A randomized, controlled trial comparing insulin lispro with human soluble insulin in patients with Type 1 diabetes on intensified insulin therapy. The UK Trial Group

Insulin analogs as an add-on to metformin after failure to oral treatment in type 2 diabetic patients increase diastole duration. The INSUlin Regimens and VASCular Functions (INSUVASC) study

BACKGROUND

Fast acting insulin analogues are known to improve arterial stiffness. The combination of metformin with insulin represents a widely used therapeutic strategy in diabetes. We hypothesized that insulin treatment in patients with type 2 diabetes (T2D) with long-acting, fast-acting or basal bolus insulin as an add-on to metformin would provide additional improvement of arterial stiffness.

METHODS

The INSUlin Regimens and VASCular Functions (INSUVASC) study is a pilot, randomized, open label three-arms study that included 42 patients with type 2 diabetes (T2D) in primary prevention, after a failure to oral antidiabetic agents. Arterial stiffness measurements were performed at fasting and after a standardized breakfast. During the first visit (V1) pre-randomization, participants took only metformin to perform the tests. The same tests were repeated after 4 weeks of insulin treatment during the second visit (V2).

RESULTS

Data were available for final analysis in 40 patients, with a mean age of 53.6±9.7 years and a mean duration of diabetes of 10.6±5.6 years. Twenty-one were females (52.5%), hypertension and dyslipidemia were present in 18 (45%) and 17 patients (42.5%), respectively. After insulin treatment, the metabolic control was associated to a decrease in oxidative stress and improvement of endothelial functions, with a post prandial diastole duration increased and a decrease of the peripheral arterial stiffness, with a better post prandial pulse pressure ratio and ejection duration after insulin. In hypertensive patients, insulin treatment provided positive effects by decreasing the pulse wave velocity and improving reflection time.

CONCLUSIONS

A short time treatment by insulin in addition to metformin improved myocardial perfusion. Moreover, insulin treatment in hypertensive patients provides a better hemodynamic profile in large arteries.

Management of Individuals With Diabetes at High Risk for Hypoglycemia: An Endocrine Society Clinical Practice Guideline

CONTEXT

Hypoglycemia in people with diabetes is common, especially in those taking medications such as insulin and sulfonylureas (SU) that place them at higher risk. Hypoglycemia is associated with distress in those with diabetes and their families, medication nonadherence, and disruption of life and work, and it leads to costly emergency department visits and hospitalizations, morbidity, and mortality.

OBJECTIVE

To review and update the diabetes-specific parts of the 2009 Evaluation and Management of Adult Hypoglycemic Disorders: Endocrine Society Clinical Practice Guideline and to address developing issues surrounding hypoglycemia in both adults and children living with diabetes. The overriding objectives are to reduce and prevent hypoglycemia.

METHODS

A multidisciplinary panel of clinician experts, together with a patient representative, and methodologists with expertise in evidence synthesis and guideline development, identified and prioritized 10 clinical questions related to hypoglycemia in people living with diabetes. Systematic reviews were conducted to address all the questions. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make recommendations.

RESULTS

The panel agreed on 10 questions specific to hypoglycemia risk and prevention in people with diabetes for which 10 recommendations were made. The guideline includes conditional recommendations for use of real-time continuous glucose monitoring (CGM) and algorithm-driven insulin pumps in people with type 1 diabetes (T1D), use of CGM for outpatients with type 2 diabetes at high risk for hypoglycemia, use of long-acting and rapid-acting insulin analogs, and initiation of and continuation of CGM for select inpatient populations at high risk for hypoglycemia. Strong recommendations were made for structured diabetes education programs for those at high risk for hypoglycemia, use of glucagon preparations that do not require reconstitution vs those that do for managing severe outpatient hypoglycemia for adults and children, use of real-time CGM for individuals with T1D receiving multiple daily injections, and the use of inpatient glycemic management programs leveraging electronic health record data to reduce the risk of hypoglycemia.

CONCLUSION

The recommendations are based on the consideration of critical outcomes as well as implementation factors such as feasibility and values and preferences of people with diabetes. These recommendations can be used to inform clinical practice and health care system improvement for this important complication for people living with diabetes.

A Systematic Review Supporting the Endocrine Society Guidelines: Management of Diabetes and High Risk of Hypoglycemia

CONTEXT

Interventions targeting hypoglycemia in people with diabetes are important for improving quality of life and reducing morbidity and mortality.

OBJECTIVE

To support development of the Endocrine Society Clinical Practice Guideline for management of individuals with diabetes at high risk for hypoglycemia.

METHODS

We searched several databases for studies addressing 10 questions provided by a guideline panel from the Endocrine Society. Meta-analysis was conducted when feasible. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess certainty of evidence.

RESULTS

We included 149 studies reporting on 43 344 patients. Continuous glucose monitoring (CGM) reduced episodes of severe hypoglycemia in patients with type 1 diabetes (T1D) and reduced the proportion of patients with hypoglycemia (blood glucose [BG] levels <54 mg/dL). There were no data on use of real-time CGM with algorithm-driven insulin pumps vs multiple daily injections with BG testing in people with T1D. CGM in outpatients with type 2 diabetes taking insulin and/or sulfonylureas reduced time spent with BG levels under 70 mg/dL. Initiation of CGM in hospitalized patients at high risk for hypoglycemia reduced episodes of hypoglycemia with BG levels lower than 54 mg/dL and time spent under 54 mg/dL. The proportion of patients with hypoglycemia with BG levels lower than 70 mg/dL and lower than 54 mg/dL detected by CGM was significantly higher than point-of-care BG testing. We found no data evaluating continuation of personal CGM in the hospital. Use of an inpatient computerized glycemic management program utilizing electronic health record data was associated with fewer patients with and episodes of hypoglycemia with BG levels lower than 70 mg/dL and fewer patients with severe hypoglycemia compared with standard care. Long-acting basal insulin analogs were associated with less hypoglycemia. Rapid-acting insulin analogs were associated with reduced severe hypoglycemia, though there were more patients with mild to moderate hypoglycemia. Structured diabetes education programs reduced episodes of severe hypoglycemia and time below 54 mg/dL in outpatients taking insulin. Glucagon formulations not requiring reconstitution were associated with longer times to recovery from hypoglycemia, although the proportion of patients who recovered completely from hypoglycemia was not different between the 2 groups.

CONCLUSION

This systematic review summarized the best available evidence about several interventions addressing hypoglycemia in people with diabetes. This evidence base will facilitate development of clinical practice guidelines by the Endocrine Society.

