Do sulfonylurea drugs increase the risk of cardiac events?

Use of Diabetes Medications before and after a Heart Failure-Related Hospitalization among Nursing Home Residents

OBJECTIVES

Sodium-glucose cotransporter-2 inhibitors (SGLT-2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) offer cardiovascular benefits, whereas thiazolidinediones (TZDs) and sulfonylureas (SUs) increase cardiovascular risk. The objective of this study was to describe the use of SGLT-2is, GLP-1RAs, TZDs, and SUs before and after a heart failure (HF)-related hospitalization in nursing home (NH) residents with type 2 diabetes (T2D).

DESIGN

This was a cohort study using a 20% sample of Medicare claims linked with Minimum Data Set resident assessments.

SETTING AND PARTICIPANTS

The study population was long-stay NH residents with T2D and an HF-related hospitalization between January 1, 2013, and August 31, 2018. For individuals with multiple HF hospitalizations, 1 hospitalization was randomly selected.

METHODS

We ascertained diabetes medications using Medicare Part D claims during the 120 days before and after hospital discharge (or skilled nursing facility discharge, where applicable). We calculated (1) the proportion of study participants who received a medication class of interest during pre- and posthospitalization periods; (2) the proportion of continuous users; and (3) the proportion of posthospitalization users who were new users.

RESULTS

A total of 12,990 NH residents with T2D and an HF-related hospitalization were included (mean age 78 years, 66% female, 19% Black). Before hospitalization, 1.5% received TZDs, 14.1% received SUs, 1.2% received GLP-1RAs, and 0.3% received SGLT-2is. Among prehospitalization users of TZDs, SUs, GLP-1RAs, and SGLT-2is, 49%, 62%, 60%, and 40% continued the medications, respectively. Among posthospitalization users of TZDs, SUs, GLP-1RAs, and SGLT-2is, 37%, 10%, 28%, and 11%, respectively, were new users.

CONCLUSIONS

Among NH residents with hospitalized HF, GLP-1RAs and SGLT-2is were seldom used. TZDs and SUs were still used by many residents with T2D after HF hospitalizations.

IMPLEMENTATIONS

Barriers may exist in the use of newer diabetes medications to prevent heart failure in NH residents with T2D, which warrants further studies in older adults with multimorbidity.

Beyond Blood Sugar: Investigating the Cardiovascular Effects of Antidiabetic Drugs

Cardiovascular disease is a major comorbidity associated with diabetes mellitus. Various antidiabetic drugs are currently used to treat type 2 diabetes mellitus and have varying effects on the cardiovascular system. Some drugs, such as glucagon-like peptide 1 (GLP-1) agonists and sodium-glucose cotransporter 2 (SGLT-2) inhibitors, are cardioprotective, whereas others, such as insulin, have deleterious effects on the cardiovascular system. This narrative review assessed the impact of antidiabetic drugs on cardiovascular health in the management of diabetes mellitus. It critically examines various classes of these medications, including conventional options such as metformin and newer agents such as incretin-based therapies and SGLT-2.

Pharmaceutical Drugs and Natural Therapeutic Products for the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is the most widespread form of diabetes, characterized by chronic hyperglycaemia, insulin resistance, and inefficient insulin secretion and action. Primary care in T2DM is pharmacological, using drugs of several groups that include insulin sensitisers (e.g., biguanides, thiazolidinediones), insulin secretagogues (e.g., sulphonylureas, meglinides), alpha-glucosidase inhibitors, and the newest incretin-based therapies and sodium-glucose co-transporter 2 inhibitors. However, their long-term application can cause many harmful side effects, emphasising the importance of the using natural therapeutic products. Natural health substances including non-flavonoid polyphenols (e.g., resveratrol, curcumin, tannins, and lignans), flavonoids (e.g., anthocyanins, epigallocatechin gallate, quercetin, naringin, rutin, and kaempferol), plant fruits, vegetables and other products (e.g., garlic, green tea, blackcurrant, rowanberry, bilberry, strawberry, cornelian cherry, olive oil, sesame oil, and carrot) may be a safer alternative to primary pharmacological therapy. They are recommended as food supplements to prevent and/or ameliorate T2DM-related complications. In the advanced stage of T2DM, the combination therapy of synthetic agents and natural compounds with synergistic interactions makes the treatment more efficient. In this review, both pharmaceutical drugs and selected natural products, as well as combination therapies, are characterized. Mechanisms of their action and possible negative side effects are also provided.

Cardiovascular Effects of Hypoglycemic Agents in Diabetes Mellitus

BACKGROUND

Despite substantial improvements over the years, diabetes mellitus is still associated with cardiovascular disease, heart failure, and excess mortality.

OBJECTIVE

The objective of this article is to examine existing data on the reduction of cardiovascular morbidity and mortality in diabetes. Control of glycemia, lipid levels, and blood pressure are described in brief. The main scope of this article is, however, to review the glucose-independent cardiovascular effect of antidiabetic pharmacological agents (mainly other than insulin).

