Insulin analogues and their potential in the management of diabetes mellitus

Incorporation of Aliphatic Proline Residues into Recombinantly Produced Insulin

Analogs of proline can be used to expand the chemical space about the residue while maintaining its uniquely restricted conformational space. Here, we demonstrate the incorporation of 4R-methylproline, 4S-methylproline, and 4-methyleneproline into recombinant insulin expressed in Escherichia coli. These modified proline residues, introduced at position B28, change the biophysical properties of insulin: Incorporation of 4-methyleneproline at B28 accelerates fibril formation, while 4-methylation speeds dissociation from the pharmaceutically formulated hexamer. This work expands the scope of proline analogs amenable to incorporation into recombinant proteins and demonstrates how noncanonical amino acid mutagenesis can be used to engineer the therapeutically relevant properties of protein drugs.

Insulin: evolution of insulin formulations and their application in clinical practice over 100 years

The first preparation of insulin extracted from a pancreas and made suitable for use in humans after purification was achieved 100 years ago in Toronto, an epoch-making achievement, which has ultimately provided a life-giving treatment for millions of people worldwide. The earliest animal-derived formulations were short-acting and contained many impurities that caused adverse reactions, thereby limiting their therapeutic potential. However, since then, insulin production and purification improved with enhanced technologies, along with a full understanding of the insulin molecule structure. The availability of radio-immunoassays contributed to the unravelling of the physiology of glucose homeostasis, ultimately leading to the adoption of rational models of insulin replacement. The introduction of recombinant DNA technologies has since resulted in the era of both rapid- and long-acting human insulin analogues administered via the subcutaneous route which better mimic the physiology of insulin secretion, leading to the modern basal-bolus regimen. These advances, in combination with improved education and technologies for glucose monitoring, enable people with diabetes to better meet individual glycaemic goals with a lower risk of hypoglycaemia. While the prevalence of diabetes continues to rise globally, it is important to recognise the scientific endeavour that has led to insulin remaining the cornerstone of diabetes management, on the centenary of its first successful use in humans.

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.

Fatty acids may influence insulin dynamics through modulation of albumin-Zn2+ interactions

Insulin is stored within the pancreas in an inactive Zn²⁺ -bound hexameric form prior to release. Similarly, clinical insulins contain Zn²⁺ and form multimeric complexes. Upon release from the pancreas or upon injection, insulin only becomes active once Zn²⁺ disengages from the complex. In plasma and other extracellular fluids, the majority of Zn²⁺ is bound to human serum albumin (HSA), which plays a vital role in controlling insulin pharmacodynamics by enabling removal of Zn²⁺ . The Zn²⁺ -binding properties of HSA are attenuated by non-esterified fatty acids (NEFAs) also transported by HSA. Elevated NEFA concentrations are associated with obesity and type 2 diabetes. Here we present the hypothesis that higher NEFA levels in obese and/or diabetic individuals may contribute to insulin resistance and affect therapeutic insulin dose-response profiles, through modulation of HSA/Zn²⁺ dynamics. We envisage this novel concept to have important implications for personalized treatments and management of diabetes-related conditions in the future.

Comparison of Insulins Glargine and Degludec in Diabetic Rhesus Macaques (Macaca mulatta) with CGM Devices

Treating and monitoring type 2 diabetes mellitus (T2DM) in NHP can be challenging. Multiple insulin and hypoglycemic therapies and management tools exist, but few studies demonstrate their benefits in a NHP clinical setting. The insulins glargine and degludec are long-acting insulins; their duration of action in humans exceeds 24 and 42 h, respectively. In the first of this study's 2 components, we evaluated whether insulin degludec could be dosed daily at equivalent units to glargine to achieve comparable blood glucose (BG) reduction in diabetic rhesus macaques (Macaca mulatta) with continuous glucose monitoring (CGM) devices. The second component assessed the accuracy of CGM devices in rhesus macaques by comparing time-stamped CGM interstitial glucose values, glucometer BG readings, and BG levels measured by using an automated clinical chemistry analyzer from samples that were collected at the beginning and end of each CGM device placement. The CGM devices collected a total of 21,637 glucose data points from 6 diabetic rhesus macaques that received glargine followed by degludec every 24 h for 1 wk each. Ultimately, glucose values averaged 29 mg/dL higher with degludec than with glargine. Glucose values were comparable between the CGM device, glucometer, and chemistry analyzer, thus validating that CGM devices as reliable for measuring BG levels in rhesus macaques. Although glargine was superior to degludec when given at the same dose (units/day), both are safe and effective treatment options. Glucose values from CGM, glucometers, and chemistry analyzers provided results that were analogous to BG values in rhesus macaques. Our report further highlights critical clinical aspects of using glargine as compared with degludec in NHP and the benefits of using CGM devices in macaques.

Advances in newer basal and bolus insulins: impact on type 1 diabetes

PURPOSE OF REVIEW

Insulin administration is vitally important to maintain a good glycaemic control in people with type 1 diabetes mellitus (T1DM). The purpose of this review is to give a clinically relevant overview of the newer basal and bolus insulin analogues and to highlight their practicalities of use and advantages in specific categories of patients with T1DM.

RECENT FINDINGS

Second-generation rapid-acting insulin analogues (i.e. faster insulin aspart and ultrarapid-acting lispro) have shown to be safe, efficient and superior in controlling postprandial plasma glucose levels without an increase in hypoglycaemia. The newest basal insulin analogues, insulin glargine U300 and degludec, have proven to be efficient in reducing hypoglycaemic events due to a more stable action profile.

SUMMARY

The second-generation rapid-acting and basal insulin analogues approach better the desired physiological insulin pattern of the beta cell. Due to a faster absorption, it is possible to inject the prandial insulin analogues more closely or even after meals without compromising postprandial glucose control. Due to more stable release patterns, basal insulins now have more reliable and longer profiles, covering basal insulin demands in a superior way, leading to a better glycaemic control with less hypoglycaemia (especially nocturnal events) and an improved quality of life.

Improving the treatment of patients with diabetes using insulin analogues: current findings and future directions

Introduction: The aim of insulin replacement in insulin-deficient people (type 1 diabetes, pancreatic causes of diabetes, long-standing type 2 diabetes) is to approximate the physiologic insulin action profile as closely as possible. However, short-acting human insulins start too slow and act too long, causing postprandial hyperglycemia and delayed hypoglycemia, while the insulin action profile of long-acting human insulins is too variable in duration and strength of action, leading to insufficient basal insulin covering and peak insulin levels after injection causing early nocturnal hypoglycemia. Insulin analogues were designed to overcome these shortcomings. In insulin-resistant people (type 2 diabetes), insulin analogues contribute to more efficient and safer insulin supplementation. Areas covered: In this review, we describe the unmet needs for insulin therapy, the currently available short- and long-acting insulin analogues and some considerations on cardiovascular outcomes, use in special populations, and cost-effectiveness. Finally, we discuss what is new in the field of insulin analogues. Expert opinion: The development of insulin analogues is an important step in diabetes treatment. Despite many patients meeting their glycemic targets with the newest analogues, hypoglycemic episodes remain a major problem. More physiologic insulin regimens, with glucose-sensitive or organ-targeting insulin analogues may be the answer to these issues.

