GUIDE study: double-blind comparison of once-daily gliclazide MR and glimepiride in type 2 diabetic patients

Hypoglycemia: The neglected complication

Hypoglycemia is an important complication of glucose-lowering therapy in patients with diabetes mellitus. Attempts made at intensive glycemic control invariably increases the risk of hypoglycemia. A six-fold increase in deaths due to diabetes has been attributed to patients experiencing severe hypoglycemia in comparison to those not experiencing severe hypoglycemia Repeated episodes of hypoglycemia can lead to impairment of the counter-regulatory system with the potential for development of hypoglycemia unawareness. The short- and long-term complications of diabetes related hypoglycemia include precipitation of acute cerebrovascular disease, myocardial infarction, neurocognitive dysfunction, retinal cell death and loss of vision in addition to health-related quality of life issues pertaining to sleep, driving, employment, recreational activities involving exercise and travel. There is an urgent need to examine the clinical spectrum and burden of hypoglycemia so that adequate control measures can be implemented against this neglected life-threatening complication. Early recognition of hypoglycemia risk factors, self-monitoring of blood glucose, selection of appropriate treatment regimens with minimal or no risk of hypoglycemia and appropriate educational programs for healthcare professionals and patients with diabetes are the major ways forward to maintain good glycemic control, minimize the risk of hypoglycemia and thereby prevent long-term complications.

Changes in body mass index following newly diagnosed type 2 diabetes and risk of cardiovascular mortality: a cohort study of 8486 primary-care patients

AIMS

Elevated body mass index (BMI) is associated with an increased risk of type 2 diabetes and cardiovascular disease (CVD). This study explored the association between BMI changes in the first 18 months of newly diagnosed type 2 diabetes and the risk of long-term CVD mortality.

METHODS

A total of 8486 patients with newly diagnosed type 2 diabetes and no previous history of CVD or cancer were identified from 84 primary-care centres in Sweden. During the first year after diagnosis, patients were grouped according to BMI change: 'Increase', or ≥+1 BMI unit; 'unchanged', or between +1 and-1 BMI unit; and 'decrease', or ≤-1 BMI unit. Associations between BMI change and CVD mortality, defined as death from stroke, myocardial infarction or sudden death, were estimated using adjusted Cox proportional hazards models (NCT 01121315).

RESULTS

Baseline mean age was 60.0 years and mean BMI was 30.2kg/m(2). Patients were followed for up to 9 years (median: 4.6 years). During the first 18 months, 53.4% had no change in their BMI, while 32.2% decreased and 14.4% increased. Compared with patients with unchanged BMI, those with an increased BMI had higher risks of CVD mortality (hazard ratio: 1.63, 95% CI: 1.11-2.39) and all-cause mortality (1.33, 1.01-1.76). BMI decreases had no association with these risks compared with unchanged BMI: 1.06 (0.76-1.48) and 1.06 (0.85-1.33), respectively.

CONCLUSION

Increased BMI within the first 18 months of type 2 diabetes diagnosis was associated with an increased long-term risk of CVD mortality. However, BMI decrease did not lower the long-term risk of mortality.

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.

Pharmacokinetic considerations for the treatment of diabetes in patients with chronic kidney disease

INTRODUCTION

People with chronic kidney disease (CKD) of stages 3 - 5 (creatinine clearance < 60 ml/min) represent ≈ 25% of patients with type 2 diabetes mellitus (T2DM), but the problem is underrecognized or neglected in clinical practice. However, most oral antidiabetic agents have limitations in case of renal impairment (RI), either because they require a dose adjustment or because they are contraindicated for safety reasons.

AREAS COVERED

The author performed an extensive literature search to analyze the influence of RI on the pharmacokinetics (PK) of glucose-lowering agents and the potential consequences for clinical practice.

EXPERT OPINION

As a result of PK interferences and for safety reasons, the daily dose should be reduced according to glomerular filtration rate (GFR) or even the drug is contraindicated in presence of severe CKD. This is the case for metformin (risk of lactic acidosis) and for many sulfonylureas (risk of hypoglycemia). At present, however, the exact GFR cutoff for metformin use is controversial. New antidiabetic agents are better tolerated in case of CKD, although clinical experience remains quite limited for most of them. The dose of DPP-4 inhibitors should be reduced (except for linagliptin), whereas both the efficacy and safety of SGLT2 inhibitors are questionable in presence of CKD.

Association between TCF7L2 Genotype and Glycemic Control in Diabetic Patients Treated with Gliclazide

Previous studies showed associations between variants in TCF7L2 gene and the therapeutic response to sulfonylureas. All sulfonylureas stimulate insulin secretion by the closure of ATP-sensitive potassium (KATP) channel. The aim of the present study was to compare TCF7L2 genotype specific effect of gliclazide binding to KATP channel A-site (Group 1) with sulfonylureas binding to AB-site (Group 2). A total of 101 patients were treated with sulfonylureas for 6 months as an add-on therapy to the previous metformin treatment. TCF7L2 rs7903146 C/T genotype was identified by real-time PCR with subsequent melting curve analysis. Analyses using the dominant genetic model showed significantly higher effect of gliclazide in the CC genotype group in comparison with combined CT + TT genotype group (1.32 ± 0.15% versus 0.73 ± 0.11%, P (adj) = 0.005). No significant difference in ΔHbA1c between the patients with CC genotype and the T-allele carriers was observed in Group 2. In the multivariate analysis, only the TCF7L2 genotype (P = 0.006) and the baseline HbA1c (P < 0.001) were significant predictors of ΔHbA1c. After introducing an interaction term between the TCF7L2 genotype and the sulfonylurea type into multivariate model, the interaction became a significant predictor (P = 0.023) of ΔHbA1c. The results indicate significantly higher difference in ΔHbA1c among the TCF7L2 genotypes in patients treated with gliclazide than in patients treated with glimepiride, glibenclamide, or glipizide.

