Premeal injection of rapid-acting insulin reduces postprandial glycemic excursions in type 1 diabetes

Guidelines of the Polish Society of Pediatric Endocrinology and Diabetology and Pediatric Section of Diabetes Poland on insulin therapy using hybrid closed-loop systems in children and adolescents with diabetes in Poland

Currently, hybrid closed loop (HCL) systems represent the most advantageous therapeutic option for people with diabetes requiring intensive insulin therapy. They make it possible to achieve optimal metabolic control of the disease in any age group while improving the quality of life of children and adolescents with diabetes and their families. Therefore, we present recommendations for the use of HCL systems in children and adolescents focusing on systems currently available in Poland. These systems should be the first choice in terms of method of insulin therapy in the paediatric population. They can be implemented at any stage of diabetes management. These recommendations are based on scientific evidence and experts' experience. They include principles for the initiation, optimisation, and ongoing management of HCL therapy, as well as the required HCL-related education.

Oral administration of linoleic acid immediately before glucose load ameliorates postprandial hyperglycemia

Introduction: Fatty acids are a major nutrient in dietary fat, some of which are ligands of long-chain fatty acid receptors, including G-protein-coupled receptor (GPR) 40 and GPR120. Pretreatment with GPR40 agonists enhanced the secretion of insulin in response to elevating blood glucose levels after glucose load in a diabetes model, but pretreatment with GPR120 agonist did not ameliorate postprandial hyperglycemia. This study examined whether oral administration of linoleic acid (LA), a GPR40 and GPR120 agonist, immediately before glucose load would affect the elevation of postprandial blood glucose levels in rats. Methods: Male rats and rats with type 1 diabetes administered streptozocin were orally administered LA, trilinolein, α-linolenic acid (α-LA), oleic acid, TAK-875, or TUG-891 immediately before glucose load. Blood glucose levels were measured before, then 15, 30, 60 and 120 min after glucose load. CACO-2 cells were used to measure the uptake of [14C] α-MDG for 30 min with or without LA. Gastric content from rats administered LA was collected 15 and 30 min after glucose load, and blood samples were collected for measurement of glucagon-like peptide 1 (GLP-1) and cholecystokinin concentrations. Results: The elevation of postprandial blood glucose levels was slowed by LA but not by trilinolein in rats without promotion of insulin secretion, and this effect was also observed in rats with type 1 diabetes. The uptake of α-MDG, an SGLT-specific substrate, was, however, not inhibited by LA. Gastric emptying was slowed by LA 15 min after glucose load, and GLP-1, but not cholecystokinin, level was elevated by LA 15 min after glucose load. TUG-891, a GPR120 agonist, ameliorated postprandial hyperglycemia but TAK-875, a GPR40 agonist, did not. Pretreatment with AH7614, a GPR120 antagonist, partially canceled the improvement of postprandial hyperglycemia induced by LA. α-LA, which has high affinity with GPR120 as well as LA, slowed the elevation of postprandial blood glucose levels, but oleic acid, which has lower affinity with GPR120 than LA, did not. Conclusion: Oral administration of LA immediately after glucose load ameliorated postprandial hyperglycemia due to slowing of gastric emptying via promotion of GLP-1 secretion. The mechanisms may be associated with GPR120 pathway.

Accelerated absorption of regular insulin administered via a vascularizing permeable microchamber implanted subcutaneously in diabetic Rattus norvegicus

In Type 1 diabetes patients, even ultra-rapid acting insulins injected subcutaneously reach peak concentrations in 45 minutes or longer. The lag time between dosing and peak concentration, as well as intra- and inter-subject variability, render prandial glucose control and dose consistency difficult. We postulated that insulin absorption from subcutaneously implantable vascularizing microchambers would be significantly faster than conventional subcutaneous injection. Male athymic nude R. norvegicus rendered diabetic with streptozotocin were implanted with vascularizing microchambers (single chamber; 1.5 cm2 surface area per side; nominal volume, 22.5 μl). Plasma insulin was assayed after a single dose (1.5 U/kg) of diluted insulin human (Humulin®R U-100), injected subcutaneously or via microchamber. Microchambers were also implanted in additional animals and retrieved at intervals for histologic assessment of vascularity. Following conventional subcutaneous injection, the mean peak insulin concentration was 22.7 (SD 14.2) minutes. By contrast, when identical doses of insulin were injected via subcutaneous microchamber 28 days after implantation, the mean peak insulin time was shortened to 7.50 (SD 4.52) minutes. Peak insulin concentrations were similar by either route; however, inter-subject variability was reduced when insulin was administered via microchamber. Histologic examination of tissue surrounding microchambers showed mature vascularization on days 21 and 40 post-implantation. Implantable vascularizing microchambers of similar design may prove clinically useful for insulin dosing, either intermittently by needle, or continuously by pump including in "closed loop" systems, such as the artificial pancreas.

Time-Action Profile of Technosphere Insulin in Children with Type 1 Diabetes

INTRODUCTION

Technosphere insulin (TI) is an inhaled dry powder ultra-rapid-acting insulin. This report describes the results of the first study of TI in children with type 1 diabetes (T1D).

METHODS

Pharmacokinetics (PK) of TI and the effect of TI on circulating glucose concentrations were evaluated in a single-arm study that enrolled children ages 8-17 years with T1D for more than 1 year, on a stable multiple daily insulin injection (MDI) regimen, and meeting pre-defined pulmonary function testing criteria (at least 70% predicted). To assess PK, subjects received an individualized single preprandial dose of TI (4-12 U, in 4-U increments) via oral inhalation, based on their usual meal-time subcutaneously injected rapid-acting insulin dose and meal content. Serum insulin and blood glucose were measured at - 30 to 250 min relative to dosing.

RESULTS

Twenty-seven children with T1D participated in this single-dose PK study. Mean subject age was 13.3 years (59% female; 81.5% White). Mean serum insulin C_max (maximum concentration) was 77.3, 119.15, and 207.7 µU/mL for doses of 4, 8, and 12 U, respectively. T_max occurred at 10.5, 13.9, and 14.6 min post-dose for 4, 8, and 12 U. Glucose lowering 30-60 min post-dose was consistent with the PK profile.

CONCLUSION

Serum insulin rapidly increased post-dose and returned to baseline by 120 min. The data suggests the PK of TI in youth with T1D ages 8-17 years was similar to that seen in previous adult studies.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02527265.

Associations between insulin pump self-management and HbA1c in type 1 diabetes

AIMS

Insulin pump self-management is important for glycaemic outcomes. We aimed to investigate associations between self-management factors and HbA1c.

METHODS

Adult insulin pump users with type 1 diabetes (n = 770) completed an online questionnaire. The latest HbA1c and demographics were extracted from national registries. Associations between HbA1c and self-management (use of advanced features, timing of infusion set change, timing of meal bolus, data-upload and pump settings adjustments) were investigated using backward selected linear regression models.

RESULTS

Of the 699 responders eligible for this study, 60% were women; the median age and diabetes duration were 49 and 25 years, respectively. Significant associations with HbA1c were found for changing infusion set every 0-4 days relative to 5-10 days (-5 mmol/mol (-0.4%), p = 0.003), and for never/rarely missing a bolus (-6 mmol/mol (-0.5%), p < 0.001) relative to often missing a bolus. Timing insulin 10-15 min before meal relative to after meal start was also associated with lower HbA1c (-3 mmol/mol (-0.3%), p = 0.023). Self-adjusting pump settings showed the strongest association with lower HbA1c (-6 mmol/mol (-0.6%), p < 0.001) relative to health care professionals doing all adjustments.

CONCLUSION

Self-adjusting insulin pump settings, optimal timing and few omissions of meal boluses, and timely change of infusion set are associated with lower HbA1c.

Real-World Impact of Switching From Insulin Glargine (Lantus®) to Basaglar® and Potential Cost Saving in a Large Public Healthcare System in Saudi Arabia

Background

The advent of Basaglar^®, which is a biosimilar insulin glargine formulation for Lantus^® has brought hope that it will result in similar outcomes and lower costs. However, some health practitioners raised some concerns about the therapeutic equivalence of this new biosimilar. Therefore, we aimed to examine the clinical and financial impact of switching from Lantus^® to Basaglar^®.