Association of Insulin Glargine Treatment with Bone Mineral Density in Patients with Type 2 Diabetes Mellitus

PURPOSE

To assess the association of type 2 diabetes mellitus (T2DM) and insulin glargine treatment with bone mineral density (BMD) in Chinese people.

METHODS

This retrospective study included 50 subjects with T2DM: 25 received oral glucose-lowering medication (ORL group), and 25 received oral glucose-lowering medication in combination with insulin glargine injection (CGI group). Thirty non-diabetic control subjects were also included. BMD was measured at lumbar vertebrae 1-4 (L1-L4), spine bone mineral density (sBMD) results summary (L2-L4), femoral neck and trochanter by dual-energy x-ray absorptiometry.

RESULTS

Compared with non-diabetic controls, people with T2DM had significantly lower mean BMD at L2 (1.073±0.120 vs 0.984±0.158), L3 (1.094±0.129 vs 0.991±0.163) and L4 (1.089±0.130 vs 0.982±0.165) (all P<0.05), significantly lower levels of serum calcium (2.02±0.22 vs 2.27±0.17 mmol/L, P<0.05), PTH (24.19±9.71 vs 31.52±8.96 pg/mL, P<0.05), and higher serum phosphate levels (1.43±0.37 vs 1.20±0.15 mmol/L, P<0.05). The CGI group had higher L2, L3 and L4 BMD and sBMD (L2-L4) (P<0.05), higher serum calcium levels (2.19±0.11 vs 1.98±0.20 mmol/L, P<0.05) and lower serum phosphate levels (1.28±0.20 vs 1.58±0.43 mmol/L, P<0.05) versus the ORL group. BMD and serum calcium levels were associated with the application of insulin glargine.

CONCLUSION

These results suggest that insulin glargine may affect bone metabolism in patients diagnosed with T2DM. The study has implications for the selection of hypoglycemic agents for diabetic patients at risk of osteoporosis.

Treatment satisfaction in patients with diabetes mellitus type 1 treated with intensified insulin therapy with insulin analogues

The outcome of diabetes treatments can and should be evaluated through the patients' treatment satisfaction. The aim of this study was to examine the patients' satisfaction with the therapy with human insulin analogues compared with previous treatment with human insulin. We evaluated patient satisfaction in patients with T1DM in our institution who were currently on IIT with human insulins. We performed testing with standard World Health Organization Diabetes Treatment Satisfaction Questionnaire (WHO DTSQ) before and after the therapy with insulin analogs. The overall DTSQ score in forty-nine patients after the third month of therapy and after the sixth month of therapy is higher than before the initiation of therapy (p < 0.001). The results of the responses on the perception of hyperglycaemia were lower after three months of therapy (p < 0.05) and after the six months of treatment than before the onset of therapy (p < 0.01). There were no differences in the perception of hypoglycaemia after three months; however, perception of hypoglycaemia after the sixth month of treatment was lower than before the onset of therapy (p < 0.001) and compared to the score after the third month of therapy (p < 0.01). Therapy of T1DM patients with insulin analogue aspart over three months led to an increase in satisfaction with therapy and a reduction of the perception of hyperglycaemia. Therapy of T1DM patients with insulin analogues (aspart and glargine) over three months led to an increase in satisfaction with therapy and a reduction of the perception of both hyperglycaemia and hypoglycamia.

Increasing secular trends in height and obesity in children with type 1 diabetes: JSGIT cohort

BACKGROUND

Recently, anthropometric indices in children with type 1 diabetes mellitus (T1DM) have begun to change.

OBJECTIVE

To examine secular trends in patients' anthropometric indices.

SUBJECTS

Japanese children with T1DM from the 1995, 2000, 2008 and 2013 cohorts of The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes.

METHODS

We analysed serum haemoglobin A1c (HbA1c) levels, the incidence of severe hypoglycaemic events, the types and doses of insulin, height standard deviation scores (SDS), body mass index (BMI) percentiles compared with healthy Japanese children and obesity prevalence over time. We also stratified the patients according to glycaemic control levels of <58 mmol/mol (optimal), 58-75 mmol/mol (suboptimal) and ≥75 mmol/mol (high-risk).

RESULTS

Data for 513-978 patients from each of the cohorts were analysed. The incidence of severe hypoglycaemic events decreased over time (from 21 to 4.8/100 patient-years), while the proportion of insulin analogue doses increased (14.6% to 98.6%). In addition, patient height SDS (-0.22 to +0.17), BMI percentile (52.1 to 58.7) and obesity prevalence (2.1% to 5.1%) increased. Height SDS increased in all of the glycaemic control subgroups, while BMI percentile and obesity prevalence increased in the suboptimal and high-risk groups.

CONCLUSIONS

Since 1995, the average height of children with T1DM has increased in parallel with increasing insulin doses. Clinicians should be aware of increased BMI in these patients and the associated risk of developing cardiovascular disease in the future.

A Model-Based Insulin Dose Optimization Algorithm for People With Type 1 Diabetes on Multiple Daily Injections Therapy

OBJECTIVE

Multiple daily injections (MDI) therapy is the most common treatment for type 1 diabetes (T1D) including basal insulin doses to keep glucose levels constant during fasting conditions and bolus insulin doses with meals. Optimal insulin dosing is critical to achieving satisfactory glycemia but is challenging due to inter- and intra-individual variability. Here, we present a novel model-based iterative algorithm that optimizes insulin doses using previous-day glucose, insulin, and meal data.

METHODS

Our algorithm employs a maximum-a-posteriori method to estimate parameters of a model describing the effects of changes in basal-bolus insulin doses. Then, parameter estimates, their confidence intervals, and the goodness of fit, are combined to generate new recommendations. We assessed our algorithm in three ways. First, a clinical data set of 150 days (15 participants) were used to evaluate the proposed model and the estimation method. Second, 60-day simulations were performed to demonstrate the efficacy of the algorithm. Third, a sample 6-day clinical experiment is presented and discussed.

RESULTS

The model fitted the clinical data well with a root-mean-square-error of 1.75 mmol/L. Simulation results showed an improvement in the time in target (3.9-10 mmol/L) from 64% to 77% and a decrease in the time in hypoglycemia (< 3.9 mmol/L) from 8.1% to 3.8%. The clinical experiment demonstrated the feasibility of the algorithm.

CONCLUSION

Our algorithm has the potential to improve glycemic control in people with T1D using MDI.

SIGNIFICANCE

This work is a step forward towards a decision support system that improves their quality of life.

Cost-Effectiveness of Insulin Glargine and Insulin Detemir in the Basal Regimen for Naïve Insulin Patients with Type 2 Diabetes Mellitus (T2DM) in Malaysia

Objective

To compare the cost-effectiveness of long-acting insulin analogue (LAIA) (insulin Detemir and insulin Glargine) versus NPH insulin in the basal insulin regime for naïve insulin T2DM Malaysian patients.