Glimepiride: evidence-based facts, trends, and observations (GIFTS). [corrected]

Type 2 diabetes mellitus is characterized by insulin resistance and progressive β cell failure; therefore, β cell secretagogues are useful for achieving sufficient glycemic control. Glimepiride is a second-generation sulfonylurea that stimulates pancreatic β cells to release insulin. Additionally, is has been shown to work via several extra pancreatic mechanisms. It is administered as monotherapy in patients with type 2 diabetes mellitus in whom glycemic control is not achieved by dietary and lifestyle modifications. It can also be combined with other antihyperglycemic agents, including metformin and insulin, in patients who are not adequately controlled by sulfonylureas alone. The effective dosage range is 1 to 8 mg/day; however, there is no significant difference between 4 and 8 mg/day, but it should be used with caution in the elderly and in patients with renal or hepatic disease. In clinical studies, glimepiride was generally associated with lower risk of hypoglycemia and less weight gain compared to other sulfonylureas. Glimepiride use may be safer in patients with cardiovascular disease because of its lack of detrimental effects on ischemic preconditioning. It is effective in reducing fasting plasma glucose, post-prandial glucose, and glycosylated hemoglobin levels and is a useful, cost-effective treatment option for managing type 2 diabetes mellitus.

Role of oral hypoglycemic agents in the management of type 2 diabetes mellitus during Ramadan

It is obligatory for all adult Muslims to observe fast during the holy month of Ramadan, but sick individuals including those with diabetes mellitus are exempted from the duty of fasting. Specific medical advice must be provided to individual patients concerning the potential risks they must accept if they decide to fast. Any alteration in medications deemed necessary to provide an effective and safe antidiabetic regimen should be instituted well before the start of Ramadan. Diet-controlled patients and those well controlled on insulin sensitizers have low risk of hypoglycemia and may safely fast with some modification in the timing of the doses. Newer generation sulfonylureas (gliclazide MR and glimepiride) have reasonable safety profile during Ramadan fasting and are economical options for a large number of diabetics worldwide, especially in the developing countries; older, long acting sulfonylureas like glibenclamide and chlorpropamide should be avoided during fasting. Oral DPP-IV inhibitors are important substitutes to sulfonylureas for patients with diabetes mellitus during fasting owing to their glucose-dependent mechanism of action, efficacy, and tolerability. This group of drugs causes a moderate A1c reduction, are weight neutral, and have a very low risk of hypoglycemia. Short-acting insulin secretagogues are an option in the subset of fasting diabetic patients who have predominantly post-prandial hyperglycemia.

Exenatide twice daily versus glimepiride for prevention of glycaemic deterioration in patients with type 2 diabetes with metformin failure (EUREXA): an open-label, randomised controlled trial

BACKGROUND

Glycaemic control deteriorates progressively over time in patients with type 2 diabetes. Options for treatment escalation remain controversial after failure of first-line treatment with metformin. We compared add-on exenatide with glimepiride for durability of glycaemic control in patients with type 2 diabetes inadequately controlled by metformin alone.

METHODS

We did an open-label, randomised controlled trial at 128 centres in 14 countries between Sept 5, 2006, and March 29, 2011. Patients aged 18-85 years with type 2 diabetes inadequately treated by metformin were randomly assigned via a computer-generated randomisation sequence to receive exenatide twice daily or glimepiride once daily as add-on to metformin. Randomisation was stratified by predetermined categories of glycated haemoglobin (HbA(1C)) concentration. The primary outcome was time to inadequate glycaemic control and need for alternative treatment, defined as an HbA(1c) concentration of more than 9% after the first 3 months of treatment, or more than 7% at two consecutive visits after the first 6 months. Analysis was by intention to treat. This trial is registered with EudraCT, number 2005-005448-21, and ClinicalTrials.gov, number NCT00359762.

FINDINGS

We randomly assigned 515 patients to the exenatide group and 514 to the glimepiride group, of whom 490 versus 487 were the intention-to-treat population. 203 (41%) patients had treatment failure in the exenatide group compared with 262 (54%) in the glimepiride group (risk difference 12·4 [95% CI 6·2-18·6], hazard ratio 0·748 [0·623-0·899]; p=0·002). 218 (44%) of 490 patients in the exenatide group, and 150 (31%) of 487 in the glimepiride group achieved an HbA(1c) concentration of less than 7% (p<0·0001), and 140 (29%) versus 87 (18%) achieved concentrations of 6·5% and less (p=0·0001). We noted a significantly greater decrease in bodyweight in patients given exenatide than in those given glimepiride (p<0·0001). Five patients in each treatment group died from causes unrelated to treatment. Significantly fewer patients in the exenatide group than in the glimepiride group reported documented symptomatic (p<0·0001), nocturnal (p=0·007), and non-nocturnal (p<0·0001) hypoglycaemia. Discontinuation because of adverse events (mainly gastrointestinal) was significantly higher (p=0·0005) in the exenatide group than in the glimepiride group in the first 6 months of treatment, but not thereafter.

INTERPRETATION

These findings provide evidence for the benefits of exenatide versus glimepiride for control of glycaemic deterioration in patients with type-2 diabetes inadequately controlled by metformin alone.

FUNDING

Eli Lilly and Company; Amylin Pharmaceuticals.

Drug-induced hypoglycaemia in type 2 diabetes

INTRODUCTION

Hypoglycaemia is a side effect caused by some therapies for type 2 diabetes, which can cause physical, social and psychological harm. Hypoglycaemia also prevents attainment of treatment goals and satisfactory glycaemic control.

AREAS COVERED

The risk of hypoglycaemia associated with commonly prescribed therapies, including metformin, sulphonylureas, dipeptidyl peptidase-4 enzyme (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) agonists and thiazolidinediones, is reviewed in this paper (insulin-induced hypoglycaemia is not included). Other medications that are frequently co-prescribed in type 2 diabetes are also discussed, including anti-hypertensive drugs, antibiotics and fibrates, along with various important patient-related risk factors.

EXPERT OPINION

Hypoglycaemia is a common and potentially dangerous side effect of some medications used for type 2 diabetes. The risk of hypoglycaemia should always be considered when selecting and implementing a therapy, with a focus on the individual. Future research into new therapies should measure the frequency of hypoglycaemia prospectively and accurately. Hypoglycaemia has been shown to be a potentially life-threatening metabolic stress; therefore therapies that effectively manage diabetes without the risk of hypoglycaemia are likely to be favoured in the future.

Persistence of initial oral antidiabetic treatment in patients with type 2 diabetes mellitus

Background

Adequate persistence of oral antidiabetic treatment is highly important to achieve proper glycemic control in patients with type 2 diabetes. The aim of this study was to evaluate the persistence of initial treatment with metformin and/or sulphonylureas in patients with type 2 diabetes.

Material/Methods

The study was performed among diabetic patients (n=256,384) who were with newly prescribed oral antidiabetic drugs (metformin and/or sulphonylureas) between 2007 and 2009. For making comparison, patients with newly prescribed statin or clopidogrel therapy (with and without percutaneous coronary intervention) were investigated. The database of the Hungarian National Health Insurance Fund Administration was used.

