Human insulin analogue [LYS(B28), PRO(B29)]: the ideal pump insulin?

Efficacy and Safety of Rapid-Acting Insulin Analogs in Special Populations with Type 1 Diabetes or Gestational Diabetes: Systematic Review and Meta-Analysis

INTRODUCTION

To assess the efficacy and safety of three available rapid-acting insulin analogs (insulins lispro, aspart and glulisine, respectively) in pregnant women, children/adolescents and people using continuous subcutaneous insulin infusion (CSII) with type 1 diabetes.

METHODS

PubMed, EMBASE and Cochrane Reviews were searched electronically, and their bibliographies examined to identify suitable studies for review and inclusion in a meta-analysis. Eligible studies were randomized controlled trials that reported data on relevant clinical outcomes. A different reviewer abstracted data for each of the three subpopulations, and one reviewer abstracted data for all three. Any differences were resolved by consensus or by consulting a fourth reviewer.

RESULTS

In people on CSII, rapid-acting insulin analogs lowered postprandial plasma glucose post-breakfast to a greater extent than did regular human insulin (RHI) (mean difference: - 1.63 mmol/L [95% confidence interval - 1.71; - 1.54]), with a comparable risk of hypoglycemia and a trend for lower glycated hemoglobin. In the pediatric population, glycemic control was similar with rapid-acting insulin analogs and RHI, with no safety concerns. Meta-analysis indicated severe hypoglycemic events were comparable for rapid-acting insulin analogs versus RHI (risk difference: 0.00 [95% confidence interval - 0.01; 0.01]). In the pregnancy group, insulin lispro and insulin aspart were safe and effective for both mother and fetus, with glycemic control being at least as good as with RHI. There were no data on insulin glulisine during pregnancy.

CONCLUSION

Rapid-acting insulin analogs appear generally safe and effective in these special populations; however, additional trials would be helpful.

FUNDING

Novo Nordisk A/S.

Evidence-based insulin treatment in type 1 diabetes mellitus

AIM

Evaluation of the evidence base for recommending different insulin treatment regimens in type 1 diabetes.

METHODS

A computerised literature survey was conducted using The Cochrane Controlled Trials Register and the Pub Med database for the period of 1982-2007.

RESULTS

A meta-analysis on only 49 out of 1295 references showed that CSII compared with conventional or multiple insulin injections therapy demonstrated a significant reduction in mean HbA1c (primary outcome) of 1.2% CI [0.73; 1.59] (P<0.001) without increasing the risk of hypoglycaemia. The evidence for using four versus two daily insulin injections was based on only one publication demonstrating an improved quality of life but no significant reduction in HbA1c or hypoglycaemia. A comparison of rapid-acting insulin analogues and human soluble insulin demonstrated a statistically significant reduction in HbA1c of 0.1% CI: [0.01; 0.16] (P=0.03) using rapid-acting insulin analogues. The mean frequency of hypoglycaemia was reduced with 14+/-3.7% (<0.05).

CONCLUSION

The scientific evidence supporting the three common insulin regimens was rather sparse. Only five studies during the past 25 years fulfil the optimal criteria for a clinical trial, and only 5 trials on insulin analogues were performed as double-blinded. Current evidence suggests that CSII treatment results in a significant reduction in HbA1c without inducing more hypoglycaemia. Rapid-acting insulin analogues compared to human soluble insulin provide statistically significant but clinically minor improvement in HbA1c but seem to reduce the risk for hypoglycaemia.

An estimation of the long-term clinical and economic benefits of insulin lispro in Type 1 diabetes in the UK

AIMS

To determine the long-term health economic benefits associated with lispro vs. regular human insulin (RHI) in UK Type 1 diabetic (T1DM) patients using the previously published and validated CORE Diabetes Model.

METHODS

A literature review designed to capture clinical benefits associated with lispro and T1DM cohort characteristics specific to UK was undertaken. Clinical benefits were derived from a Cochrane meta-analysis. The estimated difference (weighted mean) in glycated haemoglobin (HbA(1c)) was -0.1% (95% confidence interval -0.2 to 0.0%) for lispro vs. RHI. Severe hypoglycaemia rates for lispro and RHI were 21.8 and 46.1 events per 100 patient years, respectively. Costs and disutilities were accounted for severe hypoglycaemia rates. All costs were accounted in 2007 poundUK from a National Health Service (NHS) perspective. Future costs and clinical benefits were discounted at 3.5% annually.