Methods

The UKPDS-Outcome Model version 2.0 (UKPDS-OM2) was used to evaluate the cost and consequence of diabetes-related complication. The effectiveness of the insulin was derived from the literature review, and the patients’ epidemiology characteristics were retrieved from the Malaysian Diabetes Registry. A discount rate of 3% was applied to both costs and health effects. Another simple mathematical model was used to compare the benefit of reducing the hypoglycemia events between LAIA and NPH insulin. The outputs of the models were combined to obtain the final result. One-way sensitivity analyses were performed to assess the uncertainties.

Results

The net cost difference (without accounting for hypoglycemia) was RM4868 for insulin Glargine and RM6026 for insulin Detemir. The saving from preventing severe hypoglycemia was RM4377 for insulin Glargine and RM12,753 for insulin Detemir. The total additional QALY gained from insulin Glargine was 0.1317 and from insulin Detemir was 0.8376. The sensitivity analysis shows the discount rate, and drug acquisition cost may affect the incremental cost-effectiveness ratio (ICER) value.

Conclusion

Both insulin Detemir and Glargine are cost-effective compared to NPH insulin for T2DM patients, especially when the benefit of reducing the hypoglycemia event rate is taken into account.

Engineered human FcγRIIa fusion: A novel strategy to extend serum half-life of therapeutic proteins

The immunoglobulin G (IgG) molecule has a long circulating serum half-life (~3 weeks) through pH- dependent FcRn binding-mediated recycling. To hijack the intracellular trafficking and recycling mechanism of IgG as a way to extend serum persistence of non-antibody therapeutic proteins, we have evolved the ectodomain of a low-affinity human FcγRIIa for enhanced binding to the lower hinge and upper CH2 region of IgG, which is very far from the FcRn binding site (CH2-CH3 interface). High-throughput library screening enabled isolation of an FcγRIIa variant (2A45.1) with 32-fold increased binding affinity to human IgG1 Fc (equilibrium dissociation constant: 9.04 × 10^-7  M for wild type FcγRIIa and 2.82 × 10^-8  M for 2A45.1) and significantly improved affinity to mouse serum IgG compared to wild type human FcγRIIa. The in vivo pharmacokinetic profile of PD-L1 fused with engineered FcγRIIa (PD-L1-2A45.1) was compared with that of PD-L1 fused with wild type FcγRIIa (PD-L1-wild type FcγRIIa) and human PD-L1 in mice. PD-L1-2A45.1 showed 11.7- and 9.7-fold prolonged circulating half-life (t_1/2 ) compared to PD-L1 when administered intravenously and intraperitoneally, respectively. In addition, the AUC_inf of PD-L1-2A45.1 was two-fold higher compared to that of PD-L1-wild type FcγRIIa. These results demonstrate that engineered FcγRIIa fusion offers a novel and successful strategy for prolonging serum half-life of therapeutic proteins.

The continuing quest for better subcutaneously administered prandial insulins: a review of recent developments and potential clinical implications

The class of rapid-acting insulin analogues were introduced more than 20 years ago to control postprandial plasma glucose (PPG) excursions better than unmodified regular human insulin. Insulins, lispro, aspart and glulisine all achieved an earlier onset of action, greater peak effect and shorter duration of action resulting in lower PPG levels and a reduced risk of late postprandial hypoglycaemia. However, the subcutaneous absorption rate of these analogues still fails to match the physiological profile of insulin in the systemic circulation following a meal. Recent reformulations of aspart and lispro have generated a second generation of more rapid-acting insulin analogue candidates, including fast-acting aspart (faster aspart), ultra-rapid lispro and BioChaperone Lispro. These modifications have the potential to mimic physiological prandial insulin secretion better with an even earlier onset of action with improved PPG control, shorter duration of effect and reduced risk of hypoglycaemia. Recent phase 3 trials in type 1 and type 2 diabetes show that faster aspart and ultra-rapid lispro compared with conventional aspart and lispro, achieved fewer PPG excursions with a small increase in post-meal hypoglycaemia but similar or marginally superior glycated haemoglobin levels, and suggest the need for parallel optimization of basal insulin replacement. Phase 1 trials for BioChaperone Lispro are equally encouraging with phase 3 trials yet to be initiated. Comparative analysis of the clinical and pharmacological evidence for these new prandial insulin candidates in the treatment of type 1 and type 2 diabetes is the main focus of this review.

Proteolysis and Oxidation of Therapeutic Proteins After Intradermal or Subcutaneous Administration

The intradermal (ID) and subcutaneous (SC) routes are commonly used for therapeutic proteins (TPs) and vaccines; however, the bioavailability of TPs is typically less than small molecule drugs given via the same routes. Proteolytic enzymes in the dermal, SC, and lymphatic tissues may be responsible for the loss of TPs. In addition, the TPs may be exposed to reactive oxygen species generated in the SC tissue and the lymphatic system in response to injection-related trauma and impurities within the formulation. The reactive oxygen species can oxidize TPs to alter their efficacy and immunogenicity potential. Mechanistic understandings of the dominant proteolysis and oxidative routes are useful in the drug discovery process, formulation development, and to assess the potential for immunogenicity and altered pharmacokinetics (PK). Furthermore, in vitro tools representing the ID or SC and lymphatic system can be used to evaluate the extent of proteolysis of the TPs after the injection and before systemic entry. The in vitro clearance data may be included in physiologically based pharmacokinetic models for improved PK predictions. In this review, we have summarized various physiological factors responsible for proteolysis and oxidation of TPs after ID and SC administration.

Cyclic Peptides that Govern Signal Transduction Pathways: From Prokaryotes to Multi-Cellular Organisms

Cyclic peptide scaffolds are key components of signal transduction pathways in both prokaryotic and eukaryotic organisms since they act as chemical messengers that activate or inhibit specific cognate receptors. In prokaryotic organisms these peptides are utilized in non-essential pathways, such as quorum sensing, that are responsible for virulence and pathogenicity. In the more evolved eukaryotic systems, cyclic peptide hormones play a key role in the regulation of the overall function of multicellular organisms, mainly through the endocrine system. This review will highlight several prokaryote and eukaryote systems that use cyclic peptides as their primary signals and the potential associated with utilizing these scaffolds for the discovery of novel therapeutics for a wide range of diseases and illnesses.

Recent Updates on Type 1 Diabetes Mellitus Management for Clinicians

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune condition that requires life-long administration of insulin. Optimal management of T1DM entails a good knowledge and understanding of this condition both by the physician and the patient. Recent introduction of novel insulin preparations, technological advances in insulin delivery and glucose monitoring, such as continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring and improved understanding of the detrimental effects of hypoglycaemia and hyperglycaemia offer new opportunities and perspectives in T1DM management. Evidence from clinical trials suggests an important role of structured patient education. Our efforts should be aimed at improved metabolic control with concomitant reduction of hypoglycaemia. Despite recent advances, these goals are not easy to achieve and can put significant pressure on people with T1DM. The approach of physicians should therefore be maximally supportive. In this review, we provide an overview of the recent advances in T1DM management focusing on novel insulin preparations, ways of insulin administration and glucose monitoring and the role of metformin or sodium-glucose co-transporter 2 inhibitors in T1DM management. We then discuss our current understanding of the effects of hypoglycaemia on human body and strategies aimed at mitigating the risks associated with hypoglycaemia.

