Hypoglycemic potential of nateglinide versus glyburide in patients with type 2 diabetes mellitus

Update on the management of diabetes in long-term care facilities

The number of patients with diabetes is increasing among older adults in the USA, and it is expected to reach 26.7 million by 2050. In parallel, the percentage of older patients with diabetes in long-term care facilities (LTCFs) will also rise. Currently, the majority of LTCF residents are older adults and one-third of them have diabetes. Management of diabetes in LTCF is challenging due to multiple comorbidities and altered nutrition. Few randomized clinical trials have been conducted to determine optimal treatment for diabetes management in older adults in LTCF. The geriatric populations are at risk of hypoglycemia since the majority are treated with insulin and have different levels of functionality and nutritional needs. Effective approaches to avoid hypoglycemia should be implemented in these settings to improve outcome and reduce the economic burden. Newer medication classes might carry less risk of developing hypoglycemia along with the appropriate use of technology, such as the use of continuous glucose monitoring. Practical clinical guidelines for diabetes management including recommendations for prevention and treatment of hypoglycemia are needed to appropriately implement resources in the transition of care plans in this vulnerable population.

Effect of Switching from Sulphonylurea to Repaglinide Twice or Three Times Daily for 4 Months on Glycemic Control in Japanese Patients with Type 2 Diabetes

Objective Switching from sulfonylureas to repaglinide in patients with type 2 diabetes improves glycemic control; however, the optimal dosage has not been fully evaluated. We designed to show that repaglinide was equivalent to sulfonylurea in Japanese patients with type 2 diabetes. We herein evaluated whether we could switch from sulfonylureas to repaglinide twice or thrice daily in Japanese adult patients who had been treated with anti-diabetic drugs, including sulfonylureas, and whose conditions were moderately well-controlled. Methods A total of 78 patients taking less than half the Japanese maximum dose of sulfonylurea were randomized into three groups: 26 in group A (switching from sulfonylureas to taking 0.25 or 0.5 mg of repaglinide just before breakfast and dinner twice daily), 27 in group B (switching from sulfonylureas to taking 0.25 or 0.5 mg of repaglinide just before meals thrice daily), and 25 in group C (continuing to take sulfonylurea). Blood samples were collected at 0, 1, 2, 3, and 4 months following the initiation of the maintenance period. Results The HbA1c and glycoalbumin levels did not significantly differ among the three groups after 4 months of treatment. Conclusion With the assumption that 1 mg of glimepiride is equivalent to 1.25 mg of glibenclamide or 40 mg of gliclazide, the administration of repaglinide (0.44 mg/meal) twice and thrice daily is similar to the efficacy of sulfonylurea (glimepiride 1.63-1.98 mg/day) after four months of treatment in Japanese patients with moderately well-controlled type 2 diabetes (HbA1c, 7-7.5%).

Comparison of sitagliptin with nateglinide on postprandial glucose and related hormones in drug-naïve Japanese patients with type 2 diabetes mellitus: A pilot study

AIMS/INTRODUCTION

Dipeptidyl peptidase-4 inhibitors and glinides are effective in reducing postprandial hyperglycemia. However, little information is available on the comparative effects of the two drugs on the levels of postprandial glucose. The aim of the present study was to compare the effects of sitagliptin and nateglinide on meal tolerance tests in drug-naïve patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

The study participants were 19 patients with type 2 diabetes mellitus, which was inadequately controlled by diet and exercise. An open-label, prospective, cross-over trial was carried out to compare the effects of single-dose sitagliptin and nateglinide on the postprandial glucose level and its related hormones during meal tests.

RESULTS

The change in area under the curve (AUC) of glucose from 0 to 180 min (AUC0-180 min) during the meal test by nateglinide was similar to that by sitagliptin. As expected, the change in active glucagon like peptide-1 was significantly higher after a single-dose of sitagliptin than nateglinide. Then, insulin secretion relative to glucose elevation (ISG) (ΔISG0-180 min: ΔAUC0-180 min insulin/AUC0-180 min glucose) was significantly enhanced by nateglinide compared with sitagliptin. Conversely, glucagon level (ΔAUC0-180 min glucagon) was increased by administration of nateglinide, whereas the glucagon level was reduced by administration of sitagliptin.

