Glycemic management of type 2 diabetes: an emerging strategy with oral agents, insulins, and combinations

Renoprotective Effects of the Dipeptidyl Peptidase-4 Inhibitor Sitagliptin: A Review in Type 2 Diabetes

Diabetic nephropathy (DN) is now the single commonest cause of end-stage renal disease (ESRD) worldwide and one of the main causes of death in diabetic patients. It is also acknowledged as an independent risk factor for cardiovascular disease (CVD). Since sitagliptin was approved, many studies have been carried out revealing its ability to not only improve metabolic control but also ameliorate dysfunction in various diabetes-targeted organs, especially the kidney, due to putative underlying cytoprotective properties, namely, its antiapoptotic, antioxidant, anti-inflammatory, and antifibrotic properties. Despite overall recommendations, many patients spend a long time well outside the recommended glycaemic range and, therefore, have an increased risk for developing micro- and macrovascular complications. Currently, it is becoming clearer that type 2 diabetes mellitus (T2DM) management must envision not only the improvement in glycaemic control but also, and particularly, the prevention of pancreatic deterioration and the evolution of complications, such as DN. This review aims to provide an overview of the current knowledge in the field of renoprotective actions of sitagliptin, namely, improvement in diabetic dysmetabolism, hemodynamic factors, renal function, diabetic kidney lesions, and cytoprotective properties.

The classification of hospitalized patients with hyperglycemia and its implication on outcome: results from a prospective observational study in Internal Medicine

The relevance of classifying hyperglycemic hospitalized subjects (HS) as known diabetes (D), newly discovered diabetes (ND), and stress hyperglycemia (SH) is unclear. The aim of this study was to determine the prevalence, in-hospital mortality, and length of stay (LOS) of three different phenotypes of HS. Fasting glucose ≥126 mg/dL (7 mmol/L) or random blood glucose ≥200 mg/dL (11.1 mmol/L) defined HS who were categorized into three groups: D; ND (no history of diabetes and HbA1c ≥48 mmol/mol); SH (no history of diabetes and HbA1c <48 mmol/mol). The end points of the study were in-hospital mortality and LOS. Of 1447 consecutive enrolled subjects, the prevalence of HS was 28.6 % (415/1447), of these 71.6 % had D, 21.2 % SH, and 7.2 % ND, respectively. In-hospital death was 3.9 % in normoglycemic and 6.0 % in hyperglycemic subjects. Individuals with SH had an increased risk of in-hospital death (7.9 %) (HR 2.17, 95 % CI 1.18-4.9; p = 0.039), while this was not observed for D and ND patients. The mean LOS was greater in ND and SH subjects. Hyperglycemia is common, and is associated with an increased risk of in-hospital mortality and extension of hospital stay. HbA1c along with clinical history is a useful tool to identify subgroups of hyperglycemic hospitalized subjects. Individuals with SH have a longer LOS, and a double risk of in-hospital mortality. Additionally, identifying previously unknown diabetes represents a remarkable opportunity for prevention of diabetes-related acute and chronic complications.

An extract of Urtica dioica L. mitigates obesity induced insulin resistance in mice skeletal muscle via protein phosphatase 2A (PP2A)

The leaf extract of Urtica dioica L. (UT) has been reported to improve glucose homeostasis in vivo, but definitive studies on efficacy and mechanism of action are lacking. We investigated the effects of UT on obesity- induced insulin resistance in skeletal muscle. Male C57BL/6J mice were divided into three groups: low-fat diet (LFD), high-fat diet (HFD) and HFD supplemented with UT. Body weight, body composition, plasma glucose and plasma insulin were monitored. Skeletal muscle (gastrocnemius) was analyzed for insulin sensitivity, ceramide accumulation and the post translational modification and activity of protein phosphatase 2A (PP2A). PP2A is activated by ceramides and dephosphorylates Akt. C2C12 myotubes exposed to excess free fatty acids with or without UT were also evaluated for insulin signaling and modulation of PP2A. The HFD induced insulin resistance, increased fasting plasma glucose, enhanced ceramide accumulation and PP2A activity in skeletal muscle. Supplementation with UT improved plasma glucose homeostasis and enhanced skeletal muscle insulin sensitivity without affecting body weight and body composition. In myotubes, UT attenuated the ability of FFAs to induce insulin resistance and PP2A hyperactivity without affecting ceramide accumulation and PP2A expression. UT decreased PP2A activity through posttranslational modification that was accompanied by a reduction in Akt dephosphorylation.

Comparative Efficacy of Adding Sitagliptin to Metformin, Sulfonylurea or Dual Therapy: A Propensity Score-Weighted Cohort Study

INTRODUCTION

The aim of this study was to assess the efficacy of co-administering sitagliptin to patients with inadequate glycemic control following treatment with metformin (MET), sulfonylurea (SU), or MET + SU.

METHODS

A cohort of 25,386 patients with type 2 diabetes mellitus (hemoglobin A1c [HbA1C] >53 mmol/mol or 7%), newly treated with sitagliptin between 2007 and 2013, was sourced from UK general practices via The Health Improvement Network database. Among these, eligible patients were segregated into three groups: MET (n = 3364), SU (n = 509), or MET + SU therapy (n = 5929). The relative efficacy of sitagliptin added to SU or MET + SU compared with sitagliptin added to MET monotherapy was assessed with regards to HbA1c and body weight changes from baseline up to 52 weeks. The glycemic efficacy was a measure of average treatment effects obtained from multivariable linear regression models and propensity score-matching analysis.

RESULTS

A total of 9802 patients were included in the study. Overall, addition of sitagliptin 100 mg once daily resulted in 5.5 mmol/mol (0.5%) HbA1c reduction (P < 0.001) and 0.8 kg weight reduction at 1 year (P < 0.001). Efficacy was similar across the treatment groups, but in patients with baseline HbA1c ≥9% adding sitagliptin to MET + SU produced a significantly smaller reduction in HbA1c when compared to the reference group MET (MET + SU vs. MET only: -0.5% vs. -0.7%, P < 0.001). The mean HbA1c reduction from baseline within this subgroup of patients was not significantly different between SU and MET monotherapies (-0.8% vs. -0.7%, respectively, P = 0.4). Across treatment groups, HbA1c reductions with add-on sitagliptin occurred after 24 weeks of treatment with a peak reduction occurring between 36 and 48 weeks, and receded after week 48.

CONCLUSION

In a real-world general practice setting, sitagliptin was effective in patients with suboptimal glycemic control with MET, SU or dual therapy, maximum between 36 and 48 weeks, but in patients with HbA1c of >9% receiving MET + SU therapy, adding sitagliptin, as a third agent, conferred minimal benefit.