Results

The 1-year persistence of initial treatment with metformin, sulphonylureas or metformin/sulphonylurea combination was 47.7%, 45.4% and 55.8%, respectively, which was significantly better than the persistence of statin therapy (26.3%) but worse than that of clopidogrel therapy in patients undergoing coronary intervention (73.2%). Within the sulphonylurea group there was a tendency of better persistence of treatment with the “modified-release” tablets at 12 months compared to the conventional sulphonylureas (47.8 vs. 42.2%). The persistence of therapy using metformin 1000 mg – 60 tablets was significantly better (60.4%) at 12 months than that of other forms of metformin therapy with lower doses and smaller boxes (with fewer tablets) analyzed together (47.7%).

Conclusions

The persistence of initial treatment with metformin and/or sulphonylureas is far from optimal. Better diabetic care and continuous patient education should be encouraged to achieve higher persistence of oral antidiabetic treatment in patients with type 2 diabetes.

KCNJ11 gene E23K variant and therapeutic response to sulfonylureas

AIMS

Potassium inwardly rectifier 6.2 subunit (Kir6.2) of the ATP-sensitive potassium (K(ATP)) channel encoded by KCNJ11 gene is a therapeutical target for sulfonylureas. KCNJ11 E23K polymorphism was associated with type 2 diabetes in genetic association studies. The aim of the present pharmacogenetic study was to examine the effect of sulfonylurea treatment on glycemic control in relationship to KCNJ11 E23K variant.

PATIENTS AND METHODS

One hundred and one patients with type 2 diabetes who failed to achieve HbA1c<7% on previous metformin monotherapy were included to the study. Sulfonylurea drug was given in addition to metformin. The main outcome of the study was reduction in HbA1c level (ΔHbA1c) after 6-month sulfonylurea therapy. KCNJ11 genotypes were determined by real-time PCR with melting curve analysis.

RESULTS

After 6-month treatment, KCNJ11 K-allele carriers had higher decrease in HbA1c compared with EE homozygotes in the dominant genetic model (1.04±0.10 vs. 0.79±0.12%, p=0.036). In the log-additive model, greater mean reduction in HbA1c by 0.16% (95% CI 0.01-0.32, p=0.038) per each K-allele was observed. The relationship of treatment response with KCNJ11 genotype was also significant in the biggest subgroup of patients treated with gliclazide (n=55).

CONCLUSIONS

Carriers of the KCNJ11 K-allele have better therapeutic response to gliclazide. This observation might help to identify patients who will have the highest benefit from sulfonylurea treatment.

Treating diabetes today with gliclazide MR: a matter of numbers

Type 2 diabetes mellitus (T2DM) is a progressive disease characterized by worsening hyperglycaemia. Lowering haemoglobin A1c to below or around 7% has been shown to reduce microvascular and neuropathic complications of diabetes. The ongoing uncertainty regarding whether intensive glycaemic control can reduce the increased risk of cardiovascular disease (CVD) in people with T2DM stirred the launch of the recent long-term megatrials. These trials compared the effects of intensive vs. standard control on vascular complications in relatively high CV risk participants with T2DM. While in Veterans Affairs Diabetes Trial, and Action to Control Cardiovascular Risk in Diabetes, the effect of glucose optimization resulted either in no protection or in an excessive CVD death, the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation trial showed that intensive glycaemic control reduced the risk of combined major macrovascular and microvascular events. In this trial, the glucose control strategy was based on gliclazide MR at randomization in all patients and then further sequential addition of other glucose-lowering drugs. Several studies showed that gliclazide has antioxidant properties, reduces markers of endothelial inflammation, and prevents glucose-induced apoptosis of endothelial cells. These positive antioxidant effects are not confined to the vascular wall but they are effective also in the β cells. These properties are important because (i) in patients with atherosclerotic process, microvascular abnormalities may hasten disease progression and (ii) slowing the microvascular complications may have a potentially remarkable effect on the natural history of macrovascular disease.

The incidence of hypoglycaemia in Muslim patients with type 2 diabetes treated with sitagliptin or a sulphonylurea during Ramadan: a randomised trial

AIMS

To compare the incidence of symptomatic hypoglycaemia in fasting Muslim patients with type 2 diabetes treated with sitagliptin or a sulphonylurea during Ramadan.

METHODS

Patients with type 2 diabetes (age ≥ 18 years) who were treated with a stable dose of a sulphonylurea with or without metformin for at least 3 months prior to screening, who had an HbA(1c) < 10% and who expressed their intention to daytime fast during Ramadan were eligible for this open-label study. Patients were randomised in a 1 : 1 ratio to either switch to sitagliptin 100 mg qd or to remain on their prestudy sulphonylurea. Patients completed daily diary cards to document information on hypoglycaemic symptoms and complications. The primary end-point was the overall incidence of symptomatic hypoglycaemia recorded during Ramadan.

RESULTS

Of the 1066 patients randomised, 1021 (n = 507 for sitagliptin and n = 514 for sulphonylurea) returned at least one completed diary card and were included in the analysis. The proportion of patients who recorded one or more symptomatic hypoglycaemic events during Ramadan was lower in the sitagliptin group (6.7%) compared with the sulphonylurea group (13.2%). The risk of symptomatic hypoglycaemia was significantly decreased with sitagliptin relative to sulphonylurea treatment (Mantel-Haenszel relative risk ratio [95% CI] = 0.51 [0.34, 0.75]; p < 0.001). There were no reported events that required medical assistance (i.e. visits to physician or emergency room or hospitalisations) or were considered severe (i.e. events that caused loss of consciousness, seizure, coma or physical injury) during Ramadan.

CONCLUSIONS

In Muslim patients with type 2 diabetes who observed the fast during Ramadan, switching to a sitagliptin-based regimen decreased the risk of hypoglycaemia compared with remaining on a sulphonylurea-based regimen. The incidence of hypoglycaemia was lower with gliclazide relative to the other sulphonylurea agents and similar to that observed with sitagliptin.