Methods

This was a single–center retrospective chart review study of adult patients (e.g., ≥18 years) with diabetes mellitus (DM) who were treated with insulin glargine (Lantus^®) for at least 12 months and then switched to Basaglar^® for another 12 months. The potential cost savings for the years 2018 to 2021 and the cost avoidance for 2022 were estimated using different conversion ratios between the two insulin glargine products (Basaglar^® and Lantus^®) and acquisition prices.

Results

One–hundred patients with DM who were previously treated with Lantus^® and switched to Basaglar^® were retrospectively recruited. About two–thirds of the patients (68%) had type 2 DM, and the male and female patients were equally represented. The mean glycated hemoglobin (A1C) at baseline was 9, and the mean difference in the A1C levels before and after switching to Basaglar^® was not significant (0.18, p-value = 0.503, 95% CI [−0.36–0.72]). Although the difference in the total daily insulin units between Lantus^® and Basaglar^® was not significant, the difference was leaning toward statistical significance despite the small sample size (−1.88, P-value = 0.25, 95% CI [−5.15–1.38]). Switching from Lantus^® to Basaglar^® could have led to significant cost savings that would range from approximately 1.77 to 23.7 million United States Dollars (USD) for the years 2018 to 2021 assuming an equal conversion ratio. However, those cost savings might not be realized if the switching to Basaglar^® required higher daily insulin units, and the difference in the public tender acquisition price between Lantus^® and Basaglar^® is less than 15%.

Conclusion

Basaglar^® and potentially other biosimilar insulin glargine products can lead to significant cost savings without compromising the quality of care. However, their acquisition prices should be discounted.

Super Bolus: a remedy for a high glycemic index meal in children with type 1 diabetes on insulin pump therapy?-study protocol for a randomized controlled trial

Background

Postprandial hyperglycemia (PPH) is a common clinical problem among patients with type 1 diabetes (T1D), which is related to high glycemic index (h-GI) meals. The main problem is linked to high, sharp glycemic spikes following hypoglycemia after h-GI meal consumption. There is a lack of effective and satisfactory solutions for insulin dose adjustment to cover an h-GI meal. The goal of this research was to determine whether a Super Bolus is an effective strategy to prevent PPH and late hypoglycemia after an h-GI meal compared to a Normal Bolus.

Methods

A total of 72 children aged 10–18 years with T1D for at least 1 year and treated with continuous subcutaneous insulin infusion for more than 3 months will be enrolled in a double-blind, randomized, crossover clinical trial. The participants will eat a h-GI breakfast for the two following days and receive a prandial insulin bolus in the form of a Super Bolus 1 day and a Normal Bolus the next day. The glucose level 90 min after the administration of the prandial bolus will be the primary outcome measure. The secondary endpoints will refer to the glucose levels at 30, 60, 120, 150, and 180 min postprandially, the area under the blood glucose curve within 180 min postprandially, peak glucose level and the time to peak glucose level, glycemic rise, the mean amplitude of glycemic excursions, and the number of hypoglycemia episodes.

Discussion

There are still few known clinical studies on this type of bolus. A Super Bolus is defined as a 50% increase in prandial insulin dose compared to the dose calculated based on the individualized patient’s insulin-carbohydrate ratio and a simultaneous suspension of basal insulin for 2 h. Our patients reported the best experience with such a combination. A comprehensive and effective solution to this frequent clinical difficulty of PPH after an h-GI meal has not yet been found. The problem is known and important, and the presented solution is innovative and easy to apply in everyday life.

Trial registration

ClinicalTrials.gov NCT04019821

Exploring the Burden of Mealtime Insulin Dosing in Adults and Children With Type 1 Diabetes

Timely and accurate mealtime insulin dosing can be an ongoing challenge for people with type 1 diabetes. This multinational, online study aimed to explore attitudes and behaviors around mealtime insulin dosing and the impact of mealtime dose timing, particularly with regard to premeal dosing (15-20 minutes before a meal). Although the majority of surveyed participants (96%) recognized the importance of accurate mealtime bolus insulin dosing, only a small proportion (35%) reported being "very confident" in accurate bolus insulin estimation. Given the choice, the majority of participants would prefer to administer insulin immediately before or after a meal, as this timing would improve their quality of life.

Carbohydrate restriction for diabetes: rediscovering centuries-old wisdom

Carbohydrate restriction, used since the 1700s to prolong survival in people with diabetes, fell out of favor after the discovery of insulin. Despite costly pharmacological and technological developments in the last few decades, current therapies do not achieve optimal outcomes, and most people with diabetes remain at high risk for micro- and macrovascular complications. Recently, low-carbohydrate diets have regained popularity, with preliminary evidence of benefit for body weight, postprandial hyperglycemia, hyperinsulinemia, and other cardiometabolic risk factors in type 2 diabetes and, with more limited data, in type 1 diabetes. High-quality, long-term trials are needed to assess safety concerns and determine whether this old dietary approach might help people with diabetes attain clinical targets more effectively, and at a lower cost, than conventional treatment.

Fast-Acting Insulin Aspart Versus Insulin Aspart Using a Second-Generation Hybrid Closed-Loop System in Adults With Type 1 Diabetes: A Randomized, Open-Label, Crossover Trial

OBJECTIVE

To evaluate glucose control using fast-acting insulin aspart (faster aspart) compared with insulin aspart (IAsp) delivered by the MiniMed Advanced Hybrid Closed-Loop (AHCL) system in adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

In this randomized, open-label, crossover study, participants were assigned to receive faster aspart or IAsp in random order. Stages 1 and 2 comprised of 6 weeks in closed loop, preceded by 2 weeks in open loop. This was followed by stage 3, whereby participants changed directly back to the insulin formulation used in stage 1 for 1 week in closed loop. Participants chose their own meals except for two standardized meal tests, a missed meal bolus and late meal bolus. The primary outcome was the percentage of time sensor glucose values were from 70 to 180 mg/dL (time in range; [TIR]).

RESULTS

Twenty-five adults (52% male) were recruited; the median (interquartile range) age was 48 (37, 57) years, and the median HbA1c was 7.0% (6.6, 7.2) (53 [49, 55] mmol/mol). Faster aspart demonstrated greater overall TIR compared with IAsp (82.3% [78.5, 83.7] vs. 79.6% [77.0, 83.4], respectively; mean difference 1.9% [0.5, 3.3]; P = 0.007). Four-hour postprandial glucose TIR was higher using faster aspart compared with IAsp for all meals combined (73.6% [69.4, 80.2] vs. 72.1% [64.5, 78.5], respectively; median difference 3.5% [1.0, 7.3]; P = 0.003). There was no ketoacidosis or severe hypoglycemia.

CONCLUSIONS

Faster aspart safely improved glucose control compared with IAsp in a group of adults with well-controlled type 1 diabetes using AHCL. The modest improvement was mainly related to mealtime glycemia. While the primary outcome demonstrated statistical significance, the clinical impact may be small, given an overall difference in TIR of 1.9%.

Fast-Acting Insulin Aspart: A Review of its Pharmacokinetic and Pharmacodynamic Properties and the Clinical Consequences

Fast-acting insulin aspart (faster aspart) is insulin aspart (IAsp) with two added excipients, l-arginine and niacinamide, to ensure formulation stability with accelerated initial absorption after subcutaneous administration compared with previously developed rapid-acting insulins. The pharmacokinetic/pharmacodynamic properties of faster aspart have been characterised in clinical pharmacology trials with comparable overall methodology. In subjects with type 1 (T1D) or type 2 (T2D) diabetes, the serum IAsp concentration–time and glucose-lowering effect profiles are left-shifted for faster aspart compared with IAsp. In addition, faster aspart provides earlier onset, doubling of initial exposure, and an up to 2.5-fold increase in initial glucose-lowering effect within 30 min of subcutaneous injection, as well as earlier offset of exposure and effect. Similar results have been shown using continuous subcutaneous insulin infusion (CSII). The improved pharmacological properties of faster aspart versus IAsp are consistent across populations, i.e. in the elderly, children, adolescents and the Japanese. Thus, the faster aspart pharmacological characteristics more closely resemble the mealtime insulin secretion in healthy individuals, giving faster aspart the potential to further improve postprandial glucose control in subjects with diabetes. Indeed, change from baseline in 1-h postprandial glucose increment is in favour of faster aspart versus IAsp when used as basal-bolus or CSII treatment in phase III trials in subjects with T1D or T2D. This review summarises the currently published results from clinical pharmacology trials with faster aspart and discusses the potential clinical benefits of faster aspart compared with previous rapid-acting insulin products.