Insulin as a Bridge between Type 2 Diabetes and Alzheimer Disease - How Anti-Diabetics Could be a Solution for Dementia

Type 2 diabetes (T2D) and Alzheimer disease (AD) are two major health issues nowadays. T2D is an ever increasing epidemic, affecting millions of elderly people worldwide, with major repercussions in the patients' daily life. This is mostly due to its chronic complications that may affect brain and constitutes a risk factor for AD. T2D principal hallmark is insulin resistance which also occurs in AD, rendering both pathologies more than mere unrelated diseases. This hypothesis has been reinforced in the recent years, with a high number of studies highlighting the existence of several common molecular links. As such, it is not surprising that AD has been considered as the "type 3 diabetes" or a "brain-specific T2D," supporting the idea that a beneficial therapeutic strategy against T2D might be also beneficial against AD. Herewith, we aim to review some of the recent developments on the common features between T2D and AD, namely on insulin signaling and its participation in the regulation of amyloid β (Aβ) plaque and neurofibrillary tangle formation (the two major neuropathological hallmarks of AD). We also critically analyze the promising field that some anti-T2D drugs may protect against dementia and AD, with a special emphasis on the novel incretin/glucagon-like peptide-1 receptor agonists.

Safety and efficacy of sitagliptin-metformin in fixed combination for the treatment of type 2 diabetes mellitus

The biguanide, metformin, is considered first-line treatment for type 2 diabetes. Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor acts through the incretin pathway and has a glucose dependent mode of action. The complementary hypoglycemic properties of these drugs make fixed dose combination treatment an attractive prospect. Evidence from recent clinical trials suggests a beneficial effect of the combination on efficacy, demonstrated by significant improvement of hemoglobin A1c (HbA1c), fasting and postprandial glucose levels. The fixed dose combination is likely to have greater patient tolerability compared with monotherapy with either agent because of low rates of hypoglycemia, weight neutrality, and lower rates of side effects. High acquisition cost and paucity of long-term safety data are, however, potential barriers to their wider use. An overview of the pharmacology and clinical outcomes from recent trials of the metformin-sitagliptin combination and how the combination could fit into the type 2 diabetes treatment algorithm is presented in this review.

Treatment of type 2 diabetes with saxagliptin: a pharmacoeconomic evaluation in Argentina

BACKGROUND

The increasing prevalence of diabetes and its inadequate management results in a heavy burden of the disease for the patients, the health and the productive system and the overall community. Consequently, it is necessary to have new effective drugs to treat people with diabetes to decrease such burden. DPP-4 inhibitors can help to cope with this demand, but its usage is challenged by its apparent high cost. The aim of the current study was to compare a simulated cost-effectiveness ratio of metformin (MET) plus one drug of the DPP-4 inhibitors family, saxagliptin (SAXA) or sulfonylurea (SU) treatment during a 20-year period, from the perspective of the social security system, in a cohort of people with Type 2 diabetes (T2DM) who did not attain glycosylated hemoglobin treatment target values only with MET.

METHODS

A discrete event simulation model (Cardiff diabetes model) based on UKPDS 68 was used to simulate disease progression and to estimate the economic and health treatment consequences in people with T2DM. The clinical efficacy parameters for SAXA administration were obtained from the literature; local standard costs were considered for drug acquisition, adverse events (AEs), and micro/macrovascular complications. Costs were expressed in US dollars (2009) with an annual 3.5% discount and a 20-year time horizon.

RESULTS

The SAXA + MET treated group had a lower number of non-fatal events than the SU + MET treated group. The model also predicted a lower number of fatal macrovascular events for the SAXA + MET group (149.6 vs. 152.8). The total cost of the SAXA + MET cohort was 15% higher than that of the SU + MET cohort. Treatment with SAXA + MET resulted in a higher number of quality-adjusted life years (QALYs) (9.54 vs. 9.32) and life-years gained (LYGs) (20.84 vs. 20.76) compared to those treated with SU + MET. The incremental cost per QALY and LYG gained was $7,374 and $20,490, respectively.

CONCLUSIONS

According to the criteria proposed by the Commission on Macroeconomics and Health, the use of the combination SAXA + MET is highly cost-effective in Argentina.

Intensification of insulin therapy in patients with type 2 diabetes mellitus: an algorithm for basal-bolus therapy

The incidence of diabetes mellitus is projected to continue to increase worldwide over the next 20 years leading to increased costs in the management of the disease and its associated co-morbidities. Insulin replacement is one of many treatment options that can help to bring about near normoglycemia in the patient with type 2 diabetes mellitus (T2DM). Glycemic control as close to normoglycemia as possible can help to reduce the risk of microvascular and macrovascular complications, yet less than one-half of patients with T2DM achieve glycemic targets as recommended by practice guidelines. The purpose of this review is to provide guidance to primary care physicians for the initiation and intensification of basal-bolus insulin therapy in patients with T2DM. Two treatment algorithms that can be both patient- and physician-driven are proposed: a stepwise approach and a multiple daily injections approach. Evidence shaping the two approaches will be discussed alongside management issues that surround the patient treated with insulin: hypoglycemia, weight gain, patient education, and quality of life.

Efficacy and safety of exenatide once-weekly vs exenatide twice-daily in Asian patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

To compare safety and efficacy of the extended-release formulation exenatide once weekly (EQW) vs exenatide twice daily (EBID) for 26 weeks in type 2 diabetes patients from China, India, Japan, South Korea and Taiwan.

MATERIALS AND METHODS

A randomized, comparator-controlled, open-label study included 681 patients with type 2 diabetes inadequately controlled (hemoglobin A1c [HbA1c] ≥7 and ≤11%) with oral antihyperglycemic medications (OAMs). Patients added 2 mg EQW or 10 μg EBID to current OAMs. Safety was re-evaluated 10 weeks after last treatment.

RESULTS

EQW was superior to EBID on HbA1c measures at week 26 (Least-squares mean treatment difference: -0.31% [95% confidence interval -0.49, -0.14%]). More EQW-treated patients achieved target HbA1c ≤7.0% (P = 0.003), ≤6.5% (P < 0.001), or ≤6.0% (P = 0.003). Fasting serum glucose reductions were greater among EQW-treated patients (P < 0.001). Blood glucose profiles improved in both treatment groups (P < 0.001). Weight loss occurred with both treatments, but was greater with EBID. Adverse events (≥10%, either group) were nausea, injection-site induration, dyslipidemia and vomiting. Injection-site induration was more frequent with EQW, whereas nausea, vomiting and hypoglycemia were less frequent. One episode each of major hypoglycemia (EBID) and pancreatitis (EQW) were reported.

CONCLUSION

In this population, EQW and EBID showed efficacious glucose and weight control; safety and tolerability were consistent with observations in non-Asian patients. This trial was registered with ClinicalTrials.gov (no. NCT00917267).