Diabetes and Ramadan: an update on use of glycemic therapies during fasting

The fasting of Ramadan is observed by a large proportion of Muslims with diabetes. Recommendations for the management of diabetes during Ramadan were last published in 2005 by the American Diabetes Association. Several studies in this field have since been published, some addressing the use of new pharmacological agents in managing diabetes during Ramadan. The incritin memetics are potentially safe during Ramadan; the DPP4 inhibitors vildagliptin and sitagliptin provide an effective and safe therapeutic option, administered either alone or in combination with metformin or sulfonylureas. There are no published studies on the use of GLP-1 receptor agonists during Ramadan. Among the sulfonylureas, gliclazide MR (modified release) and glimepride can be safely used during Ramadan, but glibenclamide should be avoided due to the associated risk of hypoglycemia. In selected patients with type 1 and type 2 diabetes, the long-acting insulin analogues glargine and detemir, as well as the premixed insulin analogues, can be used with minimal risk of metabolic derangement or hypoglycemia; the risk is higher in type 1 diabetes. Insulin pumps can potentially empower patients with diabetes and enable safe fasting during the month of Ramadan. Further clinical trials are needed to evaluate the safety and efficacy of new antidiabetic agents and new diabetes-related technologies during Ramadan.

Medically minimising the impact of hypoglycaemia in type 2 diabetes: a review

INTRODUCTION

Some therapies for type 2 diabetes (T2DM) are limited by hypoglycaemia, and this underestimated side effect carries an associated morbidity and financial burden. Large trials that have examined strict glycaemic control and cardiovascular outcomes in T2DM have highlighted the potential harm of exposure to hypoglycaemia in people with coronary heart disease.

AREAS COVERED

The responses to, and the morbidity associated with, hypoglycaemia in T2DM are discussed with identification of people most at risk of severe hypoglycaemia. The evidence base for non-pharmacological strategies and the risks of hypoglycaemia associated with various treatment modalities are examined. This review provides the clinician with a rational approach to the selection of different anti-diabetes drugs to minimize the risk of hypoglycaemia.

EXPERT OPINION

When managing T2DM, insulin and insulin secretagogues should be used judiciously and glycaemic targets individualized to avoid hypoglycaemia. Incretin mimetics present a lower risk of hypoglycaemia with similar efficacy as traditional agents in treating hyperglycaemia. The potential relationship between hypoglycaemia and precipitation of acute cardiovascular events is a highly topical area of research and may help determine what glycaemic targets are appropriate in people with T2DM.

Hypoglycaemia in sulphonylurea-treated subjects with type 2 diabetes undergoing Ramadan fasting: a five-country observational study

OBJECTIVES

To determine the incidence of hypoglycaemia during Ramadan in Muslim subjects with type 2 diabetes treated with a sulphonylurea.

METHODS

In an observational study, eligible subjects were Muslims with type 2 diabetes (age ≥18 years) who were treated with glimepiride, gliclazide, or glibenclamide with or without metformin and who expressed their intention to fast during Ramadan in 2009. Subjects were recruited by clinicians in India, Malaysia, Israel, the United Arab Emirates (UAE), and Saudi Arabia. Each day during Ramadan, patients completed diary cards, which collected information regarding hypoglycaemic symptoms and complications, time from last meal and from last medication, self-monitored blood glucose measurements, and need for assistance. The overall incidence of symptomatic hypoglycaemia recorded during Ramadan was the primary endpoint of interest.

RESULTS

Of the enrolled subjects (N = 1397), 1378 returned their diary cards at study end and were included in the analysis. Overall, 89% of subjects who expressed their intention to fast prior to Ramadan reported that they observed the fast during Ramadan. A total of 271 subjects (19.7%) experienced one or more symptomatic hypoglycaemic events during Ramadan, with incidences of 25.6%, 16.8%, and 14.0% observed in subjects treated with glibenclamide, glimepiride, and gliclazide, respectively. By country, the highest incidence of hypoglycaemia was reported by subjects from Israel (40%) followed by those from Malaysia (24%), the UAE (18%), India (13%), and Saudi Arabia (10%). The overall incidence of severe hypoglycaemic events (i.e., events requiring medical or non-medical assistance) was 6.7%, with the highest incidence occurring in the glibenclamide group.

LIMITATIONS

This was an observational study and as such subjects were not randomised to treatments. While baseline measures appeared comparable, it is possible that differences in measured and unmeasured patient characteristics (e.g., measures of glycaemic control) could partially explain these results. Lastly, no inferential testing was performed on the comparisons between sulphonylurea types and/or countries.

CONCLUSIONS

In this five-country observational study, nearly 20% of sulphonylurea-treated Muslim subjects with type 2 diabetes experienced symptomatic hypoglycaemia while fasting during Ramadan, with variations across sulphonylureas and countries.

Sulfonylureas: do we need to introspect safety again?

INTRODUCTION

Sulfonylureas (SUs) are the most commonly prescribed medications for type 2 diabetes mellitus worldwide. Differences among SUs for kinetic and adenosine triphosphate sensitive potassium (KATP) channels selectivity and consequential extrapancreatic effects, although recognized in literature, are not considered by treatment guidelines.

AREAS COVERED

The roles of SUs in various system-related adverse effects have not been well understood. Inconsistencies in the literature and lack of clinical trials assessing the long-term effects of monotherapy or combination therapy with SUs add to the concern. This review provides insights in issues concerning safety of SUs based on literature published between 1980 and 2011. A comprehensive search was carried out on PubMed, Embase and Cochrane databases using the search terms: sulfonylureas, sulfonylureas and KATP channels, sulfonylureas and cardiovascular (CV) effects and sulfonylureas side effects.

EXPERT OPINION

SUs have been linked to CV events, growth hormone (GH) disorder, malignancy, weight gain, erectile dysfunction and central nervous system (CNS) adverse effects. These adverse effects generally get masked as they are thought to be related to diabetes per se. The current article will allow the fraternity to ponder and undertake further research on the ill effects of largely prescribed antidiabetic medication.

