Glycemic control with Humalog Mix25 in type 2 diabetes inadequately controlled with glyburide

Shift of Glucose Peak Time During Oral Glucose Tolerance Test is Associated with Changes in Insulin Secretion and Insulin Sensitivity After Therapy with Antidiabetic Drugs in Patients with Type 2 Diabetes

INTRODUCTION

Delay in peak blood glucose during an oral glucose tolerance test (OGTT) predicts declining β-cell function and poor ability to regulate glucose metabolism. Glucose peak time has not been used as a comparative indicator of the improvement in islet function after treatment with exenatide, insulin, or oral antidiabetic drugs (OADs). We evaluated the efficacy of three types of antidiabetic drugs on the basis of blood glucose peak time in patients with non-newly diagnosed type 2 diabetes.

METHODS

The data from 100 patients with diabetes who completed two OGTTs within 6 months were collected. Thirty-seven of them with type 2 diabetes were treated with Humalog Mix25, 28 patients with OADs (metformin, acarbose, and gliclazide), and 35 patients with exenatide.

RESULTS

Glycated hemoglobin improved in all three groups after treatment (P < 0.05). Subcutaneous adipose tissue (P < 0.01) and visceral adipose tissue (P < 0.0001) significantly decreased in the exenatide group. The insulinogenic index (IGI) (P = 0.01) and IGI × oral glucose insulin sensitivity (OGIS) (P = 0.01) improved in the exenatide group only. Homeostatic assessment of β-cell function (HOMA-β) and OGIS were greater in the exenatide and OAD groups than in the Humalog Mix25 group (all P < 0.05). A shift to an earlier peak was observed in 57.1%, 35.7%, and 27.0% of patients in the exenatide, OAD, and Humalog Mix25 groups, respectively (P = 0.029). OGIS (odds ratio [OR] 0.54, 95% confidence interval [CI] 0.33-0.89, P = 0.026) and IGI × OGIS (OR 1.72, 95% CI 0.44-6.68, P = 0.012) were independently related to shifts in glucose peak time.

CONCLUSION

Exenatide, Humalog Mix25, and OADs improved glycemic metabolism. However, exenatide exhibited superior efficacy in shifting blood glucose peak time to an earlier point, while it improved insulin secretion and insulin sensitivity. Hence, the shift of glucose peak time may be considered an indicator for the evaluation of the effect of hypoglycemic drugs.

Number-Based Approach to Insulin Taxonomy

This article describes a number-based system for the classification of insulin regimes. It utilizes a patient-centered variable (number of injections per day) and pharmacokinetic/dynamic characteristics to craft a taxonomic system that is able to incorporate all available insulin preparations and coformulations. This framework of systematics is robust enough to include various molecules that have been recently developed. It serves to enhance understanding of the subject, and facilitates the practical or clinical usage of theoretical knowledge. We propose that number-based insulin taxonomic models should be used in clinical guidelines and recommendations rather than restricting ourselves to pharmaceutical-based classifications. PubMed articles including both review articles and clinical trials published since the year 1990 were searched, to gather evidence and information on the various types of insulins available, and how they can be used, based on the number or frequency of injections prescribed per day.

Insulin lispro protamine suspension in the treatment of patients with type 1 and type 2 diabetes mellitus: a systematic review of published data

INTRODUCTION

Insulin lispro protamine suspension (ILPS) is a protamine-based insulin lispro formulation that allows 24-h coverage while limiting the number of daily injections. ILPS was developed to be the basal insulin component of premixed biphasic formulations with insulin lispro, i.e., the lispro/ILPS 25/75 and 50/50 mixed compounds, but has recently also been marketed as a basal insulin analog formulation, with an indication for the therapy of diabetic patients.

AREAS COVERED

This article reviews the available literature on pharmacokinetics/pharmacodynamics (PK/PD), efficacy and safety of ILPS administered as basal insulin, or in premixed biphasic formulations, in patients with type 1 and type 2 diabetes mellitus.