CONCLUSIONS

The effects of sitagliptin on postprandial glucose levels were similar to those of nateglinide in drug-naïve type 2 diabetes patients. However, the induced changes in insulin, active glucagon-like peptide-1 and glucagon during meal loading suggest that reduction of postprandial hyperglycemia was achieved by the unique effect of each drug.

[Evaluation of the association between the use of oral anti-hyperglycemic agents and hypoglycemia in Japan by data mining of the Japanese Adverse Drug Event Report (JADER) database]

Hypoglycemia due to treatment with oral anti-hyperglycemic agents (OHAs) is a major clinical problem in patients with type 2 diabetes mellitus. The aim of the present study was to evaluate the risk of hypoglycemia due to OHA use by using the Japanese Adverse Drug Event Report (JADER) database. To this end, reports of hypoglycemia events included in the JADER database between 2004 and 2012 were analyzed by calculating the reporting odds ratio (OR). The Medical Dictionary for Regulatory Activities Preferred Terms was used to identify hypoglycemia; 254392 reports were found in the JADER database, of which 13269 were excluded because the age and sex of the patient were not reported. Finally, 241123 reports were analyzed. Among OHAs, sulfonylureas showed the highest adjusted OR (adjusted OR, 10.13; 95% confidence interval, 9.08-11.26). The adjusted ORs for meglitinides, biguanide, thiazolidinedione, alpha-glucosidase inhibitors, and dipeptidyl peptidase-4 inhibitors were significantly lower than that of sulfonylureas. The adjusted OR of meglitinides (3.17; 95% confidence interval, 2.23-4.36) was significantly higher than that of alpha-glucosidase inhibitors or thiazolidinedione. We observed no difference between the adjusted ORs for biguanide, thiazolidinedione, alpha-glucosidase inhibitors, and dipeptidyl peptidase-4 inhibitors. Data mining of the JADER database was useful for analyzing OHA-associated hypoglycemia events. The results of our study suggested a low risk of hypoglycemia associated with biguanide, thiazolidinedione, alpha-glucosidase inhibitors, and dipeptidyl peptidase-4 inhibitors in clinical practice.

Evaluating insulin secretagogues in a humanized mouse model with functional human islets

OBJECTIVE

To develop a rapid, easy and clinically relevant in vivo model to evaluate novel insulin secretagogues on human islets, we investigated the effect of insulin secretagogues on functional human islets in a humanized mouse model.

MATERIALS/METHODS

Human islets were transplanted under the kidney capsule of streptozotocin (STZ)-induced diabetic mice with immunodeficiency. Human islet graft function was monitored by measuring non-fasting blood glucose levels. After diabetes was reversed, human islet transplanted mice were characterized physiologically by oral glucose tolerance and pharmacologically with clinically proven insulin secretagogues, glucagon-like peptide-1 (GLP-1), exenatide, glyburide, nateglinide and sitagliptin. Additionally, G protein-coupled receptor 40 (GPR40) agonists were evaluated in this model.

RESULTS

Long-term human islet graft survival could be achieved in immunodeficient mice. Oral glucose challenge in human islet transplanted mice resulted in an immediate incremental increase of plasma human C-peptide, while the plasma mouse C-peptide was undetectable. Treatments with GLP-1, exenatide, glyburide, nateglinide and sitagliptin effectively increased plasma human C-peptide levels and improved postprandial glucose concentrations. GPR40 agonists also stimulated human C-peptide secretion and significantly improved postprandial glucose in the human islet transplanted mice.

CONCLUSIONS

Our studies indicate that a humanized mouse model with human islet grafts could mimic the in vivo characteristics of human islets and could be a powerful tool for the evaluation of novel insulin secretagogues or other therapeutic agents that directly and/or indirectly target human β cells.

