Comparison of thrice daily 'high' vs. 'medium' premixed insulin aspart with respect to evening and overnight glycaemic control in patients with type 2 diabetes

High-mix insulins

Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use.

Insulin aspart : an evidence-based medicine review

This paper provides a review and evaluation of the published evidence relating to the efficacy, safety and ease of administration of the rapid-acting insulin analogue insulin aspart in comparison with human insulin (HI) in diabetes mellitus in the following categories: (a) in adults, (b) in children, and (c) in continuous subcutaneous insulin infusion (CSII). A search for publications on insulin aspart was conducted for the following databases: Cochrane, BIOSIS, EMBASE-DP and MEDLINE. Publications were examined for relevance by two independent assessors and were graded using a system developed by the Oxford Centre for Evidence-Based Medicine. Overall, the evidence comparing insulin aspart with HI was of high quality, with all three categories graded as grade A evidence. Studies showed strong evidence for better glycaemic control, without an increased risk of hypoglycaemia, together with evidence supporting improved convenience and flexibility in administration of insulin aspart compared with regular HI in adult diabetic patients. Evidence from three trials in adults with type 1 diabetes showed a lower incidence of major nocturnal hypoglycaemia with insulin aspart versus regular HI. Published evidence also confirmed the more rapid action of insulin aspart versus HI, and a comparable efficacy and safety profile for both insulin types in type 1 paediatric patients. There was also strong evidence that insulin aspart is well tolerated and efficacious for CSII/pump use. Insulin aspart better mimics the physiological response to meals than regular HI, and may offer advantages in terms of glycaemic control and reduction of hypoglycaemia combined with flexibility and convenience of administration. Overall, there is a good body of evidence to support the efficacy, tolerability and ease of administration of insulin aspart in patients with type 1 and type 2 diabetes.

Switching to biphasic insulin aspart 30/50/70 from biphasic human insulin 30/50 in patients with type 2 diabetes in normal clinical practice: observational study results

OBJECTIVE

To investigate the safety and efficacy of switching to biphasic insulin aspart (BIAsp) 30, 50 or 70 in patients with type 2 diabetes previously treated with biphasic human insulin (BHI) 30/50 (with or without oral glucose-lowering drugs) in routine clinical practice.

METHODS

This was a 26-week, prospective, observational study conducted in Belgium and Luxembourg. Data were collected at baseline before patients switched and at 12 and 26 weeks after starting BIAsp 30, 50 or 70. Safety endpoints were incidence and rate of hypoglycemia (major, minor, nocturnal), adverse events and body-weight changes. Efficacy assessments included HbA(1c) and 7-point self-measured plasma glucose (PG) profiles. Changes from baseline were analyzed using paired t-tests.

RESULTS

Of 592 patients analyzed, 72% switched to twice-daily BIAsp and 20% to three-times daily BIAsp. Upon switching, 27% of patients received intensified treatment (i.e., more daily doses than with their previous BHI). At all three data-collection points, approximately two-thirds of patients were taking BIAsp 30 and approximately one-third were taking BIAsp 50; very few patients took BIAsp 70. Mean total daily insulin dose increased significantly from baseline (51.2 U) to 26 weeks (54.3 U) and mean time of intake before meals changed from 17 minutes for BHI to ∼3 minutes with BIAsp. Incidence of hypoglycemia did not change during the study (baseline: 30.7%, week 26: 29.2%). HbA(1c) improved significantly from baseline (7.9 %) to weeks 12 and 26 (7.6% and 7.5%, respectively; p < 0.001). Mean PG profiles also showed significant improvements. As this is an observational study, some limitations should be considered such as the absence of a control group and a possible bias of increased medical attention.

CONCLUSIONS

Patients with long-standing type 2 diabetes can switch safely from BHI to BIAsp therapy, even if they receive intensified treatment, and they have no problems changing the timing of their insulin injections.

Intensifying existing premix therapy (BIAsp 30) with BIAsp 50 and BIAsp 70: A consensus statement

In 2009, consensus guidelines were published on intensification of insulin therapy using the premix analog biphasic insulin aspart (BIAsp) 30 in the treatment of type 2 diabetes, based on the recommendations of an international, independent expert panel. The guidelines included recommendations and titration algorithms for intensification from basal insulin once (OD) or twice daily (BID) to BIAsp 30 BID, from OD BIAsp 30 to BID, and from BID BIAsp 30 to three times daily (TID). Building on these recommendations, the objective was to develop similar, simple and effective guidelines for intensification switch from a BIAsp 30 to a mid-/high-ratio premix regimen for the vast majority of patients with type 2 diabetes. A panel of independent experts with extensive clinical experience in premix analog therapy met in October 2009 to review the therapeutic role of mid- and high-ratio premixes (BIAsp 50 and 70, respectively). The panel outlined a series of algorithms for intensifying BIAsp 30 BID and TID with mid-/high-ratio premixes, along with practical suggestions relating to intensification for individual patients. A simple tool to aid dose adjustment was also developed. The guidelines suggested here should assist physicians in introducing mid-/high-ratio premixes to optimize the insulin therapy of patients with type 2 diabetes who are failing to achieve glycemic targets on a BIAsp 30 BID or TID regimen.