Lithium reduces blood glucose levels, but aggravates albuminuria in BTBR-ob/ob mice

Glycogen synthase kinase 3 (GSK3) plays an important role in the development of diabetes mellitus and renal injury. GSK3 inhibition increases glucose uptake in insulin-insensitive muscle and adipose tissue, while it reduces albuminuria and glomerulosclerosis in acute kidney injury. The effect of chronic GSK3 inhibition in diabetic nephropathy is not known. We tested the effect of lithium, the only clinical GSK3 inhibitor, on the development of diabetes mellitus and kidney injury in a mouse model of diabetic nephropathy. Twelve-week old female BTBR-ob/ob mice were treated for 12 weeks with 0, 10 and 40 mmol LiCl/kg after which the development of diabetes and diabetic nephropathy were analysed. In comparison to BTBR-WT mice, ob/ob mice demonstrated elevated bodyweight, increased blood glucose/insulin levels, urinary albumin and immunoglobulin G levels, glomerulosclerosis, reduced nephrin abundance and a damaged proximal tubule brush border. The lithium-10 and -40 diets did not affect body weight and resulted in blood lithium levels of respectively <0.25 mM and 0.48 mM. The Li-40 diet fully rescued the elevated non-fasting blood glucose levels. Importantly, glomerular filtration rate was not affected by lithium, while urine albumin and immunoglobulin G content were further elevated. While lithium did not worsen the glomerulosclerosis, proximal tubule function seemed affected by lithium, as urinary NGAL levels were significantly increased. These results demonstrate that lithium attenuates non-fasting blood glucose levels in diabetic mice, but aggravates urinary albumin and immunoglobulin G content, possibly resulting from proximal tubule dysfunction.

Improvement in glycemic control through changes in insulin regimens: findings from a Japanese cohort of children and adolescents with type 1 diabetes

OBJECTIVE

Although insulin analogs have dramatically changed diabetes treatment, scarce evidence is available on those effects. We aimed to explore whether glycemic control had improved, the use of insulin analogs had been increased, and hypoglycemic events had decreased over time in Japanese pediatric patients with type 1 diabetes (T1D).

METHODS

Glycated hemoglobin A1c (HbA1c) values, proportion of insulin regimens, incidence of severe hypoglycemic events, and pubertal increase in HbA1c were compared in three cohorts of childhood-onset Japanese T1D patients (567 subjects in the 1995 cohort, 754 subjects in the 2000 cohort, and 806 subjects in the 2008 cohort).

RESULTS

Mean HbA1c values tended to decrease [78.5 mmol/mol (9.33%) in the 1995 cohort, 68.2 mmol/mol (8.39%) in the 2000 cohort, and 61.2 mmol/mol (7.75%) in the 2008 cohort; P < .0001]. The proportion of patients who received basal-bolus treatment tended to increase with statistical significance, as did the proportion on insulin analogs. The incidence of severe hypoglycemic events (events/100 patients/y) had decreased (19.1 in the 2000 cohort and 8.7 in the 2008 cohort; P = .02). The pubertal increase in HbA1c tended to decrease [males, 12.0 mmol/mol (1.10%) in 1995, 9.4 mmol/mol (0.85%) in 2008, and 9.4 mmol/mol (0.86%) in 2008; P = .55; females, 14.0 mmol/mol (1.28%) in 1995, 10.3 mmol/mol (0.94%) in 2000, and 4.2 mmol/mol (0.38%) in 2008; P = .0003].

CONCLUSIONS

Glycemic control and incidence of severe hypoglycemic events were chronologically improved, especially in female adolescents.

Pharmacological efficacy of FGF21 analogue, liraglutide and insulin glargine in treatment of type 2 diabetes

Fibroblast growth factor 21 (FGF21) is a promising regulator of glucose and lipid metabolism with multiple beneficial effects including hypoglycemic and lipid-lowering. Previous studies have reported that FGF21 is expected to become a new drug for treatment of diabetes. Liraglutide and insulin glargine are the two representative anti-diabetic biological drugs. In the current study, we aim to compare the long-term pharmacological efficacy of mFGF21 (an FGF21 analogue), liraglutide and insulin glargine in type 2 diabetic db/db mice. Db/db mice were initially treated with three kinds of proteins (25nmol/kg/day) by subcutaneous injection once a day for 4weeks, then subsequently be treated with once every two days for next 4weeks. After 8weeks of treatments, the blood glucose levels, body weights, glycosylated hemoglobin levels, fasting insulin levels, serum lipid profiles, hepatic biochemical parameters, oral glucose tolerance tests and hepatic mRNA expression levels of several proteins (GK, G6P, GLUT-1 and GLUT-4) associated with glucose metabolism of the experimental mice were detected. Results demonstrated that three proteins could significantly decrease the fed blood glucose levels of db/db mice. After treatment for 1week, the fed blood glucose levels of db/db mice in liraglutide group were significantly lower than those in mFGF21 and insulin glargine groups. However, after 2weeks of administration, the long-lasting hypoglycemic effect of mFGF21 was superior to liraglutide and insulin glargine up to the end of the experiments. Compared with liraglutide and insulin glargine, mFGF21 significantly reduced the glycosylated hemoglobin levels and improved the ability on glycemic control, insulin resistance, serum lipid and liver function states in db/db mice after 8weeks treatments. In addition, mFGF21 regulated glucose metabolism through increasing the mRNA expression levels of GK and GLUT-1, and decreasing the mRNA expression level of G6P. But liraglutide and insulin glargine could only up-regulate the mRNA expression of GLUT-4. In summary, as a hypoglycemic drug for long-term treatment, mFGF21 has the potential to be an ideal drug candidate for the therapy of type 2 diabetes.

Systematic Review of the Cost Effectiveness of Insulin Analogues in Type 1 and Type 2 Diabetes Mellitus

BACKGROUND

Insulin analogues have a pharmacokinetic advantage over human insulin and are increasingly used to treat diabetes mellitus. A summary of their cost effectiveness versus other available treatments was required.

OBJECTIVE

Our objective was to systematically review the published cost-effectiveness studies of insulin analogues for the treatment of patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM).

METHODS

We searched major databases and health technology assessment agency reports for economic evaluation studies published up until 30 September 2015. Two reviewers performed data extraction and assessed the quality of the data using the CHEERS (Consolidated Health Economic Evaluation Reporting Standards) guidelines.

RESULTS

Seven of the included studies assessed short-acting insulin analogues, 12 assessed biphasic insulin analogues, 30 assessed long-acting insulin analogues and one assessed a combination of short- and long-acting insulin analogues. Only 17 studies involved patients with T1DM, all were modelling studies and 12 were conducted in Canada. The incremental cost-effectiveness ratios (ICERs) for short-acting insulin analogues ranged from dominant to $US435,913 per quality-adjusted life-year (QALY) gained, the ICERs for biphasic insulin analogues ranged from dominant to $US57,636 per QALY gained and the ICERs for long-acting insulin analogues ranged from dominant to $US599,863 per QALY gained. A total of 15 studies met all the CHEERS guidelines reporting quality criteria. Only 26 % of the studies assessed heterogeneity in their analyses.