Simultaneous quantification of metformin and glipizide in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study

A selective, sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated to determine metformin and glipizide simultaneously in human plasma using phenacetin as internal standard (IS). After one-step protein precipitation of 200 μL plasma with methanol, metformin, glipizide and IS were separated on a Kromasil Phenyl column (4.6 × 150 mm, 5 µm) at 40°C with an isocratic mobile phase consisting of methanol-10 mmol/L ammonium acetate (75:25, v/v) at a flow rate of 0.35 mL/min. Electrospray ionization source was applied and operated in the positive mode. Multiple reaction monitoring using the precursor → product ion combinations of m/z 130 → m/z 71, m/z 446 → m/z 321 and m/z 180 → m/z 110 were used to quantify metformin, glipizide and IS, respectively. The linear calibration curves were obtained over the concentration ranges 4.10-656 ng/mL for metformin and 2.55-408 ng/mL for glipizide. The relative standard deviation of intra-day and inter-day precision was below 10% and the relative error of accuracy was between -7.0 and 4.6%. The presented HPLC-MS/MS method was proved to be suitable for the pharmacokinetic study of metformin hydrochloride and glipizide tablets in healthy volunteers after oral administration.

Initial therapy with the fixed-dose combination of sitagliptin and metformin results in greater improvement in glycaemic control compared with pioglitazone monotherapy in patients with type 2 diabetes

AIMS

To evaluate the efficacy and safety of initial therapy with a fixed-dose combination (FDC) of sitagliptin and metformin compared with pioglitazone in drug-naÏve patients with type 2 diabetes.

METHODS

After a 2-week single-blind placebo run-in period, patients with type 2 diabetes, HbA1c of 7.5-12% and not on antihyperglycaemic agent therapy were randomized in a double-blind manner to initial treatment with a FDC of sitagliptin/metformin 50/500 mg twice daily (N = 261) or pioglitazone 30 mg per day (N = 256). Sitagliptin/metformin and pioglitazone were up-titrated over 4 weeks to doses of 50/1000 mg twice daily and 45 mg per day, respectively. Both treatments were then continued for an additional 28 weeks.

RESULTS

From a mean baseline HbA1c of 8.9% in both groups, least squares (LS) mean changes in HbA1c at week 32 were -1.9 and -1.4% for sitagliptin/metformin and pioglitazone, respectively (between-group difference = -0.5%; p < 0.001). A greater proportion of patients had an HbA1c of <7% at week 32 with sitagliptin/metformin vs. pioglitazone (57% vs. 43%, p < 0.001). Compared with pioglitazone, sitagliptin/metformin treatment resulted in greater LS mean reductions in fasting plasma glucose (FPG) [-56.0 mg/dl (-3.11 mmol/l) vs. -44.0 mg/dl (-2.45 mmol/l), p < 0.001] and in 2-h post-meal glucose [-102.2 mg/dl (-5.68 mmol/l) vs. -82.0 mg/dl (-4.56 mmol/l), p < 0.001] at week 32. A substantially greater reduction in FPG [-40.5 mg/dl (-2.25 mmol/l) vs. -13.0 mg/dl (-0.72 mmol/l), p < 0.001] was observed at week 1 with sitagliptin/metformin vs. pioglitazone. A greater reduction in the fasting proinsulin/insulin ratio and a greater increase in homeostasis model assessment of β-cell function (HOMA-β) were observed with sitagliptin/metformin than with pioglitazone, while greater decreases in fasting insulin and HOMA of insulin resistance (HOMA-IR), and a greater increase in quantitative insulin sensitivity check index (QUICKI) were observed with pioglitazone than with sitagliptin/metformin. Both sitagliptin/metformin and pioglitazone were generally well tolerated. Sitagliptin/metformin led to weight loss (-1.4 kg), while pioglitazone led to weight gain (3.0 kg) (p < 0.001 for the between-group difference). Higher incidences of diarrhoea (15.3% vs. 4.3%, p < 0.001), nausea (4.6% vs. 1.2%, p = 0.02) and vomiting (1.9% vs. 0.0%, p = 0.026), and a lower incidence of oedema (1.1% vs. 7.0%, p < 0.001), were observed with sitagliptin/metformin vs. pioglitazone. The between-group difference in the incidence of hypoglycaemia did not reach statistical significance (8.4 and 4.3% with sitagliptin/metformin and pioglitazone, respectively; p = 0.055).

CONCLUSION

Compared with pioglitazone, initial therapy with a FDC of sitagliptin and metformin led to significantly greater improvement in glycaemic control as well as a higher incidence of prespecified gastrointestinal adverse events, a lower incidence of oedema and weight loss vs. weight gain.

Evolving treatment strategies for the management of type 2 diabetes

It is well known that improved metabolic control significantly reduces both micro- and macrovascular complications in diabetes. As it relates to specific treatment of type 2 diabetes mellitus, clinicians have traditionally initiated lifestyle intervention and progressed therapy using various drug treatments first as monotherapy and then as combination therapy throughout the course of the disease. This "stepwise" strategy has not always achieved the desired outcome of normal glycemic control; consequently, several clinical problems, such as hypoglycemia, weight gain and postprandial hyperglycemia, persist. However, new therapies that improve glycemic control and have favorable effects to address the unmet clinical problems have recently been developed or are still in development. These therapies include 2 classes of incretin-directed therapy, the dipeptidyl peptidase-4 inhibitors and the glucagon-like peptide-1 agonists, which help restore physiologic levels and activity of the incretin glucagon-like peptide-1. Also in development are additional therapies that have effects on the kidney to promote glucose excretion. These therapies are proposed to treat the key metabolic abnormalities associated with type 2 diabetes mellitus and minimize the side effects noted with conventional therapies.

Comprehensive evidence-based assessment and prioritization of potential antidiabetic medicinal plants: a case study from canadian eastern james bay cree traditional medicine

Canadian Aboriginals, like others globally, suffer from disproportionately high rates of diabetes. A comprehensive evidence-based approach was therefore developed to study potential antidiabetic medicinal plants stemming from Canadian Aboriginal Traditional Medicine to provide culturally adapted complementary and alternative treatment options. Key elements of pathophysiology of diabetes and of related contemporary drug therapy are presented to highlight relevant cellular and molecular targets for medicinal plants. Potential antidiabetic plants were identified using a novel ethnobotanical method based on a set of diabetes symptoms. The most promising species were screened for primary (glucose-lowering) and secondary (toxicity, drug interactions, complications) antidiabetic activity by using a comprehensive platform of in vitro cell-based and cell-free bioassays. The most active species were studied further for their mechanism of action and their active principles identified though bioassay-guided fractionation. Biological activity of key species was confirmed in animal models of diabetes. These in vitro and in vivo findings are the basis for evidence-based prioritization of antidiabetic plants. In parallel, plants were also prioritized by Cree Elders and healers according to their Traditional Medicine paradigm. This case study highlights the convergence of modern science and Traditional Medicine while providing a model that can be adapted to other Aboriginal realities worldwide.

Sitagliptin more effectively achieves a composite endpoint for A1C reduction, lack of hypoglycemia and no body weight gain compared with glipizide

Sitagliptin and glipizide added to metformin provided similar degrees of glycemic efficacy in patients with type 2 diabetes with inadequate glycemic control on metformin monotherapy at 1 year; however, significantly more patients in the sitagliptin group achieved an A1C reduction of >0.5% without hypoglycemia and without an increase in body weight.