Nateglinide, alone or in combination with metformin, is effective and well tolerated in treatment-naïve elderly patients with type 2 diabetes

AIM

The aim of this work was to assess the efficacy and tolerability of nateglinide alone or in combination with metformin in elderly patients with type 2 diabetes (T2DM).

METHODS

Study 1 was a 12-week, multicentre, randomized, double blind and placebo-controlled study of nateglinide monotherapy (120 mg, before meals) in 66 drug-naïve patients with T2DM aged >or=65 years. Study 2 was a 104-week, multicentre, randomized, double blind and active-controlled study of nateglinide (120 mg, before meals) or glyburide (up to 5 mg bid) in combination with metformin (up to 1000 mg bid) in 69 treatment-naïve patients with T2DM aged >or=65 years. HbA(1c), fasting and postprandial glucose levels, and safety assessments were made.

RESULTS

In Study 1, nateglinide significantly reduced HbA(1c) from baseline (7.6 +/- 0.1% to 6.9 +/- 0.1%; Delta = -0.7 +/- 0.1%, p < 0.001) and compared with placebo (between-group difference = -0.5%, p = 0.004 vs. nateglinide). No hypoglycaemia was reported. In Study 2, combination therapy with nateglinide/metformin significantly reduced HbA(1c) from baseline (7.8 +/- 0.2% to 6.6 +/- 0.1%; Delta = -1.2 +/- 0.2%, p < 0.001), as did glyburide/metformin (7.7 +/- 0.1% to 6.5 +/- 0.1%; Delta = -1.2 +/- 0.1%, p < 0.001). There was no difference between treatments (p = 0.310). One nateglinide/metformin-treated patient experienced a mild hypoglycaemic episode compared with eight episodes in eight patients on glyburide/metformin; one severe episode led to discontinuation. Target HbA(1c) (<7.0%) was achieved by 60% of patients receiving nateglinide (Study 1) and 70% of nateglinide/metformin-treated patients (Study 2).

CONCLUSION

Initial drug treatment with nateglinide, alone or in combination with metformin, is well tolerated and produces clinically meaningful improvements in glycaemic control in elderly patients with T2DM.

Impact of therapeutic advances on hypoglycaemia in type 2 diabetes

Patients with type 2 diabetes experience hypoglycaemia less frequently than those with type 1 diabetes. Some protection against hypoglycaemia is afforded by the relatively intact glucose counter-regulatory pathways that characterize the pathophysiology of early type 2 diabetes. To some extent, this protection explains why hypoglycaemic episodes in intensively treated individuals with type 2 diabetes, when they occur, are rarely severe. As diabetes progresses and therapy intensifies to achieve recommended glycaemic goals, hypoglycaemia frequency and severity increase. Thus, when it comes to instituting intensive therapy, fear of hypoglycaemia may contribute to health-care providers' 'clinical inertia'. Because maintaining glycaemic control is so important to both public and individual health, many new therapies and technologies have been developed. This manuscript reviews and considers whether these advancements in therapy make glycaemic goals easier to achieve by minimizing hypoglycaemia. Putting the hypoglycaemia experienced by type 2 diabetes patients into appropriate clinical perspective, the impact of recent progress made in pharmacotherapy, drug delivery systems, and BG monitoring on hypoglycaemia incidence is largely positive. The extent to which this progress can effect improvement over traditional therapies will, however, depend upon patient (and provider) education, motivation and behaviour change.

Emergency Management of Oral Hypoglycemic Drug Toxicity

There are several classes of oral diabetes medications available in the United States, including sulfonylureas, meglitinides, biguanides, glitazones, and alpha-glucosidase inhibitors. These different classes have various mechanisms of action, giving each class a unique potential for toxicity that necessitates a distinct approach to evaluation, treatment, and disposition of each class of drug. The practicing emergency physician must have an understanding of these differences to safely care for patients exposed to these medications.