CONCLUSION

Current evidence indicates that insulin analogues are cost effective for T1DM; however, evidence for their use in T2DM is not convincing. Additional evidence regarding compliance and efficacy is required to support the broader use of long-acting and biphasic insulin analogues in T2DM. The value of insulin analogues depends strongly on reductions in hypoglycaemia event rates and its efficacy in lowering glycated haemoglobin (HbA_1c).

Insulin Glulisine—A Comprehensive Preclinical Evaluation

Receptor binding and signaling and the mitogenic potential of insulin glulisine (glulisine), regular human insulin (RHI), and Asp(B10) were compared in vivo and in vitro. Insulin and insulin-like growth factor 1 (IGF-1) receptor binding was studied with human insulin receptors (293HEK cells) and the human osteosarcoma-derived cell line B10. Insulin receptor–mediated signaling was assessed in rat-1 fibroblasts overexpressing insulin receptors. Activation of insulin receptor substrates 1 and 2 (IRS-1/IRS-2) was studied in rat and human myoblasts and rat cardiomyocytes. DNA synthesis induction was assessed by [3H] thymidine incorporation in the human epithelial breast cell line MCF10. Interaction with the IGF-1 receptor, DNA synthesis, and intracellular signal transduction were assessed in cardiac K6 myoblasts. Immunohistochemical examination of Sprague-Dawley rat tissue treated with glulisine for 6 months ( n = 40), and glulisine and RHI for 12 months ( n = 60), was performed. Steady-state insulin receptor binding affinity was slightly lower for glulisine versus RHI (~0.70). IGF-1 receptor binding affinity was lower (four-to fivefold) for glulisine, but significantly higher (four-fold) for Asp(B10) versus RHI. Glulisine, Asp(B10), and RHI showed similar insulin receptor–association kinetics; however, Asp(B10) revealed increased insulin receptor affinity. Glulisine and RHI showed similar insulin receptor–mediated phosphorylation and IRS-2 activation. Activation of IRS-1 was 6- to 10-fold lower with glulisine; glulisine was less potent and Asp(B10) slightly more potent in stimulating DNA synthesis versus RHI. Stimulation of DNA synthesis was comparable for glulisine and RHI in K6 myoblasts. At 12 months, there was no significant difference between glulisine and RHI in proliferative activity. This preclinical evaluation suggests that structural changes in glulisine versus RHI are not associated with any safety issues.

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.

Biphasic insulin Aspart 30 vs. NPH plus regular human insulin in type 2 diabetes patients; a cost-effectiveness study

BACKGROUND

The aim of this study was to compare the efficacy, safety, costs, and cost-effectiveness of biphasic insulin aspart 30 (BIAsp 30) with NPH plus regular human insulin (NPH/Reg) in patients with type 2 diabetes mellitus (T2DM).

METHODS

It was a Single-center, parallel-group, randomized, clinical trial (Trial Registration: NCT01889095). One hundred and seventy four T2DM patients with poorly controlled diabetes (HbA1c ≥ 8 % (63.9 mmol/mol)) were randomly assigned to trial arms (BIAsp 30 and NPH/Reg) and were followed up for 48 weeks. BIAsp 30 was started at an initial dose of 0.2-0.6 IU/Kg in two divided doses and was titrated according to the glycemic status of the patient. Similarly, NPH/Reg insulin was initiated at a dose of 0.2-0.6 IU/Kg with a 2:1 ratio and was subsequently titrated. Level of glycemic control, hypoglycemic events, direct and indirect costs, quality adjusted life year (QALY) and incremental cost-effectiveness ratio have been assessed.

RESULTS

HbA1c, Fasting plasma glucose (FPG), and two-hour post-prandial glucose (PPG) were improved in both groups during the study (P < 0.05 for all analyses). Lower frequencies of minor, major, and nocturnal hypoglycemic episodes were observed with BIAsp 30 (P < 0.05). Additionally, BIAsp 30 was associated with less weight gain and also higher QALYs (P < 0.05). Total medical and non-medical costs were significantly lower with BIAsp 30 as compared with NPH/Reg (930.55 ± 81.43 USD vs. 1101.24 ± 165.49 USD, P = 0.004). Moreover, BIAsp 30 showed lower ICER as a dominant alternative.

CONCLUSIONS

Despite being more expensive, BIAsp 30 offers the same glycemic control as to NPH/Reg dose-dependently and also appears to cause fewer hypoglycemic events and to be more cost-effective in Iranian patients with type 2 diabetes.

Intradermal insulin infusion achieves faster insulin action than subcutaneous infusion for 3-day wear

Rapid uptake previously demonstrated by intradermal (ID) drug administration indicates compound delivery within the dermis may have clinical and pharmacological advantages for certain drug therapies. This study is the first clinical trial to evaluate continuous microneedle-based drug infusion, device wearability, and intradermal microneedle insulin kinetics over a multi-day (72 h) wear period. This was a single center, open-label, two-period crossover study in T1DM patients on continuous subcutaneous insulin infusion (CSII). Patients received treatment during interventional visits: one SC and one ID basal/bolus infusion of insulin aspart (NovoRapid® U-100) administered over 3 days in a randomized order. Twenty-eight patients were randomized and exposed to trial product, and 23 completed the study. Bolus insulin infusions were given prior to standardized breakfast and lunch test meals on each of the three treatment days. Blood samples were drawn at predefined time points for measurements of insulin aspart and blood glucose in serum. The primary endpoint insulin Tmax demonstrated that ID bolus infusion was associated with a significantly shorter Tmax with statistically significantly smaller intra-subject variability, compared to SC infusion, and this difference was maintained over three treatment days. Analyses of secondary PK endpoints corresponded with the primary endpoint findings. Postprandial glycemic response was significantly less pronounced after ID bolus: For most endpoints ID vs. SC, differences were statistically significant within the 0–1.5 or 0–2 h time period. Intradermal delivery of insulin is a viable delivery route alternative providing reduced time for insulin absorption with less intra-subject variability and lower glycemic response.

Clinically and pharmacologically relevant interactions of antidiabetic drugs

Patients with type 2 diabetes mellitus often require multifactorial pharmacological treatment due to different comorbidities. An increasing number of concomitantly taken medications elevate the risk of the patient experiencing adverse drug effects or drug interactions. Drug interactions can be divided into pharmacokinetic and pharmacodynamic interactions affecting cytochrome (CYP) enzymes, absorption properties, transporter activities and receptor affinities. Furthermore, nutrition, herbal supplements, patient's age and gender are of clinical importance. Relevant drug interactions are predominantly related to sulfonylureas, thiazolidinediones and glinides. Although metformin has a very low interaction potential, caution is advised when drugs that impair renal function are used concomitantly. With the exception of saxagliptin, dipeptidyl peptidase-4 (DPP-4) inhibitors also show a low interaction potential, but all drugs affecting the drug transporter P-glycoprotein should be used with caution. Incretin mimetics and sodium-glucose cotransporter-2 (SGLT-2) inhibitors comprise a very low interaction potential and are therefore recommended as an ideal combination partner from the clinical-pharmacologic point of view.