Improved glycemic control and reduced bodyweight with exenatide: A double-blind, randomized, phase 3 study in Japanese patients with suboptimally controlled type 2 diabetes over 24 weeks

Aims/Introduction:  To evaluate the efficacy and safety of the glucagon-like peptide-1 receptor agonist, exenatide, in Japanese patients with type 2 diabetes mellitus suboptimally controlled despite therapeutic doses of a sulfonylurea alone or combined with a biguanide or thiazolidinedione.

MATERIALS AND METHODS

  Patients were randomized to a placebo or exenatide, either 5 or 10 μg, given subcutaneously b.i.d. in addition to oral therapy. Patients randomized to 10 μg exenatide received 5 μg b.i.d. for the first 4 weeks, followed by 10 μg b.i.d. for the last 20 weeks.

RESULTS

  A total of 179 patients received the study drug and composed the full analysis set (n = 35, placebo; n = 72, exenatide 5 μg; n = 72, exenatide 10 μg; 68% male; 58 ± 10 years; body mass index 25.5 ± 4.1 kg/m(2); HbA1c 8.2 ± 0.9%; means ± standard deviations). Baseline to end-point (least-squares means ± standard errors) HbA1c changes (%) were -0.28 ± 0.15 (placebo), -1.34 ± 0.11 (exenatide 5 μg) and -1.62 ± 0.11 (exenatide 10 μg) (both P < 0.001, exenatide vs placebo). Baseline to end-point bodyweight changes (kg) were -0.47 ± 0.39 (placebo), -0.39 ± 0.28 (exenatide 5 μg) and -1.54 ± 0.27 (exenatide 10 μg; P = 0.026, exenatide 10 μg vs placebo). Nausea, generally mild to moderate, was reported in 8.6% (placebo), 25.0% (exenatide 5 μg) and 36.1% (exenatide 10 μg) of patients. Mild to moderate hypoglycemia was reported in 22.9% (placebo), 51.4% (exenatide 5 μg) and 58.3% (exenatide 10 μg) of patients.

CONCLUSIONS

  Over 24 weeks, exenatide vs the placebo improved glycemic control, reduced bodyweight (10 μg) and was well tolerated in Japanese patients with type 2 diabetes mellitus suboptimally controlled, despite oral therapy including a sulfonylurea. This trial was registered with ClinicalTrials.gov (no. NCT00577824). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00084.x, 2011).

Clinical utility of fixed combinations of sitagliptin-metformin in treatment of type 2 diabetes

Adequate glycemic control in type 2 diabetes remains a difficult but achievable goal. The development of new classes of glucose-lowering medications, including in particular the incretin-based therapies, provides an opportunity to utilize combinations of medications which target multiple physiologic abnormalities in type 2 diabetes. Complementary combination therapy with sitagliptin-metformin lowers glucose via enhancement of insulin secretion, suppression of glucagon secretion, and insulin sensitization. Use of this combination in diabetes management will provide a greater degree of glycosylated hemoglobin-lowering than that seen with the use of either drug as monotherapy, is unlikely to cause significant hypoglycemia, and is generally associated with weight loss. The effectiveness, tolerability, and potential cost savings associated with the use of sitagliptin-metformin combination therapy make this an attractive option in diabetes management. The possible beneficial effects of this therapy on beta cell function, as well as its cardiovascular impact, remain inadequately explored but are of significant interest.

An extract of Artemisia dracunculus L. enhances insulin receptor signaling and modulates gene expression in skeletal muscle in KK-A(y) mice

An ethanolic extract of Artemisia dracunculus L. (PMI 5011) has been observed to decrease glucose and insulin levels in animal models, but the cellular mechanisms by which insulin action is enhanced in vivo are not precisely known. In this study, we evaluated the effects of PMI 5011 to modulate gene expression and cellular signaling through the insulin receptor in skeletal muscle of KK-A(y) mice. Eighteen male KK-A(y) mice were randomized to a diet (w/w) mixed with PMI 5011 (1%) or diet alone for 8 weeks. Food intake, adiposity, glucose and insulin were assessed over the study, and at study completion, vastus lateralis muscle was obtained to assess insulin signaling parameters and gene expression. Animals randomized to PMI 5011 were shown to have enhanced insulin sensitivity and increased insulin receptor signaling, i.e., IRS-associated PI-3 kinase activity, Akt-1 activity and Akt phosphorylation, in skeletal muscle when compared to control animals (P<.01, P<.01 and P<.001, respectively). Gene expression for insulin signaling proteins, i.e., IRS-1, PI-3 kinase and Glut-4, was not increased, although a relative increase in protein abundance was noted with PMI 5011 treatment. Gene expression for specific ubiquitin proteins and specific 20S proteasome activity, in addition to skeletal muscle phosphatase activity, i.e., PTP1B activity, was significantly decreased in mice randomized to PMI 5011 relative to control. Thus, the data demonstrate that PMI 5011 increases insulin sensitivity and enhances insulin receptor signaling in an animal model of insulin resistance. PMI 5011 may modulate skeletal muscle protein degradation and phosphatase activity as a possible mode of action.

Current concepts about chromium supplementation in type 2 diabetes and insulin resistance

Chromium has been established to be an essential trace element in mammals in regard to maintenance of normal carbohydrate metabolism. Studies that provided chromium to human subjects in documented deficiency states noted improved glucose levels. However, controversy exists as to whether dietary supplementation with chromium should be routinely recommended in subjects without documented deficiencies. Over the recent past, several well-designed clinical trials have provided evidence in favor of and against a beneficial effect of chromium. It appears that across all subject phenotypes (eg, lean and obese, insulin sensitive and insulin resistant), a consistent significant and beneficial effect of chromium may not be observed. Specifically, recent data fail to demonstrate significant improvement in carbohydrate metabolism in individuals with metabolic syndrome, impaired glucose tolerance, or consistently in individuals with type 2 diabetes. However, patient selection may be an important factor in determining clinical response, as it was concluded that a clinical response to chromium (ie, decreased glucose and improved insulin sensitivity) may be more likely in insulin-resistant individuals with type 2 diabetes who have more elevated fasting glucose and hemoglobin A(1c) levels.

Management of progressive type 2 diabetes: role of insulin therapy

Insulin is an effective treatment for achieving tight glycemic control and improving clinical outcomes in patients with diabetes. While insulin therapy is required from the onset of diagnosis in type 1 disease, its role in type 2 diabetes requires consideration as to when to initiate and advance therapy. In this article, we review a case study that unfolds over 5 years and discuss the therapeutic decision points, initiation and advancement of insulin regimens, and analyze new data regarding the advantages and disadvantages of tight management of glucose levels.

Drug titration patterns and HbA 1c levels in type 2 diabetes

OBJECTIVE

To evaluate oral antidiabetes drug (OAD) use, haemoglobin A(1c) (HbA(1c)) testing and glycaemic control in type 2 diabetes patients.

STUDY DESIGN

Retrospective analysis based on claims data from the Integrated Healthcare Information Services (IHCIS) National Managed Care Benchmark Database.