METHODS

The article is a narrative review based on recently published reviews and meta-analyses complemented with data from individual trials, when relevant.

RESULTS AND DISCUSSION

Older data suggest a cardioprotective role of metformin (an inexpensive and safe drug); a role to date not convincingly challenged. The cardiovascular effects of thiazolidinediones, sulphonylurea, and glinides are debatable. Recent large-scale cardiovascular outcome trials suggest a neutral profile of dipeptidyl peptidase 4 inhibitors, yet provide compelling evidence of cardioprotective effects of glucagon-like 1 receptor antagonists and sodium-glucose transporter 2 inhibitors.

CONCLUSION

Metformin may have a role in primary and secondary prevention of cardiovascular disease; glucagon-like 1 receptor antagonists and sodium-glucose co-transporter 2 inhibitors play a role in secondary prevention of atherosclerotic cardiovascular disease. Sodium-glucose transporter 2 inhibitors have a role to play in both primary and secondary prevention of heart failure; yet, they carry a small risk of the potentially dangerous adverse effect, euglycemic diabetic ketoacidosis.

Sixty Years of Drug Discovery for Type 2 Diabetes: Where Are We Now?

Today, excluding insulin, there are eight classes of anti-diabetic medicines that have been added to the pharmacy since the introduction of metformin in the mid-1950s; the sulfonylureas, biguanides, thiazolidinediones, α-glucosidase inhibitors, meglitinides, incretins, and sodium glucose transport 2 inhibitors. Does the fact that metformin is still first-line treatment suggest that our drug discovery efforts over the past 60 years have not been good enough? Or does it suggest that diabetes is such a complex disorder that no single treatment, other than gastric bypass surgery, can affect true normalization of not only blood sugar but also the underlying pathologies? Our understanding of the disease has most definitely improved which may bring hope for the future in terms of science, but for it to be beneficial, this science has to be translated into better drug treatments for the disease. In this review, I have examined the eight classes of anti-diabetes drugs from a drug discovery perspective.

A Review of Cardiovascular Outcomes Trials of Glucose-Lowering Therapies and Their Effects on Heart Failure Outcomes

Type 2 diabetes mellitus has long been recognized as a major risk factor for adverse atherosclerotic cardiovascular disease events; however, recent data indicate that heart failure is now emerging as the most common and morbid cardiovascular complication of type 2 diabetes mellitus. When heart failure develops in patients with type 2 diabetes, prognosis is ominous, highlighting the need for glucose-lowering therapies that can prevent heart failure, improve outcomes, or both. Prior to 2008, there was a paucity of randomized controlled trials evaluating long-term cardiovascular outcomes with glucose-lowering therapies. This changed after guidance on the assessment of novel glucose-lowering agents was issued by both the US Food and Drug Administration and the European Medicines Agency. Since then, significant progress has been made as a result of large cardiovascular outcomes trials. Though randomized controlled trials on insulin, sulfonylureas, and metformin are still limited, cardiovascular outcomes trials on newer glucose-lowering agents have included hundreds of thousands of patients with multiple years of follow-up. The increased risk of thiazolidinediones on heart failure had been well theorized and is now established; however, the increase in heart failure hospitalization with certain dipeptidyl peptidase-4 inhibitors was unexpected. The reasons for discrepancies with regard to heart failure risk with different dipeptidyl peptidase-4 inhibitors remain unclear, and further mechanistic studies are ongoing. The role of glucagon-like peptide-1 receptor agonists among patients with heart failure also remains unclear, and their effects may differ in patients with and without established heart failure, particularly those with decompensated heart failure with reduced ejection fraction.

The Effect of an Aerobic Exercise Programme on Blood Glucose Level, Cardiovascular Parameters, Peripheral Oxygen Saturation, and Body Mass Index among Southern Nigerians with Type 2 Diabetes Mellitus, Undergoing Concurrent Sulfonylurea and Metformin Treatment

BACKGROUND

Diabetes mellitus increases the risk of cardiovascular diseases and all-cause mortality. The present study investigated the effect of an eight-week aerobics programme on fasting blood sugar (FBS), cardiovascular parameters, peripheral oxygen saturation (SpO2), and body mass index (BMI) among subjects with type-2 diabetes mellitus (T2DM).

METHODS

A pretest-posttest experimental design was employed. Fifty subjects, diagnosed with T2DM, attending the Diabetes Clinic of the University of Nigeria Teaching Hospital, Enugu, were conveniently recruited, gender and age-matched, and randomised into exercise and control groups. The intervention included an eight-week aerobic exercise at 60%-79% HRmax for 45 min-60 min, 3-days per week. The FBS, SpO2, BMI, resting heart rate (RHR), and systolic (SBP) and diastolic blood pressure (DBP) of the subjects were measured before and after the intervention. The paired and independent t-test(s) were used for the analyses within and between the groups, respectively (P ≤ 0.05).

RESULTS

The exercise group had a significantly lower SBP (15.0 mmHg, P = 0.001), DBP (7.9 mmHg, P = 0.001), RHR (4.8 bpm, P = 0.001), FBS (34.9 mg/dl, P = 0.001), and BMI (2.3, P = 0.001), while the SpO2 improved by 3.9% with P = 0.001, relative to the control group.

