointestinal complaints that subside as treatment continues. They can be minimised through the use of an appropriate stepwise dosing regimen and careful choice of diet. Acarbose is therefore a valuable option for the management of type 2 diabetes and, as the only oral antidiabetes agent approved for the treatment of prediabetes, can help to improve clinical management across the dysglycaemic disease continuum.

Diabetes: the latest trends in glycemic control

The increasing pervasiveness of diabetes mellitus on a global stage has been well documented. Many groundbreaking studies have detailed the consequences of inadequate glycemic control, but only recently have data supported evidence that demonstrates benefits in the acute setting. Consensus is lacking with regard to how to achieve glycemic control in the hospital setting. This article discusses glycemic control, with special emphasis on the perioperative patient. Emerging therapeutic treatments and less frequently encountered protocols such as insulin pump management and insulin infusion are considered.

Differential effects of oral hypoglycemic agents on glucose control and cardiovascular risk

Cardiovascular disease (CVD) burden remains the predominant cause of mortality and morbidity in the United States and in most of the developed world. The ongoing twin epidemics of obesity and type 2 diabetes mellitus provide a groundswell source for sustaining this trend for the foreseeable future (increasing the prevalence of CVD by 2-4 times), unless radical changes are made in public health policy. Oral hypoglycemic agents (OHAs) remain a mainstay for management of type 2 diabetes in most practice settings. Although these agents are primarily prescribed to achieve better glycemic control, it is important to evaluate what effects they have on cardiovascular risk and whether there are significant differences in effects among the different OHAs. This review presents the available data on the effects of the various OHAs on cardiovascular risk surrogates and actual events in retrospective and prospective study design settings.

Cardiovascular benefits of acarbose in impaired glucose tolerance and type 2 diabetes

Impaired glucose metabolism is associated with an increased risk of cardiovascular events and cardiovascular-associated mortality. Postprandial hyperglycaemia is one of the earliest identifiable indicators of impaired glucose control. It contributes to the progression from impaired glucose tolerance to overt type 2 diabetes and exacerbates chronic hyperglycaemia in established diabetes. It is also an independent risk factor for cardiovascular disease in patients with impaired glucose tolerance and type 2 diabetes. Thus, an important strategy to reduce cardiovascular risk in patients with impaired glucose metabolism is to reduce postprandial glucose excursions. Acarbose, an alpha (alpha)-glucosidase inhibitor, reduces postprandial hyperglycaemia by delaying carbohydrate absorption from the small intestine. This mechanism of action provides glycaemic control without increasing insulin levels and exacerbating coexisting cardiovascular risk factors. The Study to Prevent Non-Insulin Dependent Diabetes Mellitus (STOP-NIDDM) assessed the ability of acarbose to reduce cardiovascular risk. In this study of 1429 individuals with impaired glucose tolerance, acarbose therapy reduced the risk of any cardiovascular event by 49% (P=0.03), of an acute myocardial infarction by 91% (P=0.02) and of developing hypertension by 34% (P=0.006). Furthermore, a retrospective meta-analysis of randomised studies of acarbose in type 2 diabetes patients showed that acarbose therapy reduced the risk of any cardiovascular event by 35% (P=0.006) and the risk of a myocardial infarction by 64% (P=0.012). These results suggest that acarbose is useful in reducing the risk of cardiovascular events in patients with impaired glucose metabolism.