One-hundred year evolution of prandial insulin preparations: From animal pancreas extracts to rapid-acting analogs

The first insulin preparation injected in humans in 1922 was short-acting, extracted from animal pancreas, contaminated by impurities. Ever since the insulin extracted from animal pancreas has been continuously purified, until an unlimited synthesis of regular human insulin (RHI) became possible in the '80s using the recombinant-DNA (rDNA) technique. The rDNA technique then led to the designer insulins (analogs) in the early '90s. Rapid-acting insulin analogs were developed to accelerate the slow subcutaneous (sc) absorption of RHI, thus lowering the 2-h post-prandial plasma glucose (PP-PG) and risk for late hypoglycemia as comparing with RHI. The first rapid-acting analog was lispro (in 1996), soon followed by aspart and glulisine. Rapid-acting analogs are more convenient than RHI: they improve early PP-PG, and 24-h PG and A1C as long as basal insulin is also optimized; they lower the risk of late PP hypoglycemia and they allow a shorter time-interval between injection and meal. Today rapid-acting analogs are the gold standard prandial insulins. Recently, even faster analogs have become available (faster aspart, ultra-rapid lispro) or are being studied (Biochaperone lispro), making additional gains in lowering PP-PG. Rapid-acting analogs are recommended in all those with type 1 and type 2 diabetes who need prandial insulin replacement.

Rapid-Acting Insulin Analogues Versus Regular Human Insulin: A Meta-Analysis of Effects on Glycemic Control in Patients with Diabetes

INTRODUCTION

The aim of this meta-analysis was to investigate the impact of rapid-acting insulin analogues (RAIAs) and regular human insulin (RHI) on glycemic control, including long- and short-term glycemic variability as measured by glycated haemoglobin (HbA1c) and pre- and postprandial glucose (PPG).

METHODS

PubMed was searched for studies published between 1999 and 29 June 2016. Randomised controlled trials of patients with diabetes that assessed the effects of RAIAs or RHI on glycemic control, focusing on preprandial glucose, PPG and HbA1c, were included. Only studies that reported both means and standard deviations for those outcomes were analysed; from these data, weighted mean differences and 95% confidence intervals were generated to yield overall point estimates. The primary outcomes of the meta-analysis were the mean differences between RAIAs and RHI at the end of the study in PPG, preprandial glucose, and HbA1c.

RESULTS

Twenty-seven studies (n = 7452) were included. The difference in PPG between RAIA- and RHI-treated patients was significant-in favour of RAIAs-in patients with type 1 diabetes (T1D) [- 22.2 mg/dL; 95% confidence interval (CI) - 27.4, - 17.0 mg/dL; P < 0.0001] but not in those with type 2 diabetes (T2D). For preprandial glucose, there was a non-significant trend favouring RHIs in T1D; no data were available for patients with T2D. In patients with T1D, the between-group difference in end-of-treatment (EOT) HbA1c favoured RAIAs (- 0.13%; 95% CI - 0.18, - 0.08%; P < 0.0001), but was not significant in patients with T2D. The main study limitations were the small number and heterogeneity of the included studies.

CONCLUSIONS

These results demonstrate that RAIAs are more effective at reducing PPG and improving HbA1c than RHIs in T1D. More data are required to assess the effect of these agents on glucose control in T2D. In patients with diabetes, the risk of complications is increased by poor control of blood glucose levels and high blood glucose variability. Complications may include cardiovascular disease, eye problems and amputation. Control and variability of blood glucose levels can be evaluated using a range of measures, including (i) glycated haemoglobin (HbA1c) level at the end of the treatment period; (ii) change in HbA1c level during the treatment period; (iii) fasting plasma glucose level; (iv) postprandial glucose (PPG) level; (v) change in blood glucose level after a meal. PPG levels following a meal are an important measure of overall metabolic control in diabetes, and reduction of glycemic variability (GV) can be achieved via reductions in PPG. Both rapid-acting insulin analogues (RAIAs; aspart, glulisine and lispro) and regular human insulin (RHI) are widely used in the management of diabetes. Using data from 27 randomised controlled trials involving more than 7000 patients, we investigated the impact of RAIAs and RHI on measures of glycemic control and variability in patients with type 1 diabetes (T1D) or type 2 diabetes (T2D). Our results show that, in patients with T1D, RAIAs are more effective than RHI at reducing PPG excursions and HbA1c. This indicates that glycemic control is better with RAIAs than with RHI. More data are required to assess the effects of RAIAs and RHI on glycemic control and variability in patients with T2D.

PLAIN LANGUAGE SUMMARY

In patients with diabetes, the risk of complications is increased by poor control of blood glucose levels and high blood glucose variability. Complications may include cardiovascular disease, eye problems and amputation. Control and variability of blood glucose levels can be evaluated using a range of measures, including (i) glycated haemoglobin (HbA1c) level at the end of the treatment period; (ii) change in HbA1c level during the treatment period; (iii) fasting plasma glucose level; (iv) postprandial glucose (PPG) level; (v) change in blood glucose level after a meal. PPG levels following a meal are an important measure of overall metabolic control in diabetes, and reduction of glycemic variability (GV) can be achieved via reductions in PPG. Both rapid-acting insulin analogues (RAIAs; aspart, glulisine and lispro) and regular human insulin (RHI) are widely used in the management of diabetes. Using data from 27 randomised controlled trials involving more than 7000 patients, we investigated the impact of RAIAs and RHI on measures of glycemic control and variability in patients with type 1 diabetes (T1D) or type 2 diabetes (T2D). Our results show that, in patients with T1D, RAIAs are more effective than RHI at reducing PPG excursions and HbA1c. This indicates that glycemic control is better with RAIAs than with RHI. More data are required to assess the effects of RAIAs and RHI on glycemic control and variability in patients with T2D.

Short-acting insulin analogues versus regular human insulin on postprandial glucose and hypoglycemia in type 1 diabetes mellitus: a systematic review and meta-analysis

INTRODUCTION

Strict glucose control using multiple doses of insulin is the standard treatment for type 1 diabetes mellitus (T1DM), but increased risk of hypoglycemia is a frequent drawback. Regular insulin in multiple doses is important for achieving strict glycemic control for T1DM, but short-acting insulin analogues may be better in reducing hypoglycemia and postprandial glucose levels.

OBJECTIVE

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effects of short-acting insulin analogues vs regular human insulin on hypoglycemia and postprandial glucose in patients with T1DM.

METHODS

Searches were run on the electronic databases MEDLINE, Cochrane-CENTRAL, EMBASE, ClinicalTrials.gov, LILACS, and DARE for RCTs published until August 2017. To be included in the study, the RCTs had to cover a minimum period of 4 weeks and had to assess the effects of short-acting insulin analogues vs regular human insulin on hypoglycemia and postprandial glucose levels in patients with T1DM. Two independent reviewers extracted the data and assessed the quality of the selected studies. The primary outcomes analyzed were hypoglycemia (total episodes, nocturnal hypoglycemia, and severe hypoglycemia) and postprandial glucose (at all times, after breakfast, after lunch, and after dinner). Glycated hemoglobin (HbA1c) levels and quality of life were considered secondary outcomes. The risk of bias of each RCT was assessed using the Cochrane Collaboration Risk of Bias table, while the quality of evidence for each outcome was assessed using the GRADEpro software. The pooled mean difference in the number of hypoglycemic episodes and postprandial glucose between short-acting insulin analogues vs. regular human insulin was calculated using the random-effects model.