Obesity does not influence the unique pharmacological properties of different biphasic insulin aspart preparations in patients with type 2 diabetes

AIM

To investigate the influence of obesity in type 2 diabetic patients upon pharmacological properties of different biphasic preparations of insulin aspart.

METHODS

A total of 75 type 2 diabetic patients were stratified according to their body mass index (BMI) into 40 non-obese (BMI 23-28 kg/m(2)) and 35 obese (BMI 30-35 kg/m(2)) subjects. The trial was a double-blinded crossover study. In two periods of 4 weeks each the patients received subcutaneous injections of biphasic insulin aspart 50 (BIAsp 50) or biphasic insulin aspart 70 (BIAsp 70) thrice daily in random order. Insulin doses were titrated individually. At the end of each period 24-h serum profiles of insulin aspart, C-peptide and glucose were recorded. The primary endpoint was the area under the curve of serum glucose concentration during 24 h (AUC(Glu)(0-24 h)).

RESULTS

The insulin concentration profiles of BIAsp 50 and 70 were as expected according to the content of protamine-bound insulin aspart (50 and 30% respectively). AUC(Glu(0-24 h)) BIAsp 50/BIAsp 70 ratios were 0.97 (95% CI: 0.90-1.05, p = 0.49) for non-obese and 0.98 (95% CI: 0.92-1.05, p = 0.55) for obese. Fasting serum glucose (FSG) BIAsp 50/BIAsp 70 ratios were 0.90 (95% CI: 0.84-0.96, p = 0.002) for non-obese and 0.90 (95% CI: 0.84-0.97, p = 0.006) for obese. During both treatment regimens the frequency of minor hypoglycaemic episodes was highest for the non-obese group.

CONCLUSIONS

The pharmacokinetic and pharmacodynamic characteristics of the two preparations of biphasic insulin aspart were different; however, they were not influenced by the degree of obesity in type 2 diabetic patients.

Mid- and high-ratio premix insulin analogues: potential treatment options for patients with type 2 diabetes in need of greater postprandial blood glucose control

Some patients with type 2 diabetes continue to have high postprandial blood glucose levels on twice-daily regimens of 'low-ratio' premix insulin formulations (up to 30% rapid-acting, with 70% protracted insulin). These patients require intensified insulin therapy, which can be provided by a twice- or thrice-daily regimen of mid-ratio (50% rapid-acting and 50% protaminated intermediate-acting insulin - human or analogue) or high-ratio (70% rapid-acting and 30% protaminated insulin - analogue only) premix insulin. Alternatively, a third daily injection of low-ratio premix insulin can be added to the regimen, with the option of incorporating one or more injections of mid- or high-ratio premix as required, and as an alternative to basal-bolus therapy. How these mid- and high-ratio formulations differ from the low-ratio premix insulins is reviewed here, with the aim of identifying the role of these formulations in diabetes management. Glucose clamp studies have shown that premix analogues give serum insulin levels proportional to their percentage of rapid-acting uncomplexed insulin: the higher the proportion, the greater the maximum level reached. Other pharmacokinetic parameters were not always significantly different between the mid- and high-ratio formulations. In clinical trials, postprandial plasma glucose and glycated haemoglobin A1c (HbA(1c)) levels were significantly reduced with thrice-daily mid- /high-ratio premix analogue when compared with twice-daily low-ratio biphasic human insulin (BHI) 30/70 or once-daily insulin glargine. Moreover, glycaemic control with mid-/high-ratio premix analogue was found to be similar to that with a basal-bolus therapy. Mid- and high-ratio premix regimens are generally well tolerated. The frequency of minor hypoglycaemia was reportedly higher with mid- /high-ratio premix analogues than with BHI 30, but nocturnal hypoglycaemia was less frequent. Although there is little evidence that clinical outcomes with mid-ratio premix analogues are different from those with high-ratio, they are useful additions to the low-ratio formulations for the management of diabetes, and addressing postprandial hyperglycaemia in particular.