EXPERT OPINION

The results of this review suggest that ILPS may be associated with a favorable time-action profile, basal and postprandial glycemic control, and efficacy in terms of rates of patients reaching glycosylated hemoglobin targets; an increased risk of hypoglycemic episodes, compared to other basal insulins, seems to be related to the percentage of patients upgrading from once- to twice-daily injections. This increased risk might be linked with the concomitant use of insulin secretagogues in patients on higher daily dosages and is generally not observed in patients using one injection of ILPS a day. Thus, ILPS can be considered a valid option both as basal insulin and as basal component of the actual premixed formulations of lispro for the therapy of diabetic patients.

Cumulative clinical experience with use of insulin lispro: critical appraisal, role in therapy, and patient considerations

We have now at our disposal the new rapid-acting insulin analogs, of which insulin lispro was the first to become commercially available. While the differences in pharmacokinetic and pharmacodynamic characteristics are indisputable, the clinical benefits attained by these changes have not been as clear. In the present review, we discuss the structure, pharmacology, and landmark studies related to insulin lispro. The clinical characteristics of insulin lispro are compared with those of insulin regular and other insulin analogs in different clinical situations. Also included are the aspects of quality of life and cost-effectiveness that may modify the modern practitioner's decision to adopt one type of insulin over another.

Efficacy and safety of prandial premixed therapy using insulin lispro mix 50/50 3 times daily compared with progressive titration of insulin lispro mix 75/25 or biphasic insulin aspart 70/30 twice daily in patients with type 2 diabetes mellitus: a randomized, 16-week, open-label study

BACKGROUND

Prandial premixed therapy 3 times daily has been proposed recently for type 2 diabetes mellitus (T2DM) patients who fail to achieve glycemic control with commonly used premixed insulin analogs, insulin lispro mix 75/25 (LM75/25) and biphasic insulin aspart 70/30 (BIAsp70/30) BID.

OBJECTIVE

The aim of this work was to compare the efficacy and safety of 3-times daily insulin lispro mix 50/50 (TID group) with progressive titration of twice-daily LM75/25 or BIAsp70/30 (BID group) administered along with metformin in T2DM patients.

METHODS

This was an open-label, 16-week, multicenter, randomized, parallel trial. End point glycosylated hemoglobin (HbA(1c)) was the primary efficacy measure; HbA(1c) reduction from baseline to end point, percentage of patients reaching target HbA(1c) (<7.0% and ≤6.5%), postprandial blood glucose (BG), and BG excursions after lunch were secondary measures. Safety was evaluated by collecting adverse events.

RESULTS

A total of 302 patients with mean (SD) age 57.7 (9.27) years, diabetes duration 11.2 (6.47) years, HbA(1c) 8.5% (1.23), fasting BG 184.0 (53.04) mg/dL, body weight 86.8 (14.79) kg, body mass index 31.7 (4.23) kg/m(2), and daily insulin dose ∼48 IU were randomized. No significant difference was observed in end point HbA(1c) between the 2 groups. Seven-point BG profiles showed lower fasting and postbreakfast BG in the BID group but lower postlunch BG in the TID group. Daily insulin dose change was similar in both groups, with more weight gain in the TID group (P = 0.0009). Overall hypoglycemic rates were similar in both groups, but nocturnal hypoglycemia was more frequent in the BID group (P = 0.0063).

CONCLUSIONS

In patients with T2DM who have not achieved adequate glycemic control with LM75/25 and BiAsp70/30 BID plus metformin and who are not candidates for basal bolus therapy, switching either to treatment with LM50/50 TID or to progressive titration of premix insulin analogs BID did not produce sufficient evidence of a difference of overall glycemic control between the 2 treatment groups. Short study duration and less intensive dose adjustments might have contributed to these results.