RESULTS

Of the 2897 articles retrieved, 22 (6235 patients) were included. Short-acting insulin analogues were associated with a decrease in total hypoglycemic episodes (risk rate 0.93, 95% CI 0.87-0.99; 6235 patients; I² = 81%), nocturnal hypoglycemia (risk rate 0.55, 95% CI 0.40-0.76, 1995 patients, I² = 84%), and severe hypoglycemia (risk rate 0.68, 95% CI 0.60-0.77; 5945 patients, I² = 0%); and with lower postprandial glucose levels (mean difference/MD - 19.44 mg/dL; 95% CI - 21.49 to - 17.39; 5031 patients, I² = 69%) and lower HbA1c (MD - 0,13%; IC 95% - 0.16 to - 0.10; 5204 patients; I² = 73%) levels.

CONCLUSIONS

Short-acting insulin analogues are superior to regular human insulin in T1DM patients for the following outcomes: total hypoglycemic episodes, nocturnal hypoglycemia, severe hypoglycemia, postprandial glucose, and HbA1c.

Reporting Severe Hypoglycemia in Type 1 Diabetes: Facts and Pitfalls

PURPOSE OF REVIEW

To describe potential factors influencing reporting of severe hypoglycemia in adult patients with type 1 diabetes and to analyze their effect on reported rates of severe hypoglycemia.

RECENT FINDINGS

Reported rates of severe hypoglycemia defined as need for third party assistance vary between 0.3-3.0 events per patient-year in unselected cohorts, corresponding to a yearly prevalence range of 10-53%. When defined as need for parenteral therapy with glucose or glucagon or need for admission to an emergency unit or hospitalization, incidence and prevalence rates of severe hypoglycemia are 0.02-0.5 events per patient-year and 1-29%, respectively. When subjects with recurrent severe hypoglycemia in the past or suffering from impaired hypoglycemia awareness are excluded from participation in studies, lower rates are reported. Studies applying anonymous reporting or reporting by partners report higher rates of severe hypoglycemia. There is a large variation between studies reporting incidence and prevalence of severe hypoglycemia in patients with type 1 diabetes, mainly explained by definition of severity, methods of reporting, and patient selection. These findings call for consensus about hypoglycemia definition and reporting in future research.

Effects of insulin analogs as an add-on to metformin on cutaneous microcirculation in type 2 diabetic patients

BACKGROUND

A single insulin injection was shown to improve microcirculatory blood flow. Our aim was to examine the effects of 4weeks of insulin therapy by three randomly assigned insulin analog regimens (Detemir, Aspart, and their combination) on cutaneous blood flow (CBF) and microcirculatory endothelial function as an add-on to metformin in type 2 diabetic patients poorly controlled on oral antidiabetic treatment.

METHODS

Fourty-two type 2 diabetic patients with no history of cardiovascular disease in secondary failure to oral antidiabetic agents had CBF measurements before and after acetylcholine (Ach) iontophoretic administration. CBF measurements were performed at fasting and after a standardized breakfast during the post-prandial period. Before randomization (Visit 1, V1) during the tests, participants took only metformin. The same tests were repeated after 4weeks of insulin treatment (Visit 2, V2).

RESULTS

Thirty-four patients had good quality recordings for both visits. During V1, CBF and CBF response to Ach increased in the post-prandial period. After 4weeks of insulin treatment, metabolic parameters improved. Compared to V1, CBF at fasting did not increase at V2 but there was an improvement in endothelial function at fasting after Ach iontophoresis, without difference across insulin regimens. Oxidative stress markers were not modified, and E-selectin and vascular cell adhesion molecule 1 levels decreased after insulin treatment, without differences between insulin groups.

CONCLUSIONS

A strategy of improving glycemic control for 4weeks with insulin analogs improves microcirculatory endothelial reactivity and reduces endothelial biomarkers at fasting, whatever the insulin regimen used. Insulin therapy associated to metformin is able to improve fasting microvascular endothelial function even before complete metabolic control.

Review: Pharmacology of insulin

Diabetes is associated with microvascular and macrovascular complications leading to significant morbidity and mortality. Glycaemic control is important to prevent and delay the progression of these complications. An ideal insulin regimen in patients with diabetes would mirror the 24-hour insulin profile of a non-diabetic person and thereby prevent hyperglycaemia without inducing hypoglycaemia. This has, until recently, proved difficult to reproduce by regular subcutaneous insulin injections due to the inherent pharmacokinetic properties of the available insulins. Normoglycaemia was rarely achieved without hypoglycaemia compromising the quality of patients' lives. The advent of the new long- and short-acting insulin analogues are expected to both improve glycaemic control leading to a reduction in diabetes-related complications and reduce the incidence of hypoglycaemia thereby offering patients a better lifestyle.

The Impact of Technology on Current Diabetes Management

Technological innovations have revolutionized the treatment of type 1 diabetes. Although technological advances can potentially improve diabetes outcomes, maintenance of target glycemic control, at the present time, remains largely dependent on patient and family motivation, competence, and adherence to daily diabetes care requirements. Trials of closed loop or "artificial pancreas" technology show great promise to automate insulin delivery and achieve near normal glucose control and reduced hypoglycemia with minimal patient intervention.

Efficacy of insulin lispro in improving glycemic control in gestational diabetes

AIM

To assess the safety and efficacy of insulin lispro in improving glycemic control in patients with gestational diabetes.

MATERIALS AND METHODS

A retrospective observational study was conducted at a single center on 201 gestational women with diabetes. Subjects who received insulin lispro performed blood glucose self-monitoring and recorded the readings in the fasting state and 1 h after each meal. At each contact (in person or telephonic contact), the insulin dose was adjusted based on the readings measured. A total of 53 subjects also recorded glucose levels post-partum. Pregnancy and post-delivery glucose level and insulin requirements of these 53 patients were compared.

RESULTS

Analysis of glucose levels both fasting and post-prandial glucose levels revealed that after using insulin lispro, the number of episodes of post-prandial hyperglycemia (1 h plasma glucose >120 mg/dL) was minimal and so was the incidence of hypoglycemia. Hypoglycemia was defined as a blood sugar value of. There was neither any congenital abnormality except for a poorly formed pinna in the right ear of one baby nor any post-partum complications of note.

CONCLUSION

Insulin lispro is an effective and safe treatment option in gestational diabetes.