Minimizing the risk of hypoglycemia with vildagliptin: Clinical experience, mechanistic basis, and importance in type 2 diabetes management

Even if the true incidence of hypoglycemia in type 2 diabetes mellitus (T2DM) remains difficult to estimate, with highly variable rates reported in the literature, it is likely more common than previously thought. While most hypoglycemic episodes in T2DM are considered "mild," they still have a substantial clinical impact. Severe hypoglycemia also exists in T2DM, with recent landmark studies prompting much debate about the potential role of severe hypoglycemia in cardiovascular morbidity and mortality, even though there is currently no definitive evidence for causality. The challenge in the treatment of T2DM remains the achievement of optimal glycemic control to lower the risk for long-term complications while avoiding hypoglycemia. Successful treatment strategies should therefore include careful selection of therapies to prevent hypoglycemia, starting early in the disease management process, in order to best preserve counterregulation. The dipeptidyl peptidase-4 inhibitor, vildagliptin, is a good treatment option to minimize the risk of hypoglycemia over time, while maintaining good glucose control. Extensive clinical experience is available for vildagliptin, with data published for all stages of the condition and with the low hypoglycemic potential stemming from a solid mechanistic basis.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

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

BACKGROUND

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

METHODS

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

RESULTS

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

INTERPRETATION

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

Comparison of metformin, gliclazide MR and rosiglitazone in monotherapy and in combination for type 2 diabetes

OBJECTIVE

To compare the efficacy and tolerability of metformin, rosiglitazone and gliclazide MR as monotherapy and in combination in the treatment of type 2 diabetes.

SUBJECTS AND METHODS

250 patients treated with oral antidiabetic agents for at least 24 weeks in monotherapy or in combination therapy were included in this retrospective study.

RESULTS

As monotherapy the reduction of fasting plasma glucose (FPG), postprandial glycemia (PPG) and HbA1c was similar with the three drugs after 24 weeks. Among patients on combination therapy, the reduction in HbA1c, FPG and PPG was significantly lower with rosiglitazone plus metformin, as compared to metformin plus gliclazide MR or gliclazide MR plus rosiglitazone. Patients treated with rosiglitazone achieved less favorable changes in lipid profile.

CONCLUSION

In monotherapy all drugs were equally effective in improving glycemic control, whereas the combination of metformin plus gliclazide MR provided the best results concerning the improvement of both, glycemic control and lipid profile.

Diabetes and Ramadan: How to Achieve a Safer Fast for Muslims with Diabetes

Ramadan is a holy month for all Muslims, when they fast from dawn to sunset. Although the Qur'an exempts the sick from fasting, many Muslims with diabetes passionately fast despite their medical condition. The main risks encountered during fasting include worsening of glycaemic control or hypoglycaemia. A better understanding about fasting Ramadan and its risks is an important step for all healthcare professionals managing Muslim people with diabetes. This entails improving patient education as well as tailoring the treatment to meet the needs of this group of people with diabetes to minimise the possible risks.

Role of vildagliptin in managing type 2 diabetes mellitus in the elderly

BACKGROUND

The prevalence of type 2 diabetes (T2DM) increases with age. Older patients have an increased likelihood for T2DM-related morbidity and mortality. The objective of this review is to provide an overview of the challenges in managing T2DM in the elderly, with an emphasis on prevention of hypoglycaemia and the role of the DPP-4 inhibitor vildagliptin in this patient population.

METHODS

A search of PubMed was conducted (from 2003 to 2010) to identify English-language articles relevant to the management of elderly patients with T2DM, with an emphasis on vildagliptin treatment. A limitation of this review is that it does not provide an overview of the entire class of dipeptidyl-peptidase-4 (DPP-4) inhibitors.

FINDINGS

Management of T2DM in elderly patients is complicated by numerous factors, including a high prevalence of cardiovascular risk factors and other comorbidities and a high frequency of polypharmacy issues. Hypoglycaemia may pose the greatest barrier to optimal glycaemic control in elderly patients, who are less likely to recognise and respond to hypoglycaemic episodes, leading to increased frequency and severity of events. Data on the DPP-4 inhibitor vildagliptin indicate that reductions in A1C in elderly patients are at least as good as those observed in younger patients and are achieved with minimal risk of hypoglycaemia. T2DM in older individuals is associated with relative hyperglucagonaemia and elevated postprandial glucose (PPG). Vildagliptin treatment appears to address both these defects. Vildagliptin improves the ability of alpha- and beta-cells to respond appropriately to changes in plasma glucose levels. This, in the face of high glucose levels, results in reduced inappropriate glucagon secretion and PPG excursions. In the face of low glucose, however, the protective glucagon response is well-preserved. These factors help explain the efficacy and minimal risk of hypoglycaemia observed with vildagliptin in elderly patients.

CONCLUSION

The elderly population with T2DM poses unique treatment challenges and have not been particularly well-represented in clinical trials, highlighting the need for additional studies to better define appropriate glucose targets and to ascertain the best strategies for achieving and maintaining appropriate glycaemic levels. Because vildagliptin does not expose patients to hypoglycaemic risk, it seems particularly suited to oral therapy of T2DM in the elderly.

Maintenance of glycaemic control with the evening administration of a long acting sulphonylurea in male type 2 diabetic patients undertaking the Ramadan fast

BACKGROUND

In Ramadan, misuse of hypoglycaemic agents, alterations in diet and hypoglycaemia are frequent. This study assessed whether switching to an evening administration of a long acting sulphonylurea during the 29-day, dawn to dusk fast, can maintain glycaemic control in patients with type 2 diabetes.

PATIENTS AND METHODS

Male type 2 diabetic patients from Bangladesh, Pakistan and India, under glycaemic control with gliclazide modified release (MR) 60 mg monotherapy, switched to evening administration of the same dose during Ramadan, and reverted to the morning schedule thereafter. The primary outcome was the difference in fasting plasma glucose (FPG) before and after Ramadan.

RESULTS

In 136 patients, mean (95% CI) FPG decreased by 0.01 mmol/l (0-0.2, p = 0.3) with evening medication by the end of the fast, and increased by 0.2 mmol/l (0.1-0.3, p = 0.01) after reverting to morning medication 20 days later. There were 5 (3.7%) hypoglycaemic episodes before, 3 (2.2%) during and 2 (1.5%) after Ramadan.

CONCLUSION

Male type 2 diabetic patients undertaking the Ramadan fast can safely maintain glycaemic control with evening administration of gliclazide MR 60 mg during the fast, and reverting to a morning schedule thereafter.

Diabetes and Cardiovascular Disease: Is intensive glucose control beneficial or deadly? Lessons from ACCORD, ADVANCE, VADT, UKPDS, PROactive, and NICE-SUGAR

Type 2 diabetes is a rather complex metabolic disorder still associated with a 2-fold increased cardiovascular (CV) mortality despite a dramatic improvement in CV risk reduction by multifactorial intervention strategies. Intensive glucose control can also reduce CV morbidity, but this effect seems to be limited to younger patients with shorter duration of disease and no CV disease. Intensive glucose control--in particular when complex insulin strategies are used--is associated with a 5-fold increased risk for severe hypoglycemia, which could induce harm in some patients. In contrast to blood pressure and lipid-lowering interventions a reduction of CV mortality cannot be seen before 10-20 years after the start of the glucose-lowering intervention (metabolic memory, legacy effect). Future ongoing outcome studies in more than 50,000 patients will clarify whether new antidiabetic drugs--not inducing hypoglycemia or weight gain--will further improve the prognosis of T2DM patients.

