Insulin pump therapy with automated insulin suspension in response to hypoglycemia: reduction in nocturnal hypoglycemia in those at greatest risk

Scientific advisory on nocturnal hypoglycemia in insulin-treated patients with diabetes: Recommendations from Indian experts

INTRODUCTION

Insulin is one of the commonly prescribed glucose lowering agents in diabetes. Hypoglycemia is the most common complication, and severe hypoglycemia is the most serious complication of insulin therapy. Almost half of all severe hypoglycemia episodes (HEs) occur at night. However, patients are often unaware of their nocturnal hypoglycaemia (NH) risk. Additionally, both healthcare professionals and patients find it difficult to manage NH. The purpose of this expert group meeting is to improve NH awareness and provide guidance for the physicians to recognize and manage NH.

METHOD

The panel of experts in an e-board deliberated extensively upon the available literature and guidelines on hypoglycemia and NH discussed the consensus on definition, detection, reporting, monitoring, treatment, and optimization of therapy in NH.

RESULT

& Conclusion: Though there are many guidelines on the management of HEs in patients with diabetes, very few touch the topic of NH. This scientific advisory on management of NH in insulin treated patients with diabetes is formulated to address this gap in understanding regarding management of NH. The experts provide recommendations for the nocturnal window, defining NH based on blood glucose values, recognition, prevention and management of NH.

The Evolution of Insulin Administration in Type 1 Diabetes

Insulin has been utilized in the treatment of type 1 diabetes (T1D) for 100 years. While there is still no cure for T1D, insulin administration has undergone a remarkable evolution which has contributed to improvements in quality of life and life expectancy in individuals with T1D. The advent of faster-acting and longer-acting insulins allowed for the implementation of insulin regimens more closely resembling normal insulin physiology. These improvements afforded better glycemic control, which is crucial for limiting microvascular complications and improving T1D outcomes. Suspension of insulin delivery in response to actual and forecasted hypoglycemia has improved quality of life and mitigated hypoglycemia without compromising glycemic control. Advances in continuous glucose monitoring (CGM) and insulin pumps, efforts to model glucose and insulin kinetics, and the application of control theory to T1D have made the automation of insulin delivery a reality. This review will summarize the past, present, and future of insulin administration in T1D.

Glucagon as a Therapeutic Approach to Severe Hypoglycemia: After 100 Years, Is It Still the Antidote of Insulin?

Hypoglycemia represents a dark and tormented side of diabetes mellitus therapy. Patients treated with insulin or drug inducing hypoglycemia, consider hypoglycemia as a harmful element, which leads to their resistance and lack of acceptance of the pathology and relative therapies. Severe hypoglycemia, in itself, is a risk for patients and relatives. The possibility to have novel strategies and scientific knowledge concerning hypoglycemia could represent an enormous benefit. Novel available glucagon formulations, even now, allow clinicians to deal with hypoglycemia differently with respect to past years. Novel scientific evidence leads to advances concerning physiopathological mechanisms that regulated glycemic homeostasis. In this review, we will try to show some of the important aspects of this field.

Current treatment options and challenges in patients with Type 1 diabetes: Pharmacological, technical advances and future perspectives

Type 1 diabetes mellitus imposes a significant burden of complications and mortality, despite important advances in treatment: subjects affected by this disease have also a worse quality of life-related to disease management. To overcome these challenges, different new approaches have been proposed, such as new insulin formulations or innovative devices. The introduction of insulin pumps allows a more physiological insulin administration with a reduction of HbA1c level and hypoglycemic risk. New continuous glucose monitoring systems with better accuracy have allowed, not only better glucose control, but also the improvement of the quality of life. Integration of these devices with control algorithms brought to the creation of the first artificial pancreas, able to independently gain metabolic control without the risk of hypo- and hyperglycemic crisis. This approach has revolutionized the management of diabetes both in terms of quality of life and glucose control. However, complete independence from exogenous insulin will be obtained only by biological approaches that foresee the replacement of functional beta cells obtained from stem cells: this will be a major challenge but the biggest hope for the subjects with type 1 diabetes. In this review, we will outline the current scenario of innovative diabetes management both from a technological and biological point of view, and we will also forecast some cutting-edge approaches to reduce the challenges that hamper the definitive cure of diabetes.