Severe hypoglycaemia in type 1 diabetes mellitus: underlying drivers and potential strategies for successful prevention

Hypoglycaemia remains an over-riding factor limiting optimal glycaemic control in type 1 diabetes. Severe hypoglycaemia is prevalent in almost half of those with long-duration diabetes and is one of the most feared diabetes-related complications. In this review, we present an overview of the increasing body of literature seeking to elucidate the underlying pathophysiology of severe hypoglycaemia and the limited evidence behind the strategies employed to prevent episodes. Drivers of severe hypoglycaemia including impaired counter-regulation, hypoglycaemia-associated autonomic failure, psychosocial and behavioural factors and neuroimaging correlates are discussed. Treatment strategies encompassing structured education, insulin analogue regimens, continuous subcutaneous insulin infusion pumps, continuous glucose sensing and beta-cell replacement therapies have been employed, yet there is little randomized controlled trial evidence demonstrating effectiveness of new technologies in reducing severe hypoglycaemia. Optimally designed interventional trials evaluating these existing technologies and using modern methods of teaching patients flexible insulin use within structured education programmes with the specific goal of preventing severe hypoglycaemia are required. Individuals at high risk need to be monitored with meticulous collection of data on awareness, as well as frequency and severity of all hypoglycaemic episodes.

Randomized crossover study to examine the necessity of an injection-to-meal interval in patients with type 2 diabetes and human insulin

OBJECTIVE

Patients with diabetes and insulin therapy with human insulin were usually instructed to use an interval of 20-30 min between the injection and meal. We examined the necessity of the injection-to-meal interval (IMI) in patients with type 2 diabetes mellitus (T2DM) and flexible insulin therapy with human insulin.

RESEARCH DESIGN AND METHODS

In this randomized, open crossover trial, 100 patients with T2DM (47% men, mean age = 66.7 years) were randomized to the IMI first group (phase 1, IMI 20 min; phase 2, no IMI) or IMI last group (phase 1, no IMI; phase 2, IMI 20 min). The main outcome measures were HbA1c, blood glucose profile, incidence of hypoglycemia, quality of life, treatment satisfaction, and patient preference.

RESULTS

Forty-nine patients were randomized to the IMI first group and 51 patients to the IMI last group. Omitting the IMI only slightly increases HbA1c (average intraindividual difference = 0.08% [95% CI 0.01-0.15]). Since the difference is not clinically relevant, a therapy without IMI is noninferior to its application (P < 0.001). In the secondary outcomes, the incidence of mild hypoglycemia also did not differ between no IMI and IMI significantly (mean of differences = -0.10, P = 0.493). No difference in the blood glucose profile of both groups was found. Treatment satisfaction increased markedly, by 8.08, if IMI was omitted (P < 0.001). The total score of the quality of life measure did not show differences between applying an IMI or not. Insulin therapy without IMI was preferred by 86.5% of patients (P < 0.001).

CONCLUSIONS

An IMI for patients with T2DM and preprandial insulin therapy is not necessary.

Comparison of Optimised MDI versus Pumps with or without Sensors in Severe Hypoglycaemia (the Hypo COMPaSS trial)

BACKGROUND

Severe hypoglycaemia (SH) is one of the most feared complications of type 1 diabetes (T1DM) with a reported prevalence of nearly 40%. In randomized trials of Multiple Daily Injections (MDI) and Continuous Subcutaneous Insulin Infusion (CSII) therapy there is a possible benefit of CSII in reducing SH. However few trials have used basal insulin analogues as the basal insulin in the MDI group and individuals with established SH have often been excluded from prospective studies. In published studies investigating the effect of Real Time Continuous Glucose Monitoring (RT-CGM) benefit in terms of reduced SH has not yet been demonstrated. The primary objective of this study is to elucidate whether in people with T1DM complicated by impaired awareness of hypoglycaemia (IAH), rigorous prevention of biochemical hypoglycaemia using optimized existing self-management technology and educational support will restore awareness and reduce risk of recurrent SH.

METHODS/DESIGN

This is a multicentre prospective RCT comparing hypoglycaemia avoidance with optimized MDI and CSII with or without RT-CGM in a 2×2 factorial design in people with type 1 diabetes who have IAH. The primary outcome measure for this study is the difference in IAH (Gold score) at 24 weeks. Secondary outcomes include biomedical measures such as HbA1c, SH incidence, blinded CGM analysis, self monitored blood glucose (SMBG) and response to hypoglycaemia in gold standard clamp studies. Psychosocial measures including well-being and quality of life will also be assessed using several validated and novel measures. Analysis will be on an intention-to-treat basis.

DISCUSSION

Most existing RCTs using this study's interventions have been powered for change in HbA1c rather than IAH or SH. This trial will demonstrate whether IAH can be reversed and SH prevented in people with T1DM in even those at highest risk by using optimized conventional management and existing technology.

TRIAL REGISTRATION

ISRCTN52164803 Eudract No: 2009-015396-27.

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.

Counter-regulatory hormone responses to spontaneous hypoglycaemia during treatment with insulin Aspart or human soluble insulin: a double-blinded randomized cross-over study

AIMS

To compare insulin Aspart and human insulin with respect to glycaemic control, hypoglycaemic frequency and counter-regulatory responses to spontaneous hypoglycaemia.

METHODS

Glycaemic control, hypoglycaemic frequency, p-insulin concentrations, insulin dosages and patients' satisfaction were examined in a randomized, double-blinded cross-over study for two periods of 8 weeks. Sixteen patients with type 1 diabetes were subjected to three daily injections of human soluble insulin or Aspart in addition to Neutral Protamine Hagedorn (NPH) insulin twice daily. Each intervention period was followed by hospitalization where episodes of spontaneous hypoglycaemia and counter-regulatory hormone responses were evaluated from frequently obtained blood samples.

RESULTS

No difference between soluble insulin and insulin Aspart was found regarding HbA1c (7.0 ± 0.2 vs. 7.0 ± 0.2%, ns), hypoglycaemic frequency (1.1 ± 0.2 vs. 0.9 ± 0.1 events per patient per week, ns), nocturnal hypoglycaemia, severe hypoglycaemic events, dosages of bolus insulin (31.8 ± 0.4 vs. 30.0 ± 0.6 IU day(-1), ns), or NPH insulin (26.7 ± 1.8 vs. 26.0 ± 1.7 IU day(-1) , ns) or in patients satisfaction (ns). Modest differences existed in the counter-regulatory responses regarding growth hormone, glucagon and ghrelin whereas no differences were found in relation to free fatty acid, cortisol, insulin-like growth factor (IGF)-I, IGF-II and IGF-binding proteins 1 and 2. Treatment with insulin Aspart resulted in well-defined peaks in serum insulin concentrations as compared with more blunted insulin peaks using human soluble insulin.