Glycaemic goals in patients with type 2 diabetes: current status, challenges and recent advances

Recommendations for the management of type 2 diabetes include rigorous control of blood glucose levels and other risk factors, such as hypertension and dyslipidaemia. In clinical practice, many patients do not reach goals for glycaemic control. Causes of failure to control blood glucose include progression of underlying pancreatic beta-cell dysfunction, incomplete adherence to treatment (often because of adverse effects of weight gain and hypoglycaemia) and reluctance of clinicians to intensify therapy. There is increasing focus on strategies that offer potential to improve glycaemic control. Structured patient education has been shown to improve glycaemic control and other cardiovascular risk factors in people with type 2 diabetes. Payment of general practitioners by results has been shown to improve glycaemic control. New classes of glucose-lowering agents have expanded the treatment options available to clinicians and patients and include the dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. These new classes of therapy and other strategies outlined above could help clinicians to individualize treatment and help a greater proportion of patients to achieve long-term control of blood glucose.

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.

Glibenclamide-related excess in total and cardiovascular mortality risks: data from large Ukrainian observational cohort study

OBJECTIVE

To compare mortality risks among type 2 diabetes (T2D) patients being treated with glibenclamide, gliclazide, or glimepiride.

METHODS

Retrospective observational cohort studies of primary care-based diabetes register were carried out. Risk of total and cardiovascular (CVD) mortality was evaluated in cohort of T2D patients that were treated with either glibenclamide (n=50,341), glimepiride (n=2479) or gliclazide (n=11,368). Cox regression was used for multifactor evaluation. A cross-sectional evaluation of oral anti-diabetic drug (OAD) structure for 2005 and 2007 was also performed, as well as age at the time of death was compared in the timeframe between 2002 and 2007.

RESULTS

Total mortality was lower for gliclazide and glimepiride, vs. glibenclamide cohort: HRs 0.33 (95% CI 0.26-0.41), p<0.001 and 0.605 (95% CI 0.413-0.886), p<0.01 respectively. CVD mortality risk reduction vs. glibenclamide was significant only in gliclazide cohort: 0.29 (95% CI 0.21-0.38), p<0.001. Glibenclamide prescriptions had changed from 64.0% (95% CI 63.5-64.5) to 59.5% (95% CI 9.7-10.4). Age at the time of death for OAD-treated patients increased by 6.27 (95% CI 3.67-8.87)yrs, p<0.001.

CONCLUSION

Glibenclamide treatment of T2D is associated with greater risk of all-cause mortality, vs. gliclazide or glimepiride treatment, and CVD mortality, vs. gliclazide treatment.

Enhanced glucose tolerance by SK4 channel inhibition in pancreatic beta-cells

OBJECTIVE

Ca(2+)-regulated K(+) channels are involved in numerous Ca(2+)-dependent signaling pathways. In this study, we investigated whether the Ca(2+)-activated K(+) channel of intermediate conductance SK4 (KCa3.1, IK1) plays a physiological role in pancreatic beta-cell function.

RESEARCH DESIGN AND METHODS

Glucose tolerance and insulin sensitivity were determined in wild-type (WT) or SK4 knockout (SK4-KO) mice. Electrophysiological experiments were performed with the patch-clamp technique. The cytosolic Ca(2+) concentration ([Ca(2+)](c)) was determined by fura-2 fluorescence. Insulin release was assessed by radioimmunoassay, and SK4 protein was detected by Western blot analysis.

RESULTS

SK4-KO mice showed improved glucose tolerance, whereas insulin sensitivity was not altered. The animals were not hypoglycemic. Isolated SK4-KO beta-cells stimulated with 15 mmol/l glucose had an increased Ca(2+) action potential frequency, and single-action potentials were broadened. These alterations were coupled to increased [Ca(2+)](c). In addition, glucose responsiveness of membrane potential, [Ca(2+)](c), and insulin secretion were shifted to lower glucose concentrations. SK4 protein was expressed in WT islets. An increase in K(+) currents and concomitant membrane hyperpolarization could be evoked in WT beta-cells by the SK4 channel opener DCEBIO (100 micromol/l). Accordingly, the SK4 channel blocker TRAM-34 (1 micromol/l) partly inhibited K(Ca) currents and induced electrical activity at a threshold glucose concentration. In stimulated WT beta-cells, TRAM-34 further increased [Ca(2+)](c) and broadened action potentials similar to those seen in SK4-KO beta-cells. SK4 channels were found to substantially contribute to K(slow) (slowly activating K(+) current).

CONCLUSIONS

SK4 channels are involved in beta-cell stimulus-secretion coupling. Deficiency of SK4 current induces elevated beta-cell responsiveness and coincides with improved glucose tolerance in vivo. Therefore, pharmacologic modulation of these channels might provide an interesting approach for the development of novel insulinotropic drugs.

Antidiabetic medications and weight gain: implications for the practicing physician

Obesity is a major risk factor for diabetes and cardiovascular disease, and most people with diabetes are overweight or obese. Weight reduction has been shown to improve glycemic control and reduce cardiovascular risk in the diabetic population. While physicians strive to achieve better glycemic control for their patients with diabetes, they are faced with the problem of weight gain that is commonly encountered with the use of antidiabetic agents, particularly insulin, insulin secretagogues, and thiazolidinediones. Weight gain in this population could offset the beneficial effects of good glycemic control and discourage patients from adhering to treatment. In this review, we discuss the effects of the various antidiabetic agents on body weight, highlighting the potential mechanisms and the implications of weight gain in this population. We also present the available therapeutic modalities that have the potential of achieving better glycemic control without adverse effects on body weight.

New insights from ADVANCE

OBJECTIVES

ADVANCE (Action in Diabetes and Vascular Disease - PreterAx and DiamicroN MR Controlled Evaluation) is a large-scale clinical trial designed to investigate the benefits of blood pressure lowering and intensive glucose control in patients with type 2 diabetes mellitus.