RESULTS

In the base-case analysis, lispro was projected to be dominant compared with RHI. Lispro was associated with improvements in quality-adjusted life expectancy (QALE) of approximately 0.10 quality-adjusted life years (QALYs) vs. RHI (7.60 vs. 7.50 QALYs). Lifetime direct medical costs per patient were lower with lispro treatment, pound70 576 vs. pound72 529. Severe hypoglycaemia rates were the key driver in terms of differences in QALE and lifetime costs. Sensitivity analyses with assumptions around time horizon, discounting rates and benefits in terms of glycaemic control or hypoglycaemic event rates revealed that lispro remained dominant.

CONCLUSIONS

Our findings suggest that lispro is likely to improve QALE, reduce frequency of diabetes-related complications and lifetime medical costs compared with RHI.

[Insulin pump therapy in patients with type 1 diabetes]

Both Continuous Subcutaneous Insulin Infusion (CSII) and Multiple Daily Injections (MDI) are effective ways of implementing intensive management of DM1 to attain near normal glycemic levels and a more flexible lifestyle. CSII is as safe as MDI and has some advantages over it mostly in diabetic patients with frequent hypoglycemias with important dawn phenomenum, gastroparesia, during pregnancy, in children and in patients with an erratic way of living. CSII allows a better chance to reach better glycemic control with less hypoglycemia, asymptomatic hypoglycemias and a better quality of life. Besides, risks are lower and adverse events are less frequent in DM1 patients under CSII as compared to MDI. To obtain results like this, a careful adjustment of basal and boluses insulin doses and an adequate patient follow-up are essential.

Efficacy and safety of insulin analogues for the management of diabetes mellitus: a meta-analysis

BACKGROUND

Although insulin analogues are commonly prescribed for the management of diabetes mellitus, there is uncertainty regarding their optimal use. We conducted meta-analyses to compare the outcomes of insulin analogues with conventional insulins in the treatment of type 1, type 2 and gestational diabetes.

METHODS

We updated 2 earlier systematic reviews of the efficacy and safety of rapid-and long-acting insulin analogues. We searched electronic databases, conference proceedings and "grey literature" up to April 2007 to identify randomized controlled trials that compared insulin analogues with conventional insulins. Study populations of interest were people with type 1 and type 2 diabetes (adult and pediatric) and women with gestational diabetes.

RESULTS

We included 68 randomized controlled trials in the analysis of rapid-acting insulin analogues and 49 in the analysis of long-acting insulin analogues. Most of the studies were of short to medium duration and of low quality. In terms of hemoglobin A1c, we found minimal differences between rapid-acting insulin analogues and regular human insulin in adults with type 1 diabetes (weighted mean difference for insulin lispro: -0.09%, 95% confidence interval [CI] -0.16% to -0.02%; for insulin aspart: -0.13%, 95% CI -0.20% to -0.07%). We observed similar outcomes among patients with type 2 diabetes (weighted mean difference for insulin lispro: -0.03%, 95% CI -0.12% to -0.06%; for insulin aspart: -0.09%, 95% CI -0.21% to 0.04%). Differences between long-acting insulin analogues and neutral protamine Hagedorn insulin in terms of hemoglobin A1c were marginal among adults with type 1 diabetes (weighted mean difference for insulin glargine: -0.11%, 95% CI -0.21% to -0.02%; for insulin detemir: -0.06%, 95% CI -0.13% to 0.02%) and among adults with type 2 diabetes (weighted mean difference for insulin glargine: -0.05%, 95% CI -0.13% to 0.04%; for insulin detemir: 0.13%, 95% CI 0.03% to 0.22%). Benefits in terms of reduced hypoglycemia were inconsistent. There were insufficient data to determine whether insulin analogues are better than conventional insulins in reducing long-term diabetes-related complications or death.

INTERPRETATION

Rapid-and long-acting insulin analogues offer little benefit relative to conventional insulins in terms of glycemic control or reduced hypoglycemia. Long-term, high-quality studies are needed to determine whether insulin analogues reduce the risk of long-term complications of diabetes.

Short acting insulin analogues versus regular human insulin in patients with diabetes mellitus

BACKGROUND

Short acting insulin analogue use for diabetic patients is still controversial, as reflected in many scientific debates.