Prandial premixed insulin analogue regimens versus basal insulin analogue regimens in the management of type 2 diabetes: an evidence-based comparison

BACKGROUND

Insulin is an effective treatment for type 2 diabetes (T2D), a progressive condition in which insulin deficiency is one of the core defects. When patients with T2D are unable to achieve glycemic goals with diet and oral antihyperglycemic medications, a common starting insulin regimen consists of basal or premixed insulin added to oral antihyperglycemic medications. When glycemic goals are not achieved with the initial insulin regimen, a basal-bolus regimen is necessary.

OBJECTIVE

This article reviews clinical-trial data on the efficacy and safety profile of prandial premixed insulin analogues (insulin aspart and insulin lispro) compared with basal insulin analogues (insulin glargine, insulin detemir, and insulin lispro protamine suspension), with or without a prandial insulin analogue, in the management of T2D.

METHODS

A systematic search of Ovid, MEDLINE, and EMBASE (1995-2007) was performed to identify published randomized controlled trials comparing prandial premixed insulin analogues with basal insulin analogues, with or without prandial insulin, in patients with T2D. The search terms were premixed insulin analogues, premixed insulin, biphasic insulin aspart, insulin aspart 70/30, insulin aspart 50/50, premixed insulin lispro, insulin lispro 75/25, insulin lispro 50/50, glargine, and detemir. Abstracts presented at the 2005 and 2006 meetings of the American Diabetes Association and the European Association for the Study of Diabetes and bibliographies of the identified studies were also reviewed. Predetermined criteria for study inclusion were treatment duration of at least 12 weeks, T2D diagnosed using valid criteria, use of a basal insulin analogue (with or without rapid-acting insulin) as a study comparator, and use of well-accepted end points (eg, glycosylated hemoglobin [HbA(1c)], hypoglycemia, preprandial and postprandial blood glucose).

RESULTS

Of the identified randomized controlled trials, 3 studies compared premixed insulin analogues containing 70% or 75% basal and 30% or 25% rapid-acting insulin analogue with basal insulin analogues only, and 3 studies evaluated premixed insulin analogues containing 50% basal and 50% rapid-acting insulin analogue with basal insulin analogues only. Use of prandial premixed insulin analogues was associated with better overall and postprandial glycemic control. In the studies that compared twice-daily premixed insulin analogues with a basal insulin analogue, changes in HbA(1c) ranged from -1.00% to -2.79% and from -0.42% to -2.36%, respectively (P < 0.01). In the studies that compared thrice-daily premixed insulin analogues with a basal insulin analogue, changes in HbA(1c) ranged from -0.72% to -1.2% and from -0.3% to -0.75%, respectively (P < 0.01). These results were achieved with some increase in overall hypoglycemia, but not in nocturnal or severe hypoglycemia. Doses of the premixed insulin analogues were adjusted during the titration period to achieve glycemic goals.

CONCLUSIONS

The results of this systematic review suggest that regimens consisting of prandial premixed insulin analogues, which provide both basal and prandial insulin coverage, may be used as an initial insulin regimen in patients with T2D to enable better overall, preprandial, and postprandial glycemic control compared with a basal insulin analogue regimen alone. Premixed insulin analogues are an effective option for initiating and intensifying insulin therapy in patients with T2D.

An exploratory study of the effect of using high-mix biphasic insulin aspart in people with type 2 diabetes

OBJECTIVE

To compare blood glucose control when using biphasic insulin aspart (BIAsp) three times a day (using 70/30 high-mix before breakfast and lunch), with biphasic human insulin (BHI, 30/70) twice daily in adults with type 2 diabetes already treated with insulin.

RESEARCH DESIGN AND METHODS

In a 60-day, open-label, crossover study, people with insulin-treated type 2 diabetes [n = 38, baseline haemoglobin A1c 8.3 +/- 0.9 (s.d.) %] were randomized to BIAsp three times a day before meals, as BIAsp 70 (70% insulin aspart and 30% protamine-complexed insulin aspart) before breakfast and lunch and BIAsp 30 (30/70 free and protamine-complexed insulin aspart) before dinner, or to human premix insulin (BHI) 30/70 twice a day before meals. A 24-h in-patient plasma glucose profile was performed at the end of each 30-day treatment period. The total daily insulin dose of BIAsp regimen was 110% of BHI and the doses were not changed during the study.

RESULTS

There was no difference between BIAsp and BHI in geometric weighted average serum glucose over 24 h [7.3 vs. 7.7 mmol/l, BIAsp/BHI ratio 0.95 (95% CI 0.88-1.02), not significant (NS)], but daytime geometric weighted average glucose concentration was significantly lower with the BIAsp regimen than with BHI [8.3 vs. 9.2 mmol/l, BIAsp/BHI ratio 0.90 (0.84-0.98), p = 0.014]. The mealtime serum glucose excursion was also lower with BIAsp than with BHI with statistically significant differences at lunchtime [difference -4.9 (-7.0 to -2.7) mmol/l, p = 0.000); the difference in glucose excursions above 7.0 mmol/l was also significant [-5.8 (-8.3 to -3.2) mmol/l, p = 0.000). The proportion of participants experiencing confirmed hypoglycaemic episodes was similar between regimens (42 vs. 43%, NS).