Non-glycemic effects of insulin therapy: a comparison between insulin aspart and regular human insulin during two consecutive meals in patients with type 2 diabetes

OBJECTIVE

To control postprandial hyperglycemia in insulin-treated type 2 diabetic patients, prandial therapy with regular human insulin (HI) or fast acting insulin analogs is used. Postprandial hyperglycemia seems to be reduced more effectively with insulin analogs than with normal insulin, but there are no data concerning the effect on lipolysis or pancreatic insulin and proinsulin secretion of normal insulin in comparison to insulin analogs.

DESIGN AND METHODS

We included 13 patients with type 2 diabetes mellitus (age 62.2±10.3 years) with preexisting insulin therapy in this crossover, prospective, open-labeled, randomized trial comparing regular HI with insulin aspart (IA) in the setting of a standardized breakfast and a standardized lunch 4 h later. Blood samples for determination of glucose, free fatty acids (FFA), triglycerides, C-peptide, and intact proinsulin were drawn during fasting and every 30 min until 4 h after the second test meal. Statistical analysis was performed with ANOVA for repeated measurements and paired Student's t-test.

RESULTS

The mean increase in blood glucose was significantly lower after IA (24.18±16.33 vs 34.92±29.07 mg/dl, P=0.02) compared with HI. Both therapies reduced FFA; however, the mean reduction was significantly higher after IA than after HI (-0.47±0.16 vs -0.35±0.15 μmol/l, P<0.001). The mean increase in intact proinsulin was significantly lower after IA than after HI (10.53±5 vs 15.20±6.83 pmol/l, P<0.001). No differences were observed in the C-peptide levels between the two groups.

CONCLUSION

In the setting of two consecutive meals, IA reduces lipolysis and proinsulin secretion more effectively than HI.

Insulin therapy in type 2 diabetes: what is the evidence?

AIM

To systematically review the literature regarding insulin use in patients with type 2 diabetes mellitus

METHODS

A Medline and Embase search was performed to identify randomized controlled trials (RCT) published in English between 1 January 2000 and 1 April 2008, involving insulin therapy in adults with type 2 diabetes mellitus. The RCTs must comprise at least glycaemic control (glycosylated haemoglobin (HbA1c), postprandial plasma glucose and /or fasting blood glucose (FBG)) and hypoglycaemic events as outcome measurements.

RESULTS

The Pubmed search resulted in 943 hits; the Embase search gave 692 hits. A total of 116 RCTs were selected by title or abstract. Eventually 78 trials met the inclusion criteria. The studies were very diverse and of different quality. They comprised all possible insulin regimens with and without combination with oral medication. Continuing metformin and/or sulphonylurea after start of therapy with basal long-acting insulin results in better glycaemic control with less insulin requirements, less weight gain and less hypoglycaemic events. Long-acting insulin analogues in combination with oral medication are associated with similar glycaemic control but fewer hypoglycaemic episodes compared with NPH insulin. Most of the trials demonstrated better glycaemic control with premix insulin therapy than with a long-acting insulin once daily, but premix insulin causes more hypoglycaemic episodes. Analogue premix provides similar HbA1c, but lower postprandial glucose levels compared with human premix, without increase in hypoglycaemic events or weight gain. Drawing conclusions from the limited number of studies concerning basal-bolus regimen seems not possible. Some studies showed that rapid-acting insulin analogues frequently result in a better HbA1c or postprandial glucose without increase of hypoglycaemia than regular human insulin.

CONCLUSION

A once-daily basal insulin regimen added to oral medication is an ideal starting point. All next steps, from one to two or even more injections per day should be taken very carefully and in thorough deliberation with the patient, who has to comply with such a regimen for many years.

Systematic review: comparative effectiveness and safety of premixed insulin analogues in type 2 diabetes

BACKGROUND

Evidence comparing premixed insulin analogues (a mixture of rapid-acting and intermediate-acting insulin analogues) with other antidiabetic agents is urgently required to guide appropriate therapy.