OBJECTIVES

To assess the effects of short acting insulin analogues versus regular human insulin.

SEARCH STRATEGY

The Cochrane Library (Issue 3, 2005), MEDLINE, EMBASE until September 2005.

SELECTION CRITERIA

Randomised controlled trials with an intervention duration of at least 4 weeks.

DATA COLLECTION AND ANALYSIS

Trial selection and evaluation of study quality was done independently by two reviewers.

MAIN RESULTS

Altogether 8274 participants took part in 49 randomised controlled studies. Most studies were of poor methodological quality. In patients with type 1 diabetes, the weighted mean difference (WMD) of HbA1c was -0.1% (95% CI: -0.2 to -0.1) in favour of insulin analogue, whereas in patients with type 2 diabetes the WMD was 0.0% (95% CI: -0.1 to 0.0). In subgroup analyses of different types of interventions in type 1 diabetic patients, the WMD in HbA1c was -0.2% (95% CI: -0.3 to -0.1) in favour of insulin analogue in studies using continuous subcutaneous insulin injections (CSII), whereas for conventional intensified insulin therapy (IIT) studies the WMD in HbA1c was -0.1% (95% CI: -0.1 to 0.0). The WMD of the overall mean hypoglycaemic episodes per patient per month was -0.2 (95% CI: -1.1 to 0.7) and -0.2 (95% CI: -0.5 to 0.1) for analogues in comparison to regular insulin in patients with type 1 diabetes and type 2 diabetes, respectively. For studies in type 1 diabetes patients the incidence of severe hypoglycaemia ranged from 0 to 247.3 (median 21.8) episodes per 100 person-years for insulin analogues and from 0 to 544 (median 46.1) for regular insulin, in type 2 the incidence ranged from 0 to 30.3 (median 0.3) episodes per 100 person-years for insulin analogues and from 0 to 50.4 (median 1.4) for regular insulin. No study was designed to investigate possible long term effects (e.g. mortality, diabetic complications), in particular in patients with diabetes related complications.

AUTHORS' CONCLUSIONS

Our analysis suggests only a minor benefit of short acting insulin analogues in the majority of diabetic patients treated with insulin. Until long term efficacy and safety data are available we suggest a cautious response to the vigorous promotion of insulin analogues. For safety purposes, we need a long-term follow-up of large numbers of patients and well designed studies in pregnant women to determine the safety profile for both the mother and the unborn child.

Patient management of long-term continuous subcutaneous insulin infusion

AIM

This paper reports a study of patients' current practice with continuous subcutaneous insulin infusions, particularly with respect to the management of the pump.

BACKGROUND

Successful implementation of continuous subcutaneous insulin infusion requires a motivated patient with a range of technical skills and self-management capabilities. The therapy should be prescribed, implemented and monitored by a skilled professional team familiar with it and capable of supporting the patient.

METHODS

A questionnaire was mailed to 102 continuous subcutaneous insulin infusion treated patients at a Swedish university hospital with experience of pump treatment for at least 6 months.

RESULTS

The questionnaire was answered by 88% of the patients, 53 women and 37 men, aged 22-71 years with a duration of continuous subcutaneous insulin infusion use of between 7 months and 19 years. The changing interval for soft infusion set ranged from 2.0 to 10.0 days (mean 4.8) and for metal needles from 1.5 to 7.5 days (mean 3.8), P = 0.001. Catheter occlusions were significantly more often reported in patients with presence of bleeding at the infusion site (P = 0.011) and among those using insulin lispro (P = 0.032).

CONCLUSIONS

Patients having long-term continuous subcutaneous insulin infusion should be carefully audited with respect to the management of the insulin pump and its accessories. In patients who frequently experience problems, shorter intervals between changes of infusion sets are strongly advocated and type of insulin preparation may be of importance in some cases.

Meta-analysis of short-acting insulin analogues in adult patients with type 1 diabetes: continuous subcutaneous insulin infusion versus injection therapy

AIMS/HYPOTHESIS

This study aimed to compare the effect of treatment with short-acting insulin (SAI) analogues versus structurally unchanged short-acting insulin (regular insulin) on glycaemic control and on the risk of hypoglycaemic episodes in type 1 diabetic patients using different insulin treatment strategies.