Insulinpumpe, kontinuierliche und kapilläre Glukosemessung bei Kindern, Jugendlichen und Erwachsenen mit Diabetes mellitus: Daten des DPV-Registers zwischen 1995 und 2019

Ziel dieser Beobachtungsstudie ist die Beschreibung der aktuellen Nutzung von Diabetestechnologien bei Patienten/-innen mit Diabetes mellitus.

Methode Auswertung von Daten des DPV-Registers zur Nutzung der Insulinpumpentherapie (CSII), kontinuierlicher Glukosemessung (CGM) und der Selbstmessung der Blutglukose (SMBG) aus 497 teilnehmenden Zentren in Deutschland, Österreich, Luxemburg und der Schweiz zwischen 1995 und 2019. Die Daten wurden bei Patienten/-innen mit Diabetes Typ 1 (Alter ≥ 0,5 Jahre) für 5 Altersgruppen ausgewertet. Zusätzlich wurden aktuelle (zwischen 2017 und 2019) Geschlechtsunterschiede in der Verwendung von Diabetestechnologie bei Typ-1-Patienten/-innen untersucht, ebenso wie die Nutzung von Insulinpumpen und CGM für Patienten/-innen mit Insulintherapie bei Typ-2-DM, bei zystischer Fibrose (CFRD), bei anderen Pankreaserkrankungen, neonatalem Diabetes und Maturity Onset Diabetes of the Young (MODY).

Ergebnisse Es zeigte sich bei Patienten/-innen mit Diabetes Typ 1 ein Anstieg der CSII-Nutzung von 1995 bis 2019 von 1 % auf 55 % (2019: < 6 Jahre: 89 %; 6–< 12 Jahre: 67 %; 12–< 18 Jahre: 52 %; 18–< 25 Jahre: 48 %; ≥ 25 Jahre: 34 %). Die CGM-Nutzung erhöhte sich ab 2016 bis 2019 von 9 % auf 56 % (2019: 67 %; 68 %; 61 %; 47 %; 19 % der jeweiligen Altersgruppe). Die SMBG nahmen von 1995 bis 2015 insbesondere in den jüngeren Altersgruppen zu, gefolgt von einem Rückgang seit dem Jahr 2016 (Alle Patienten: 1995: 3,3/Tag; 2016: 5,4/Tag; 2019: 3,8/Tag). Weibliche Patienten mit Typ-1-Diabetes führten häufiger eine CSII und mehr SMBG als männliche Patienten durch (56 %/48 %, jeweils p-Wert: < 0,0001), während sich bei der CGM-Nutzung keine signifikanten Unterschiede zeigten.

Zwischen 2017 und 2019 erfolgte eine Nutzung von Insulinpumpen und CGM bei neonatalem Diabetes (CSII 87 %; CGM 38 %), bei MODY (CSII 14 %; CGM 28 %) und bei CFRD (CSII 18 %; CGM 22 %). CGM und CSII wurden dagegen nur selten von Menschen mit Insulintherapie und Diabetes Typ 2 (CSII < 1 %; CGM 1 %) und bei anderen Pankreaserkrankungen (CSII 3 %; CGM 4 %) genutzt.

Schlussfolgerung Moderne Diabetestechnologien werden derzeit insbesondere von pädiatrischen Patienten/-innen mit Diabetes Typ 1, aber auch von Menschen mit neonatalem Diabetes breit genutzt, von Patienten/-innen mit MODY und CFRD sowie Erwachsenen mit Diabetes Typ 1 in etwas geringerem Maße mit ansteigendem Trend. Dagegen sind diese Technologien in der Therapie des Typ-2-Diabetes und bei anderen Pankreaserkrankungen zurzeit nur wenig verbreitet.

A Glucose-Insulin Mixture Model and Application to Short-Term Hypoglycemia Prediction in the Night Time

OBJECTIVE

Insulin-induced hypoglycemia is recognized as a critical problem for diabetic patients, especially at night. To give glucose prediction and advance warning of hypoglycemia of at least 30 minutes, various glucose-insulin models have been proposed. Recognizing the complementary nature of the models, this research proposes a Glucose-Insulin Mixture (GIM) model to predict the glucose values for hypoglycemia detection, by optimally fusing different models with its adjusted parameters to address the inter- and intra-individual variability.