PURPOSE

To summarize the English-language literature on the effectiveness and safety of premixed insulin analogues compared with other antidiabetic agents in adults with type 2 diabetes.

DATA SOURCES

The authors searched MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials from inception to February 2008 and sought unpublished data from the U.S. Food and Drug Administration, European Medicines Agency, and industry.

STUDY SELECTION

Studies with control groups that compared premixed insulin analogues with another antidiabetic medication in adults with type 2 diabetes.

DATA EXTRACTION

2 reviewers using standardized protocols performed serial abstraction.

DATA SYNTHESIS

Evidence from clinical trials was inconclusive for clinical outcomes, such as mortality. Therefore, the review focused on intermediate outcomes. Premixed insulin analogues were similar to premixed human insulin in decreasing fasting glucose levels, hemoglobin A(1c) levels, and the incidence of hypoglycemia but were more effective in decreasing postprandial glucose levels (mean difference, -1.1 mmol/L; 95% CI, -1.4 to -0.7 mmol/L [-19.2 mg/dL; 95% CI, -25.9 to -12.5 mg/dL]). Compared with long-acting insulin analogues, premixed insulin analogues were superior in decreasing postprandial glucose levels (mean difference, -1.5 mmol/L; CI, -1.9 to -1.2 mmol/L [-27.9 mg/dL; CI, -34.3 to -21.5 mg/dL]) and hemoglobin A(1c) levels (mean difference, -0.39% [CI, -0.50% to -0.28%]) but were inferior in decreasing fasting glucose levels (mean difference, 0.7 mmol/L; CI, 0.3 to 1.0 mmol/L [12.0 mg/dL; CI, 6.0 to 18.1 mg/dL]) and were associated with a higher incidence of hypoglycemia. Compared with noninsulin antidiabetic agents, premixed insulin analogues were more effective in decreasing fasting glucose levels (mean difference, -1.1 mmol/L; CI, -1.7 to -0.6 mmol/L [-20.5 mg/dL; CI, -29.9 to -11.2 mg/dL]), postprandial glucose levels (mean difference, -2.1 mmol/L; CI, -3.4 to -0.8 mmol/L [-37.4 mg/dL; CI, -61.0 to -13.7 mg/dL]), and hemoglobin A(1c) levels (mean difference, -0.49% [CI, -0.86% to -0.12%]) but were associated with a higher incidence of hypoglycemia.

LIMITATIONS

The literature search was restricted to studies published in English. Data on clinical outcomes were limited. The small number of studies for each comparison limited assessment of between-study heterogeneity.

CONCLUSION

Premixed insulin analogues provide glycemic control similar to that of premixed human insulin and may provide tighter glycemic control than long-acting insulin analogues and noninsulin antidiabetic agents.

A systematic review and meta-analysis of hypoglycemia and cardiovascular events: a comparison of glyburide with other secretagogues and with insulin

OBJECTIVE

Glyburide is the most widely used sulfonylurea but has unique pharmacodynamic properties that may increase harm. We hypothesized that glyburide causes more hypoglycemia and cardiovascular events than other secretagogues or insulin.

RESEARCH DESIGN AND METHODS

Data sources were Medline, Embase, Cochrane, and three other web-based clinical trial registers (1966-2005). Parallel, randomized, controlled trials in people with type 2 diabetes comparing glyburide monotherapy with monotherapy using secretagogues or insulin were selected. Outcomes were hypoglycemia, glycemic control, cardiovascular events, body weight, and death. Titles and abstracts of 1,806 publications were reviewed in duplicate and 21 relevant articles identified. Data on patient characteristics, interventions, outcomes, and validity were extracted in duplicate using predefined criteria.