METHODS

OAD use and HbA(1c) testing were analysed for patients with >or= 2 claims indicating diagnosis of type 2 diabetes and >or= 1 90-day OAD treatment period between 1 January, 2000 and 30 June, 2006. Likelihood of HbA(1c) testing was examined using multivariable logistic regression analyses, adjusting for OAD regimen and patients' sociodemographical characteristics.

RESULTS

Patients were classified based on initial OAD regimen: metformin (MET) (n = 22,203; 41.3%), sulphonylurea (SFU) (n = 18,439; 34.3%), thiazolidinedione (TZD) (n = 7663; 14.3%), SFU + MET (n = 5467; 10.2%) and TZD + MET (n = 2355; 4.2%). A total of 51.5% of patients had HbA(1c) testing during 90 days preceding OAD initiation through regimen completion. Approximately, 65% of MET and 58% of SFU patients had no titration of initial regimen. Patients demonstrating inadequate glucose control decreased from 68.5% at baseline to 46.9% within 90 days of regimen initiation. Multivariable logistic regression indicated several negative predictors of HbA(1c) testing, including SFU use, age 65+ years, moderate insurance copayment and preindex inpatient utilisation. Multivariable logistic regression of variables associated with reduced likelihood of up-titration included TZD, SFU + MET, or TZD + MET treatment, age 18-34 years, Medicare insurance and any preindex healthcare utilisation.

CONCLUSIONS

Patients are not being transitioned to additional OADs in a stepwise fashion and/or are receiving inadequate titration on current OAD regimens. The low rate of HbA(1c) testing and rates of control are contributing factors.

Metformin--the gold standard in type 2 diabetes: what does the evidence tell us?

Metformin is a cornerstone of oral antidiabetic treatment. Recent joint American and European guidelines recommend instituting metformin therapy along with lifestyle modification at the time type 2 diabetes mellitus (T2DM) is diagnosed. Metformin acts to reduce hepatic gluconeogenesis and improve glucose uptake, and it may exert protective effects on pancreatic islet cells. Although metformin therapy produces substantial reductions in HbA1c, it does not produce body weight gain, is not associated with substantial risk for hypoglycaemia and has neutral to positive effects on lipids and blood pressure. The major adverse events associated with metformin are gastrointestinal. T2DM progresses even with initially effective monotherapy, and most patients will therefore receive combination therapy. When selecting agents to coadminister with metformin, a physician must consider efficacy in glycaemic control, safety, tolerability and any effects that may compromise overall efficacy (e.g. effects on body weight, lipids or blood pressure). In this regard, incretin-based therapies have characteristics that make them particularly suitable for add-on therapy with metformin.

New combination treatments in the management of diabetes: focus on sitagliptin-metformin

Type 2 diabetes mellitus is an increasingly prevalent condition worldwide. The complications of this disease are known to significantly increase the morbidity and mortality of those affected, resulting in substantial direct and indirect costs. Although good glycemic control has been shown to reduce the incidence and progression of diabetes-related microvascular complications, blood glucose levels are not adequately controlled in most individuals with diabetes. The reasons for this are many, and include issues such as poor adherence to complex medication regimes; costs of prescribed therapies; and the failure of traditionally prescribed medications to preserve beta cell function over time. However, our armamentarium of glucose-lowering drugs has expanded recently with the development of medications that act via the incretin pathway. Sitagliptin, the first commercially available dipeptidyl peptidase-4 inhibitor, inhibits the metabolism and inactivation of the incretin hormones GLP-1 and GIP. The subsequent elevation in levels of these hormones and associated prolongation of their actions has been shown to increase insulin secretion and suppress glucagon secretion in a glucose-appropriate fashion. Sitagliptin therapy in individuals with type 2 diabetes has been found to lower significantly hemoglobin A1c (Hb1c) levels with a minimum of adverse side effects such as weight gain or hypoglycemia. Use of sitagliptin in conjunction with the insulin-sensitizing medication metformin has been shown to decrease HbA1c levels more significantly than does either drug alone. This combination of medications is generally well tolerated, with no adverse effects on weight and a very low likelihood of treatment-related hypoglycemia. Use of both drugs will positively affect many of the underlying metabolic abnormalities associated with type 2 diabetes, including the disordered secretion of insulin and glucagon as well as impaired sensitivity to insulin which are known to accompany this disease. Animal studies also suggest that dipeptidyl peptidase-4 inhibitor treatment may help to preserve beta cell mass; however, it is unclear at present whether or not this will prove to be the case in humans.

Exenatide exhibits dose-dependent effects on glycemic control over 12 weeks in Japanese patients with suboptimally controlled type 2 diabetes

This study assessed the dose-dependent efficacy and safety of exenatide over 12 weeks in Japanese patients with type 2 diabetes suboptimally controlled despite therapeutic doses of sulfonylurea (SU), SU plus biguanide, or SU plus thiazolidinedione. Patients were randomly assigned to placebo (N = 40), 2.5 microg (N = 38), 5 microg (N = 37), or 10 microg (N = 38) exenatide administered subcutaneously twice daily (BID). Patients randomly assigned to 10 microg exenatide received 5 microg BID for the first 4 weeks, with the dose escalated to 10 microg BID for the final 8 weeks. Patients were 60.3 +/- 9.7 years old, with body mass index 25.3 +/- 4.3 kg/m(2) and hemoglobin A1c (HbA1c) 8.0 +/- 0.8%. Baseline-to-endpoint HbA1c changes (%) were +0.02 +/- 0.1 (placebo), -0.9 +/- 0.1 (2.5 microg), -1.2 +/- 0.1 (5 microg), and -1.4 +/- 0.1 (10 microg) (all p < 0.001 vs. placebo). Of patients with baseline HbA1c -7%, 5.1% (placebo), 50.0% (2.5 microg), 71.4% (5 microg), and 79.4% (10 microg) achieved HbA1c <7% at endpoint (p < 0.001, trend test). Baseline-to-endpoint fasting plasma glucose changes (mg/dL) were +6.0 +/- 4.8 (placebo), -18.6 +/- 5.7 (2.5 microg), -25.0 +/- 7.0 (5 microg), and -28.9 +/- 5.9 (10 microg) (all p < or = 0.001 vs. placebo). Treatment-emergent adverse events were mostly mild; dose-dependent increases in incidence were observed for hypoglycemia, nausea, anorexia, decreased appetite, and diarrhea (all p < or = 0.044, trend test). Over 12 weeks, exenatide dose-dependently improved glycemic control in Japanese patients with type 2 diabetes.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of exenatide once weekly in Japanese patients with type 2 diabetes