METHODS

Two types of classic glucose-insulin models, the Ruan model, with single-compartment glucose kinetics, and the Hovorka model, with two-compartment glucose kinetics, are selected as two candidate models. Based on Bayesian inference, GIM is introduced with quantified contributions from the models with the associated parameters. GIM is then applied to predict the glucose values and hypoglycemia events.

RESULTS

The proposed model is validated by the nocturnal glucose data collected from 12 participants with type 1 diabetes. The GIM model has promising fitting of RMSE within 0.3465 mmol/L and predicting of RMSE within 0.5571 mmol/L. According to the literature, the hypoglycemia is defined as 3.9 mmol/L, and the GIM model shows good short-term hypoglycemia prediction performance with the data collected within the last hour (accuracy: 95.97%, precision: 91.77%, recall: 95.60%). In addition, the probability of hypoglycemia event in 30 minutes is inferred.

CONCLUSION

GIM, by fusing various glucose-insulin models via Bayesian inference, has the promise to capture glucose dynamics and predict hypoglycemia.

SIGNIFICANCE

GIM based short-term hypoglycemia prediction has potential clinical utility for timely intervention.

New technical approach to the diabetes therapy

Optimal glycemic control remains challenging in individuals with type 1 diabetes. With the comprehensive clinical evidence on safety and efficiency, the adoption of continuous glucose monitoring (CGM), insulin pumps, and control algorithms merging the two into closed-loop systems is rapidly increasing. Particularly the CGM and intermittently scanned CGM improved diabetes management outcomes in large populations. A meaningful translation from clinical trials in highly controlled settings to numerous evaluations of closed-loop technology in the unrestricted home environment ended with its commercialization and use in routine clinical practice. Although it is still not a cure, the closed-loop currently seems to be the most promising advancement in the treatment of diabetes, with promising results also reported from routine clinical practice in children and adults with type 1 diabetes. We summarize different aspects of a technological approach to diabetes care, list currently available devices and systems in the pipeline, and the key supporting clinical evidence for their use. We consider human factors associated with technology use and the importance of health economics to support implementation and reimbursement.

Treatment and prevention of severe hypoglycaemia in people with diabetes: Current and new formulations of glucagon

Some therapies for diabetes increase the risk of hypoglycaemia, in particular all insulins and insulin secretagogues, including the glinides and sulfonylureas. Hypoglycaemia remains a major limiting factor to successful glycaemic management, despite the availability of prevention options such as insulin analogues, continuous glucose monitoring, insulin pumps, and dogs that have been trained to detect hypoglycaemia. Non-severe (self-treated) and severe (requiring assistance for recovery) hypoglycaemia rates are higher in people with type 1 diabetes, but those with insulin-treated type 2 diabetes are also at risk. Education and regular review are essential between people with diabetes and their caregivers and healthcare professionals about symptoms, prevention and treatment. Awareness of the potential dangers of hypoglycaemia is fundamental to the optimal management of diabetes. When therapy is intensified to achieve glycaemic targets, it is important that people at risk of severe hypoglycaemia, and particularly their caregivers, have ready access to effective treatment for hypoglycaemia emergencies. The current and potential formulations of glucagon available for treatment of severe hypoglycaemia are reviewed.

Prediction of Nocturnal Hypoglycemia in Adults with Type 1 Diabetes under Multiple Daily Injections Using Continuous Glucose Monitoring and Physical Activity Monitor

(1) Background: nocturnal hypoglycemia (NH) is one of the most challenging side effects of multiple doses of insulin (MDI) therapy in type 1 diabetes (T1D). This work aimed to investigate the feasibility of a machine-learning-based prediction model to anticipate NH in T1D patients on MDI. (2) Methods: ten T1D adults were studied during 12 weeks. Information regarding T1D management, continuous glucose monitoring (CGM), and from a physical activity tracker were obtained under free-living conditions at home. Supervised machine-learning algorithms were applied to the data, and prediction models were created to forecast the occurrence of NH. Individualized prediction models were generated using multilayer perceptron (MLP) and a support vector machine (SVM). (3) Results: population outcomes indicated that more than 70% of the NH may be avoided with the proposed methodology. The predictions performed by the SVM achieved the best population outcomes, with a sensitivity and specificity of 78.75% and 82.15%, respectively. (4) Conclusions: our study supports the feasibility of using ML techniques to address the prediction of nocturnal hypoglycemia in the daily life of patients with T1D on MDI, using CGM and a physical activity tracker.