METHODS

We performed a meta-analysis of 27 randomised controlled trials that compared the effect of SAI analogues with regular insulin in patients with type 1 diabetes mellitus. The treatments were administered either via continuous subcutaneous insulin infusion (CSII) or by conventional intensified insulin therapy (IIT) with short-acting insulin injections before meals and basal insulin administered once or twice daily in most cases.

RESULTS

HbA(1)c levels were reported for 20 studies. For studies using CSII, the weighted mean difference between values obtained using SAI analogues and regular insulin was -0.19% (95% CI: -0.27 to -0.12), whereas the corresponding value for injection studies was -0.08% (95% CI: -0.15 to -0.02). For the analysis of overall hypoglycaemia, we used the results from nine studies that reported the mean frequency of hypoglycaemic episodes per patient per month. For studies using CSII, the standardised mean difference between SAI analogues and regular insulin was -0.07 (95% CI: -0.43 to 0.28), whereas for IIT studies the corresponding value was -0.04 (95% CI: -0.24 to 0.16).

CONCLUSIONS/INTERPRETATION

Taking into consideration the low quality of the trials included, we can conclude that use of a short-acting insulin analogue in CSII therapy provides a small, but statistically significant improvement in glycaemic control compared with regular insulin. An even smaller effect was obtained with the use of ITT. The rate of overall hypoglycaemic episodes was not significantly reduced with short-acting insulin analogues in either injection regimen.

Short acting insulin analogues versus regular human insulin in patients with diabetes mellitus

BACKGROUND

In short acting insulin analogues the dissociation of hexamers is facilitated, achieving peak plasma concentrations about twice as high and within approximately half the time compared to regular human insulin. According to these properties this profile resembles the shape of non-diabetic patients more than that of regular human insulins. Despite this theoretical superiority of short acting insulin analogues over regular human insulin, the risk-benefit ratio of short acting insulin analogues in the treatment of diabetic patients is still unclear.

OBJECTIVES

To assess the effect of treatment with short acting insulin analogues versus regular human insulin.

SEARCH STRATEGY

A highly sensitive search for randomised controlled trials combined with key terms for identifying studies on short acting insulin analogues versus regular human insulin was performed using the Cochrane Library (issue 4, 2003), MEDLINE and EMBASE. Date of last search was December 2003.

SELECTION CRITERIA

We included randomised controlled trials with diabetic patients of all ages that compared short acting insulin analogues to regular human insulin. Intervention duration had to be at least 4 weeks.

DATA COLLECTION AND ANALYSIS

Trial selection as well as evaluation of study quality was done by two independent reviewers. The quality of reporting of each trial was assessed according to a modification of the quality criteria as specified by Schulz and Jadad.

MAIN RESULTS

Altogether 7933 participants took part in 42 randomised controlled studies. Most studies were of poor methodological quality. In patients with type 1 diabetes, the weighted mean difference (WMD) of HbA1c was estimated to be -0.1% (95% CI: -0.2% to -0.1%) in favour of insulin analogue, whereas in patients with type 2 diabetes the WMD was estimated to be 0.0% (95% CI: -0.1% to 0.1%). In subgroup analyses of different types of interventions in type 1 diabetic patients, the WMD in HbA1c was -0.2% (95% CI: -0.3% to -0.1%) in favour of insulin analogue in studies using continuous subcutaneous insulin injections (CSII) whereas for conventional intensified insulin therapy (IIT) studies the WMD in HbA1c was -0.1% (95% CI: -0.2% to -0.0%). The WMD of the overall mean hypoglycaemic episodes per patient per month was -0.2 (95% CI: -1.2 to 0.9) and -0.2 (95%CI: -0.5 to 0.1) for analogues in comparison to regular insulin in patients with type 1 diabetes and type 2 diabetes, respectively. For studies in type 1 diabetic patients the incidence of severe hypoglycaemia ranged from 0 to 247.3 (median 20.3) episodes per 100 person-years for insulin analogues and from 0 to 544 (median 37.2) for regular insulin, in type 2 the incidence ranged from 0 to 30.3 (median 0.6) episodes per 100 person-years for insulin analogues and from 0 to 50.4 (median 2.8) for regular insulin. No study was designed to investigate possible long term effects (e.g. mortality, diabetic complications), in particular in patients with diabetes related complications.