METHODS AND PARTICIPANTS

ADVANCE is a 2 x 2 factorial randomized trial evaluating the benefits of the low-dose fixed combination of perindopril and indapamide versus placebo to lower blood pressure and of an intensive gliclazide-MR-based regimen, targeting glycosylated haemoglobin (HbA1c) levels of 6.5% or less versus standard therapy to lower blood glucose. The two primary outcomes, taken separately and jointly, are a composite macrovascular endpoint and a composite microvascular endpoint.

RESULTS

A total of 11 140 participants were randomized between July 2001 and March 2003 from among 12 878 individuals with type 2 diabetes recruited from 215 centres in 20 countries, who entered a 6-week run-in phase. The average (SD) baseline blood pressure of 145(22)/81 (11) mmHg fell by 8/3 mmHg during the run-in phase during which participants received one tablet of open-labelled perindopril 2 mg-indapamide 0.625 mg. Only 3.6% of the 12 878 patients who entered the run-in phase withdrew because of suspected intolerance to perindopril-indapamide. With over 4 years of follow-up on average so far, over 80% of participants are still adhering to randomized therapy. Follow-up of the blood pressure arm will be completed during 2007.

CONCLUSION

The safety and efficacy of perindopril-indapamide in lowering blood pressure and of a gliclazide-MR-based regimen in lowering blood glucose have been established with the completion of a 6-week run-in phase and of more than 4 years of post-randomization follow-up. It is anticipated that ADVANCE will provide many new insights including: whether blood pressure lowering with perindopril-indapamide reduces the risk of both macrovascular and microvascular events irrespective of baseline blood pressure; whether more intensive blood pressure lowering with a gliclazide-MR-based regimen targeting on HbA1c levels of 6.5% or less reduces these two outcomes compared with standard guidelines therapy; and finally whether the separate benefits of these two treatment regimens are additive.

Treating type 2 diabetes: how safe are current therapeutic agents?

Sulphonylureas (SUs) and biguanides (metformin) are the current mainstays in the treatment of type 2 diabetes (T2DM) and represent the most commonly used oral hypoglycaemic agents (OHAs). In recent years, a variety of new OHAs have become available, including thiazolidinediones, glinides, alpha-glucosidase inhibitors, glucagon-like peptide-1 agonists, amylin analogues and dipeptidyl peptidase-IV inhibitors, providing physicians with a larger therapeutic catalogue than ever before. The traditional drugs metformin and SUs have an established safety profile through long-term use. However, long-term clinical trials and routine use are lacking for many of the new agents, and some potentially serious side effects have been reported with several of these compounds. Until adequate data is obtained, it is difficult to assess the risk-benefit ratio of these agents in relation to the traditional drugs. Until that becomes fully documented, it may be wise to start pharmacologic treatment of patients on an individual basis, weighing the benefits and costs of each medication. Thus, there remains a place for well-established drugs that have a proven safety record and are supported by years of clinical use for the treatment of T2DM.

The efficacy of self-monitoring of blood glucose in the management of patients with type 2 diabetes treated with a gliclazide modified release-based regimen. A multicentre, randomized, parallel-group, 6-month evaluation (DINAMIC 1 study)

AIM

To determine if therapeutic management programmes for type 2 diabetes that include self-monitoring of blood glucose (SMBG) result in greater reductions in glycated haemoglobin (HbA1c) compared with programmes without SMBG in non-insulin requiring patients.

METHODS

Multicentre, randomized, parallel-group trial. A total of 610 patients were randomized to SMBG or non-SMBG groups. Patients in both groups received the same oral antidiabetic therapy using a gliclazide modified release (MR)-based regimen for 27 weeks. The primary efficacy end-point was the difference between groups in HbA1c at the end of observation.

RESULTS

A total of 610 patients were randomized: 311 to the SMBG group and 299 to the non-SMBG group. HbA1c decreased from 8.12 to 6.95% in the SMBG group and from 8.12 to 7.20% in the non-SMBG group; between-group difference was 0.25% (95% CI: 0.06, 1.03; p = 0.0097). Symptoms suggestive of mild to moderate hypoglycaemia was the most commonly reported adverse event, reported by 27 (8.7%) and 21 (7.0%) patients in the SMBG and non-SMBG groups, respectively; the incidence of symptomatic hypoglycaemia was lower in the SMBG group.

CONCLUSION

In patients with type 2 diabetes, the application of SMBG as an adjunct to oral antidiabetic agent therapy results in further reductions in HbA1c.

Evaluation of adverse events of oral antihyperglycemic monotherapy experienced by a geriatric population in a real-world setting: a retrospective cohort analysis

BACKGROUND AND OBJECTIVE

To evaluate and compare the risk of adverse events (AEs) associated with the use of metformin, sulfonylureas and thiazolidinediones among geriatric patients in a usual care setting.

METHODS

An electronic medical record database was utilized to identify geriatric patients with type 2 diabetes mellitus aged > or =65 years from 1996 to 2005. Patients naive to oral antihyperglycemic drug (OAD) therapy were followed for 395 days post initiation of metformin, sulfonylurea or thiazolidinedione treatment. AEs related to study drugs were evaluated during the follow-up period, and the risks of developing an AE were evaluated and adjusted for differences in baseline characteristics by OAD treatment.

RESULTS

A total of 5438 patients (mean age 73.2 [SD 5.08] years, 56.1% female) were identified. During the follow-up period, 12.5% of patients experienced an AE (8.3% of metformin, 13.9% of sulfonylurea and 19.8% of thiazolidinedione recipients). Sulfonylurea (odds ratio [OR] 1.74; 95% CI 1.41, 2.13) and thiazolidinedione (OR 2.86; 95% CI 2.23, 3.65) recipients were more likely to experience an AE than metformin recipients, after adjustment for baseline demographic and co-morbidity differences. The average time to onset of a metformin AE (175 days) was less than that for sulfonylurea or thiazolidinedione treatment (192 and 201 days, respectively). The most common AEs were abdominal pain with metformin (42.3%) and weight gain >4.5 kg for sulfonylureas (63.2%) and thiazolidinediones (68.2%). Hypoglycaemia occurred in 2.6% and 2.2% of sulfonylurea and thiazolidinedione recipients, respectively.