CONCLUSION

Although insulin Aspart treatment was associated with clear postprandial insulin peaks, no improvement in glycaemic control was obtained and no difference in the hypoglycaemic frequency was observed. However, insulin Aspart elicited a slightly different physiological response to spontaneous hypoglycaemia compared with human insulin.

Prevalence of injection-meal interval usage and its association with variables of metabolic control in patients with Type 1 and Type 2 diabetes

OBJECTIVE

Regular human insulin is usually recommended with an injection-meal interval. It is not known how many patients follow these recommendations and, of those who do, the injection-meal interval remains incompletely studied. We investigated the injection-meal interval in patients with Type 1 and Type 2 diabetes and the association with metabolic control in routine care.

METHODS

Four hundred and seventy-one consecutive patients with Type 1 or Type 2 diabetes were interviewed to determine their injection-meal interval in a university outpatient clinic setting in Germany in 2006. Four hundred and thirty-three interviews were suitable for analysis (143 Type 1 diabetes, 290 Type 2 diabetes). HbA(1c) was Diabetes Control and Complications Trial adjusted.

RESULTS

Among those with Type 1 diabetes, 27% 'always', 27% 'sometimes' and 46% 'never' used an injection-meal interval. Forty-three per cent of patients with Type 2 diabetes always used an injection-meal interval, 12% sometimes and 45% never. Among patients with Type 1 diabetes, there was no difference in HbA(1c) between those who always used an injection-meal interval (n=39, age 58 years, duration of diabetes 21.1 years, BMI 28.7 kg/m², HbA(1c) 7.50%/58 mmol/mol) compared with those who never used an injection-meal interval (n=66, age 47.3 years, duration of diabetes 17.4 years, BMI 27.3 kg/m², HbA(1c) 7.55%/59 mmol/mol). Among patients with Type 2 diabetes, HbA(1c) in those who always used an injection-meal interval (n = 124, age 65 years, duration of diabetes 13.8 years, BMI 32.6 kg/m², HbA(1c) 7.31%/56 mmol/mol) is 0.27% lower compared with those who never used an injection-meal interval (n=130, age 64.3 years, duration of diabetes 16 years, BMI 32.8 kg/m², HbA(1c) 7.58%/59 mmol/mol).

CONCLUSION

Nearly half of insulin-treated patients do not use an injection-meal interval. We found no significant association between adherence to injection-meal interval and HbA(1c) in patients with Type 1 diabetes, but a slightly lower HbA(1c) in patients with Type 2 diabetes who always use an injection-meal interval.

Incidence of severe nocturnal hypoglycemia in patients with type 1 diabetes treated with insulin lispro or regular human insulin in addition to basal insulin glargine

BACKGROUND AND AIMS

Once-daily (OD) basal insulin glargine (GLA) can be used as part of a multiple daily injection regimen in patients with type 1 diabetes mellitus. This randomized, multicenter study compared GLA+prandial regular human insulin (RHI) with GLA+prandial insulin lispro (LIS) in reducing the incidence of severe nocturnal hypoglycemia at endpoint. In addition, the effects on glycemic control of both treatments were investigated.

METHODS AND RESULTS

Patients (489) previously on neutral protamine Hagedorn (NPH) insulin or GLAR plus RHI/LIS were switched to, or continued on GLA (target fasting blood glucose [FBG]=5.0-6.7 mmol/L [90-120 mg/dL]) for 8 weeks (qualification phase) prior to randomization; patients continued with their previous bolus insulin. Patients (n=395) were then randomized to LIS (n=193) or RHI (n=202) and treated for 16 weeks. The proportion of patients experiencing severe nocturnal hypoglycemia at the end of the study was 1.55% (n=3) in the RHI group and 1.11% (n=2) in the LIS group (p=0.938 between groups); the mean difference was 0.44% (95% CI: -1.77, 2.21), suggesting non-inferiority of RHI versus LIS. At the end of the study, both treatments did not differ with respect to glycemic control, as measured by hemoglobin A(1c) and FBG.

CONCLUSION

These results suggest that GLA+LIS and GLA+RHI treatments were associated with a similar and low rate of severe nocturnal hypoglycemia. Further studies with greater patient sizes are necessary to verify the findings from the current study.

Contemporary management of patients with type 1 diabetes

The current standard of care for patients with type 1 diabetes (T1D) employs a system of intensive diabetes management aimed at near-normal glycemia, which reduces the risk of micro- and macrovascular complications. Optimal management is an ongoing process based on a patient-centered collaboration with a primary care clinician and a multidisciplinary diabetes team that provides diabetes management, including education and psychosocial support. Intensive diabetes therapy attempts to mimic physiologic insulin replacement. Over the past 15 years, there has been widespread use of multiple-dose insulin regimens using a variety of insulin analogs, administered either by injection or insulin pump therapy, together with medical nutrition therapy, frequent self-monitoring of blood glucose and, more recently, continuous logo glucose monitoring. It is now possible to achieve previously unattainable levels of glycemic control with less risk of severe hypoglycemia, and yet only a minority of patients achieves target hemoglobin A1c values. This review discusses contemporary management of T1D with a focus on health outcomes.

Addressing hyperglycemia from hospital admission to discharge

BACKGROUND

This review examines glycemia management practices in hospitalized patients. Optimal glycemic control remains a challenge among hospitalized patients. Recent studies have questioned the benefit of tight glycemic control and have raised concerns regarding the safety of this approach. As a result, medical societies have updated glycemic targets and have published new consensus guidelines for management of glycemia in hospitalized patients. This review highlights recent inpatient glycemic trials, the new glycemic targets and recommended strategies for management of glycemia in hospitalized patients.

METHODS

Medline and PubMed searches (diabetes, hyperglycemia, hypoglycemia, intensive therapy insulin, tight glycemic control, and hospital patients) were performed for English-language articles on treatment of diabetes, insulin therapy, hyperglycemia or hypoglycemia in hospitalized patients published from 2004 to present. Earlier works cited in these papers were surveyed. Clinical studies, reviews, consensus/guidelines statements, and meta-analyses relevant to the identification and management of diabetes and hyperglycemia in hospitalized patients were included and selected. This is not an exhaustive review of the published literature.

RESULTS

Insulin remains the most appropriate agent for a majority of hospitalized patients. In critically ill patients insulin is given as a continuous intravenous (IV) infusion and in non-critically ill inpatients hyperglycemia is best managed using scheduled subcutaneous (SC) basal-bolus insulin regimens supplemented with correction doses as needed and adjusted daily with the guidance of frequent blood glucose monitoring. Prevention of hypoglycemia is equally as important to patient outcomes and is an equally necessary part of any effective glucose control program. Modern insulin analogs offer advantages over the older human insulins (e.g., regular and neutral protamine Hagedorn [NPH] insulin) because their time-action profiles more closely correspond to physiological basal and prandial insulin requirements, and have a lower propensity for inducing hypoglycemia than human insulin formulations. Long-acting basal insulin analogs (glargine, detemir) are suitable and preferred for the basal component of therapy; rapid-acting insulin analogs (aspart, lispro, glulisine) are recommended for bolus and correction doses. Sliding-scale insulin (SSI) regimens are not effective and should not be used, especially as this excludes a basal insulin component from the therapy.