REVIEWERS' CONCLUSIONS

Our analysis suggests only a minor benefit of short acting insulin analogues in the majority of diabetic patients treated with insulin. Until long term efficacy and safety data are available we suggest a cautious response to the vigorous promotion of insulin analogues. Due to fears of potentially carcinogenic and proliferative effects, most studies to date have excluded patients with advanced diabetic complications. For safety purposes, we need a long-term follow-up of large numbers of patients who use short acting insulin analogues. Furthermore, we need well designed studies in pregnant women to determine the safety profile for both the mother and the unborn child.

Are analogue insulins better than soluble in continuous subcutaneous insulin infusion? Results of a meta-analysis

AIMS

The properties of rapid-acting insulin analogues are thought to be particularly appropriate for use in continuous subcutaneous insulin infusion (CSII) or insulin pump therapy. We conducted a systematic review and meta-analysis of trials comparing rapid-acting insulin analogues with soluble insulin in CSII.

METHODS

The following databases were searched (last search June 2002): MEDLINE 1985-2002; Embase 1980-2002; PubMed internet version, records added June 2001 to June 2002; Science Citation Index 1990-2002; BIOSIS 1999-2002; Web of Science Proceedings 1990-2002; and the Cochrane Library, including DARE and the HTA databases. Randomized controlled trials and crossover studies with at least 10 weeks on each treatment were included. Data extraction and quality assessment were undertaken by one reviewer and checked by a second. A meta-analysis was undertaken using a random effects model.

RESULTS

A significant improvement of 0.26% (95% confidence interval -0.47, -0.06%) in glycated haemoglobin was demonstrated with lispro. Some studies reported fewer hypoglycaemic episodes with analogue insulin but this varied according to the definitions used. No differences in insulin dosage or weight were seen. Two studies reported patient preference, with analogues preferred in both. The extra cost per annum ranges from pound 72 (at 40 units per day) to pound 150 (at 84 units per day).

CONCLUSIONS

Insulin analogues result in a modest but significant reduction in HbA1c compared with soluble insulin when used in CSII, and are preferred by patients.

Assessment of Therapy with Continuous Subcutaneous Insulin Infusion in an Academic Diabetes Clinic

OBJECTIVE

To assess the results of continuous subcutaneous insulin infusion (CSII) therapy in patients with type 1 diabetes mellitus, especially relative to glycemic control and rate of discontinuation of insulin pump therapy.

METHODS

A retrospective review of the medical records of 107 patients with type 1 diabetes who were receiving CSII at the Diabetes Care Center at the University of Washington Medical Center was performed to evaluate clinical outcomes. All patients considering CSII therapy participated in a class to learn the details of insulin pump treatment.

RESULTS

The mean age of our patient population was 36.0 +/- 10.4 years (mean value +/- standard deviation). The mean duration of diabetes at the initiation of insulin pump therapy was 17.0 +/- 9.1 years. The mean duration of CSII use was 36.1 +/- 25.5 months (median, 26.2 months). Insulin lispro was used by 89.7% of the patients. Six patients (5.6%) discontinued CSII therapy after a mean of 19.1 +/- 14.7 months for a variety of reasons. Despite no significant difference in home blood glucose monitoring (number of tests per day) before initiation of CSII, mean hemoglobin A1c levels decreased from 7.6% to 7.1% (P<0.0001), and the occurrence of severe hypoglycemic episodes decreased 73.8% (P = 0.0003).

CONCLUSION

In our academic diabetes clinic with a formal insulin pump program, we noted a significant improvement in hemoglobin A1c values, a significant reduction in the frequency of severe hypoglycemic episodes, and a low rate of discontinuation of CSII. CSII therapy, when provided in conjunction with a standard educational program, should continue to be an important treatment option in appropriately selected patients with type 1 diabetes.

Glycaemic control with continuous subcutaneous insulin infusion compared with intensive insulin injections in patients with type 1 diabetes: meta-analysis of randomised controlled trials

OBJECTIVE

To compare glycaemic control and insulin dosage in people with type 1 diabetes treated by continuous subcutaneous insulin infusion (insulin infusion pump therapy) or optimised insulin injections.

DESIGN

Meta-analysis of 12 randomised controlled trials.

PARTICIPANTS

301 people with type 1 diabetes allocated to insulin infusion and 299 allocated to insulin injections for between 2.5 and 24 months.