Efficacy and safety of fast-acting insulin aspart compared with insulin aspart in combination with insulin degludec in Japanese adults with type 1 diabetes: a subgroup analysis of the randomized onset 8 trial

This study aimed to confirm the efficacy and safety of mealtime and post-meal fast-acting insulin aspart versus insulin aspart, both with basal insulin degludec, in Japanese patients with type 1 diabetes. This was a subgroup analysis of onset 8, a randomized multicenter, treat-to-target trial of mealtime fast-acting insulin aspart (subgroup n = 73), mealtime insulin aspart (n = 83), or open-label post-meal fast-acting insulin aspart (n = 89), all for 26 weeks. Change from baseline in HbA_1c was considered the primary endpoint. After 26 weeks, the estimated treatment difference (ETD, 95% CI) for change from baseline in HbA_1c between mealtime fast-acting insulin aspart or post-meal fast-acting insulin aspart vs. insulin aspart was 0.01% (-0.16;0.19) and 0.10% (-0.07;0.27), respectively. Following a standardized meal test, ETD for change from baseline in postprandial glucose (PPG) increment at 1 hour was -16.91 mg/dL (-32.15;-1.68) for mealtime fast-acting insulin aspart and 40.16 mg/dL (25.46;54.87) for post-meal fast-acting insulin aspart, both versus insulin aspart. Mean self-measured blood glucose 1-hour PPG increments also showed a trend towards improved PPG control with mealtime fast-acting insulin aspart versus insulin aspart. Rates of overall hypoglycemia (35.56, 37.72 and 38.75 per patient-year of exposure with mealtime fast-acting insulin aspart, post-meal fast-acting insulin aspart and insulin aspart, respectively) and meal-related hypoglycemia were similar between treatment arms. Consistent with findings of onset 8, this analysis confirmed mealtime and post-meal fast-acting insulin aspart provided effective HbA_1c and PPG control versus insulin aspart, with similar safety profiles, in Japanese adults with type 1 diabetes.

Ultrafast acting insulin analog - a new way to prevent postprandial hyperglycemia and improve quality of life in type 1 diabetes patients - case reports

The aim of modern insulin therapy used in the treatment of type 1 diabetes mellitus is to mimic the physiological secretion of insulin in order to ensure stable normoglycemia while maintaining the greatest possible comfort of life for diabetic patients. New ultra-fast insulin analogs that can be administered immediately before a meal contribute to the improvement of postprandial glycemia and the quality of life of patients. We presented two cases illustrating the effectiveness and safety of the use of an ultra-fast-acting insulin analog in the treatment of postprandial hyperglycemia in children with type 1 diabetes.

Effect of Varying Molecular Weight of Oat β-Glucan Taken just before Eating on Postprandial Glycemic Response in Healthy Humans

To see if the molecular weight (MW) and viscosity of oat β-glucan (OBG) when taken before eating determine its effect on postprandial glycemic responses (PPRG), healthy overnight-fasted subjects (n = 16) were studied on eight separate occasions. Subjects consumed 200 mL water alone (Control) or with 4 g OBG varying in MW and viscosity followed, 2-3 min later, by 113 g white-bread. Blood was taken fasting and at 15, 30, 45, 60, 90, and 120 min after starting to eat. None of the OBG treatments differed significantly from the Control for the a-priori primary endpoint of glucose peak-rise or secondary endpoint of incremental area-under-the-curve (iAUC) over 0-120 min. However, significant differences from the Control were seen for glucose iAUC over 0-45 min and time to peak (TTP) glucose. Lower log(MW) and log(viscosity) were associated with higher iAUC 0-45 (p < 0.001) and shorter TTP (p < 0.001). We conclude that when 4 g OBG is taken as a preload, reducing MW does not affect glucose peak rise or iAUC0-120, but rather accelerates the rise in blood glucose and reduces the time it takes glucose to reach the peak. However, this is based on post-hoc calculation of iAUC0-45 and TTP and needs to be confirmed in a subsequent study.

High-protein meals require 30% additional insulin to prevent delayed postprandial hyperglycaemia

AIM

To determine the amount of additional insulin required for a high-protein meal to prevent postprandial hyperglycaemia in individuals with type 1 diabetes using insulin pump therapy.

METHODS

In this randomized cross-over study, 26 participants aged 8-40 years, HbA_1c < 65 mmol/mol (8.1%), received a 50 g protein, 30 g carbohydrate, low-fat (< 1 g) breakfast drink over five consecutive days at home. A standard insulin dose (100%) was compared with additional doses of 115, 130, 145 and 160% for the protein, in randomized order. Doses were commenced 15-min pre-drink and delivered over 3 h using a combination bolus with 65% of the standard dose given up front. Postprandial glycaemia was assessed by 4 h of continuous glucose monitoring.

RESULTS

The 100% dosing resulted in postprandial hyperglycaemia. From 120 min, ≥ 130% doses resulted in significantly lower postprandial glycaemic excursions compared with 100% (P < 0.05). A 130% dose produced a mean (sd) glycaemic excursion that was 4.69 (2.42) mmol/l lower than control, returning to baseline by 4 h (P < 0.001). From 120 min, there was a significant increase in the risk of hypoglycaemia compared with control for 145% [odds ratio (OR) 25.4, 95% confidence interval (CI) 5.5-206; P < 0.001) and 160% (OR 103, 95% CI 19.2-993; P < 0.001). Some 81% (n = 21) of participants experienced hypoglycaemia following a 160% dose, whereas 58% (n = 15) experienced hypoglycaemia following a 145% dose. There were no hypoglycaemic events reported with 130%.

CONCLUSIONS

The addition of 30% more insulin to a standard dose for a high-protein meal, delivered using a combination bolus, improves postprandial glycaemia without increasing the risk of hypoglycaemia.

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.

Evaluation of Glycaemic Control, Glucose Variability and Hypoglycaemia on Long-Term Continuous Subcutaneous Infusion vs. Multiple Daily Injections: Observational Study in Pregnancies With Pre-Existing Type 1 Diabetes

INTRODUCTION

We evaluated the effectiveness of long-term continuous subcutaneous insulin infusion (CSII) compared with multiple daily insulin (MDI) injections for glycaemic control and variability, hypoglycaemic episodes and maternal/neonatal outcomes in pregnant women with pre-existing type 1 diabetes (pT1D).

METHODS

Our observational cohort study included 128 consecutive pregnant women with pT1D, who were treated from 1 January 2010 to 31 December 2017. Of 128 participants, 48 were on CSII and 80 were on MDI. Glycaemic control was determined by glycated haemoglobin (HbA1c) (captured in preconception and each trimester of pregnancy). Glucose variability (GV) was expressed as the coefficient of variation (CV) [calculated from self-monitoring of blood glucose (SMBG) values], and hypoglycaemia was defined as glucose values < 3.9 mmol/l. The data on maternal and neonatal outcomes were collected from obstetrical records.

RESULTS

Duration of the treatment was 8.8 ± 5.3 years in the CSII and 12.6 ± 8.0 years in the MDI group. The CSII lowered HbA1c in preconception (7.1 ± 0.1 vs. 7.9 ± 0.2%, p = 0.03) and the first (6.9 ± 0.1 vs. 7.7 ± 0.2%, p = 0.02), second (6.6 ± 0.1 vs. 7.2 ± 0.1%, p = 0.003) and third (6.5 ± 0.1 vs. 6.8 ± 0.1%, p = 0.02) trimesters significantly better than MDI. Significantly lower CV was observed only for fasting glycaemia in the first trimester (17.1 vs 28.4%, p < 0.001) in favour of CSII. Moreover, the CSII group had significantly lower mean hypoglycaemic episodes/week/patient only during the first trimester (2.0 ± 1.7 vs 4.8 ± 1.5, p < 0.01). In early pregnancy, the majority of women on CSII had less hypoglycaemia than on MDI (0-3: 79.1 vs. 29.1%; 4-6: 18.8 vs. 65.8%; ≥ 7: 2.1 vs. 5.1%, p < 0.01, respectively). We found no difference in the incidence of adverse maternal/neonatal outcomes.