DISCUSSION AND CONCLUSIONS

Geriatric patients in a real-world setting experienced AEs with metformin, sulfonylurea and thiazolidinedione therapy, although rates differed from those seen in clinical trials, particularly for weight gain and hypoglycaemia. Lactic acidosis occurred at a higher rate with metformin therapy than has been reported in clinical trials, but our results were in the same range for abdominal pain and lower for diarrhoea, nausea/vomiting and dyspepsia. AEs related to sulfonylurea therapy were in the same range as in clinical trials for weight gain but lower for hypoglycaemia, dizziness and headaches. AEs related to thiazolidinedione therapy were more common in our study than in clinical trials, and within the same range for weight gain and elevated liver enzymes but lower for hypoglycaemia and oedema. While AE reporting is likely to be different in a real-world setting than in clinical trials, the observed variances may also be due to the aetiology of diabetes and the physiological response to hypoglycaemia in an older population.

Ameliorating effects of sulfonylurea drugs on insulin resistance in Otsuka long-evans Tokushima Fatty rats

OLETF (Otsuka Long-Evans Tokushima Fatty) rats are characterized by obesity-related insulin resistance, which is a phenotype of type 2 diabetes. Sulfonylurea drugs or benzoic acid derivatives as inhibitors of the ATP-sensitive potassium (K(ATP)) channel are commercially available to treat diabetes. The present study compared sulfonylurea drugs (glimepiride and gliclazide) with one of benzoic acid derivatives (repaglinide) in regard to their long-term effect on ameliorating insulin sensitivity in OLETF rats. Each drug was dissolved and fed with drinking water from 29 weeks of age. On high glucose loading at 45 weeks of age, response of blood glucose recovery was the greatest in the group treated with glimepiride. On immunohistochemistry analysis for the Kir6.2 subunit of K(ATP) channels, insulin receptor beta-subunits, and glucose transporters (GLUT) type 2 and 4 in liver, fat and skeletal muscle tissues, the sulfonylurea drugs (glimepiride and gliclazide) were more effective than repaglinide in recovery from their decreased expressions in OLETF rats. From these results, it seems to be plausible that K(ATP)-channel inhibitors containing sulfonylurea moiety may be much more effective in reducing insulin resistance than those with benzoic acid moiety. In contrast to gliclazide, non-tissue selectivity of glimepiride on K(ATP) channel inhibition may further strengthen an amelioration of insulin sensitivity unless considering other side effects.

Design and development of gliclazide mucoadhesive microcapsules: in vitro and in vivo evaluation

In this study an attempt was made to prepare mucoadhesive microcapsules of gliclazide using various mucoadhesive polymers designed for oral controlled release. Gliclazide microcapsules were prepared using sodium alginate and mucoadhesive polymer such as sodium carboxymethyl cellulose (sodium CMC), carbopol 934P or hydroxy propylmethyl cellulose (HPMC) by orifice-ionic gelation method. The microcapsules were evaluated for surface morphology and particle shape by scanning electron microscope. Microcapsules were also evaluated for their microencapsulation efficiency, in vitro wash-off mucoadhesion test, in vitro drug release and in vivo study. The microcapsules were discrete, spherical and free flowing. The microencapsulation efficiency was in the range of 65-80% and microcapsules exhibited good mucoadhesive property in the in vitro wash off test. The percentage of microcapsules adhering to tissue at pH 7.4 after 6 h varied from 12-32%, whereas the percentage of microcapsules adhering to tissue at pH 1.2 after 6 h varied from 35-68%. The drug release was also found to be slow and extended for more than 16 h. In vivo testing of the mucoadhesive microcapsules in diabetic albino rats demonstrated significant antidiabetic effect of gliclazide. The hypoglycemic effect obtained by mucoadhesive microcapsules was for more than 16 h whereas gliclazide produced an antidiabetic effect for only 10 h suggesting that mucoadhesive microcapsules are a valuable system for the long term delivery of gliclazide.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A review of the effects of antihyperglycaemic agents on body weight: the potential of incretin targeted therapies

BACKGROUND

Current American Diabetes Association (ADA)/European Association for the Study of Diabetes (EASD) treatment guidelines recommend metformin (which does not promote weight gain) as the first-line antihyperglycaemic drug for patients with type 2 diabetes. However, when metformin fails, the recommended add-on treatment options (sulphonylureas, glitazones and basal insulin) can lead to significant weight gain. This article reviews the effect on body weight of current treatments for type 2 diabetes and discusses the potential impact of weight gain in this patient group.

SCOPE

MEDLINE searches were performed to evaluate the prevalence and impact of changes in body weight in type 2 diabetes (articles published between January 1966 and August 2006) and the effects of sulphonylureas, glitazones, insulin, dipeptidyl peptidase-4 (DPP-4) inhibitors and incretin analogs on body weight in these patients (search between January 2004 and September 2006).

FINDINGS

Weight gain in general affects not only the physiological capability of patients with diabetes to achieve glycaemic control, but also their psychological well-being, quality of life and persistence with antihyperglycaemic treatment. Excess body weight and obesity in patients with diabetes are also associated with increased healthcare resource utilisation. Development of obesity is also associated with increased cardiovascular risk, although a link between drug-induced weight gain per se and increased cardiovascular risk has not been established. Initial clinical trial experience with the new oral DPP-4 inhibitors such as sitagliptin and vildagliptin suggests that these agents are weight-neutral, while providing improved glycaemic control when added to metformin.

CONCLUSIONS

Because currently available add-on treatments can cause weight gain, physicians initiating add-on therapy in patients who can no longer achieve glycaemic control with metformin are faced with the problem of improving glycaemic control while causing weight gain. Initial clinical trial experience with oral DPP-4 inhibitors such as sitagliptin and vildagliptin suggest that these agents may represent an important oral treatment option for weight-neutral, glycaemic control when added to metformin. The new oral DPP-4 inhibitors, therefore, represent a potentially important addition to the oral treatment options currently available for the management of type 2 diabetes mellitus. Long-term clinical trials are now required to evaluate the relative risk/benefit profile of these drugs compared with the established antihyperglycaemic drug classes.

Oral antidiabetic agents: how much kidney disease can we tolerate?

Type 2 diabetes mellitus and chronic kidney disease in mild and moderate stages is a common and underestimated comorbidity with relevant therapeutic consequences. Available oral antidiabetic agents are effectively used in keeping blood glucose levels within the guideline range but long lists of contraindications often limit their use. Chronic kidney disease is a very common reason to withhold or discontinue an oral antidiabetic therapy, precluding many patients from drugs with proven benefit, such as metformin. Often contraindications are not based on data but on theoretical grounds or expert opinion. In this review, we critically review threshold levels of kidney function for common oral antidiabetic agents, the evidence from which they were derived and offer advice on how to monitor kidney function as an important procedure in clinical practice.