CONCLUSION

Aerobics is an efficacious adjunct therapy in controlling the FBS level, blood pressure, BMI, and improving SpO2 among T2DM subjects.

Heart failure in the patient with diabetes: Epidemiology, aetiology, prognosis, therapy and the effect of glucose-lowering medications

In people with type 2 diabetes the frequency of heart failure (HF) is increased and mortality from HF is higher than with non-diabetic HF. The increased frequency of HF is attributable to the cardiotoxic tetrad of ischaemic heart disease, left ventricular hypertrophy, diabetic cardiomyopathy and an extracellular volume expansion resistant to atrial natriuretic peptides. Activation of the renin-angiotensin-aldosterone system and sympathetic nervous systems results in cardiac remodelling, which worsens cardiac function. Reversal of remodelling can be achieved, and cardiac function improved in people with HF with reduced ejection fraction (HFrEF) by treatment with angiotensin-converting enzyme inhibitors and β-blockers. However, with HF with preserved ejection fraction (HFpEF), only therapy for the underlying risk factors helps. Blockers of mineralocorticoid receptors may be beneficial in both HFrEF and HFpEF. Glucose-lowering drugs can have a negative effect (insulin, sulphonylureas, dipeptidyl peptidase-4 inhibitors and thiazolidinediones), a neutral effect (α-glucosidase inhibitors and glucagon-like peptide-1 receptor agonists) or a positive effect (sodium-glucose co-transporter-2 inhibitors and metformin).

Cardiovascular mortality and oral antidiabetic drugs: protocol for a systematic review and network meta-analysis

INTRODUCTION

Cardiovascular diseases are the leading cause of morbidity and mortality among individuals with diabetes. Despite the beneficial effects of antidiabetic drugs (ADDs) in terms of lowering haemoglobin A1c, several ADDs have been shown to increase the risk of cardiovascular events. Given the high prevalence of cardiovascular disease among individuals with diabetes, it is important to weigh the benefits of ADDs against their cardiovascular safety. Therefore, the objective of the current study is to conduct a systematic review with network meta-analysis to compare the effects of different oral pharmacological classes of ADDs on cardiovascular safety.

METHODS AND ANALYSIS

Randomised clinical trials (RCTs) and observational studies published in English up to 31 January 2017, and which include direct and/or indirect evidence, will be included. Studies will be retrieved by searching four electronic databases and cross-referencing. Dual selection and abstraction of data will occur. The primary outcome will be cardiovascular mortality. Secondary outcomes will include all-cause mortality, new event of acute myocardial infarction, stroke (haemorrhagic and ischaemic), hospitalisation for acute coronary syndrome and urgent revascularisation procedures. Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument for RCTs and the Strengthening the Reporting of Observational Studies in Epidemiology instrument for observational studies. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of ADDs that increase cardiovascular mortality.

DISSEMINATION

The results of this study will be presented at a professional conference and submitted to a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42017051220.

Pro- and Antiarrhythmic Actions of Sulfonylureas: Mechanistic and Clinical Evidence

Sulfonylureas are the most commonly used second-line drug class for treating type 2 diabetes mellitus (T2DM). While the cardiovascular safety of sulfonylureas has been examined in several trials and nonrandomized studies, little is known of their specific effects on sudden cardiac arrest (SCA) and related serious arrhythmic outcomes. This knowledge gap is striking, because persons with DM are at increased risk of SCA. In this review, we explore the influence of sulfonylureas on the risk of serious arrhythmias, with specific foci on ischemic preconditioning, cardiac excitability, and serious hypoglycemia as putative mechanisms. Elucidating the relationship between individual sulfonylureas and serious arrhythmias is critical, especially as the diabetes epidemic intensifies and SCA incidence increases in persons with diabetes.

Diabetes treatments and risk of heart failure, cardiovascular disease, and all cause mortality: cohort study in primary care

OBJECTIVE

 To assess associations between risks of cardiovascular disease, heart failure, and all cause mortality and different diabetes drugs in people with type 2 diabetes, particularly newer agents, including gliptins and thiazolidinediones (glitazones).

DESIGN

 Open cohort study.

SETTING

 1243 general practices contributing data to the QResearch database in England.

PARTICIPANTS

 469 688 people with type 2 diabetes aged 25-84 years between 1 April 2007 and 31 January 2015.

EXPOSURES

 Diabetes drugs (glitazones, gliptins, metformin, sulphonylureas, insulin, other) alone and in combination.

MAIN OUTCOME MEASURE

 First recorded diagnoses of cardiovascular disease, heart failure, and all cause mortality recorded on the patients' primary care, mortality, or hospital record. Cox proportional hazards models were used to estimate hazard ratios for diabetes treatments, adjusting for potential confounders.