CONCLUSIONS

Treatment with CSII resulted in a favourable reduction of HbA1c in the preconception period and each trimester in pregnancy. Moreover, long-term CSII treatment demonstrated more stable metabolic control with less GV of fasting glycaemia and fewer hypoglyacemic episodes only during early pregnancy.

Dynamic Rule-Based Algorithm to Tune Insulin-on-Board Constraints for a Hybrid Artificial Pancreas System

The artificial pancreas (AP) is a system intended to control blood glucose levels through automated insulin infusion, reducing the burden of subjects with type 1 diabetes to manage their condition. To increase patients' safety, some systems limit the allowed amount of insulin active in the body, known as insulin-on-board (IOB). The safety auxiliary feedback element (SAFE) layer has been designed previously to avoid overreaction of the controller and thus avoiding hypoglycemia. In this work, a new method, so-called “dynamic rule-based algorithm,” is presented in order to adjust the limits of IOB in real time. The algorithm is an extension of a previously designed method which aimed to adjust the limits of IOB for a meal with 60 grams of carbohydrates (CHO). The proposed method is intended to be applied on hybrid AP systems during 24 h operation. It has been designed by combining two different strategies to set IOB limits for different situations: (1) fasting periods and (2) postprandial periods, regardless of the size of the meal. The UVa/Padova simulator is considered to assess the performance of the method, considering challenging scenarios. In silico results showed that the method is able to reduce the time spent in hypoglycemic range, improving patients' safety, which reveals the feasibility of the approach to be included in different control algorithms.

Assessment of optimal insulin administration timing for standard carbohydrates-rich meals using continuous glucose monitoring in children with type 1 diabetes: A cross-over randomized study

AIMS/INTRODUCTION

The present study was an assessment of postprandial glucose concentration after carbohydrates-rich meals using continuous glucose monitoring in 30 children with type 1 diabetes treated using continuous subcutaneous insulin infusion with a rapid-acting insulin analog.

MATERIALS AND METHODS

Over a period of 3 days, participants administered simple boluses with different delay times between insulin administration and the beginning of carbohydrates-rich meal consumption (meal no. 1 containing 197 kcal, no. 2 containing 247 kcal and meal no. 3 containing 323 kcal; containing practically no protein and fat). In the present cross-over randomized study, we analyzed the average glucose concentration profiles in 5-min intervals, mean glucose at insulin administration, mean glucose after 120 and 180 min, mean and peak glucose, glucose peak time, areas under the glucose and glucose increase curves, and time period lengths with glucose <50, 70 mg/dL, and >140 and 200 mg/dL.

RESULTS

For test meals at 20-min versus 0-min delay time, the study exposed a longer median time period to reach peak glucose (95 vs 65 min, P = 0.01) after meals. A tendency to the lowest peak and mean glucose, and the longest time with glucose within a normal range was observed in patients who administered bolus insulin 20 min before a meal.

CONCLUSIONS

For carbohydrates-rich meals, administration of a proper dose of a rapid-acting insulin analog is crucial. The influence of rapid-acting insulin analog administration timing seems to be of minor importance in comparison with correct insulin dose adjustment; however, a tendency to achieve more balanced glucose profiles was found in a group who administered insulin 20 min before a meal.

Pharmacologic treatment options for type 1 diabetes: what's new?

INTRODUCTION

The expanding variety of insulins, including biosynthetic human insulin and rapid and long-acting insulin analogs, have dramatically transformed the management of type 1 diabetes (T1D) over the past 25 years. Moreover, increasing interest in the use of novel drugs developed for the treatment of type 2 diabetes (T2D) as adjunctive therapies for T1D remains a work in progress. Areas Covered: We reviewed articles published up to December 2018 in PubMed and ClinicalTrials.gov for recent developments in the pharmacologic treatment of T1D, including inhaled insulin, ultrafast and ultralong-acting insulins and adjunctive therapies including pramlintide, metformin, GLP-1 receptor agonists, DPP-4 inhibitors, SGLT-2, and SGLT1/2 inhibitors. Expert Opinion: With the creation of ultrafast-acting insulin analogs and very prolonged duration of action of basal insulins, it is possible to more closely mimic physiologic insulin secretion. Adjunctive therapies, likewise, may also overcome some of the abnormal physiology that is a hallmark of T1D. Therefore, individualized consideration of the efficacy of these agents must be measured alongside the potential adverse effects when choosing an adjunctive therapy.

Ultra-rapid BioChaperone Lispro improves postprandial blood glucose excursions vs insulin lispro in a 14-day crossover treatment study in people with type 1 diabetes

AIM

To investigate the safety and efficacy of BioChaperone Lispo (BCLIS), an ultra-rapid formulation of insulin lispro (LIS) in people with type 1 diabetes.

MATERIALS AND METHODS

In this randomized, double-blind study, participants self-administered individualized bolus doses of BCLIS or LIS during two 14-day periods in a crossover fashion. Postprandial blood glucose (BG) was assessed after individualized solid mixed meal tests (MMTs) (50% carbohydrate, 29% fat, 21% protein), with additional randomization for the sequence of timing of insulin administration, immediately (t0), 15 minutes before (t - 15) and 15 minutes after (t + 15) meal start on days 1, 2 and 3, and with t0 administration on day 14. Pharmacokinetic (PK) variables were assessed for t0 MMTs. Participants also used individualized BCLIS or LIS doses immediately before meals during two 10-day outpatient periods with an unchanged basal insulin regimen.

RESULTS

Overall, 35 participants completed both treatment periods. In MMTs with t0 administration, the higher early postprandial PK exposure of BCLIS led to significant reductions in 1- to 2-hour postprandial BG excursions by 30% to 40% vs LIS and the accelerated absorption and action of BCLIS persisted over 14 days. There was no difference in glucose excursion over the full 360-minute postprandial period. Postprandial BG control was similar between BCLIS injected at t + 15 and LIS injected at t0. BCLIS was shown to have safety and tolerability similar to LIS. No injection site reactions occurred with BCLIS.

CONCLUSIONS

BCLIS was well tolerated and safe over 14 days of treatment and significantly improved postprandial BG vs LIS when administered at mealtime.

Comparison between preprandial vs. postprandial insulin aspart in patients with type 1 diabetes on insulin pump and real-time continuous glucose monitoring

BACKGROUND

The objective was to compare glycemic control between preprandial and postprandial bolus administration (15 min before [PRE] or immediately after the meal [POST]) in patients with type 1 diabetes using insulin pump and real-time continuous glucose monitoring.

METHODS

Between September 2015 and February 2016, a single-centre, open randomized, 2-way crossover study of patients on bolus insulin aspart administration was conducted during two 14-day periods and according to 2 administration regimen schedules (PRE/POST or POST/PRE). Inclusion criteria were as follows: patients with type 1 diabetes, ≥18 and ≤ 65 years old, treated with insulin aspart using a Medtronic® insulin pump and trained on functional insulin therapy. Patients were randomly assigned to either regimen schedule. At the beginning of each period, each patient was provided with a standardized high fat meal. Primary outcome was the area under the curve for interstitial glucose above 140 mg/dL per minute (AUC > 140 mg/dL/min) during each period. Secondary outcomes were time spent in hypo/eu/hyperglycemia, glycemic variability indices, and AUC during 4 hours after high fat meal calculated with continuous glucose monitoring data.

RESULTS

Twenty-two patients were included. Mean AUC > 140 mg/dL/min was statistically higher in patients on POST (43.70 mg/dL/min; 95%CI: 34.08 to 53.31) versus PRE insulin aspart regimen (37.24 mg/dL/min 95%CI: 27.63 to 46.85) (P = 0.03). Mean interstitial glycemia and glycemic variability indices were also increased (P < 0.05) on POST regimen. The mean AUC 4 hours after the high fat meal was higher on POST regimen but not statistically different (P = 0.06).