RESULTS

Glyburide was associated with a 52% greater risk of experiencing at least one episode of hypoglycemia compared with other secretagogues (relative risk 1.52 [95% CI 1.21-1.92]) and with 83% greater risk compared with other sulfonylureas (1.83 [1.35-2.49]). Glyburide was not associated with an increased risk of cardiovascular events (0.84 [0.56-1.26]), death (0.87 [0.70-1.07]), or end-of-trial weight (weighted mean difference 1.69 kg [95% CI -0.41 to 3.80]) compared with other secretagogues. Limitations included suboptimal reporting of original trials. Loss to follow-up exceeded 20% in some studies, and major hypoglycemia was infrequently reported.

CONCLUSIONS

Glyburide caused more hypoglycemia than other secretagogues and other sulfonylureas. Glyburide was not associated with an increased risk of cardiovascular events, death, or weight gain.

Insulin Lispro

Insulin lispro, alone (Humalog) or as premixture (Humalog Mix25 or Humalog Mix50) is indicated for the treatment of hyperglycaemia in diabetes mellitus in many countries worldwide. It is a recombinant human insulin analogue and, except for the transposition of two amino acids, is identical to endogenous human insulin. Insulin lispro has a faster onset of action and shorter duration of activity than regular human insulin, and the time-action profile of insulin lispro mimics that of the physiological response of endogenous human insulin to food intake. In diabetic patients, from young children to the elderly, it has demonstrated postprandial blood glucose control similar to or better than that achieved with regular human insulin, without an increased risk of hypoglycaemia. In some trials, the risk of hypoglycaemia, including nocturnal episodes, was less in insulin lispro recipients than in regular human insulin recipients. Insulin lispro alone, or as a premixture with the longer-acting insulin neutral protamine lispro, can be administered immediately before or after meals. This convenient and flexible injection schedule may enable patients, including those with a non-routine lifestyle or unpredictable eating or exercising habits, to achieve the tight glycaemic control required to minimise long-term complications of diabetes and contributes to patient satisfaction with treatment.

Premixed Insulin Analogues for the Treatment of Diabetes Mellitus

Premixed insulin analogues, consisting of rapid-acting and intermediate-acting insulin analogues, were developed to more closely mimic physiological endogenous insulin secretion and meet the needs of patients who require both basal and prandial insulin but wish to limit the number of daily injections. There is considerable variability in onset and duration of action, as well as peak insulin levels, obtained with human insulin formulations such as premixed human insulin 70/30. To overcome these limitations, premixed insulin analogues were developed. Peak insulin levels are twice as high and reached in half the time with the rapid-acting insulin component of a premixed insulin analogue. In the US, two premixed insulin analogue formulations are currently available: insulin lispro 75/25 (75% insulin lispro protamine suspension and 25% insulin lispro) and biphasic insulin aspart 70/30 (BIAsp 70/30; 70% insulin aspart protamine suspension and 30% insulin aspart). They are generally administered twice daily, just before breakfast and dinner. Data from various randomised trials show that both insulin lispro 75/25 and BIAsp 70/30 provide more effective postprandial control of blood glucose than premixed human insulin 70/30 or human insulin isophane suspension (NPH insulin). Longer-term glycaemic control, evaluated as changes in glycosylated haemoglobin, is comparable for premixed insulin analogues and premixed human insulin 70/30 in most studies. Three comparative, randomised trials have shown that patients with type 2 diabetes mellitus using premixed insulin analogues twice daily are more likely to reach glycaemic goals than those using only insulin glargine once daily. Some patients can also reach glycaemic goals with once-daily administration of a premixed insulin analogue. Although the incidence of hypoglycaemia is low, direct comparison across trials of premixed insulin analogues is difficult because of inconsistencies in reporting. Within trials, the incidence of both major (rare) and minor hypoglycaemic episodes during treatment with premixed insulin analogues is low and comparable with rates found with human insulin 70/30. Premixed insulin analogues can be safely used, and are effective and convenient for achieving overall glycaemic control in patients with diabetes. In addition, given the convenience of mealtime dose administration, compliance with insulin therapy may increase with premixed insulin analogues.