Effects of nateglinide and glibenclamide on prothrombotic factors in naïve type 2 diabetic patients treated with metformin: a 1-year, double-blind, randomized clinical trial

OBJECTIVE

To evaluate the effect on coagulation and fibrinolysis parameters and on non-conventional cardiovascular risk factors of metformin plus nateglinide or glibenclamide in naïve type 2 diabetes patients.

PATIENTS AND METHODS

A total of 248 type 2 diabetic patients were enrolled and randomly assigned to receive nateglinide or glibenclamide, and metformin for 12 months. We assessed body mass index (BMI), glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), postprandial plasma insulin (PPI), homeostasis model assessment index (HOMA index), lipid profile with lipoprotein (a) [Lp(a)], fibrinogen (Fg), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), homocysteine (Hcy), systolic blood pressure (SBP), diastolic blood pressure (DBP).

RESULTS

After 9 months of treatment, both tested drug combinations were similarly associated with a significant reduction in FPG (nateglinide, -17.2%; glibenclamide, -16.9%, both p<0.05) compared to the baseline, while HbA1c (-17.3%, p<0.05) and PPG (-15.2%, p<0.05) significantly decreased only in the nateglinide group. After one year of treatment, compared to the baseline the nateglinide group showed a significant reduction in HbA1c (-21%, p<0.01), FPG (-20.7%), p<0.01, PPG (-21.5%, p<0.05), HOMA index (-25.4%, p<0.05); the glibenclamide group, showed a significant reduction in HbA1c (-11%, p<0.05), FPG (-23.2%, p<0.05), PPG (-11.2%, p<0.05), and HOMA index (-23.9%, p<0.05) but to a minor extent. Moreover, the HbA1c difference value from baseline observed in the nateglinide-treated group was significantly higher than that observed in the glibenclamide group. Therefore the nateglinide-treated patients showed a significant reduction in some prothrombotic parameters (PAI-1=-19%, Lp(a)=-31%, and Hcy=-32.3%, all p<0.05), whereas the glibenclamide-treated patients did not.

CONCLUSION

Nateglinide appears to improve glycemic control as well as the levels of some prothrombotic parameters compared to glibenclamide when administered in combination with metformin.

Comparison of nateglinide and gliclazide in combination with metformin, for treatment of patients with Type 2 diabetes mellitus inadequately controlled on maximum doses of metformin alone

AIM

To compare the effects of nateglinide plus metformin with gliclazide plus metformin on glycaemic control in patients with Type 2 diabetes.

METHODS

Double-blind, double-dummy, parallel group, randomized, multicentre study over 24 weeks. Patients with inadequate glucose control on maximal doses of metformin were randomized to additionally receive nateglinide (n = 133) or gliclazide (n = 129). Changes from baseline in HbA1c, fasting plasma glucose (FPG) and mealtime glucose and insulin excursions were examined.

RESULTS

HbA1c was significantly (P < 0.001) decreased from baseline in both treatment groups (mean changes: nateglinide -0.41%, gliclazide -0.57%), but with no significant difference between treatments. Proportions of patients achieving a reduction of HbA1c >or= 0.5% or an end point HbA1c < 7% were also similar (nateglinide 58.1%, gliclazide 60.2%). Changes from baseline in FPG were similarly significant in both treatment groups (nateglinide -0.63, gliclazide -0.82 mmol/l). Reduction from baseline in maximum postprandial glucose excursion were significant in the nateglinide group only (nateglinide -0.71, gliclazide -0.10 mmol/l; P = 0.037 for difference). Postprandial insulin levels were significantly higher with nateglinide compared with gliclazide. The overall rate of hypoglycaemia events was similar in the nateglinide group compared with the gliclazide group.

CONCLUSIONS

No significant difference was seen between nateglinide plus metformin and gliclazide plus metformin in terms of HbA1c. However, the nateglinide combination demonstrated better postprandial glucose control.