Evolution of Diabetes Technology

Technological innovations have fundamentally changed diabetes care. Insulin pump use and continuous glucose monitoring are associated with improved glycemic control along with a better quality of life; automated insulin-dosing advisors facilitate and improve decision making. Glucose-responsive automated insulin delivery enables the highest targets for time in range, lowest rate and duration of hypoglycemia, and favorable quality of life. Clear targets for time in ranges and a standard visualization of the data will help the diabetes technology to be used more efficiently. Decision support systems within and integrated cloud environment will further simplify, unify, and improve modern routine diabetes care.

Severe Hypoglycemia: Is It Still a Threat for Children and Adolescents With Type 1 Diabetes?

Severe hypoglycemia is defined as a condition with serious cognitive dysfunction, such as a convulsion and coma, requiring external help from other persons. This condition is still lethal and is reported to be the cause of death in 4-10% in children and adolescents with type 1 diabetes. The incidence of severe hypoglycemia in the pediatric population was previously reported as high as more than 50-100 patient-years; however, there was a decline in the frequency of severe hypoglycemia during the past decades, and relationship with glycemic control became weaker than previously reported. A lot of studies have shown the neurological sequelae with severe hypoglycemia as cognitive dysfunction and abnormalities in brain structure. This serious condition also provides negative psychosocial outcomes and undesirable compensatory behaviors. Various possible factors, such as younger age, recurrent hypoglycemia, nocturnal hypoglycemia, and impaired awareness of hypoglycemia, are possible risk factors for developing severe hypoglycemia. A low HbA_1c level is not a predictable value for severe hypoglycemia. Prevention of severe hypoglycemia remains one of the most critical issues in the management of pediatric patients with type 1 diabetes. Advanced technologies, such as continuous glucose monitoring (CGM), intermittently scanned CGM, and sensor-augmented pump therapy with low-glucose suspend system, potentially minimize the occurrence of severe hypoglycemia without worsening overall glycemic control. Hybrid closed-loop system must be the most promising tool for achieving optimal glycemic control with preventing the occurrence of severe hypoglycemia in pediatric patients with type 1 diabetes.

The Predictive Low Glucose Management System in Prevention of Clinically Significant Hypoglycemia in Type 1 Diabetes. A Preliminary Study Identifying the Most Common Events Leading Up to Hypoglycemia During Insulin Pump Therapy

BACKGROUND/AIM

Prevention of hypoglycemia remains a major challenge in diabetic management, despite the introduction of modern insulin pumps in daily clinical practice. The Low Glucose Suspend (LGS) and the newer Predictive Low Glucose Management (PLGM) systems incorporated in the Medtronic insulin pumps have shown promising results in prevention of hypoglycemia. Our aim was to evaluate the effect of the 2 systems relative to the frequency of clinically significant hypoglycemia in Type 1 diabetes (T1DM). In addition, we investigated the events preceding clinically significant hypoglycemia episodes.

METHODS

A cross-sectional study was conducted in 30 T1DM patients using the MiniMed 640G vs. 30 using the MiniMed Veo sensor-augmented insulin pump. All data was recorded during patients' normal daily activity and living conditions. The patients were matched for age and duration of diabetes.

RESULTS

PLGM use was associated with lower incidence of clinically significant hypoglycemia (1.9±1.4 vs. 3.6±1.9 episodes per week), along with reduced exposure to hypoglycemia. The data indicated that both pump systems are effective in preventing severe hypoglycemic episodes. In both groups the most common events preceding hypoglycemic episodes included adjustment of hyperglycemia, basal rate increase and miscalculation of carbohydrates.

CONCLUSIONS

The results indicated that the use of the Minimed 640G pump system can help reduce the frequency of clinically significant hypoglycemia. Management of hyperglycemia must be addressed in diabetes education programs in order to encourage proper adjustment of high blood glucose levels. Future studies would be useful in exploring the details of the events preceding hypoglycemia episodes in insulin pump users.