RESULTS

 During follow-up, 21 308 patients (4.5%) received prescriptions for glitazones and 32 533 (6.9%) received prescriptions for gliptins. Compared with non-use, gliptins were significantly associated with an 18% decreased risk of all cause mortality, a 14% decreased risk of heart failure, and no significant change in risk of cardiovascular disease; corresponding values for glitazones were significantly decreased risks of 23% for all cause mortality, 26% for heart failure, and 25% for cardiovascular disease. Compared with no current treatment, there were no significant associations between monotherapy with gliptins and risk of any complications. Dual treatment with gliptins and metformin was associated with a decreased risk of all three outcomes (reductions of 38% for heart failure, 33% for cardiovascular disease, and 48% for all cause mortality). Triple treatment with metformin, sulphonylureas, and gliptins was associated with a decreased risk of all three outcomes (reductions of 40% for heart failure, 30% for cardiovascular disease, and 51% for all cause mortality). Compared with no current treatment, monotherapy with glitazone was associated with a 50% decreased risk of heart failure, and dual treatment with glitazones and metformin was associated with a decreased risk of all three outcomes (reductions of 50% for heart failure, 54% for cardiovascular disease, and 45% for all cause mortality); dual treatment with glitazones and sulphonylureas was associated with risk reductions of 35% for heart failure and 25% for cardiovascular disease; triple treatment with metformin, sulphonylureas, and glitazones was associated with decreased risks of all three outcomes (reductions of 46% for heart failure, 41% for cardiovascular disease, and 56% for all cause mortality).

CONCLUSIONS

 There are clinically important differences in risk of cardiovascular disease, heart failure, and all cause mortality between different diabetes drugs alone and in combination. Overall, use of gliptins or glitazones was associated with decreased risks of heart failure, cardiovascular disease, and all cause mortality compared with non-use of these drugs. These results, which do not account for levels of adherence or dosage information and which are subject to confounding by indication, might have implications for prescribing of diabetes drugs.

Cardiovascular safety of sulphonylureas: over 40 years of continuous controversy without an answer

More than 40 years after publication of the University Group Diabetes Program trial, the cardiovascular safety of sulphonylureas is still contentious. Although several hypotheses linking sulphonylureas to adverse cardiovascular effects exist, none provide conclusive evidence. Adding to the controversy, current clinical trials and observational studies provide inconsistent, and sometimes conflicting, evidence for the cardiovascular effects of sulphonylureas. Overall, observational evidence suggests that an increased risk of adverse cardiovascular outcomes is associated with sulphonylureas; however, these data may be subject to residual confounding and bias. Although evidence from randomized controlled trials has suggested a neutral effect, the majority of these studies were not specifically designed to assess the effect of sulphonylureas on adverse cardiovascular event risk. Current ongoing large clinical trials may provide some clarity on the cardiovascular safety of sulphonylureas, but the results are not expected for several years. With the continued uncertainties concerning the cardiovascular safety of all antidiabetic drugs, a clear answer with regard to sulphonylureas is warranted. The objectives of the present article were to provide an overview of the controversy surrounding sulphonylurea-related cardiovascular effects, to discuss the limitations of the current literature, and to provide recommendations for future studies aiming to elucidate the true relationship between sulphonylureas and adverse cardiovascular effects in people with type 2 diabetes.

[Pharmaceutical and insulin therapy of diabetes mellitus type 2. Update]

BACKGROUND

The prevalence of diabetes mellitus type 2 in the adult population is > 7 %. Despite new therapy options and modern insulins, the therapy remains a challenge. Especially in patients with obesity or high insulin resistance it is often difficult to achieve the necessary target values. In most cases the disease is initially asymptomatic so that the aim is the early recognition and avoidance of complications.

MATERIAL AND METHODS

This article provides an update on the approach options of modern therapy forms in diabetes management.

RESULTS

The foundations of every treatment program are lifestyle interventions, including diabetes schooling. When these fail a pharmaceutical therapy must be initiated which among others is oriented to hemoglobin A1c (HbA1c). The HbA1c target value should take patient-specific circumstances into consideration and should be determined together with the patient. If no contraindications or intolerances are present, metformin is the medication of choice. Apart from metformin, the available data which can be used for guidance are limited. A combination therapy with one or two other oral or injectable medications is suitable to keep the side effects as low as possible. The advantages of other substances in individual cases could be a lower risk of hypoglycemia, reduced weight increase, oral administration and compatibility with renal insufficiency. Ultimately, insulin therapy will be necessary for many patients, either as monotherapy or in combination with other substances. Therapy decisions should be made together with the patient, taking personal preferences into consideration and should include age, body weight, comorbidities, occupational situation and compliance.

CONCLUSION

The Reorganization of the Pharmaceutical Market Act represents a momentarily perceived clear barrier. In the interests of an individualized therapy and personalized disease management, a target-aimed flexibility in diabetes management should be possible in the future.