CONCLUSIONS

Optimal glycemic management in the hospital setting requires judicious treatment of hyperglycemia while avoiding hypoglycemia. Insulin is the most appropriate agent for management of hyperglycemia for the majority of hospitalized patients. Intravenous insulin infusion is still preferred during and immediately after surgery, but s.c. basal insulin analogs with prandial or correction doses should be used after the immediate post-operative period, and also should be used in non-critically ill patients. Frequent and effective glucose monitoring is critical for avoiding wide deviations from acceptable glucose levels, which under a recently promulgated consensus guideline currently range between 140 mg/dL and 180 mg/dL. Glucose targets near 140 mg/dL are recommended as being the most appropriate for all hospitalized patients.

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 glulisine in the management of diabetes

Insulin glulisine is appealing in principle, but the advantages of this drug over the other rapid-acting insulin analogs are still relatively unknown. The frequency of hypoglycemia, convenience in the timing of administration, and improvements in terms of HbA(1c) seem similar among the rapid-acting insulin analogs, including insulin glulisine. Only properly randomized long-term clinical studies with insulin glulisine will reveal the true value of this novel insulin analog.

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.

Insulin analogues: an example of applied medical science

Insulin analogues were developed to try and achieve more physiological insulin replacement from injection in the subcutaneous site. Their pharmacokinetics and pharmacodynamics differ from human insulin when injected subcutaneously because of alterations in the amino acid sequence of the insulin molecule. The rapid-acting insulin analogues, lispro, aspart and glulisine, have a rapid onset of action and shorter duration of action because of changes to the B26-30 portion of insulin inhibiting formation of dimers and hexamers. They appear to improve postprandial glucose, incidence of hypoglycaemia and patient satisfaction and, when used in combination with basal insulin analogues, improve glycosylated haemoglobin in comparison to conventional insulin therapy. Additionally, they have been successfully used in children, pregnant women, in pump therapy and as part of premixed biphasic regimens. The two basal insulin analogues, glargine and detemir, developed by adjusting the isoelectric point and adding a fatty acid residue, respectively, have a protracted duration of action and a relatively smooth profile. Their pharmacokinetic and pharmacodynamic profiles have been assessed using euglycaemic clamp protocols. Both analogues have a longer duration of action, less of a peak of activity and a reduced variability with repeated injection. There is some evidence to suggest that detemir may have a slight hepatoselective effect. Clinical studies have shown a lower relative risk of hypoglycaemia and detemir appears to have a weight-sparing action. Insulin analogues represent a successful example of applied medical science.

Recruitment to a clinical trial improves glycemic control in patients with diabetes

OBJECTIVE

We assessed the effect upon A1C of recruitment to a clinical trial in patients with diabetes who had been screened and interviewed to determine eligibility but whose therapy was otherwise unchanged.

RESEARCH DESIGN AND METHODS

Eligible trials were selected from the global program of an insulin manufacturer. Included were studies in which patients were seen on a single screening visit, pharmaceutical therapy was not altered before randomization, and A1C was measured in a central laboratory at both screening and randomization. Three trials involving patients with type 1 diabetes (n = 429) and three trials involving patients with type 2 diabetes (n = 611) were identified for analysis. The main outcome measure was change in A1C. Separate regression equations on the change in A1C were fitted for type 1 and type 2 diabetes and included effects of baseline A1C and the interval between the screening and randomization visits.

RESULTS

A1C changed by -0.13% (range +0.09 to -0.26%) in those with type 1 diabetes at a median of 28 days and by -0.16% (-0.14 to -0.27%) for those with type 2 diabetes at a median of 14 days. The mean change in A1C in those with an interval of >or=28 days was -0.24% for those with type 1 diabetes and -0.23% for those with type 2 diabetes. The reduction was proportional to initial A1C, with large decreases in those with the poorest initial control but no overall change in those at or below the 10th percentile of A1C.

CONCLUSIONS

Recruitment to a clinical trial, independent of any therapeutic intervention, produces improvements in glucose control.

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.

Physiologic insulin replacement in type 2 diabetes: optimizing postprandial glucose control

PURPOSE

The purpose of this article is to review physiologic insulin replacement using a basal-prandial approach and focus on the role of postprandial glucose control. In addition, therapeutic options for optimizing glycemic control are described, including diabetes education, currently available agents, treatment regimens, and strategies.

METHODS

This article reviews the benefits of treating with a basal-prandial insulin approach and focuses on post-prandial glucose-targeted therapies, including rapid-acting insulin analogs.

RESULTS

Data from landmark clinical trials in type 2 diabetes suggest that intensive glycemic control can reduce the frequency and severity of diabetes complications. A basal-prandial insulin regimen combines a long-acting insulin analog with a rapid-acting insulin to mimic normal physiologic insulin secretion, providing a flexible tool to enhance patient self-management.

CONCLUSIONS

Strategies that include patient education, improved health care provider/patient communication, and basal-prandial insulin treatment can help patients achieve good glycemic control. The optimal setting for successful diabetes treatment is a team approach with the health care provider, nurse/certified diabetes educator, and patient as essential members.

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.

Insulin Therapy: Current Alternatives

In normal humans, blood glucose and insulin are maintained within a narrow range despite wide variations in physical activity and dietary intake. At present, reproducing this pattern is an impossible task in type 1 diabetes and extremely difficult in type 2 DM. New approaches using novel insulin analogs and routes of administration, attempting to replicate physiological insulin secretion in diabetic patients, are improving the profiles of glucose levels and, thus, the quality of life. Ultra-short-acting insulin analogues and ultra-long-acting analogues are being used for prandial and basal effects with better results, lower prevalence of hypoglycemia, and, hopefully, fewer chronic complications. Non-invasive routes of administration are being developed. The most promising appears to be inhaled insulin according to studies demonstrating excellent control, apparently without significant side effects, although in relatively short-term trials. Longer-term studies to assure the safety are still necessary before recommending its extended use. This is an extensive, up-to-date review of recent advances in insulin therapy.