CONCLUSIONS

An insulin regimen using high-mix BIAsp (BIAsp 70) before breakfast and lunch and BIAsp 30 before dinner can achieve lower blood glucose levels during the day through reduced mealtime glucose excursions in particular at lunchtime than a twice-daily premix regimen.

Three different premixed combinations of biphasic insulin aspart - comparison of the efficacy and safety in a randomized controlled clinical trial in subjects with type 2 diabetes

AIM

To evaluate clinical efficacy and safety of biphasic insulin aspart (BIAsp) 30 twice daily (b.i.d.) vs. BIAsp 50 or BIAsp 70 (high-mix regimens) thrice daily (t.i.d.) all in combination with metformin in a 36-week clinical trial in subjects with type 2 diabetes.

METHODS

Efficacy measurements included haemoglobin A(1c) (HbA(1c)) and eight-point plasma glucose (PG); safety included adverse events (AEs) and hypoglycaemic episodes. The three treatment groups (approximately 200 subjects in each group) were well matched regarding sex ratio, ethnicity, age and body mass index.

RESULTS

After 12 weeks, 43% and 54% in the BIAsp 50 and 70 groups, respectively, switched their dinner insulin to BIAsp 30. Both high-mix regimens were non-inferior to BIAsp 30 b.i.d., as measured by change in HbA(1c), and the BIAsp %50 regimen was superior. The odds for meeting the American Diabetes Association and The American Association of Clinícal Endocrinologist HbA(1c) targets of <7% and < or =6.5%, respectively, were significantly higher with the BIAsp 50 regimen than with BIAsp 30. A significantly lower PG level was achieved from lunch until 02:00 hours with both high-mix regimens compared with BIAsp 30 b.i.d. AEs were mild or moderate with all three regimens. Frequency of hypoglycaemic episodes was comparable for the BIAsp 50 and the BIAsp 30 b.i.d. regimens but was significantly higher with BIAsp 70 t.i.d.

CONCLUSIONS

Glycaemic control improved with BIAsp 50 t.i.d. without higher incidence of hypoglycaemia compared with BIAsp 30 b.i.d.; with BIAsp 70 t.i.d. lower PG levels from lunch to 02.00 hours, but more hypoglycaemic episodes were obtained compared with BIAsp 30 b.i.d.

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.

Improved glycaemic control of thrice-daily biphasic insulin aspart compared with twice-daily biphasic human insulin; a randomized, open-label trial in patients with type 1 or type 2 diabetes

AIM

This trial evaluated the potential for improving glycaemic control by intensifying a conventional twice-daily therapy with premixed human insulin (HI) to a thrice-daily regimen using premixed formulations of biphasic insulin aspart (BIAsp) in patients with type 1 or type 2 diabetes.

METHODS

This was a multicentre, open-label, parallel group trial. After a 4-week run-in period, patients were randomized 1 : 1 to 16 weeks of treatment. A total of 748 patients were screened, 664 were exposed to trial drug and 604 completed the trial.

RESULTS

Haemoglobin A(1c), the primary efficacy endpoint, was shown to be significantly lower for the BIAsp treatment group compared with the biphasic HI (BHI) 30 group [estimated mean difference: -0.32, 95% confidence interval (CI) (-0.48; -0.16), p = 0.0001]. The average blood glucose level was significantly lower in the BIAsp group [estimated mean difference: -0.79, 95% CI (-1.17; -0.40), p = 0.0001]. There were few major hypoglycaemic episodes, 11 in the BIAsp group and 7 in the BHI 30 group. Although intensification of insulin therapy with BIAsp three times a day was associated with a higher risk of minor hypoglycaemia (relative risk = 1.58, p = 0.0038), the overall rate of minor hypoglycaemia remained low with both the BIAsp and the BHI treatments (13.1 vs. 8.3 episodes/patient year respectively). Overall safety and patient satisfaction were similar with the two insulin therapies.

CONCLUSIONS

This trial confirmed that a thrice-daily BIAsp regimen can safely be used to intensify treatment for patients inadequately controlled on twice-daily BHI. A treat-to-target trial is required to explore the full potential of the BIAsp regimens and evaluate their use as a viable alternative to intensification with a basal-bolus regimen.