This randomized, placebo-controlled, double-blind, parallel study assessed the safety, tolerability, pharmacokinetics, and pharmacodynamics of exenatide once weekly (QW) in 30 Japanese patients with type 2 diabetes (T2D) suboptimally controlled by diet and exercise alone or combined with biguanide, sulfonylurea, thiazolidinedione, or combinations of these agents (58.6% male; 58+/-9 years; body mass index 26.3+/-2.9 kg/m(2); hemoglobin A(1c) [HbA(1c)] 7.4+/-0.8%; fasting plasma glucose [FPG] 156.1+/-29.1 mg/dL; duration of T2D 6+/-5 years; means +/- SD). Patients were randomized in a 1:1:1 ratio to subcutaneous placebo QW, exenatide QW 0.8 mg, or exenatide QW 2.0 mg for 10 weeks. All evaluable patients were analyzed (placebo QW, n=10; exenatide QW 0.8 mg, n=10; exenatide QW 2.0 mg, n=9), unless otherwise stated. Steady-state plasma exenatide concentrations were observed by Week 8 of the study. For the evaluable pharmacokinetic population, geometric mean (90% confidence interval) steady-state plasma concentrations (pg/mL) were 81.2 (68.3-96.4) and 344.5 (256.5-462.7) with exenatide QW 0.8 mg (n=8) and exenatide QW 2.0 mg (n=5), respectively. Baseline-to-Week 10 glycemic improvements with placebo QW, exenatide QW 0.8 mg, and exenatide QW 2.0 mg, respectively, were: HbA(1c) (%): -0.4+/-0.3, -1.0+/-0.7, and -1.5+/-0.7; FPG (mg/dL): -20.5+/-20.4, -25.2+/-10.9, and -50.8+/-27.8; and 2-hour postprandial plasma glucose excursions (mg/dL): -8.8+/-26.9, -50.0+/-41.1, and -59.7+/-26.8 (means +/- SD). No serious adverse events (AEs) were reported and no AEs led to study discontinuation in any group. The most frequent AE observed was mild-to-moderate injection site induration. No serious hypoglycemia was reported. Exenatide QW for 10 weeks was well tolerated and improved short-term glycemic control in Japanese patients with suboptimally controlled T2D.

The role of insulin analogs in type 2 diabetes in the rural community

OBJECTIVE

Type 2 diabetes is a progressive disease requiring constant monitoring of patients to ensure maintenance of glycemic goals and advancement of therapy when necessary. The challenges of treatment in rural areas may be different from those in urban areas. This review article will evaluate the barriers to treatment of type 2 diabetes and the role of insulin analogs in overcoming such barriers and in treating the disease, particularly with respect to rural communities.

RESEARCH DESIGN AND METHODS

A literature review of English language articles in the Medline Database was conducted to identify published articles through April 2008. Search terms included rural, diabetes, insulin, treatment, and treatment challenges/barriers and were used either alone or in various combinations with one another. Articles were included if they pertained to rural communities in the United States. Barriers related to treatment of type 2 diabetes and the role of insulin analogs in treatment and in overcoming such barriers, were examined.

RESULTS

Health-care providers and patients in rural areas face barriers both common to the general population and unique to the rural setting. Challenges include limited access to health care, lack of health-care resources, and lack of multidisciplinary staff.

CONCLUSIONS

A number of strategies exist, including simple, stepwise treatment algorithms for insulin therapy, to manage type 2 diabetes in rural populations effectively. Because this article focused on rural communities in the United States, barriers in other rural communities may not have been identified. Additionally, although Medline is one of the largest and most comprehensive databases of published medical literature, publications not in the Medline database have not been included in this analysis.

Efficacy and safety of sitagliptin when added to ongoing metformin therapy in patients with type 2 diabetes

AIM

To assess the addition of sitagliptin to ongoing metformin therapy in patients with type 2 diabetes who were inadequately controlled [haemoglobin A(1c) (HbA(1c)) 7-11%] on metformin monotherapy.

METHODS

Patients (n = 273) on metformin (>/=1500 mg/day) were randomized to receive the addition of once-daily placebo, sitagliptin 100 mg or rosiglitazone 8 mg in a 1 : 1 : 1 ratio for 18 weeks. The efficacy analysis was based on the all-patients-treated population using an analysis of co-variance with change in HbA(1c) from baseline as the primary endpoint.

RESULTS

The mean baseline HbA(1c) was 7.7% for the entire cohort. After 18 weeks, both active add-on therapies led to greater improvements in HbA(1c) from baseline: -0.73% for sitagliptin (p < 0.001 vs. placebo) and -0.79% for rosiglitazone compared with -0.22% for placebo. No difference was observed between the sitagliptin and rosiglitazone treatments (0.06% [95% confidence interval (CI): -0.14 to 0.25]). The proportion of patients achieving an HbA(1c) < 7% was greater with sitagliptin (55%) and rosiglitazone (63%) compared with placebo (38%). Body weight increased from baseline with rosiglitazone (1.5 kg) compared with body weight reduction with sitagliptin (-0.4 kg) and placebo (-0.8 kg). The difference in body weight between the sitagliptin and rosiglitazone groups was 1.9 kg (95% CI: 1.3-2.5). In a prespecified analysis, the proportion of patients experiencing a greater than 3-kg increase in body weight was 21% in the rosiglitazone group compared with 2% in both the sitagliptin and placebo groups. Both active treatments were generally well tolerated, with no increased risk of hypoglycaemia or gastrointestinal adverse events compared with placebo.

CONCLUSIONS

In this 18-week study, the addition of sitagliptin was effective and well tolerated in patients with type 2 diabetes inadequately controlled with metformin monotherapy. Treatment with sitagliptin produced similar reductions in HbA(1c) compared with the addition of rosiglitazone.

Type 2 diabetes among women: clinical considerations for pharmacological management to achieve glycemic control and reduce cardiovascular risk

The purpose of this paper is to highlight specific considerations in the medical management of women with type 2 diabetes mellitus (T2DM). T2DM, a significant source of morbidity and mortality, has become an ever growing epidemic within the United States. Although it is well understood that diabetes can significantly increase the risk for microvascular and macrovascular complications, there has been limited research examining the differential impact of these complications on men and women. Women, in particular, are subject to especially high risk for the development of myocardial infarction (MI), claudication, and stroke and are disproportionately afflicted by cardiovascular, cerebrovascular, and peripheral vascular disease. There is new evidence that tight glycemic control and earlier initiation of insulin therapy can improve outcomes and thereby reduce the risk for development of both macrovascular and microvascular complications of the disease. Although there are many commonalities in the treatment of men and women, women with diabetes have several unique issues, including the possible effects of therapy on reproductive health, fetal health, breastfeeding, potential interactions with hormonal contraceptives, and effects on bone health, that should be considered when determining a therapeutic approach. This paper presents evidence-based treatment strategies for reducing the risk of diabetes-associated complications overall and cardiovascular disease in particular through glycemic control. Special attention is paid to the selection of antidiabetic agents that are best suited to the unique needs of women.

Time to insulin in type-2 diabetes: high hurdles or Santiago way?