CONCLUSIONS

In our study, postprandial administration of insulin aspart appears to mildly increase glycemic excursion and glycemic variability.

Efficacy and safety of fast-acting insulin aspart in comparison with insulin aspart in type 1 diabetes (onset 1): A 52-week, randomized, treat-to-target, phase III trial

AIMS

To compare the safety and efficacy of fast-acting insulin aspart (faster aspart) with conventional insulin aspart (IAsp) in adults with type 1 diabetes (T1D).

MATERIALS AND METHODS

onset 1 was a randomized, multicentre, treat-to-target, phase III, 52-week (initial 26 weeks + additional 26 weeks) trial conducted at 165 sites across 9 countries. Adults with T1D were randomly allocated to double-blind mealtime faster aspart or IAsp, each with once- or twice-daily insulin detemir. The primary endpoint, change in glycated haemoglobin (HbA1c) from baseline after the initial 26 weeks, has been reported previously. In the present paper, we report data from the full 52-week study period.

RESULTS

Between August 2013 and June 2015, 381 participants were assigned to double-blind faster aspart and 380 participants to IAsp. After 52 weeks, estimated mean changes from baseline in HbA1c levels were -0.08% (faster aspart) and +0.01% (IAsp); estimated treatment difference significantly favoured faster aspart (-0.10% [95% confidence interval {CI} -0.19;-0.00]; P = .0424). Changes from baseline in 1-hour postprandial plasma glucose (PPG) increment (meal test; faster aspart -1.05 mmol/L; IAsp -0.14 mmol/L) also significantly favoured faster aspart (estimated treatment difference -0.91 mmol/L [95% CI -1.40;-0.43]; -16.48 mg/dL [95% CI -25.17;-7.80]; P = .0002). There was no difference in overall severe or blood glucose-confirmed hypoglycaemic episodes or treatment-emergent adverse events between treatments.

CONCLUSIONS

At 52 weeks, overall glycaemic control had significantly improved with faster aspart vs IAsp, consistent with the 26-week study findings. Achieving an insulin profile closer to physiological insulin secretion with faster aspart translates into lower PPG and HbA1c levels compared with those achieved with IAsp in people with T1D.

Optimal prandial timing of bolus insulin in diabetes management: a review

The inability to achieve optimal diabetes glucose control in people with diabetes is multifactorial, but one contributor may be inadequate control of postprandial glucose. In patients treated with multiple daily injections of insulin, both the dose and timing of meal-related rapid-acting insulin are key factors in this. There are conflicting opinions and evidence on the optimal time to administer mealtime insulin. We performed a comprehensive literature search to review the published data, focusing on the use of rapid-acting insulin analogues in patients with Type 1 diabetes. Pharmacokinetic and pharmacodynamic studies of rapid-acting insulin analogues, together with postprandial glucose excursion data, suggest that administering these 15-20 min before food would provide optimal postprandial glucose control. Data from clinical studies involving people with Type 1 diabetes receiving structured meals and rapid-acting insulin analogues support this, showing a reduction in post-meal glucose levels of ~30% and less hypoglycaemia when meal insulin was taken 15-20 min before a meal compared with immediately before the meal. Importantly, there was also a greater risk of postprandial hypoglycaemia when patients took rapid-acting analogues after eating compared with before eating.

Pharmacokinetic and Pharmacodynamic Properties of Faster-Acting Insulin Aspart versus Insulin Aspart Across a Clinically Relevant Dose Range in Subjects with Type 1 Diabetes Mellitus

Background

Absorption of current rapid-acting insulins is too slow for patients with diabetes mellitus to achieve optimal postprandial glucose control. Faster-acting insulin aspart (faster aspart) is insulin aspart in a new formulation with faster early absorption. We compared the pharmacokinetic/pharmacodynamic properties of faster aspart and insulin aspart across a clinically relevant dose range.

Methods

In this randomised, double-blind, crossover trial, 46 subjects with type 1 diabetes mellitus received single subcutaneous doses of faster aspart and insulin aspart at 0.1, 0.2 (repeated three times to estimate within-subject variability) and 0.4 U/kg in a euglycaemic clamp setting (target 5.5 mmol/L).

Results

Consistently for the three doses, faster aspart demonstrated faster onset and greater early absorption and glucose-lowering effect versus insulin aspart. Across all three doses, onset of appearance occurred approximately twice as fast (approximately 5 min earlier) and early insulin exposure (AUC_{IAsp,0–30min}) was approximately 1.5- to 2-fold greater for faster aspart versus insulin aspart. Likewise, onset of action occurred approximately 5 min faster and early glucose-lowering effect (AUC_{GIR,0–30min}) was approximately 1.5- to 2-fold larger for faster aspart versus insulin aspart. Relative bioavailability was approximately 100% and total glucose-lowering effect was similar for faster aspart versus insulin aspart. Dose–concentration and dose–response relationships were comparable between faster aspart and insulin aspart. Within-subject variability in glucose-lowering effect was low for faster aspart (coefficient of variation approximately 20%) and not significantly different from insulin aspart.

Conclusion

The faster onset and greater early insulin exposure and glucose-lowering effect with faster aspart versus insulin aspart are preserved across a broad range of doses and consistently observed from day to day.

ClinicalTrials.gov identifier

NCT02033239.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-016-0473-5) contains supplementary material, which is available to authorized users.

Automated blood glucose control in type 1 diabetes: A review of progress and challenges

Since the 2000s, research teams worldwide have been working to develop closed-loop (CL) systems able to automatically control blood glucose (BG) levels in patients with type 1 diabetes. This emerging technology is known as artificial pancreas (AP), and its first commercial version just arrived in the market. The main objective of this paper is to present an extensive review of the clinical trials conducted since 2011, which tested various implementations of the AP for different durations under varying conditions. A comprehensive table that contains key information from the selected publications is provided, and the main challenges in AP development and the mitigation strategies used are discussed. The development timelines for different AP systems are also included, highlighting the main evolutions over the clinical trials for each system.

A Pooled Analysis of Clinical Pharmacology Trials Investigating the Pharmacokinetic and Pharmacodynamic Characteristics of Fast-Acting Insulin Aspart in Adults with Type 1 Diabetes

Background

Fast-acting insulin aspart (faster aspart) is insulin aspart (IAsp) in a new formulation aiming to mimic the fast endogenous prandial insulin release more closely than currently available insulin products. In a post hoc analysis of pooled data from six clinical pharmacology trials, the pharmacological characteristics of faster aspart and IAsp were compared.

Methods

The analysis included 218 adult subjects with type 1 diabetes from six randomised, double-blind, crossover trials in the faster aspart clinical development programme. Subjects received subcutaneous dosing (0.2 U/kg) of faster aspart and IAsp. In three trials, a 12-h euglycaemic clamp was performed (target 5.5 mmol/L; 100 mg/dL) to assess pharmacodynamics.

Results

The pharmacokinetic and pharmacodynamic profiles were left-shifted for faster aspart versus IAsp. Onset of appearance occurred 4.9 min earlier (95% confidence interval [CI] faster aspart-IAsp: [−5.3 to −4.4], p < 0.001), early exposure (AUC_{IAsp,0–30min}) was two times greater (estimated ratio faster aspart/IAsp 2.01 [1.87–2.17], p < 0.001) and offset of exposure (t_{Late 50% Cmax}) occurred 12.2 min earlier [−17.9 to −6.5] (p < 0.001) for faster aspart versus IAsp. Accordingly, onset of action occurred 4.9 min earlier [−6.9 to −3.0] (p < 0.001), early glucose-lowering effect (AUC_{GIR,0–30min}) was 74% greater (1.74 [1.47–2.10], p < 0.001) and offset of glucose-lowering effect (t_{Late 50% GIRmax}) occurred 14.3 min earlier [−22.1 to −6.5] (p < 0.001) for faster aspart versus IAsp. Total exposure and total glucose-lowering effect did not differ significantly between treatments.