Probing SGLT2 as a therapeutic target for diabetes: basic physiology and consequences

Traditional treatments for type 1 and type 2 diabetes are often associated with side effects, including weight gain and hypoglycaemia that may offset the benefits of blood glucose lowering. The kidneys filter and reabsorb large amounts of glucose, and urine is almost free of glucose in normoglycaemia. The sodium-dependent glucose transporter (SGLT)-2 in the early proximal tubule reabsorbs the majority of filtered glucose. Remaining glucose is reabsorbed by SGLT1 in the late proximal tubule. Diabetes enhances renal glucose reabsorption by increasing the tubular glucose load and the expression of SGLT2 (as shown in mice), which maintains hyperglycaemia. Inhibitors of SGLT2 enhance urinary glucose excretion and thereby lower blood glucose levels in type 1 and type 2 diabetes. The load-dependent increase in SGLT1-mediated glucose reabsorption explains why SGLT2 inhibitors in normoglycaemic conditions enhance urinary glucose excretion to only ~50% of the filtered glucose. The role of SGLT1 in both renal and intestinal glucose reabsorption provides a rationale for the development of dual SGLT1/2 inhibitors. SGLT2 inhibitors lower blood glucose levels independent of insulin and induce pleiotropic actions that may be relevant in the context of lowering cardiovascular risk. Ongoing long-term clinical studies will determine whether SGLT2 inhibitors have a safety profile and exert cardiovascular benefits that are superior to traditional agents.

Mortality risk among sulfonylureas: a systematic review and network meta-analysis

BACKGROUND

Sulfonylureas are common second-line options for management of type 2 diabetes; however, they are associated with a higher risk of cardiovascular events compared with other antidiabetic drugs. Since tissue selectivity and risk of hypoglycaemia differ among sulfonylureas, we aimed to assess whether mortality and the risk of cardiovascular events also varies.

METHODS

We searched Medline and Embase from inception to June 11, 2014, to identify controlled studies reporting the risk of all-cause mortality, cardiovascular-related mortality, or myocardial infarction for at least two sulfonylureas. We examined differences in cardiovascular event risk among sulfonylureas with random effects models for direct pairwise comparisons and network meta-analyses to incorporate direct and indirect data.

FINDINGS

14 970 (9%) of 167 327 patients in 18 studies died: 841 (4%) of 19 334 gliclazide users, 5482 (11%) of 49 389 glimepiride users, 2106 (15%) of 14 464 glipizide users, 5296 (7%) of 77 169 glibenclamide users, 1066 (17%) of 6187 tolbutamide users, and 179 (23%) of 784 chlorpropamide users. Inconsistency was low for the network meta-analysis of all-cause mortality, and the relative risk of death compared with glibenclamide was 0·65 (95% credible interval 0·53-0·79) for gliclazide, 0·83 (0·68-1·00) for glimepiride, 0·98 (0·80-1·19) for glipizide, 1·13 (0·90-1·42) for tolbutamide, and 1·34 (0·98-1·86) for chlorpropamide. Similar associations were noted for cardiovascular-related mortality: the relative risk compared with glibenclamide was 0·60 (95% credible interval 0·45-0·84) for gliclazide, 0·79 (0·57-1·11) for glimepiride, 1·01 (0·72-1·43) for glipizide, 1·11 (0·79-1·55) for tolbutamide, and 1·45 (0·88-2·44) for chlorpropamide.

INTERPRETATION

Gliclazide and glimepiride were associated with a lower risk of all-cause and cardiovascular-related mortality compared with glibenclamide. Clinicians should consider possible differences in risk of mortality when selecting a sulfonylurea.

FUNDING

None.

What are the preferred strategies for control of glycaemic variability in patients with type 2 diabetes mellitus?

The aim of therapy in type 2 diabetes in terms of blood glucose control is to reduce to target levels HbA1c and to reduce glycaemic variability in order to avoid both hypoglycaemia and wide excursions of postprandial glucose. The first approach to reduce glycaemic variability should consider a dietary and behavioural approach aiming to limit the glycaemic index and the glycaemic load of food and the prescription and implementation of a physical activity plan appropriate for the subject. From the pharmacological point of view, the diabetes specialist has now a much richer therapeutic armamentarium. The therapeutic algorithms can help the physician to choose the most appropriate drug. The traditional approach involves: i) metformin, acting mainly on fasting blood glucose; ii) sulphonylureas, that have shown a number of drawbacks, including the high risk of hypoglycemia; iii) pioglitazone, with a substantial effect on fasting and postprandial glucose and a low risk of hypoglycaemia; iv) insulin, that can be utilized with the basal or prandial approach. The new drugs belonging to the class of dipeptidyl peptidase-4 inhibitors have shown the reduction of postprandial glucose, a neutral effect on weight increase, a good safety profile and preliminary positive cardiovascular effects. When excess weight prevails, the glucagon-like peptide-1 agonists may be the preferred choice for their effect on weight reduction, reduction of hyperinsulinism and glycaemic variability.