Impact of insulin on microvascular blood flow and endothelial cell function in the postprandial state in patients with Type 1 diabetes

The aim of the present study was to investigate postprandial microvascular blood flow following a standardized test meal in nondiabetic subjects and in patients with Type 1 diabetes after regular insulin or insulin lispro. In this open-label, randomised cross-over study, 20 nondiabetic participants and 20 patients with Type 1 diabetes were enrolled. To valuate the postprandial time course of skin microvascular blood flow, laser Doppler flux (LDF) readings were obtained at baseline and every 30 min following a standardized test meal. Furthermore, the microvascular response to acetylcholine (Ach) was measured, and blood was collected for the measurement of serum insulin and blood glucose levels. Patients with Type 1 diabetes received single doses of regular insulin or insulin lispro, respectively, in a randomised sequence, while in nondiabetics, no insulin substitution was performed. In nondiabetic participants, skin microvascular blood flow showed an early increase in LDF by median 6.0 arbitrary units (AU; interquartile range: 1.8-14.0 AU) within the first postprandial hour. The microvascular response to Ach also increased with a median response of 26.0 (19.0-49.3) AU at 30 min pp and 50.0 (31.7-65.1) AU at 60 min pp. In patients with Type 1 diabetes, the time course of postprandial LDF measurements observed after the administration of insulin lispro was nearly similar to the one observed in nondiabetic controls and differed from that after subcutaneous regular insulin treatment. The postprandial microvascular response to Ach was stronger following insulin lispro compared with regular insulin [30 min pp: 26.0 (19.0-49.3) vs. 20.9 (9.7-26.1) AU, P=.0001]. Postprandial microvascular blood flow is disturbed in patients with Type 1 diabetes. Improvement of postprandial metabolic control was found to improve postprandial microvascular function.

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.

Glycaemic control in a type 1 diabetes clinic for younger adults

BACKGROUND

In the Diabetes Control and Complications Trial (DCCT, 1993) tight diabetes control (HbA1c <7%) was associated with significantly less microvascular complications compared to 'conventionally' treated type 1 patients.

AIM

To assess the effectiveness of a dedicated young-adult type 1 diabetes clinic in achieving HbA1c levels <7% between 1991 and 2001.

DESIGN

Retrospective review of case-notes.

METHODS

All patients who attended the clinic in the first six years (1991 to 1996) were studied. All were offered at least two appointments per year. Case-notes were reviewed up to December 2001.

RESULTS

We treated 386 type 1 patients (59.8% male, mean age 28.7 years, mean duration diabetes 9.5 years). After a mean follow-up of 7.7 years, 261 (67.6%) had attended in the past 2 years, 22 (5.8%) were known to have died, 11 (2.8%) had transferred to another clinic and 92 (23.8%) had repeatedly failed to attend appointments for 2 years. Over 11 years, the total mean (SD) HbA1c was 9.19% (1.3). Only 3.4% of patients achieved an average HbA1c of <7% during the study period, and 80% of patients had average HbA1c levels of >8%.

DISCUSSION

Despite regular specialist physician, specialist diabetes nurse and dietician input, encouragement of multiple daily insulin injections and repeatedly following-up failed appointments (including home visits), fewer than 1:20 patients achieved the DCCT target of mean HbA1c <7%. Tight diabetes control is rare in a routine clinic setting.

Preprandial vs. postprandial insulin lispro-a comparative crossover trial in patients with Type 1 diabetes

AIMS

Administration of bolus insulin after eating may be a useful therapeutic option for some patients. This 6-month, crossover study compared metabolic effects of routine use of preprandial vs. postprandial injection of bolus insulin lispro.

METHODS

Thirty-one patients with Type 1 diabetes injected insulin lispro either preprandially or postprandially for a 3-month period followed by the alternate regimen for a further 3 months. HbA1c, fructosamine and eight-point self-determined blood glucose profiles were measured and analysed using an anova model appropriate for a crossover design.

RESULTS

Mean HbA1c decreased slightly from baseline with preprandial (-0.15 +/- 0.41%) and increased slightly with postprandial (0.11 +/- 0.48%) insulin lispro so that there was a significant (P = 0.008) difference between treatments in final HbA1c level. Mean fructosamine also decreased slightly with preprandial (-15 +/- 31 micro mol/l) but was almost unchanged (1 +/- 39 micro mol/l) with postprandial insulin lispro. Overall daily blood glucose was not different (P = 0.312) for preprandial compared with postprandial administration. However, mean preprandial glucose was lower (7.5 +/- 2.01 vs. 6.6 +/- 1.22 mmol/l; P = 0.026), whereas mean postprandial glucose was higher (7.7 +/- 1.8 vs. 8.7 +/- 2.1 mmol/l; P = 0.031) with postprandial insulin lispro administration. Mean blood glucose excursions were higher with postprandial compared with preprandial insulin lispro, indicating greater daily fluctuations. No difference in incidence of hypoglycaemia was observed with the two treatment regimens.

CONCLUSIONS

Postprandial insulin lispro administration appeared to be an acceptable treatment regimen and may be of benefit in certain situations. However, the benefits of postprandial administration may have to be balanced against poorer glycaemic control with continuous long-term use.

Nocturnal hypoglycemia: clinical manifestations and therapeutic strategies toward prevention

OBJECTIVE

To review the features of nocturnal hypoglycemia and various preventive strategies.

METHODS

We discuss the physiologic changes, the potential precipitating factors, the immediate and long-term effects, and the currently available options for treatment of nocturnal hypoglycemia in patients with diabetes.

RESULTS

Nocturnal hypoglycemia is common in patients with type 1 diabetes and is usually asymptomatic. Nocturnal hyperinsulinemia frequently occurs with insulin therapy, and although blood glucose levels are often low during sleep, they are seldom measured routinely. Almost 50% of all episodes of severe hypoglycemia occur at night during sleep. Such episodes can cause convulsions and coma and have been implicated as a precipitating factor in cardiac arrhythmias resulting in sudden death--the "dead-in-bed syndrome." Nocturnal hypoglycemia seems to have no immediate detrimental effect on cognitive function; however, on the following day, mood and well-being may be adversely affected. Recurrent exposure to nocturnal hypoglycemia may impair cognitive function; other substantial long-term morbidity includes the development of acquired hypoglycemia syndromes, such as impaired awareness of hypoglycemia, through the putative effect of unsuspected recurrent episodes of nocturnal hypoglycemia.

CONCLUSION

In efforts to decrease the risk of nocturnal hypoglycemic episodes, various strategies can be used to minimize the nocturnal hyperinsulinemia that is associated with many insulin replacement regimens. Regular blood glucose monitoring (particularly at bedtime), the ingestion of appropriate bedtime snacks, and the utilization of short- and long-acting insulin analogues may all help to prevent or minimize the frequency of nocturnal hypoglycemia.

Prevention and treatment of type 2 diabetes mellitus in children, with special emphasis on American Indian and Alaska Native children. American Academy of Pediatrics Committee on Native American Child Health

The emergence of type 2 diabetes mellitus in the American Indian/Alaska Native pediatric population presents a new challenge for pediatricians and other health care professionals. This chronic disease requires preventive efforts, early diagnosis, and collaborative care of the patient and family within the context of a medical home.