Conclusions

Faster aspart has the potential to better mimic the physiologic prandial insulin secretion and thereby to improve postprandial glucose control compared with IAsp.

ClinicalTrials.gov identifiers: NCT02035371, NCT01924637, NCT02131246, NCT02033239, NCT02003677, NCT01618188.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-017-0514-8) contains supplementary material, which is available to authorized users.

POSTPRANDIAL DOSING OF BOLUS INSULIN IN PATIENTS WITH TYPE 1 DIABETES: A CROSS-SECTIONAL STUDY USING DATA FROM THE T1D EXCHANGE REGISTRY

OBJECTIVE

To assess the prevalence and characteristics of patients with type 1 diabetes (T1D) who dose bolus insulin postprandial (PostP) versus preprandial (PreP).

METHODS

Data for this cross-sectional study were obtained from 21,533 participants in the T1D Exchange Registry. Data were drawn from the enrollment questionnaire. Patients who dosed 'immediately before meal' or 'several minutes before meal' were classified as PreP. Patients who dosed 'during meal' or 'after meal' were classified as PostP. Data reported (PostP vs. PreP) are mean ± SD and percentage, as appropriate.

RESULTS

After exclusion of patients who did not answer the dose-timing question or who selected 'not given regularly' or 'depends on glucose level prior to meal,' (4,229 of 25,762), 21,533 patients were included in the study. Ninety-nine percent of patients used rapid-acting insulin analogues; 32% dosed insulin PostP. Compared to PreP, children <18 years of age dosing PostP were characterized by higher glycated hemoglobin (HbA1c) (8.7 ± 1.5% [72 ± 16.4 mmol/mol] vs. 8.4 ± 1.7% [68 ± 18.6 mmol/mol]), larger insulin dose (1.2 ± 0.7 IU/kg/day vs. 1.1 ± 0.7 IU/kg/day), greater prevalence of history of hypoglycemia, and diabetic ketoacidosis. Adults who dosed PostP were characterized by younger age (33.0 ± 15.3 years vs. 39.5 ± 16.6 years), higher HbA1c (8.3 ± 1.5% [67 ± 16.4 mmol/mol] vs. 7.8 ± 1.5% [62 ± 16.4 mmol/mol]), and larger insulin dose (1.0 ± 0.6 IU/kg/day vs. 0.9 ± 0.5 IU/kg/day) than PreP.

CONCLUSION

This study reveals that a large proportion of patients dose bolus insulin PostP. Despite the use of current rapid-acting insulin analogues, patients who dose PostP are characterized by poorer glycemic control in all patients and a greater prevalence of history of severe hypoglycemia and diabetic ketoacidosis in children.

ABBREVIATIONS

BMI = body mass index; CGM = continuous glucose monitoring; DKA = diabetic ketoacidosis; HbA1c = glycated hemoglobin; PostP = postprandial; PreP = preprandial; SMBG = self-monitored blood glucose; T1D = type 1 diabetes.

Fast-Acting Insulin Aspart Improves Glycemic Control in Basal-Bolus Treatment for Type 1 Diabetes: Results of a 26-Week Multicenter, Active-Controlled, Treat-to-Target, Randomized, Parallel-Group Trial (onset 1)

OBJECTIVE

This multicenter, treat-to-target, phase 3 trial evaluated the efficacy and safety of fast-acting insulin aspart (faster aspart) versus conventional insulin aspart (IAsp) in adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

The primary end point was change from baseline in HbA_1c after 26 weeks. After an 8-week run-in, subjects were randomized (1:1:1) to double-blind mealtime faster aspart (n = 381), IAsp (n = 380), or open-label postmeal faster aspart (n = 382)-each with insulin detemir.

RESULTS

HbA_1c was reduced in both treatment groups, and noninferiority to IAsp was confirmed for both mealtime and postmeal faster aspart (estimated treatment difference [ETD] faster aspart-IAsp, mealtime, -0.15% [95% CI -0.23; -0.07], and postmeal, 0.04% [-0.04; 0.12]); mealtime faster aspart statistically significantly reduced HbA_1c versus IAsp (P = 0.0003). Postprandial plasma glucose (PPG) increments were statistically significantly lower with mealtime faster aspart at 1 h (ETD -1.18 mmol/L [95% CI -1.65; -0.71], -21.21 mg/dL [-29.65; -12.77]; P < 0.0001) and 2 h (-0.67 mmol/L [-1.29; -0.04], -12.01 mg/dL [-23.33; -0.70]; P = 0.0375) after the meal test; superiority to IAsp for the 2-h PPG increment was confirmed. The overall rate of severe or blood glucose-confirmed (plasma glucose <3.1 mmol/L [56 mg/dL]) hypoglycemic episodes and safety profiles were similar between treatments.

CONCLUSIONS

Faster aspart effectively improved HbA_1c, and noninferiority to IAsp was confirmed, with superior PPG control for mealtime faster aspart versus IAsp. Subjects randomized to postmeal faster aspart for all meals maintained HbA_1c noninferior to that obtained with mealtime IAsp.

Improved Postprandial Glycemic Control with Faster-Acting Insulin Aspart in Patients with Type 1 Diabetes Using Continuous Subcutaneous Insulin Infusion

BACKGROUND

Faster aspart is insulin aspart (IAsp) in a new formulation, which in continuous subcutaneous insulin infusion (CSII) in subjects with type 1 diabetes has shown a faster onset and offset of glucose-lowering effect than IAsp.

METHODS

This double-blind, randomized, crossover active-controlled trial compared 2-h postprandial plasma glucose (PPG) response, following 2 weeks of CSII with faster aspart or IAsp. Primary endpoint: mean change in PPG 2 h after a standardized meal test (ΔPG_av,0-2h). Subjects (n = 43) had masked continuous glucose monitoring (CGM) throughout.

RESULTS

Faster aspart provided a statistically significantly greater glucose-lowering effect following the meal versus IAsp: ΔPG_av,0-2h: 3.03 mmol/L versus 4.02 mmol/L (54.68 mg/dL vs. 72.52 mg/dL); estimated treatment difference (ETD) [95% CI]: -0.99 mmol/L [-1.95; -0.03] (-17.84 mg/dL [-35.21; -0.46]; P = 0.044). One hour postmeal, PG levels were -1.64 mmol/L (-29.47 mg/dL) lower with faster aspart versus IAsp (P = 0.006). Interstitial glucose (IG) profiles supported these findings; the largest differences were observed at breakfast: 9.08 versus 9.56 mmol/L (163.57 vs. 172.19 mg/dL; ETD [95% CI]: -0.48 mmol/L [-0.97; 0.01]; -8.62 mg/dL [-17.49; 0.24]; P = 0.057). Duration of low IG levels (≤3.9 mmol/L [70 mg/dL] per 24 h) was statistically significantly shorter for faster aspart versus IAsp (2.03 h vs. 2.45 h; ETD [95% CI]: -0.42 [-0.72; -0.11]; P = 0.008). No unexpected safety findings were observed.

CONCLUSIONS

CSII delivery of faster aspart had a greater glucose-lowering effect than IAsp after a meal test. CGM results recorded throughout all meals supported this finding, with less time spent with low IG levels.

Insulin Aspart in the Management of Diabetes Mellitus: 15 Years of Clinical Experience

Limiting excessive postprandial glucose excursions is an important component of good overall glycemic control in diabetes mellitus. Pharmacokinetic studies have shown that insulin aspart, which is structurally identical to regular human insulin except for the replacement of a single proline amino acid with an aspartic acid residue, has a more physiologic time-action profile (i.e., reaches a higher peak and reaches that peak sooner) than regular human insulin. As expected with this improved pharmacokinetic profile, insulin aspart demonstrates a greater glucose-lowering effect compared with regular human insulin. Numerous randomized controlled trials and a meta-analysis have also demonstrated improved postprandial control with insulin aspart compared with regular human insulin in patients with type 1 or type 2 diabetes, as well as efficacy and safety in children, pregnant patients, hospitalized patients, and patients using continuous subcutaneous insulin infusion. Studies have demonstrated that step-wise addition of insulin aspart is a viable intensification option for patients with type 2 diabetes failing on basal insulin. Insulin aspart has shown a good safety profile, with no evidence of increased receptor binding, mitogenicity, stimulation of anti-insulin antibodies, or hypoglycemia compared with regular human insulin. In one meta-analysis, there was evidence of a lower rate of nocturnal hypoglycemia compared with regular human insulin and, in a trial that specifically included patients with a history of recurrent hypoglycemia, a significantly lower rate of severe hypoglycemic episodes. The next generation of insulin aspart (faster-acting insulin aspart) is being developed with a view to further improving on these pharmacokinetic/pharmacodynamic properties.