The prevalence of obesity has been increasing dramatically in the last decades; the major metabolic complication of obesity is insulin resistance and type-2 diabetes because there are pathogenetic mechanisms linking obesity and type-2 diabetes. Diabetes is also rapidly increasing worldwide; such a description of the key stages in the evolution of type-2 diabetes may be of great interest for implementing antidiabetes treatment. In recent times, type-2 diabetes therapy has been based on drugs, which improve insulin sensibility or stimulate insulin secretion or slow down glucose absorption. Recently, an ADA and EASD consensus has been released to develop a common approach for the management of hyperglycaemia in adults. The development of new classes of blood-glucose-lowering medications to supplement the older therapies, such as lifestyle-directed interventions, insulin, sulfonylureas, and metformin, has increased the different possible options for the treatment of type-2 diabetes. Therapeutic approaches aiming to potentiate the biological effects of incretins include degradation-resistant GLP-1 receptor agonists (incretin mimetics), and inhibitors of dipeptidyl peptidase-IV (DPP-IV) activity (incretin enhancers) will be very useful to slow down type-2 diabetes progression. Weight-loss interventions, such as a hypocaloric diet and physical exercise, in addition to agents such as orlistat, sibutramine and cannabinoid receptor antagonists, may have favourable effects upon fat storage, nutrient metabolism and ultimately glucose tolerance or type-2 diabetes. When the therapeutic target is not achieved, insulin with metformin could be suggested, but is this approach the ideal one for all patients? Perhaps it is possible to delay the initiation of insulin therapy, therefore, the actual and future therapeutical options are considered in the present review.

2-year effects of pioglitazone add-on to sulfonylurea or metformin on oral glucose tolerance in patients with type 2 diabetes

AIM

We report the effectiveness of the thiazolidinedione, pioglitazone, as add-on medication to metformin or sulfonylurea in reducing post-load serum glucose levels, as assessed by 3-h oral glucose tolerance testing (OGTT).

METHODS

Adult patients with Type 2 diabetes took part in one of two large-scale, 2-year clinical trials. One study compared pioglitazone treatment as add-on to failing metformin therapy (N=317) with add-on gliclazide treatment to metformin (N=313). The other study compared combination therapy with pioglitazone added to existing failing sulfonylurea therapy (N=319) with metformin treatment in addition to sulfonylurea (N=320). HbA(1c) and fasting plasma glucose concentrations were measured at baseline and throughout the study and at the final visit at week 104. At selected centers (N=299 patients), a 3-h OGTT was performed at baseline and at week 104.

RESULTS

At week 104, mean HbA(1c) reduction from baseline was 0.89% for pioglitazone and 0.77% for gliclazide addition to metformin (p=0.200) and 1.03% with pioglitazone and 1.16% with metformin addition to sulfonylurea (p=0.173) in the total patient cohort. In the 299 patients who underwent OGTT, 2 years of treatment with pioglitazone, whether added to existing metformin or sulfonylurea medication, resulted in decreases in glucose excursions after an oral glucose load without increasing post-load serum insulin concentrations. In contrast, gliclazide in combination with metformin therapy caused increases in both post-load serum glucose and insulin excursions after 2 years, whereas metformin add-on to sulfonylurea did not have a significant effect on post-load serum glucose concentrations and resulted in an increase in insulin levels.

CONCLUSIONS

There were no significant differences in HbA(1c) levels between groups. However, 2-year treatment with pioglitazone as an add-on to either failing metformin or sulfonylurea therapy improved post-load glucose excursions without affecting insulin secretion. In contrast, glucose excursions were not improved by gliclazide or metformin add-on therapy, despite increases in post-load insulin levels. These data suggest that pioglitazone reduces peripheral insulin resistance via mechanisms different from those of metformin.

[Types of insulin therapy]

Diabetes mellitus is a chronic disease associated with a series of long-term microvascular and macrovascular complications that requires continuing therapeutic control. In recent years, the pharmaceutical industry has developed new types of insulin and administration systems in order to more closely mimic human insulin secretion. In this way, insulin therapy is divided into conventional and intensive regimens according to their complexity. In type 1 diabetes mellitus (T1DM) patients, the treatment of choice is the one which achieves intensive glycemic control. In type 2 diabetes mellitus, we can start with a simplified conventional regimen which could progress into an intensive one similar to that of T1DM treatment. Both types of diabetes require an individualized treatment prescription based on the needs and characteristics of each patient.

Update on type 2 diabetes mellitus: understanding changes in the diabetes treatment paradigm

Type 2 diabetes mellitus, which is increasingly prevalent in the United States and responsible for the bulk of diabetes-related healthcare costs, has not been adequately managed over the long term with the most commonly prescribed oral hypoglycaemic medications. Although there is evidence that successful management of type 2 diabetes must address both beta-cell deficiency and insulin resistance, most oral agents now prescribed do not prevent the progressive loss of beta-cell function that has traditionally continued during treatment. Increasingly aggressive management guidelines have led to the recommendation that metformin therapy be initiated along with lifestyle modification at the time of diagnosis. It seems unlikely, however, that this strategy will impede the progression of beta-cell dysfunction. Treatment paradigms are emerging that combine routinely used drug categories with newer agents based on the incretin pathway to achieve long-term glycaemic control. The current review discusses the clinical implications of these newer therapeutic alternatives, which enhance insulin secretion through glucose-dependent and physiologic mechanisms.

Pharmaco-economic issues for diabetes therapy

A systematic review was undertaken to analyse pharmaco-economic issues in diabetes, with evidence selected on the basis of relevance and immediacy. Pharmaco-economics in diabetes primarily relates to making choices about antidiabetic pharmaceuticals, and this is being influenced by global trends. Trends include increasing numbers of patients with diabetes, with increasing costs of caring for people with diabetes, and an ever-present focus on the costs of pharmaceuticals which are predicted to increase as the pace of development of new medications parallels the increasing incidence of the condition. These developments have influenced the demand for health care in diabetes in the last decade, and will continue to determine this in the coming decade. Recent national experiences are cited to illustrate current issues and to focus specifically upon the challenges facing a raft of new diabetes treatment options now hitting the marketplace, although supported by fewer completed long-term trials. It can be anticipated that these newer agents will be appraised for their cost-effectiveness or value for money. Economic analyses for some of the new technologies are summarized; in general, the peer-reviewed publications using well-accepted and validated models have reported that these technologies are cost-effective. Endorsement of any technology in a national setting is not awarded simply because the incremental cost-effectiveness ratio (ICER) falls below the threshold regarded as value for money. In most national observations the reviewers expressed concerns about assumptions used in economic modelling which resulted in the ICERs being deemed optimistic at best, generally highly uncertain, and resulting in the cost-effectiveness appearing better than it really would be in clinical practice. This has often led to the authorities concluding that the price advantage of new technologies over comparators could not be justified, essentially leading to restrictions in use compared to their licence. In general, a paucity of robust evidence on longer-term outcome data together with a lack of health-related quality of life (HRQOL) data collected in a reliable manner in appropriate patients and amenable to utility (and hence quality adjusted life year or QALY) estimation have resulted in problems for these new drugs at the so-called fourth (cost-effectiveness) hurdle. In the light of these findings, the implications for generating credible fit-for-purpose cost-effectiveness analyses of new technologies in diabetes are discussed. Throughout this chapter, the interested reader is referred to a number of excellent review articles for further details.