Effect of the rapid-acting insulin analogue insulin aspart on quality of life and treatment satisfaction in patients with Type 1 diabetes

AIMS

To compare quality of life (QoL) and treatment satisfaction in patients with Type 1 diabetes receiving the rapid-acting insulin analogue, insulin aspart (IAsp), with that in patients receiving soluble human insulin (HI).

METHODS

In this 6-month, multinational, randomized, open-label trial, 424 patients from German-speaking countries were subjected to psychometric assessment before and after randomization (ratio 2 : 1) to basal-bolus treatment with either IAsp (n = 283) or HI (n = 141). Patients on HI were advised to keep an injection-meal interval of 30 min, whereas patients on IAsp were advised to inject immediately before meals. Treatment satisfaction and diabetes-related QoL were assessed using validated instruments to measure the domains of patients' individual treatment goals, physical complaints, worries about the future, social relations, leisure time flexibility, daily hassles, diet restrictions, burdens and fear of hypoglycaemia, blood glucose fluctuations, self-efficacy, and fear of insulin analogues.

RESULTS

After 6 months, IAsp was associated with significantly greater improvement in treatment satisfaction than HI in two different scales (P < 0.01), and in QoL with respect to diet restrictions (P < 0.01). Improved satisfaction was mainly due to increased dietary and leisure time flexibility (P < 0.0001). Twenty-three percent of the IAsp group vs. 14% of the HI group achieved small but important improvements of total QoL (between-group difference, P < 0.06). The number needed to treat (NNT) with IAsp for an important increase in QoL was calculated to be 10. Regression analyses of potential predictors of improvement in QoL highlighted patients intensely striving for physical strength (P < 0.01; NNT = 7) and patients feeling less protected against hypoglycaemia (P < 0.005; NNT = 8) as being the most likely to benefit from IAsp.

CONCLUSIONS

Under these study conditions, IAsp improved treatment satisfaction and quality of life regarding diet restrictions when compared with human insulin. The 'numbers needed to treat' for important quality of life benefits indicate that the effect of IAsp in this regard is not trivial.

Insulin lispro: a useful advance in insulin therapy

Insulin lispro, the first insulin analogue to be used clinically, was engineered to incorporate the pharmacological advantages of insulin-like growth factor-1 (IGF-1), which has a reduced tendency to self associate, compared to conventional soluble insulin. It is absorbed more quickly following a subcutaneous injection, reaching peak concentrations (approximately twice as much as conventional insulin) and then falls more rapidly. These more physiological insulin profiles are reflected in the results of clinical trials involving patients with Type 1 diabetes, which generally show comparable glycaemic control but reduced rates of hypoglycaemia, particularly at night. The reduction in the rate of hypoglycaemia in the early trials has been generally fairly modest, but more recent publications suggest that increasing experience and more individualised insulin adjustment may lead to a greater impact. Other indications include its use in continuous subcutaneous insulin infusion and postprandially in young children.

A comparison of postprandial and preprandial administration of insulin aspart in children and adolescents with type 1 diabetes

OBJECTIVE

The aim of this study was to compare the glycemic control of preprandial versus postprandial injections of the new rapid-acting insulin analogue aspart in children and adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Forty-two children (aged 6-12 years) and 34 adolescents (13-17 years) were randomized to preprandial (immediately before meal start) and postprandial (immediately after a meal or a maximum of 30 min after meal start) treatment with insulin aspart (at least thrice daily) as part of a basal/bolus regimen in a multicenter study with an open labeled, two-period cross-over design (6-week periods). Of this group, 49% were boys, 55% were aged <or=13 years, and duration of diabetes was 4.4 years (range 1.0-9.4).

RESULTS

Glycemic control for postprandial treatment was not worse than preprandial treatment as assessed by fructosamine week 0 vs. 6 (mean +/- SD, preprandial 367 +/- 74 vs. 378 +/- 90 micro mol/l; postprandial 383 +/- 83 vs. 385 +/- 77 micro mol/l) and HbA(1c) (preprandial 7.9 +/- 1.3 vs. 8.0 +/- 1.5%; postprandial 8.0 +/- 1.4 vs. 8.3 +/- 1.5%, P = 0.14). The only statistically significant finding from the seven-point blood glucose profiles and derived parameters between preprandial and postprandial treatment was a lower postprandial glucose level 120 min after breakfast (mean +/- SEM, -2.08 +/- 0.74 mmol/l, P = 0.016). The relative risk of hypoglycemia (blood glucose <3.9 mmol/l) preprandially to postprandially was not significantly different (mean 1.1; 95% CI 0.91-1.35; P = 0.31). Overall treatment satisfaction was equally high for both regimens with both patients and parents.

CONCLUSIONS

Although preprandial administration of insulin aspart is generally preferable, this study shows that in children and adolescents, postprandial administration of insulin aspart is a safe and effective alternative.

A direct comparison of insulin aspart and insulin lispro in patients with type 1 diabetes

OBJECTIVE

Both rapid-acting insulin analogs, insulin aspart and lispro, attenuate prandial glucose excursion compared with human soluble insulin. This trial was performed to study the pharmacokinetic and pharmacodynamic profiles of insulin aspart and insulin lispro in type 1 diabetic patients in a direct comparison and to investigate whether the administration of one analog results in favorable effects on prandial blood glucose control.

RESEARCH DESIGN AND METHODS

A total of 24 type 1 diabetic patients (age 36 +/- 8 years, 16 men and 8 women, BMI 24.3 +/- 2.6 kg/m(2), diabetes duration 17 +/- 11 years, HbA(1c) 7.9 +/- 0.8%) on intensified insulin therapy were recruited into a single-center, randomized, double-blind, two-period, cross-over, glucose clamp trial. The subjects were given an individual need-derived dose of prandial insulin lispro or aspart immediately before a standard mixed meal.

RESULTS

With respect to blood glucose excursions from time 0 to 6 h (Exc(glu(0-6 h))) and from time 0 to 4 h (Exc(glu(0-4 h))), the pharmacodynamic effect of insulin aspart and insulin lispro can be declared equivalent. This was supported by comparison with maximum postprandial blood glucose excursions (C(max(glu))) (estimated ratio aspart/lispro ANOVA [90% CI]: 0.95 [0.80-1.13], 0.97 [0.82-1.17], and 1.01 [0.95-1.07] for Exc(glu(0-6 h)), Exc(glu(0-4 h)), and C(max(glu)), respectively). For pharmacokinetic end points (maximum postprandial insulin excursions and area under the curve for insulin from time 0 to 6 h and from time 0 to 4 h), equivalence was indicated. No difference concerning absorption or elimination for time to maximal insulin concentration, time to half-maximum insulin concentration, and time to decrease to 50% of maximum insulin concentration was observed.

CONCLUSIONS

These data suggest that in type 1 diabetic patients, both insulin analogs are equally effective for control of postprandial blood glucose excursions.