Pharmacokinetics and pharmacodynamics of insulin glargine-insulin glulisine basal-bolus and twice-daily premixed analog insulin in type 1 diabetes mellitus patients during three standardized meals

AIMS

To evaluate the pharmacokinetics and pharmacodynamics of basal insulin glargine with mealtime insulin glulisine or twice daily 75/25 premixed neutral protamine insulin lispro and insulin lispro in individuals with type 1 diabetes during three standardized meals over a 24 hour duration and compare to physiologic insulin and glucose responses in healthy non-diabetic individuals.

METHODS

Twelve healthy (4 male/8 female) and thirteen individuals with type 1 diabetes (8 male/5 female) were studied during three sequential standardized meals. Individuals with type 1 diabetes received either glargine and glulisine injected 5 minutes subcutaneously before each meal or premixed insulin lispro injected 5 minutes before breakfast and dinner in a randomized fashion separated by eight weeks.

RESULTS

The incremental systemic insulin AUC, maximal insulin concentration, and rate of rise of systemic insulin (0-30 minutes) during all three meal intervals were similar between glargine/glulisine and healthy controls. Incremental glucose AUC with glargine/glulisine was similar to controls at lunch and dinner. With premix 75/25 insulin, insulin AUC was lower and incremental glucose AUC was greater at lunch compared to the healthy and glargine/glulisine. Hypoglycemic events before lunch were greater with premix insulin group than with glargine/glulisine (p < 0.0001).

CONCLUSIONS

Glargine/glulisine pharmacokinetics in type 1 diabetes can closely approximate physiologic insulin responses in healthy individuals during a day in which three standardized meals are consumed. Additionally, when glulisine is dosed only five minutes pre-meal, systemic insulin concentration rises as rapidly as prandial endogenous insulin levels. This present study compared glargine and glulisine administered in an approximate 50/50 proportion. Future studies of alternate meal times, meal content and differing premixed insulin preparations are indicated.

Pharmacokinetics and Pharmacodynamics of NPH Insulin in Type 1 Diabetes: The Importance of Appropriate Resuspension Before Subcutaneous Injection

OBJECTIVE

Crystalline NPH insulin comes in a two-phase solution with either a solvent or a rapid-acting insulin (in premixed formulations) and needs adequate mixing for complete resuspension before injection. The aim of this study was to establish pharmacokinetics (PK) and pharmacodynamics (PD) after injection of appropriately resuspended versus nonresuspended NPH insulin.

RESEARCH DESIGN AND METHODS

PK and PD were assessed after subcutaneous injection of NPH insulin 0.35 units/kg at steady state by pen either resuspended (R+, tipping of insulin pen 20 times) or nonresuspended (pen maintained in fixed position either horizontally [R- horizontal] or vertically with tip up [R- up] or tip down [R- down]). Eleven subjects with type 1 diabetes (age 31.5 ± 12 years, diabetes duration 17.5 ± 7.7 years, BMI 22.9 ± 1.5 kg/m2, A1C 7.2 ± 0.4% [55.2 ± 4.4 mmol/mol]) were studied (euglycemic clamp) with a randomized crossover design.

RESULTS

Compared with resuspended NPH insulin (R+), nonresuspended NPH insulin resulted in profound PK/PD differences with either reduced (R- horizontal and R- up) or increased (R- down) plasma insulin concentrations [FIRI_AUC(0-end of study) (free immunoreactive insulin area under the concentration-time curve between 0 and end of study)] and PD activity [glucose infusion rate (GIR)_AUC(0-end of study)] (all P < 0.05). Duration of NPH insulin action was shorter in R- up (9.4 ± 1.7 h) but longer in R- down (15.4 ± 2.3 h) compared with R+ (11.8 ± 2.6 h) (P < 0.05). Within-subject variability (percent coefficient of variation) among studies was as high as 23% for PK [FIRI_AUC(0-end of study)] and 62% for PD [GIR_AUC(0-end of study)].

CONCLUSIONS

Compared with resuspended NPH insulin, lack of resuspension profoundly alters PK/PD and may importantly contribute to day-to-day glycemic variability of type 1 diabetes.

Safety considerations with pharmacological treatment of gestational diabetes mellitus

The number of women with gestational diabetes mellitus (GDM: diabetes first diagnosed in pregnancy) continues to grow, as do the associated risks of antenatal and postnatal complications and the chance of future diabetes and obesity in both mother and offspring. Recent randomised controlled trials have demonstrated clear benefits for intensive management of GDM using lifestyle modification, self blood glucose monitoring, close clinical supervision and, where glycaemia remains inadequately controlled, insulin therapy. More recently, metformin and glibenclamide have been shown to adequately reduce hyperglycaemia as part of a stepped approach to GDM management, with a switch to insulin therapy where necessary. Other oral medications have not been shown to be safe in pregnancy. Human insulin therapy is safe within the limits of hypoglycaemia and weight gain. Most insulin analogues are also now considered safe for use in pregnancy (insulin lispro, aspart and detemir). Metformin therapy is oral, and therefore preferred to insulin, but is associated with more gastrointestinal adverse effects, although not hypoglycaemia or weight gain. Conversely, glibenclamide is also an oral therapy but is associated with hypoglycaemia and weight gain. However, metformin crosses the placenta and it remains unclear whether glibenclamide crosses the placenta or not: long-term risks have not been shown, and are thought to be minimal, but further studies are needed. Metformin is seen by some as the treatment of choice where weight gain is an issue, providing that the unanswered questions over the long-term safety of oral agents have been discussed.

Trials and tribulations of managing type 1 diabetes

Effective type 1 diabetes mellitus (T1DM) management tools are education, empowerment, insulin, and diet control. Exercise should be of moderate intensity so as to avoid hypoglycaemia. It is prudent to ensure that the required insulin levels are achieved in all children in order to manage the disorder well. The total daily dose of insulin may be 0.6-1.0 u/kg body weight, and it may be 2/3, 1/3 for split mixed insulin, and 50/50 for multiple subcutaneous injections. The dosages for the pump also vary from child to child. Basal bolus regimen is important and necessary in all T1DM children. It is not necessary to use all types of insulin analogs in all T1DM children, and the decision should depend on cost and delivery limiting factors. The advantages of using analogues are that some of these exhibit low hypoglycemic events (especially nocturnal events with basal insulin) and a few offer flexibility of administration to patients (most prandial analogs and some basal analogs).

Serum C-peptide assay of patients with hyperglycemic emergencies at the Lagos State University Teaching Hospital (LASUTH), Ikeja

INTRODUCTION

HE are common acute complications of diabetes mellitus (DM) and include diabetic ketoacidosis (DKA), normo-osmolar hyperglycemic state (NHS) and hyperosmolar hyperglycemic state (HHS). They contribute a lot to the mortality and morbidity of DM. The clinical features include dehydration, hyperglycemia, altered mental status and ketosis. The basic mechanism of HE is a reduction in the net effective action of circulating insulin, resulting in hyperglycemia and ketonemia (in DKA) causing osmotic diuresis and electrolytes loss. Infection is a common precipitating factor. Measurement of serum C-peptide provides an accurate assessment of residual β-cell function and is a marker of insulin secretion in DM patients.