Combine and conquer: advantages and disadvantages of fixed-dose combination therapy

The majority of patients with type 2 diabetes mellitus (T2DM) do not achieve the glycaemic goals recommended by leading diabetes organizations using monotherapy alone, and often require multiple antihyperglycaemic agents to achieve glycaemic control. Fixed-dose combination (FDC) therapies offer a means to simplify complex treatment regimens, and have several advantages that help patients reach their glycaemic goals. In this review, four key benefits are identified and discussed in support of FDCs for treatment of patients with T2DM: (i) Greater efficacy compared with higher dose monotherapy, (ii) Reduced risk of adverse reactions relative to higher dose monotherapy, (iii) Lower overall costs and (iv) Improved medication concordance. Given these advantages, the place of fixed combination therapy in the course of treatment is discussed. Establishing a therapeutic strategy that incorporates fixed combination therapy (including combinations with insulin) will simplify the treatment of diabetes, ideally resulting in improved medication concordance, clinical outcomes and quality of life for patients with T2DM.

Protective effects of Quercus salicina on alloxan-induced oxidative stress in HIT-T15 pancreatic β cells

The present study was designed to investigate the protective effect of hot water extracts from Quercus salicina leaves (QSWE) on alloxan-induced oxidative stress in HIT-T15 Syrian hamster pancreatic insulinoma cells. The HIT-T15 cells were treated with alloxan (1 mM) for 1 h and then co-incubated with the QSWE for 24 h. Alloxan significantly decreased the viability of the HIT-T15 cells (P<0.05). QSWE did not exhibit significantly cytotoxic effects and increased the viability of the HIT-T15 cells in a concentration-dependent manner. To further investigate the protective effects of QSWE on alloxan-induced oxidative stress in HIT-T15 cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation and endogenous antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px), were analyzed. QSWE decreased the intracellular levels of ROS and lipid peroxidation and increased the activity of antioxidant enzymes. These results suggest that QSWE exerted cytoprotective activity against alloxan-induced oxidative stress in HIT-T15 cells through the inhibition of lipid peroxidation, reduction of ROS levels and stimulation of antioxidant enzyme activity. In addition, QSWE also increased the insulin secretion activity of the alloxan-treated HIT-T15 cells.

Inpatient treatment of type 2 diabetes

BACKGROUND

Type 2 diabetes is common in hospitalized patients and is often accompanied by comorbidities; it is thus reasonable to ask whether the current standard treatments for type 2 diabetes are suitable for in-hospital use. We discuss the current glucose-lowering strategies and glycemic targets and derive practical recommendations for their application in hospitalized patients.

METHODS

The pertinent literature, including clinical trials, review articles, guidelines, and manufacturers' information is selectively reviewed.

RESULTS

In critically ill patients with diabetes, the glucose concentration target value should be 140 to 180 mg/dL. In stable patients, the target should be less than 140 mg/dL in the fasting state and less than 180 mg/dL after meals. Hypoglycemic episodes should be strictly avoided. Temporary treatment with insulin is indicated for most hospitalized patients with diabetes, although oral antidiabetic agents may be continued if the hospitalization is expected to be brief. Intravenous insulin is advisable in certain situations, e.g., long operations or metabolic decompensation. Glucose-lowering strategies must be chosen individually for each patient, with consideration of the relevant comorbidities (e.g. coronary heart disease, congestive heart failure, cirrhosis, renal failure) and special conditions (e.g. prolonged fasting, administration of contrast agents, high-dose glucocorticoid treatment).

CONCLUSION

The treatment of patients with type 2 diabetes in the hospital is very different from their treatment at home. The particular conditions and comorbidities that can arise in the hospital necessitate flexible, individualized strategies for lowering blood glucose concentration.

Glycemic control and cardiovascular disease: what's a doctor to do?

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in individuals with diabetes mellitus. Moreover, rates of CVD mortality are two to four times higher in diabetes than in those without diabetes. It was conventional thinking that achieving near-normoglycemia would help reduce CVD risk and overall mortality in type 2 diabetes mellitus. Several recent large trials attempted to answer this question using a randomized control trial design with a conventional therapy and an intensive control arm. Surprisingly, these trials did not demonstrate neither mortality nor a CVD advantage with intensive glycemic control. Moreover, some studies (e.g., the ACCORD [Action to Control Cardiovascular Risk in Diabetes] study) showed increased mortality in the intensive control arm. In this review, our goal is to summarize the findings of the major trials in this field and to explore the potential reasons for why these trials had largely negative results. We conclude with some lessons that may be applied to the clinical management of patients with diabetes.

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.

Strategies for optimizing glycemic control and cardiovascular prognosis in patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) is a major cardiovascular (CV) risk factor and, as such, is considered a coronary artery disease risk equivalent. Although glycemic control is associated with decreased CV events epidemiologically, many prospective clinical trials have failed to conclusively demonstrate that aggressive glycemic control improves the CV prognosis of patients with type 2 DM, especially those with long-standing DM. Many therapies for type 2 DM with widely divergent mechanisms of action are available. Some of these drugs, in addition to their glucose-lowering actions, have properties that may reduce or increase CV events. Agents that lower both insulin resistance and postprandial hyperglycemia while at the same time avoiding hypoglycemia may be beneficial for CV health. This article reviews the evidence regarding the use of these agents and appropriate glycemic control targets for improving the adverse CV prognosis associated with type 2 DM. We conducted a systematic review of English articles using MEDLINE and the Cochrane Controlled Trials Register (1970-2010) using the following search terms: cardiovascular disease, randomized trials, hypoglycemia, and insulin resistance.