MAIN OUTCOME MEASURES

Glycaemic control measured by mean blood glucose concentration and percentage of glycated haemoglobin. Total daily insulin dose.

RESULTS

Mean blood glucose concentration was lower in people receiving continuous subcutaneous insulin infusion compared with those receiving insulin injections (standardised mean difference 0.56, 95% confidence interval 0.35 to 0.77), equivalent to a difference of 1.0 mmol/l. The percentage of glycated haemoglobin was also lower in people receiving insulin infusion (0.44, 0.20 to 0.69), equivalent to a difference of 0.51%. Blood glucose concentrations were less variable during insulin infusion. This improved control during insulin infusion was achieved with an average reduction of 14% in insulin dose (difference in total daily insulin dose 0.58, 0.34 to 0.83), equivalent to 7.58 units/day.

CONCLUSIONS

Glycaemic control is better during continuous subcutaneous insulin infusion compared with optimised injection therapy, and less insulin is needed to achieve this level of strict control. The difference in control between the two methods is small but should reduce the risk of microvascular complications.

Continuous subcutaneous insulin infusion at 25 years: evidence base for the expanding use of insulin pump therapy in type 1 diabetes

Continuous subcutaneous insulin infusion (CSII) is used in selected type 1 diabetic subjects to achieve strict blood glucose control. A quarter of a century after its introduction, world-wide use of CSII is increasing. We review the evidence base that justifies this increase, including effectiveness compared with modern intensified insulin injection regimens and concern about possible complications. Review of controlled trials shows that, in most patients, mean blood glucose concentrations and glycated hemoglobin percentages are either slightly lower or similar on CSII versus multiple insulin injections. However, hypoglycemia is markedly less frequent than during intensive injection therapy. Ketoacidosis occurs at the same rate. Nocturnal glycemic control is improved with insulin pumps, and automatic basal rate changes help to minimize a prebreakfast blood glucose increase (the "dawn phenomenon") often seen with injection therapy. Patients with "brittle" diabetes characterized by recurrent ketoacidosis are often not improved by CSII, although there may be exceptions. We argue that explicit clinical indications for CSII are helpful; we suggest the principal indications for health service or health insurance-funded CSII should include frequent, unpredictable hypoglycemia or a marked dawn phenomenon, which persist after attempts to improve control with intensive insulin injection regimens. In any circumstances, candidates for CSII must be motivated, willing and able to undertake pump therapy, and adequately psychologically stable. Some diabetic patients with well-defined clinical problems are likely to benefit substantially from CSII and should not be denied a trial of the treatment. Their number is relatively small, as would therefore be the demand on funds set aside for this purpose.

Recent advances in the pharmacologic management of diabetes mellitus

The importance of glucose control in reducing the complications of diabetes mellitus has been clearly demonstrated. The emergency physician routinely is expected to treat a wide range of problems related to this disease, including making the initial diagnosis of type 2 and occasionally type 1 diabetes. Also common are patients with poorly controlled diabetes. The recent introduction of new classes of agents to lower blood glucose, especially in type 2 diabetes, should improve the control in this category of patient and reduce the complication rate. Some of these agents, such as troglitazone, have potentially fatal complications and require careful monitoring. Emergency physicians should be aware of the common complications of these drugs because patients can present to the ED with them. Hypoglycemia, a common cause of 911 calls and emergency visits, is not a side effect of either metformin or acarbose. Insulin lispro has improved postprandial glycemic control for type 1 and some insulin-requiring type 2 diabetics. Hypoglycemia is less of a risk with insulin lispro, and quality of life is better with this rapidly acting insulin. Newer methods of insulin delivery, such as continuous subcutaneous infusion, have greatly improved glucose control, given greater freedom to patients, and reduced the risks of hypoglycemia.

Impact of insulin lispro on HbA1c values in insulin pump users

AIM

To compare the therapeutic efficacy of the short-acting insulin analogue insulin lispro (Humalog) with that of buffered regular human insulin (Velosulin) in patients on insulin pump therapy.

PATIENTS AND METHODS

Sixty-two (45 women and 17 men) young patients with type 1 diabetes using insulin pump therapy were compared while using buffered regular human insulin for a mean +/- s.e.m. of 20.1+/-1.2 months or insulin lispro for a mean +/- s.e.m. of 19.7+/-0.5 months. The initial mean +/- s.e.m. age and duration of diabetes were 29.1+/-0.9 and 17.7+/-0.9 years, respectively. The mean HbA1c values, basal insulin dosages, premeal insulin dosages and number of low blood sugars were recorded during treatment with both insulins.