Combining continuous glucose monitoring and insulin pumps to automatically tune the basal insulin infusion in diabetes therapy: a review

For individuals affected by Type 1 diabetes (T1D), a chronic disease in which the pancreas does not produce any insulin, maintaining the blood glucose (BG) concentration as much as possible within the safety range (70–180 mg/dl) allows avoiding short- and long-term complications. The tuning of exogenous insulin infusion can be difficult, especially because of the inter- and intra-day variability of physiological and behavioral factors. Continuous glucose monitoring (CGM) sensors, which monitor glucose concentration in the subcutaneous tissue almost continuously, allowed improving the detection of critical hypo- and hyper-glycemic episodes. Moreover, their integration with insulin pumps for continuous subcutaneous insulin infusion allowed developing algorithms that automatically tune insulin dosing based on CGM measurements in order to mitigate the incidence of critical episodes. In this work, we aim at reviewing the literature on methods for CGM-based automatic attenuation or suspension of basal insulin with a focus on algorithms, their implementation in commercial devices and clinical evidence of their effectiveness and safety.

Characteristics of Automated Insulin Suspension and Glucose Responses with the Predictive Low-Glucose Management System

BACKGROUND

The Predictive Low-Glucose Management (PLGM) system suspends basal insulin when hypoglycemia is predicted and reduces hypoglycemia. The aim of this analysis was to explore the characteristics of automated insulin suspension and sensor glucose (SG) responses following PLGM-initiated pump suspension.

RESEARCH DESIGN AND METHODS

Children and adolescents with type 1 diabetes used the Medtronic MiniMed™ 640G pump as part of a randomized controlled trial. Data collected on a subgroup of participants on PLGM (suspend before low enabled) from CareLink^® Therapy Management Software were analyzed to explore the time and duration of PLGM-initiated pump suspension. Day and nighttime were defined as 06:00 am to 10:00 pm and 10:00 pm to 6:00 am, respectively.

RESULTS

There were 20,183 suspend before low events in 8523 days (2.37 events/day). The mean suspend duration was 55.0 ± 32.7 min (day 50.0 ± 30.1, night 71.7 ± 35.1; P < 0.001). Although a 2-h pump suspension was more frequent at night (day 5%, night 18%), a patient-initiated resumption occurred more during day (day 34%, night 12%). SG values did not reach <3.5 and <3 mmol/L in 79% and 91% of the events, respectively. The 2-h SG following pump resumption was higher following autoresumption during the day (day vs. night 9.3 mmol/L vs. 8.4 mmol/L; P < 0.001).

CONCLUSIONS

Longer suspends and fewer glycemic excursions occur at night compared with day. The higher glycemic daytime excursions could be due to carbohydrate consumption to increase glucose levels and highlights the need for health care professionals to educate patients about carbohydrate intake around pump suspension.

Study of MiniMed 640G Insulin Pump with SmartGuard in Prevention of Low Glucose Events in Adults with Type 1 Diabetes (SMILE): Design of a Hypoglycemia Prevention Trial with Continuous Glucose Monitoring Data as Outcomes

BACKGROUND

Sensor-integrated pump systems with low-glucose suspend (also known as threshold suspend) functions have markedly transformed the management of type 1 diabetes, but most studies to date have excluded patients at high risk of hypoglycemia. The SMILE study is investigating the efficacy of the MiniMed™ 640G insulin pump with the SmartGuard™ predictive low-glucose management (PLGM) feature in the prevention of hypoglycemia in adults with type 1 diabetes, who are at high risk of hypoglycemia.

METHODS

SMILE is a prospective, randomized, open-label, controlled trial being undertaken in four European countries and Canada. Following a 2-week run-in phase, eligible participants will be randomized to use either the MiniMed 640G system with continuous glucose monitoring (CGM) and the SmartGuard PLGM feature on continuously for 24 weeks (treatment arm), or the MiniMed 640G without CGM and with blinded continuous glucose measurements between weeks 10-12, 16-18, and 22-24 (control arm). The primary endpoint is the mean number of hypoglycemic events, defined as sensor glucose ≤55 mg/dL (≤3.0 mmol/L) for >20 consecutive minutes. Secondary endpoints include various glycemic indices in the hypoglycemic and hyperglycemic ranges, as well as glycated hemoglobin. Data on patient-reported outcomes such as hypoglycemia awareness and treatment satisfaction will also be collected.

CONCLUSIONS

It is anticipated that the SMILE study will provide important insights into the effectiveness of SmartGuard technology in adult patients with type 1 diabetes.

Continuous Subcutaneous Insulin Infusion Characteristics in Type 1 Diabetes Children and Adolescents in Qatar

AIM

To describe continuous subcutaneous insulin infusion (CSII) characteristics in type 1 diabetes mellitus (T1DM) children and adolescents using a standardized protocol in routine clinical settings in Qatar.