Comparison of the alteration of the concentration of C-peptide in 24-h urine according to the combination patterns of hypoglycemic agents in type 2 diabetes patients

AIMS

Urinary C-peptide (UCP) has been considered as a simple method for monitoring beta-cell function in diabetic patients clinically. The aim of the study is to compare the changes of 24-h urinary C-peptide levels according to subgroups divided by therapeutic agents for subjects with type 2 diabetes.

METHODS

In 206 participants, under treatment for type 2 diabetes, 24-h urinary C-peptide levels were assessed yearly for 3 years. All participants were subdivided into four groups according to the therapeutic agents. Changes for the measured values during the follow-up were compared between groups.

RESULTS

Mean HbA1C was 7.1% and mean 24-h UCP was 61.7 microg/24h and mean duration of diabetes was 8.7 years in all subjects at baseline. Mean 24-h UCP levels increased significantly from a baseline to at 36 months in the insulin sensitizers (IS) only group, in the IS plus sulfonylurea combination group and in IS plus insulin combination group (p<0.001), whereas in the sulfonylurea only group, we could not find statistically significant changes (p=0.152). Treatment with only IS significantly reduced fasting plasma glucose (FPG) and HbA1C level (p=0.045, p<0.001). Differences between baseline and last 24-h UCP were significantly different between-groups and this difference was more significant after adjustment in FPG, HbA1C, and the duration of diabetes (p=0.024). Especially, IS plus sulfonylurea combination group resulted in greatest increase of 24-h UCP (DeltaC-peptide=51.19 microg/24h).

CONCLUSIONS

This study suggested that IS, in mono- or in combination, significantly improved pancreatic beta-cell function, especially when combined with sulfonylurea as evidenced by the increase of 24-h UCP.

The incretin mimetic exenatide as a monotherapy in patients with type 2 diabetes

BACKGROUND

Exenatide is an adjunctive therapy for type 2 diabetes, and preliminary evidence suggests that its glucoregulatory effects may be similar in the absence of oral therapy.

METHODS

Study A was a randomized, double-blind, placebo-controlled study of 99 patients with type 2 diabetes that received either 10 microg twice-daily, 10 microg once-daily, or 20 microg once-daily exenatide or placebo for 28 days in the absence of background pharmacotherapy. Study B was an open-label extension of a short-term study of 127 patients with type 2 diabetes treated with metformin or diet and exercise. Patients received exenatide 5 microg twice-daily for 4 weeks followed by 10 microg for 26 weeks. Subjects treated with metformin continued oral therapy.

RESULTS

Monotherapeutic treatment with 10 microg of exenatide twice-daily for 28 days resulted in significant mean reductions in glycosylated hemoglobin (A1C) of -0.4 +/- 0.1% and fasting plasma glucose of -36.1 +/- 11.0 mg/dL compared to increases of +0.2 +/- 0.1% and +11.0 +/- 12.7 mg/dL with placebo. Self-monitored blood glucose profiles showed significant mean reductions in daily blood glucose concentrations in exenatide-treated patients compared to placebo. Exenatide treatment for 30 weeks in an open-label extension study resulted in similar mean reductions from baseline in A1C and body weight in patients treated with diet and exercise alone (-1.0 +/- 0.2% and -4.3 +/- 1.3 kg, respectively) as those treated on a background of metformin (-0.9 +/- 0.1% and -3.7 +/- 0.5 kg, respectively). In both studies, the most frequent adverse events were gastrointestinal and predominantly mild to moderate in intensity. Incidence of mild-to-moderate hypoglycemia was low, with no severe hypoglycemia.

CONCLUSIONS

Exenatide twice-daily monotherapy resulted in glycemic improvements and reductions in body weight comparable to that of exenatide combination therapy with metformin in patients with type 2 diabetes.

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.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor, sitagliptin, compared with the sulfonylurea, glipizide, in patients with type 2 diabetes inadequately controlled on metformin alone: a randomized, double-blind, non-inferiority trial

AIM

To compare the efficacy and safety of sitagliptin vs. glipizide in patients with type 2 diabetes and inadequate glycaemic control [haemoglobin A(1c) (HbA(1c)) > or = 6.5 and < or = 10%] on metformin monotherapy.

METHODS

After a metformin dose titration/stabilization period (> or = 1500 mg/day), 1172 patients were randomized to the addition of sitagliptin 100 mg q.d. (N = 588) or glipizide 5 mg/day (uptitrated to a potential maximum 20 mg/day) (N = 584) for 52 weeks. The primary analysis assessed whether sitagliptin was non-inferior to glipizide regarding HbA(1c) changes from baseline at Week 52 using a per-protocol approach.

RESULTS

From a mean baseline of 7.5%, HbA(1c) changes from baseline were -0.67% at Week 52 in both groups, confirming non-inferiority. The proportions achieving an HbA(1c) < 7% were 63% (sitagliptin) and 59% (glipizide). Fasting plasma glucose changes from baseline were -0.56 mmol/l (-10.0 mg/dl) and -0.42 mmol/l (-7.5 mg/dl) for sitagliptin and glipizide, respectively. The proportion of patients experiencing hypoglycaemia episodes was significantly (p < 0.001) higher with glipizide (32%) than with sitagliptin (5%), with 657 events in glipizide-treated patients compared with 50 events in sitagliptin-treated patients. Sitagliptin led to weight loss (change from baseline =-1.5 kg) compared with weight gain (+1.1 kg) with glipizide [between-treatment difference (95% confidence interval) =-2.5 kg (-3.1, -2.0); p < 0.001].

CONCLUSIONS

In this study, the addition of sitagliptin compared with glipizide provided similar HbA(1c)-lowering efficacy over 52 weeks in patients on ongoing metformin therapy. Sitagliptin was generally well tolerated, with a lower risk of hypoglycaemia relative to glipizide and with weight loss compared with weight gain with glipizide.

Design and synthesis of a novel class of dual PPARγ/δ agonists

The design and synthesis of dual PPAR gamma/delta agonist (R)-3-{2-ethyl-4-[3-(4-ethyl-2-pyridin-2-yl-phenoxy)-butoxy]-phenyl}propionic acid is described. This compound dose-dependently lowered plasma glucose in hyperglycemic male Zucker diabetic fatty (ZDF) rats and produced less weight gain relative to rosiglitazone at an equivalent level of glucose control.

Management of Diabetes in Older Adults

Enhanced life expectancy and the aging of society have conspired with rising rates of obesity and physical inactivity to cause an unprecedented increase in diabetes prevalence worldwide. The disease and its chronic complications have unique presentations and challenges in the elderly. Postprandial hyperglycemia may be the predominant manifestation, comorbid health conditions are often present, and the risk of cardiovascular disease is vastly increased. Periodic screening is essential for early diagnosis and proper treatment. The principles of multidisciplinary management emphasizing nutrition, exercise, education, psychosocial care, attention to concomitant metabolic risk factors, and prudent use of pharmacologic agents are the mainstay of therapy for older adults. Treatment should be tailored to the individual patient, and the assistance of family and caregivers should be combined with rational utilization of community resources. An evidence-based, comprehensive, and proactive approach is needed to reduce the burden of morbidity and mortality from diabetes in the elderly.