AIM AND OBJECTIVES

To assess the level of pancreatic beta cell function in HE patients, using the serum C-peptide.

METHODOLOGY

The biodata and clinical characteristics of the 99 subjects were collated using a questionnaire. All subjects had their serum C-peptide, glucose, electrolytes, urea, creatinine levels, urine ketones determined at admission. Results of statistical analysis were expressed as mean ± standard deviation (SD). A p value <0.05 was regarded statistically significant. Correlation between levels of serum C-peptide and admission blood glucose levels and the duration of DM respectively was done.

RESULTS

The mean age of the subjects was 51 (SD ± 16) years and comparable in both sexes. Mean duration of DM was 6.3 (SD ± 7.1) years, with 35% newly diagnosed at admission. The types of HE in this study are: DKA (24.7%), NHS (36.1%), and HHS (39.2%). Mean blood glucose in this study was 685 mg/dL, significantly highest in HHS and lowest in NHS. Mean serum C-peptide level was 1.6 ng/dL. It was 0.9 ng/dL in subjects with DKA and NHS while 2.7 ng/dL in HHS (p>0.05). Main precipitating factors were poor drug compliance, new-onset of DM and infection.

CONCLUSION

Most (70%) of subjects had poor pancreatic beta cell function, this may be a contributory factor to developing HE. Most subjects with high C-peptide levels had HHS.

Insulin degludec/insulin aspart combination for the treatment of type 1 and type 2 diabetes

Glycemic control remains the major therapeutic objective to prevent or delay the onset and progression of complications related to diabetes mellitus. Insulin therapy represents a cornerstone in the treatment of diabetes and has been used widely for achieving glycemic goals. Nevertheless, a large portion of the population with diabetes does not meet the internationally agreed glycemic targets. Moreover, insulin treatment, especially if intensive, may be associated with emergency room visits and hospitalization due to hypoglycemic events. Therefore, fear of hypoglycemia or hypoglycemic events represents the main barriers to the attainment of glycemic targets. The burden associated with multiple daily injections also remains a significant obstacle to initiating and maintaining insulin therapy. The most attractive insulin treatment approach should meet the patients’ preference, rather than demanding patients to change or adapt their lifestyle. Insulin degludec/insulin aspart (IDegAsp) is a new combination, formulated with ultra-long-acting insulin degludec and rapid-acting insulin aspart, with peculiar pharmacological features, clinical efficacy, safety, and tolerability. IDegAsp provides similar, noninferior glycemic control to a standard basal–bolus regimen in patients with type 1 diabetes mellitus, with additional benefits of significantly lower episodes of hypoglycemia (particularly nocturnal) and fewer daily insulin injections. Moreover, although treatment strategy and patients’ viewpoint are different in type 1 and type 2 diabetes, trial results suggest that IDegAsp may be an appropriate and reasonable option for initiating insulin therapy in patients with type 2 diabetes inadequately controlled on maximal doses of conventional oral agents. This paper will discuss the role of IDegAsp combination as a novel treatment option in diabetic patients.

Insulin and wound healing

Skin is a dynamic and complex organ that relies on the interaction of different cell types, biomacromolecules and signaling molecules. Injury triggers a cascade of events designed to quickly restore skin integrity. Depending on the size and severity of the wound, extensive physiological and metabolic changes can occur, resulting in impaired wound healing and increased morbidity resulting in higher rates of death. While wound dressings provide a temporary barrier, they are inherently incapable of significantly restoring metabolic upsets, post-burn insulin resistance, and impaired wound healing in patients with extensive burns. Exogenous insulin application has therefore been investigated as a potential therapeutic intervention for nearly a century to improve wound recovery. This review will highlight the important achievements that demonstrate insulin's ability to stimulate cellular migration and burn wound recovery, as well as providing a perspective on future therapeutic applications and research directions.

Insulin therapy in children and adolescents with type 1 diabetes

Treatment of type 1 diabetes mellitus (T1DM) requires lifelong administration of exogenous insulin. The primary goal of treatment of T1DM in children and adolescents is to maintain near-normoglycemia through intensive insulin therapy, avoid acute complications, and prevent long-term microvascular and macrovascular complications, while facilitating as close to a normal life as possible. Effective insulin therapy must, therefore, be provided on the basis of the needs, preferences, and resources of the individual and the family for optimal management of T1DM. To achieve target glycemic control, the best therapeutic option for patients with T1DM is basal-bolus therapy either with multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII). Many formulations of insulin are available to help simulate endogenous insulin secretion as closely as possible in an effort to eliminate the symptoms and complications of hyperglycemia, while minimizing the risk of hypoglycemia secondary to therapy. When using MDI, basal insulin requirements are given as an injection of long- or intermediate-acting insulin analogs, while meal-related glucose excursions are controlled with bolus injections of rapid-acting insulin analogs. Alternatively, CSII can be used, which provides a 24-h preselected but adjustable basal rate of rapid-acting insulin, along with patient-activated mealtime bolus doses, eliminating the need for periodic injections. Both MDI treatment and CSII therapy must be supported by comprehensive education that is appropriate for the individual needs of the patient and family before and after initiation. Current therapies still do not match the endogenous insulin profile of pancreatic β-cells, and all still pose risks of suboptimal control, hypoglycemia, and ketosis in children and adolescents. The safety and success of a prescribed insulin regimen is, therefore, dependent on self-monitoring of blood glucose and/or a continuous glucose monitoring system to avoid critical hypoglycemia and glucose variability. Regardless of the mode of insulin therapy, doses should be adapted on the basis of the daily pattern of blood glucose, through regular review and reassessment, and patient factors such as exercise and pubertal status. New therapy options such as sensor-augmented insulin pump therapy, which integrates CSII with a continuous glucose sensor, along with emerging therapies such as the artificial pancreas, will likely continue to improve safe insulin therapy in the near future.

Standard and Novel Treatment Options for Metabolic Syndrome and Diabetes Mellitus

OPINION STATEMENT

Type II diabetes and metabolic syndrome are 2 intertwined conditions that are critical to the healthcare landscape in the United States and abroad. Patients with either diabetes or metabolic syndrome can have a dramatically increased risk of developing cardiovascular disease. Numerous treatment options have existed for some time, which include nonpharmacologic and pharmacologic therapies. In addition, within the last decade, a multiple of novel treatment options have emerged for the management of hyperglycemia in particular. By targeting novel pathways beyond the secretion and supply of insulin, these new therapeutics provide a valuable adjunct to the currently available therapies for diabetes and metabolic syndrome. Here we discuss the current guideline-driven usage of standard therapies with some novel indications. In addition, we discuss the novel therapies for the treatment of hyperglycemia, their mechanisms of action, and appropriate therapeutic indications.

Stability and performance of rapid-acting insulin analogs used for continuous subcutaneous insulin infusion: a systematic review

AIM

We review and summarize the literature on the safety and stability of rapid-acting insulin analogs used for continuous subcutaneous insulin infusion (CSII) in patients with diabetes.

METHODS

Two predefined search strategies were systematically implemented to search Medline and the Cochrane Register of Clinical Trials for publications between 1996 and 2012.