METHODS

A total of 138 T1DM patients (62 males; 76 females; mean age 9.8 ± 3.4 years) with a mean diabetes duration of 2.4 ± 1.9 years initiated CSII (MiniMed^® Veo^®™ and MiniMed^® 640 G insulin pumps; Medtronic, Northridge, CA, USA) in 2016 and 2017. CSII characteristics and glycated hemoglobin (HbA1c) were evaluated 1 year after treatment initiation.

RESULTS

At 1 year after treatment initiation, the insulin dose had significantly increased (from 0.59 ± 0.23 to 0.74 ± 0.26 U/kg body weight per 24; P < 0.05), and the HbA1c level had significantly decreased (from 9.7 ± 1.3 to 8.1 ± 0.6%; P < 0.05). More than 92% of patients used the Bolus Wizard feature of the insulin pump at the following settings: insulin-to-carbohydrate ratio 19.2 ± 9.3 g; insulin sensitivity factor 131 ± 68 mg/dl; target range 91 ± 9.3-135 ± 14.2 mg/dl; active insulin time 3.8 ± 0.8 h.

CONCLUSION

Our results show that CSII may significantly improve glucose control in T1D children and adolescents who use a standardized protocol. A reduction of HbA1c by - 1.6% was achieved at 1 year after CSII initiation. These results need to be confirmed in a study with a longer duration.

Prevention and Management of Severe Hypoglycemia and Hypoglycemia Unawareness: Incorporating Sensor Technology

PURPOSE OF REVIEW

In addition to assisting in achieving improved glucose control, continuous glucose monitoring (CGM) sensor technology may also aid in detection and prevention of hypoglycemia. In this paper, we report on the current scientific evidence on the effectiveness of this technology in the prevention of severe hypoglycemia and hypoglycemia unawareness.

RECENT FINDINGS

Recent studies have found that the integration of CGM with continuous subcutaneous insulin infusion (CSII) therapy, a system known as sensor-augmented pump (SAP) therapy, very significantly reduces the occurrence of these conditions by providing real-time glucose readings/trends and automatically suspending insulin infusion when glucose is low (LGS) or, even, before glucose is low but is predicted to soon be low (PLGS). Initial data indicate that even for patients with type 1 diabetes treated with multiple daily injections, real-time CGM alone has been found to reduce both severe hypoglycemia and hypoglycemia unawareness. Closed loop systems (artificial pancreas) comprised of CGM and CSII without patient intervention to adjust basal insulin, which automatically reduce, increase, and suspend insulin delivery, represent a potential new option that is moving toward becoming a reality in the near future. Sensor technology promises to continue to improve patients' lives not only by attaining glycemic control but also by reducing hypoglycemia, a goal best achieved in conjunction with structured individualized patient education.

Sustained Reduction in Severe Hypoglycemia in Adults With Type 1 Diabetes Complicated by Impaired Awareness of Hypoglycemia: Two-Year Follow-up in the HypoCOMPaSS Randomized Clinical Trial

OBJECTIVE

Severe hypoglycemia is a feared complication of type 1 diabetes; yet, few trials have targeted prevention using optimized self-management (educational, therapeutic, and technological support). We aimed to investigate whether improved awareness and reduced severe hypoglycemia, achieved during an intensive randomized clinical trial (RCT), were sustained after return to routine care.

RESEARCH DESIGN AND METHODS

Ninety-six adults with type 1 diabetes (29 ± 12 years' duration) and impaired awareness of hypoglycemia at five U.K. tertiary referral diabetes centers were recruited into a 24-week 2 × 2 factorial RCT (HypoCOMPaSS). Participants were randomized to pump (continuous subcutaneous insulin infusion [CSII]) or multiple daily injections (MDIs) and real-time continuous glucose monitoring (RT-CGM) or self-monitoring of blood glucose (SMBG), with equal education/attention to all groups. At 24 weeks, participants returned to routine care with follow-up until 24 months, including free choice of MDI/CSII; RT-CGM vs. SMBG comparison continued to 24 months. Primary outcome was mean difference (baseline to 24 months [between groups]) in hypoglycemia awareness.