Nateglinide--current and future role in the treatment of patients with type 2 diabetes mellitus

Therapy for type 2 diabetes mellitus should aim to control not only fasting, but also postprandial glucose levels. Nateglinide, a d-phenylalanine derivative, restores postprandial early phase insulin secretion in a transient and glucose-sensitive manner without affecting basal insulin levels. As nateglinide is administered immediately before meals it provides greater lifestyle flexibility than agents that require patients to eat to avoid hypoglycemic events (e.g. long-acting sulfonylureas). In randomised, double-blind trials in patients with type 2 diabetes, nateglinide monotherapy (mealtime treatment of 120 mg three times daily) significantly improved long-term glycaemic control by significantly reducing glyated haemoglobin (HbA 1c) and preventing mealtime glucose spikes. The combination of nateglinide with insulin-sensitising agents, for example, metformin and thiazolidinediones, addresses the dual defects of loss of insulin secretion and insulin resistance to provide optimal management of type 2 diabetes, and more patients achieve HbA 1c goal with nateglinide combination therapy rather than with monotherapy with other oral agents. Nateglinide also restores early insulin secretion and reduces postprandial hyperglycaemia in prediabetic subjects with impaired glucose tolerance (IGT) and appears similarly effective in elderly and non-elderly populations with type 2 diabetes. It has an excellent safety and tolerability profile, with a low propensity to cause hypoglycaemia due to its transient, selective effect on early phase insulin secretion. Nateglinide as monotherapy or combination therapy is an effective option to reduce mealtime glucose in patients with type 2 diabetes. The results of ongoing research into its potential role in delaying progression to overt diabetes, and protecting against cardiovascular events, in prediabetic patients with IGT are awaited.

PRESERVE-beta: two-year efficacy and safety of initial combination therapy with nateglinide or glyburide plus metformin

OBJECTIVE

To compare long-term efficacy and safety of initial combination therapy with nateglinide/metformin versus glyburide/metformin.

RESEARCH DESIGN AND METHODS

We conducted a randomized, multicenter, double-masked, 2-year study of 428 drug-naïve patients with type 2 diabetes. Patients received 120 mg a.c. nateglinide or 1.25 mg q.d. glyburide plus 500 mg q.d. open-label metformin for the initial 4 weeks. During a subsequent 12-week titration period, glyburide and metformin were increased by 1.25- and 500-mg increments to maximum daily doses of 10 and 2,000 mg, respectively, if biweekly fasting plasma glucose (FPG) > or = 6.7 mmol/l. Nateglinide was not titrated. Blinding was maintained by use of matching placebo for nateglinide and glyburide. An 88-week monitoring period followed, during which HbA1c (A1C), FPG, and postprandial glucose excursions (PPGEs) during an oral glucose tolerance test were measured.

RESULTS

In nateglinide/metformin-treated patients, mean A1C was 8.4% at baseline and 6.9% at week 104. In glyburide/metformin-treated patients, mean A1C was 8.3% at baseline and 6.8% at week 104 (P < 0.0001 vs. baseline for both treatments, NS between treatments). The deltaPPGE averaged -96 +/- 19 (P < 0.0001) and -57 +/- 22 mmol.l(-1).min(-1) (P < 0.05) in patients receiving nateglinide/metformin and glyburide/metformin, respectively, whereas deltaFPG was -1.6 +/- 0.2 (P < 0.0001) and -2.4 +/- 0.2 mmol/l (P < 0.0001) in patients receiving nateglinide/metformin and glyburide/metformin, respectively (P < 0.01 between groups). Thus, the two treatments achieved similar efficacy with differential effects on FPG versus PPGE. Hypoglycemia occurred in 8.2 and 17.7% of patients receiving nateglinide/metformin and glyburide/metformin, respectively.

CONCLUSIONS

Similar good glycemic control can be maintained for 2 years with either treatment regimen, but nateglinide/metformin may represent a safer approach to initial combination therapy.