RESULTS

Twenty studies were included in the review: 13 in vitro studies and 7 clinical studies. In vitro studies investigated the effects of extreme CSII conditions (high temperature and mechanical agitation) on the risk of catheter occlusions and insulin stability factors, such as potency, purity, high molecular weight protein content, pH stability, and preservative content (m-cresol, phenol). Under these conditions, the overall stability of rapid-acting insulin analogs was similar for insulin lispro, insulin aspart, and insulin glulisine, although insulin glulisine showed greater susceptibility to insulin precipitation and catheter occlusions. A limited number of clinical trials were identified; this evidence-based information suggests that the rate of catheter occlusions in patients with type 1 diabetes using CSII treatment may vary depending on the rapid-acting analog used.

CONCLUSIONS

Based on a limited amount of available data, the safety, stability, and performance of the three available rapid-acting insulin analogs available for use with CSII were similar. However, there is limited evidence suggesting that the risk of occlusion may vary with the insulin preparation under certain circumstances.

Discovery of high potency, single-chain insulin analogs with a shortened B-chain and nonpeptide linker

A series of novel, single chain insulin analogs containing polyethylene glycol based connecting segments were synthesized by native chemical ligation and tested for biological activity. While the full length single chain insulin analogs exhibited low potency, deletion of amino acids B26-B30 unexpectedly generated markedly higher activity. This observation is unprecedented in all previous studies of single chain insulin analogs and is consistent with the presumption that in the native hormone this sequence must translocate to achieve high potency insulin receptor interaction. Optimization of the sequence yielded an insulin analog with potency and selectivity comparable to that of native insulin. These results establish a basis for discovery of novel higher potency, single chain insulin analogs of shortened length.

Single-molecule assays for investigating protein misfolding and aggregation

Protein misfolding and aggregation are relevant to many fields. Recently, their investigation has experienced a revival as a central topic in the research of numerous human diseases, including Parkinson's and Alzheimer's. Much has been learned from ensemble biochemical approaches, but the inherently heterogeneous nature of the underlying processes has obscured many important details. Single-molecule techniques offer unique capabilities to study heterogeneous systems, while providing high temporal and structural resolution to characterize them. In this Perspective, we give an overview of the single-molecule assays that have been applied to protein misfolding and aggregation, which are mainly based on fluorescence and force spectroscopy. We describe some of the technical challenges involved in studying aggregation at the single-molecule level and discuss what has been learned about aggregation mechanisms from the different approaches.

Better glycemic control and weight loss with the novel long-acting basal insulin LY2605541 compared with insulin glargine in type 1 diabetes: a randomized, crossover study

OBJECTIVE To compare effects of LY2605541 versus insulin glargine on daily mean blood glucose as part of a basal-bolus regimen for type 1 diabetes. RESEARCH DESIGN AND METHODS In this randomized, Phase 2, open-label, 2 × 2 crossover study, 137 patients received once-daily basal insulin (LY2605541 or glargine) plus mealtime insulin for 8 weeks, followed by crossover treatment for 8 weeks. Daily mean blood glucose was obtained from 8-point self-monitored blood glucose profiles. The noninferiority margin was 10.8 mg/dL. RESULTS LY2605541 met noninferiority and superiority criteria compared with insulin glargine in daily mean blood glucose (144.2 vs. 151.7 mg/dL, least squares mean difference = -9.9 mg/dL [90% CI -14.6 to -5.2], P < 0.001). Fasting blood glucose variability and A1C were reduced with LY2605541 compared with insulin glargine (both P < 0.001). Mealtime insulin dose decreased with LY2605541 and increased with insulin glargine. Mean weight decreased 1.2 kg with LY2605541 and increased 0.7 kg with insulin glargine (P < 0.001). The total hypoglycemia rate was higher for LY2605541 (P = 0.04) and the nocturnal hypoglycemia rate was lower (P = 0.01), compared with insulin glargine. Adverse events (including severe hypoglycemia) were similar, although more gastrointestinal-related events occurred with LY2605541 (15% vs. 4%, P < 0.001). Mean changes (all within normal range) were higher for alanine aminotransferase, aspartate aminotransferase, triglycerides, and LDL-cholesterol and lower for HDL-cholesterol with LY2605541 compared with insulin glargine (all P < 0.02). CONCLUSIONS In type 1 diabetes, compared with insulin glargine, LY2605541, a novel, long-acting basal insulin, demonstrated greater improvements in glycemic control, increased total hypoglycemia, and reduced nocturnal hypoglycemia, as well as reduced weight and lowered mealtime insulin doses.

Glycemic variability in type 2 diabetes mellitus: oxidative stress and macrovascular complications

Diabetes mellitus is a world-wide health issue with potential for significant negative health outcomes, including microvascular and macrovascular complications. The relationship of hemoglobin HbA1c and other glycosylation end products (AGEs) to these complications, particularly microvascular disease, is well understood. More recent evidence suggests that glycemic variability may be associated with diabetes macrovascular complications. As HbA1c is better representative of average glucose levels and does not account as well for glycemic variability, hence new methods to assess and treat this variability is needed to reduce incidence of complications. In this chapter, the relationship of glycemic control to diabetes complications will be explored with focus on the mechanisms of tissue damage from this variability along with the oxidative stress. Additionally, treatment strategies to optimize HbA1c and glycemic variability with the goal of reducing risk of complications in persons with diabetes are reviewed.

Safety of rapid-acting insulin analogs versus regular human insulin

Insulin is the most effective treatment for both type 1 and type 2 diabetes mellitus. There are several differences in the safety profiles of each type of insulin, including rapid-acting insulin analogs and regular human insulin. The pharmacokinetic and pharmacodynamic properties of those insulin types also differ, as do their safety parameters. Treatment with rapid-acting analogs results in less hypoglycemia overall and decreased frequency of both severe and nocturnal hypoglycemia. In addition, the more rapid onset and shorter duration of action of rapid-acting insulin analogs are associated with greater control of postprandial glucose than regular human insulin. This review will describe the similarities and differences between the safety profiles of rapid-acting insulin analogs.

Efficacy and safety of insulin lispro protamine suspension as basal supplementation in patients with type 2 diabetes

The three currently marketed long-acting insulin analogs, glargine, detemir and insulin lispro protamine suspension (ILPS), represent the most significant advances in basal insulin supplementation since the 1940s and 1950s and the introduction of the intermediate-acting NPH (neutral protamine Hagedorn) insulin. As injection of NPH insulin lacks chronic maintenance of a steady-state low-level basal insulin during fasting periods, which can also expose patients to unpredictable nocturnal hypoglycemia, long-acting insulin analogs have been developed to overcome this important limitation of NPH insulin. ILPS is a protamine-based, intermediate-acting insulin formulation of the short-acting analog insulin lispro: its pharmacokinetic and pharmacodynamic characteristics are quite similar to the other basal insulin analogs glargine and detemir. In recent head-to-head randomized controlled trials of insulin-naïve patients with type 2 diabetes, ILPS achieved similar glycemic control compared with glargine or detemir. ILPS administered once daily is an effective and safe way to maintain a steady-state low-level basal insulin during night time, not dissimilar from that currently obtained with a one-day glargine or detemir administration.