Continuous subcutaneous insulin infusion therapy and multiple daily insulin injections in type 1 diabetes mellitus: a comparative overview and future horizons

INTRODUCTION

Continuous subcutaneous insulin infusion (CSII) therapy is currently accepted as a treatment strategy for type 1 diabetes. Transition from multiple daily injection therapy (MDI; including basal-bolus regimens) to CSII is based on expectations of better metabolic control and fewer hypoglycaemic events. Evidence to date has not been always conclusive.

AREAS COVERED

Evidence for CSII and MDI in terms of glycaemic control, hypoglycaemia and psychosocial outcomes is reviewed in the adult and paediatric population with type 1 diabetes. Findings from studies on threshold-based insulin pump suspension and predictive low glucose management (PLGM) are outlined. Limitations of current CSII application and future technological developments are discussed.

EXPERT OPINION

Glycaemic control and quality of life (QOL) may be improved by CSII compared to MDI depending on baseline HbA1c and hypoglycaemia rates. Future studies are expected to provide evidence on clinical and cost effectiveness in those who will benefit the most. Training, structured education and support are important to benefit from CSII. Novel technological approaches linking continuous glucose monitoring (CGM) and CSII may help mitigate against frequent hypoglycaemia in those at risk. Development of glucose-responsive automated closed-loop insulin delivery systems may reduce the burden of disease management and improve outcomes in type 1 diabetes.

Towards a Physiological Prandial Insulin Profile: Enhancement of Subcutaneously Injected Prandial Insulin Using Local Warming Devices

The need to develop an insulin delivery system that can closely mimic physiologically induced changes in prandial insulin release has been a major research target since the discovery of insulin. The challenges facing existing insulin delivery systems, related to relatively slow pharmacokinetics and pharmacodynamics, have been further highlighted by rapid advances in diabetes technology and progress in artificial pancreas research. Despite the growing interest in alternative routes of insulin administration, the subcutaneous route remains-at least for now-the preferred route for insulin administration. In this article, we review efforts aimed at developing subcutaneously injected ultrafast-acting insulin and measures aimed at enhancing insulin absorption, focusing on local warming devices.

Faster-acting insulin aspart: earlier onset of appearance and greater early pharmacokinetic and pharmacodynamic effects than insulin aspart

AIMS

To evaluate the pharmacokinetics and pharmacodynamics of faster-acting insulin aspart and insulin aspart in a randomized, single-centre, double-blind study.

METHODS

Fifty-two patients with type 1 diabetes (mean age 40.3 years) received faster-acting insulin aspart, insulin aspart, or another faster aspart formulation (not selected for further development), each as a single 0.2 U/kg subcutaneous dose, under glucose-clamp conditions, in a three-way crossover design (3-12 days washout between dosing).

RESULTS

Faster-acting insulin aspart had a faster onset of exposure compared with insulin aspart, shown by a 57% earlier onset of appearance [4.9 vs 11.2 min; ratio 0.43, 95% confidence interval (CI) 0.36; 0.51], a 35% earlier time to reach 50% maximum concentration (20.7 vs 31.6 min; ratio 0.65, 95% CI 0.59; 0.72) and a greater early exposure within 90 min after dosing. The greatest difference occurred during the first 15 min, when area under the serum insulin aspart curve was 4.5-fold greater with faster-acting insulin aspart than with insulin aspart. Both treatments had a similar time to maximum concentration, total exposure and maximum concentration. Faster-acting insulin aspart had a significantly greater glucose-lowering effect within 90 min after dosing [largest difference: area under the curve for the glucose infusion rate (AUC(GIR), 0-30 min) ratio 1.48, 95% CI 1.13; 2.02] and 17% earlier time to reach 50% maximum glucose infusion rate (38.3 vs 46.1 min; ratio 0.83, 95% CI 0.73; 0.94). The primary endpoint (AUC(GIR, 0-2 h)) was 10% greater for faster-acting insulin aspart, but did not reach statistical significance (ratio 1.10, 95% CI 1.00; 1.22). Both treatments had similar total and maximum glucose-lowering effects, indicating similar overall potency.

CONCLUSIONS

Faster-acting insulin aspart was found to have earlier onset and higher early exposure than insulin aspart, and a greater early glucose-lowering effect, with similar potency.

Suspension of basal insulin to avoid hypoglycemia in type 1 diabetes treated with insulin pump

Treatment with continuous s.c. insulin infusion (CSII) provides better glycemic control and lower risk of hypoglycemia than conventional therapy with multiple daily insulin injections. These benefits have been related to a more reliable absorption and an improved pharmacokinetic profile of insulin delivered through CSII therapy. However, even for patients treated with CSII, exaggerated postmeal hyperglycemic excursions and late postabsorptive hypoglycemia can still constitute a therapeutic challenge. Two female patients with type 1 diabetes who began treatment with CSII required to increase their previous breakfast insulin-to-carbohydrate ratio in order to achieve postprandial glycemic goals. However, they simultaneously presented recurrent episodes of late hypoglycemia several hours after breakfast bolus. Advancing the timing of the bolus was ineffective and bothersome for patients. In both cases, the best therapeutic option was to set a basal insulin rate of zero units per hour during 6 h after breakfast. Even so, they need to routinely take a midmorning snack with 10–20 g of carbohydrates to avoid late postabsorptive hypoglycemia. They have been using this insulin schedule for about 3 years without complications. The action of prandial insulin delivered through insulin pumps can be inappropriately delayed for the requirements of some patients. Although suspension of basal rate can be an acceptable therapeutic alternative for them, these cases demonstrate that new strategies to improve the bioavailability of prandial insulin infused through CSII are still needed.

Preliminary evaluation of a new semi-closed-loop insulin therapy system over the prandial period in adult patients with type 1 diabetes: the WP6.0 Diabeloop study

There is room for improvement in the algorithms used in closed-loop insulin therapy during the prandial period. This pilot study evaluated the efficacy and safety of the Diabeloop algorithm (model predictive control type) during the postprandial period. This 2-center clinical trial compared interstitial glucose levels over two 5-hour periods (with/without the algorithm) following a calibrated lunch. On the control day, the amount of insulin delivered by the pump was determined according to the patient's usual parameters. On the test day, 50% or 75% of the theoretical bolus required was delivered, while the algorithm, informed of carbohydrate intake, proposed changes to insulin delivery every 15 minutes using modeling to forecast glucose levels. The primary endpoint was percentage of time spent at near normoglycemia (70-180 mg/dl). Twelve patients with type 1 diabetes (9 men, age 35.6 ± 12.7 years, HbA1c 7.3 ± 0.8%) were included. The percentage of time spent in the target range was 84.5 ± 20.8 (test day) versus 69.2 ± 33.9% (control day, P = .11). The percentage of time spent in hypoglycemia < 70 mg/dl was 0.2 ± 0.8 (test) versus 4.4 ± 8.2% (control, P = .18). Interstitial glucose at the end of the test (5 hours) was 127.5 ± 40.1 (test) versus 146 ± 53.5 mg/dl (control, P = .25). The insulin doses did not differ, and no differences were observed between the 50% and 75% boluses. In a semi-closed-loop configuration with manual priming boluses (25% or 50% reduction), the Diabeloop v1 algorithm was as successful as the manual method in determining the prandial bolus, without any exposure to excessive hypoglycemic risk.

Multicenter closed-loop/hybrid meal bolus insulin delivery with type 1 diabetes

BACKGROUND

This study evaluated meal bolus insulin delivery strategies and associated postprandial glucose control while using an artificial pancreas (AP) system.