Risk of cardiovascular disease and all cause mortality among patients with type 2 diabetes prescribed oral antidiabetes drugs: retrospective cohort study using UK general practice research database

OBJECTIVE

To investigate the risk of incident myocardial infarction, congestive heart failure, and all cause mortality associated with prescription of oral antidiabetes drugs.

DESIGN

Retrospective cohort study.

SETTING

UK general practice research database, 1990-2005.

PARTICIPANTS

91,521 people with diabetes.

MAIN OUTCOME MEASURES

Incident myocardial infarction, congestive heart failure, and all cause mortality. Person time intervals for drug treatment were categorised by drug class, excluding non-drug intervals and intervals for insulin.

RESULTS

3588 incident cases of myocardial infarction, 6900 of congestive heart failure, and 18,548 deaths occurred. Compared with metformin, monotherapy with first or second generation sulphonylureas was associated with a significant 24% to 61% excess risk for all cause mortality (P<0.001) and second generation sulphonylureas with an 18% to 30% excess risk for congestive heart failure (P=0.01 and P<0.001). The thiazolidinediones were not associated with risk of myocardial infarction; pioglitazone was associated with a significant 31% to 39% lower risk of all cause mortality (P=0.02 to P<0.001) compared with metformin. Among the thiazolidinediones, rosiglitazone was associated with a 34% to 41% higher risk of all cause mortality (P=0.14 to P=0.01) compared with pioglitazone. A large number of potential confounders were accounted for in the study; however, the possibility of residual confounding or confounding by indication (differences in prognostic factors between drug groups) cannot be excluded.

CONCLUSIONS

Our findings suggest a relatively unfavourable risk profile of sulphonylureas compared with metformin for all outcomes examined. Pioglitazone was associated with reduced all cause mortality compared with metformin. Pioglitazone also had a favourable risk profile compared with rosiglitazone; although this requires replication in other studies, it may have implications for prescribing within this class of drugs.

Impact of glycemic treatment choices on cardiovascular complications in type 2 diabetes

As the diabetic population has significant morbidity and mortality from cardiovascular disease (CVD), much of its medical care focuses on CVD prevention and treatment. Some medications used to treat hyperglycemia may have beneficial effects on CV outcomes, others may have negative effects, while still others seem to have no direct effect. Although past epidemiological studies have shown a relationship between glycated hemoglobin levels and CV events in patients with type 2 diabetes, recent large randomized clinical trials (ACCORD, ADVANCE, and VADT) lasting 3.5 to 5.6 years have found that intensive glycemic control either has no impact on CV outcomes or even worsens them. Results of the 10-year follow-up of the UKPDS suggest that tight glycemic control of younger, newly diagnosed patients with type 2 diabetes may have CV benefits many years later. Because the pathogenesis of atherosclerosis spans decades, it may be that beneficial effects of tight glycemic control on CV outcomes are mainly in younger patients without established macrovascular disease. There is an emerging notion that tight glycemic control may be beneficial in primary prevention of CVD in younger patients with diabetes, but may become deleterious in older patients with established or subclinical CVD. Thus, while tight control may lessen microvascular disease, it may increase the risk of hypoglycemia and possibly of adverse CV events. In each patient, the goals of glycemic control need to be individualized based on age, overall prognosis, presence of macrovascular disease, and risk of hypoglycemia.

The risk of developing coronary artery disease or congestive heart failure, and overall mortality, in type 2 diabetic patients receiving rosiglitazone, pioglitazone, metformin, or sulfonylureas: a retrospective analysis

Oral anti-diabetic agents have been associated with adverse cardiovascular events in type 2 diabetes (DM2). We investigated the risk of coronary artery disease (CAD), congestive heart failure (CHF), and mortality using multivariable Cox models in a retrospective cohort of 20,450 DM2 patients from our electronic health record (EHR). We observed no differences in CAD risk among the agents. Metformin was associated with a reduced risk of CHF (HR 0.76, 95% CI 0.64-0.91) and mortality (HR 0.54, 95% CI 0.46-0.64) when compared to sulfonylurea. Pioglitazone was also associated with a lower risk of mortality when compared to sulfonylurea (HR 0.59, 95% CI 0.43-0.81). No other significant differences were found between the oral agents. In conclusions, our results did not identify an increased CAD risk with rosiglitazone in clinical practice. However, the results do reinforce a possible increased risk of adverse events in DM2 patients prescribed sulfonylureas.

Risk of coronary artery disease associated with initial sulphonylurea treatment of patients with type 2 diabetes: a matched case-control study

AIMS

This study sought to assess the risk of developing coronary artery disease (CAD) associated with initial treatment of type 2 diabetes with different sulphonylureas.