RESULTS

Mean +/- s.e.m. HbA1c values were significantly lower (p < 0.001; paired Wilcoxon t-test) during insulin lispro treatment (7.4+/-0.1%) as compared to treatment with buffered regular human insulin (7.9+/-0.1%). Total units of insulin (mean +/- s.e.m.)/kg/day was significantly (p = 0.03) lower (0.61+/-0.02) during the insulin lispro treatment period as compared to the buffered regular human insulin treated period (0.65+/-0.03). Total mean +/- s.e.m. (U/kg/day) of basal insulin administered per day was higher when patients received insulin lispro treatment (0.44+/-0.02 vs. 0.42+/-0.01 for buffered regular human insulin treated period; p = 0.002). The premeal insulin boluses (mean +/- s.e.m.) for the two treatment groups were significantly different with less insulin required for the insulin lispro treatment period for all three meals (p < 0.001, t-test). The number of mild/moderate and severe hypoglycaemic episodes were similar in the two groups.

CONCLUSION

We conclude that use of insulin lispro in pump therapy significantly lowers HbA1c values in comparison to therapy with buffered regular human insulin insulin without increasing hypoglycaemic episodes.

A rational approach to drug therapy of type 2 diabetes mellitus

Several new pharmacological agents have recently been developed to optimise the management of type 2 (non-insulin-dependent) diabetes mellitus. The aim of this article is to briefly review the various therapeutic agents available for management of patients with type 2 diabetes mellitus and to suggest a potential approach to drug selection. There are three general therapeutic modalities relevant to diabetes care. The first modality is lifestyle adjustments aimed at improving endogenous insulin sensitivity or insulin effect. This can be achieved by increased physical activity and bodyweight reduction with diet and behavioural modification, and the use of pharmacological agents or surgery. This first modality is not discussed in depth in this article. The second modality involves increasing insulin availability by the administration of exogenous insulin, insulin analogues, sulphonylureas and the new insulin secretagogue, repaglinide. The most frequently encountered adverse effect of these agents is hypoglycaemia. Bodyweight gain can also be a concern, especially in patients who are obese. The association between hyperinsulinaemia and premature atherosclerosis is still a debatable question. The third modality consists of agents such as biguanides and thiazolidinediones which enhance insulin sensitivity, or agents that decrease insulin requirements like the alpha-glucosidase inhibitors. Type 2 diabetes mellitus is a heterogeneous disease with multiple underlying pathophysiological processes. Therapy should be individualised based on the degree of hyperglycaemia, hyperinsulinaemia or insulin deficiency. In addition, several factors have to be considered when prescribing a specific therapeutic agent. These factors include efficacy, safety, affordability and ease of administration.

Hypoglycemia and insulin analogues: is there a reduction in the incidence?

Rapid-acting insulin analogues were developed in answer to the need for a more appropriate time-action profile for prandial insulin substitution therapy. Improvements in at least one of three important endpoints needs to be demonstrated-metabolic control, hypoglycemic events, and/or quality of life-if there is to be a case for use of a new insulin preparation. This paper considers the data available on hypoglycemic events in the 24 controlled clinical trials (19 open, unblinded, and 5 double-blind) reported to date with rapid-acting insulin analogues (22 studies with insulin lispro). A significant reduction in the incidence of mild hypoglycemia was observed in 5 of 22 studies (22%). No change in frequency of severe hypoglycemic episodes was observed 10 of 12 studies (83%) reporting such events. A decrease in the frequency of nocturnal hypoglycemia has been reported in six studies; however, in the other 18 studies, no similar decrease in numbers were reported. There is no evidence for a reduction in patient awareness of hypoglycemia with rapid-acting insulin analogues. Even a slight reduction in hypoglycemic events would be welcomed by diabetic patients. However, rapid-acting insulins are only appropriate for use in patients using an intensive insulin regimen. Such patients are well motivated and well educated and will be able to adapt their insulin therapy to take account of the changes in the time-action profile of the rapid-acting insulin analogues. Thus, rapid-acting insulin analogues do not appear to have revolutionized insulin therapy, but appropriate use should result in benefits such as improved metabolic control for diabetic patients.