SUBJECTS AND METHODS

This study was a multicenter trial in 53 patients, 12-65 years of age, with type 1 diabetes for at least 1 year and use of continuous subcutaneous insulin infusion for at least 6 months. Four different insulin bolus strategies were assessed: standard bolus delivered with meal (n=51), standard bolus delivered 15 min prior to meal (n=40), over-bolus of 30% delivered with meal (n=40), and bolus purposely omitted (n=46). Meal carbohydrate (CHO) intake was 1 g of CHO/kg of body weight up to a maximum of 100 g for the first three strategies or up to a maximum of 50 g for strategy 4.

RESULTS

Only three of 177 meals (two with over-bolus and one with standard bolus 15 min prior to meal) had postprandial blood glucose values of <60 mg/dL. Postprandial hyperglycemia (blood glucose level >180 mg/dL) was prolonged for all four bolus strategies but was shorter for the over-bolus (41% of the 4-h period) than the two standard bolus strategies (73% for each). Mean postprandial blood glucose level was 15.9 mg/dL higher for the standard bolus with meal compared with the prebolus (baseline-adjusted, P=0.07 for treatment effect over the 4-h period).

CONCLUSIONS

The AP handled the four bolus situations safely, but at the expense of having elevated postprandial glucose levels in most subjects. This was most likely secondary to suboptimal performance of the algorithm.

Short acting insulin analogues in intensive care unit patients

Blood glucose control in intensive care unit (ICU) patients, addressed to actively maintain blood glucose concentration within defined thresholds, is based on two major therapeutic interventions: to supply an adequate calories load and, when necessary, to continuously infuse insulin titrated to patients needs: intensive insulin therapy (IIT). Short acting insulin analogues (SAIA) have been synthesized to improve the chronic treatment of patients with diabetes but, because of the pharmacokinetic characteristics that include shorter on-set and off-set, they can be effectively used also in ICU patients and have the potential to be associated with a more limited risk of inducing episodes of iatrogenic hypoglycemia. Medical therapies carry an intrinsic risk for collateral effects; this can be more harmful in patients with unstable clinical conditions like ICU patients. To minimize these risks, the use of short acting drugs in ICU patients have gained a progressively larger room in ICU and now pharmaceutical companies and researchers design drugs dedicated to this subset of medical practice. In this article we report the rationale of using short acting drugs in ICU patients (i.e., sedation and treatment of arterial hypertension) and we also describe SAIA and their therapeutic use in ICU with the potential to minimize iatrogenic hypoglycemia related to IIT. The pharmacodynamic and pharmachokinetic characteristics of SAIA will be also discussed.

A 7-year follow-up retrospective, international, multicenter study of insulin pump therapy in children and adolescents with type 1 diabetes

We evaluated the long-term glycemic control in children with type 1 diabetes, using continuous subcutaneous insulin infusion (CSII) for at least 5 years in three diabetes centers from three different countries: Canada, Italy and Spain. This was an observational retrospective multicenter cohort study. Subjects were included if they were followed at one of the participating centers, had type 1 diabetes, age 5-20 years at time of data collection and used CSII for more than 5 years. Data collected included gender, age, disease duration, age at CSII initiation, body mass index (BMI), hemoglobin A1c (HbA1c), insulin requirement and serious adverse events (SAE) at baseline and every 12 months during follow-up. One hundred fifteen patients were included in the study (55% males), aged 5-20 years (mean: 13.5 ± 3.8 years), with mean diabetes duration of 6.3 ± 3.4 years, using CSII for mean of 6.9 ± 1.2 years (range 5-12 years.). HbA1c significantly improved after 1 year of CSII treatment and during follow-up (p = 0.02). When HbA1c was compared between countries, a difference was observed, with slightly lower values in Italy than in Canada and Spain (p = 0.04). When evaluated by gender, HbA1c was similar at baseline, but significantly improved only in males during all follow-up (p = 0.004). No significant differences were observed for BMI, insulin requirement or SAE. Insulin pump therapy is safe and effective in the pediatric population, although in this study, the major benefit in HbA1c was seen in males. The use of advanced pump features was associated with greater improvement in HbA1c.

Postprandial blood glucose control in type 1 diabetes for carbohydrates with varying glycemic index foods

Treatment of type 1 diabetes consists of maintaining postprandial normoglycemia using the correct prandial insulin dose according to food intake. Nonetheless, it is hardly achieved in practice, which results in several diabetes-related complications. In this study we present a feedforward plus feedback blood glucose control system that considers the glycemic index of foods. It consists of a preprandial insulin bolus whose optimal bolus dose and timing are stated as a minimization problem, which is followed by a postprandial closed-loop control based on model predictive control. Simulation results show that, for a representative carbohydrate intake of 50 g, the present control system is able to maintain postprandial glycemia below 140 mg/dL while preventing postprandial hypoglycemia as well.

Day and night closed-loop control in adults with type 1 diabetes: a comparison of two closed-loop algorithms driving continuous subcutaneous insulin infusion versus patient self-management

OBJECTIVE

To compare two validated closed-loop (CL) algorithms versus patient self-control with CSII in terms of glycemic control.

RESEARCH DESIGN AND METHODS

This study was a multicenter, randomized, three-way crossover, open-label trial in 48 patients with type 1 diabetes mellitus for at least 6 months, treated with continuous subcutaneous insulin infusion. Blood glucose was controlled for 23 h by the algorithm of the Universities of Pavia and Padova with a Safety Supervision Module developed at the Universities of Virginia and California at Santa Barbara (international artificial pancreas [iAP]), by the algorithm of University of Cambridge (CAM), or by patients themselves in open loop (OL) during three hospital admissions including meals and exercise. The main analysis was on an intention-to-treat basis. Main outcome measures included time spent in target (glucose levels between 3.9 and 8.0 mmol/L or between 3.9 and 10.0 mmol/L after meals).

RESULTS

Time spent in the target range was similar in CL and OL: 62.6% for OL, 59.2% for iAP, and 58.3% for CAM. While mean glucose level was significantly lower in OL (7.19, 8.15, and 8.26 mmol/L, respectively) (overall P = 0.001), percentage of time spent in hypoglycemia (<3.9 mmol/L) was almost threefold reduced during CL (6.4%, 2.1%, and 2.0%) (overall P = 0.001) with less time ≤2.8 mmol/L (overall P = 0.038). There were no significant differences in outcomes between algorithms.

CONCLUSIONS

Both CAM and iAP algorithms provide safe glycemic control.

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.

Feasibility of a bihormonal closed-loop system to control postexercise and postprandial glucose excursions

BACKGROUND

The aim of this pilot study was to test the feasibility of a bihormonal (glucagon and insulin) closed-loop (CL) system by challenging the system with two meals and 30 min exercise.

METHODS

Ten patients with type 1 diabetes treated with continuous subcutaneous insulin infusion underwent a standardized protocol on three different occasions: 40 g carbohydrate breakfast followed 2 h later by 30 min of moderate-intensity exercise, followed 1.5 h later by a standardized 60 g carbohydrate lunch. An open-loop (OL) day served as control, the first CL day as tuning experiment, and the second CL day to compare with OL.

RESULTS

The overall mean venous glucose was similar: 9 (5.4-13.5) mmol/liter in OL versus 8.7 (6.4-11.0) mmol/liter in CL, p = .74. The postbreakfast glucose concentrations tended to be lower in OL than in CL [9.5 (4.3-13.3) versus 11.4 (7-16.2) mmol/liter; p = .07] and higher in OL than in CL postlunch [9.4 (6.0-14.9) versus 7.7 (5.5-9.0) mmol/liter,p = .15]. The postexercise glucose concentrations were similar in OL and CL: 7.5 (4.6-13) versus 8.2 (5.5-13.1) mmol/liter; p = .45. In those patients coming in with baseline glucose above 7 mmol/liter, there was initial overinsulinization in CL. During OL, two hypoglycemic episodes occurred compared with four hypoglycemic episodes in three participants during CL. Glucagon seemed mostly effective in preventing hypoglycemia.

CONCLUSIONS

Overall, CL glucose control was comparable to OL control, but there was overinsulinization in those patients with baseline glucose above 7 mmol/liter.