METHODS

In type 2 diabetic patients, cases who developed CAD were compared retrospectively with controls that did not. The 20-year risk of CAD at diagnosis of diabetes, using the UKPDS risk engine, was used to match cases with controls.

RESULTS

The 76 cases of CAD were compared with 152 controls. The hazard of developing CAD (95% CI) associated with initial treatment increased by 2.4-fold (1.3-4.3, P=0.004) with glibenclamide; 2-fold (0.9-4.6, P=0.099) with glipizide; 2.9-fold (1.6-5.1, P=0.000) with either, and was unchanged with metformin. The hazard decreased 0.3-fold (0.7-1.7, P=0.385) with glimepiride, 0.4-fold (0.7-1.3, P=0.192) with gliclazide, and 0.4-fold (0.7-1.1, P=0.09) with either.

CONCLUSIONS

Initiating treatment of type 2 diabetes with glibenclamide or glipizide is associated with increased risk of CAD in comparison to gliclazide or glimepiride. If confirmed, this may be important because most Indian patients receive the cheaper older sulphonylureas, and present guidelines do not distinguish between individual agents.

Glucokinase activator PSN-GK1 displays enhanced antihyperglycaemic and insulinotropic actions

AIMS/HYPOTHESIS

We evaluated the insulinotropic and antihyperglycaemic actions of glucokinase activators (GKAs), especially through acute and subchronic studies in rodent diabetes models with (2R)-2-(4-cyclopropanesulphonylphenyl)-N-(5-fluorothiazol-2-yl)-3-(tetrahydropyran-4-yl)propionamide (PSN-GK1), a novel and potent GKA.

MATERIALS AND METHODS

The action of PSN-GK1 on or in the following were investigated: (1) on human liver glucokinase, insulin secretion from MIN6 cells and 2-deoxy-D: -[(3)H]glucose (2-DG) uptake into rat hepatocytes; and (2) in Zucker diabetic fatty rats and in non-diabetic C57Bl/6, diabetic db/db and ob/ob mice.

RESULTS

At 5 mmol/l glucose, PSN-GK1 activated glucokinase (4.3-fold, median effective concentration [EC(50)] 130 nmol/l), increased MIN6 insulin secretion (26-fold, EC(50) 267 nmol/l) and 2-DG hepatocytic uptake (threefold, EC(50) 1 micromol/l); at higher glucose concentrations, EC(50)s and fold-effectiveness were both lower. In C57Bl/6 mice, PSN-GK1 reduced blood glucose at 1 and 10 mg/kg (by mouth), but insulin was increased significantly at only the higher dose. In hyperinsulinaemic 10-mmol/l glucose clamps, PSN-GK1 increased 2-DG incorporation into liver glycogen sixfold, directly demonstrating liver effects. PSN-GK1 improved glycaemic profiles in db/db mice and Zucker diabetic fatty rats, diabetic animal models in which GKA efficacy has not previously been described, without causing hypoglycaemia. In ob/ob mice, it dose-dependently reduced excursions in OGTTs. Moreover, after subchronic administration, no tachyphylaxis was evident and glycaemia was improved without alterations to lipid levels, liver weight, glycogen content or body weight.

CONCLUSIONS/INTERPRETATION

PSN-GK1 was potently antihyperglycaemic through its effects on insulin release and hepatic glucose metabolism. It is one of the most potent GKAs described in the literature and is active in diabetic animal models where GKAs have not been reported to show efficacy to date. Ongoing human trials are investigating the potential of this novel therapeutic approach.

Progress in the treatment of type 2 diabetes: new pharmacologic approaches to improve glycemic control

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a leading cause of morbidity and mortality that places a substantial economic and health burden on the public. Successful management of T2DM requires strict control of glycemia as well as other risk factors to prevent disease progression. Despite the availability of multiple classes of oral antidiabetic drugs and insulin, the majority of patients fail to attain or maintain tight glycemic control over time, raising their risk of serious microvascular and macrovascular complications.

SCOPE

This review briefly outlines current standards of diabetes treatment and explores several new and investigational approaches. It is based on MEDLINE literature searches (1966-August 2006) and on abstracts from the American Diabetes Association Scientific Sessions (2002-2006) and the European Association for the Study of Diabetes Annual Meetings (1998-2006). Articles concerning basic science, preclinical, and clinical trial results were selected for this review based on their originality and relevance.

FINDINGS

Medical professional societies and other specialist groups have proposed a series of practical steps to enable more patients with T2DM to reach treatment goals. Among their most important recommendations is a call for new drugs to stabilize or reverse the progressive pancreatic islet-cell dysfunction that characterizes the disease. New modalities, such as incretin mimetics and DPP-4 inhibitors, are now emerging from clinical development and will provide patients with more treatment options.

CONCLUSIONS

It appears likely that early and aggressive treatment with multiple drug combinations will become more common in the management of T2DM. The new treatment modalities discussed here offer hope for improved outcomes and for meeting the considerable public health challenges posed by this complex condition. However, long-term studies are needed to determine durability of treatment effects, as well as the ultimate role of these new agents in the management of patients with T2DM.