RESULTS

Improvement in hypoglycemia awareness was sustained (Gold score at baseline 5.1 ± 1.1 vs. 24 months 3.7 ± 1.9; P < 0.0001). Severe hypoglycemia rate was reduced from 8.9 ± 12.8 episodes/person-year over the 12 months prestudy to 0.4 ± 0.8 over 24 months (P < 0.0001). HbA_1c improved (baseline 8.2 ± 3.2% [66 ± 12 mmol/mol] vs. 24 months 7.7 ± 3.1% [61 ± 10 mmol/mol]; P = 0.003). Improvement in treatment satisfaction and reduced fear of hypoglycemia were sustained. There were no significant differences between interventions at 24 months.

CONCLUSIONS

Optimized insulin replacement and glucose monitoring underpinned by hypoglycemia-focused structured education should be provided to all with type 1 diabetes complicated by impaired awareness of hypoglycemia.

Technology in the management of type 1 diabetes mellitus - current status and future prospects

Type 1 diabetes mellitus (T1DM) represents 5-10% of diabetes cases worldwide. The incidence of T1DM is increasing, and there is no immediate prospect of a cure. As such, lifelong management is required, the burden of which is being eased by novel treatment modalities, particularly from the field of diabetes technologies. Continuous glucose monitoring has become the standard of care and includes factory-calibrated subcutaneous glucose monitoring and long-term implantable glucose sensing. In addition, considerable progress has been made in technology-enabled glucose-responsive insulin delivery. The first hybrid insulin-only closed-loop system has been commercialized, and other closed-loop systems are under development, including dual-hormone glucose control systems. This Review focuses on well-established diabetes technologies, including glucose sensing, pen-based insulin delivery, data management and data analytics. We also cover insulin pump therapy, threshold-based suspend, predictive low-glucose suspend and single-hormone and dual-hormone closed-loop systems. Clinical practice recommendations for insulin pump therapy and continuous glucose monitoring are presented, and ongoing research and future prospects are highlighted. We conclude that the management of T1DM is improved by diabetes technology for the benefit of the majority of people with T1DM, their caregivers and guardians and health-care professionals treating patients with T1DM.

Hypoglycaemia in type 1 diabetes: technological treatments, their limitations and the place of psychology

Advances in technology allowing improved insulin delivery and glucose monitoring can significantly reduce the burden of hypoglycaemia when used appropriately. However, limitations of the current technology, and the skills, commitment and motivation required to use them, mean that it does not work for all people. Education and informed professional support are key to success. In the context of problematic hypoglycaemia, data suggest that newer technology has lower efficacy and uptake in those with most need. Identifying the causes of hypoglycaemia and understanding some of the underlying behavioural drivers may prove useful and psycho-educational strategies may be effective in selected individuals. Ultimately, as in many spheres of medicine, successful management of problematic hypoglycaemia depends upon matching the right treatment to the right individual.

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial

BACKGROUND

Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy.

DESIGN

Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI.

SETTING

Eight secondary care diabetes centres in the UK.

PARTICIPANTS

Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps.

INTERVENTIONS

Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm^® Veo^TM (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK).

MAIN OUTCOME MEASURES

Primary outcome - change in glycated haemoglobin (HbA_1c) at 2 years in participants whose baseline HbA_1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA_1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness.

RESULTS

We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA_1c of ≥ 7.5%. HbA_1c and severe hypoglycaemia improved in both groups. The drop in HbA_1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA_1c change at 2 years, at which the baseline HbA_1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews.

LIMITATION

Blinding of pump therapy was not possible, although an objective primary outcome was used.

CONCLUSION

Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM.

RESEARCH PRIORITY

To understand why few patients achieve a HbA_1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN61215213.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 20. See the NIHR Journals Library website for further project information.

The risks of nocturnal hypoglycaemia in insulin-treated diabetes

Over half of all episodes of severe hypoglycaemia (requiring external help) occur during sleep, but nocturnal hypoglycaemia is often asymptomatic and unrecognised. The precise incidence of nocturnal hypoglycaemia is difficult to determine with no agreed definition, but continuous glucose monitoring has shown that it occurs frequently in people taking insulin. Attenuation of the counter-regulatory responses to hypoglycaemia during sleep may explain why some episodes are undetected and more prolonged, and modifies cardiovascular responses. The morbidity and mortality associated with nocturnal hypoglycaemia is probably much greater than realised, causing seizures, coma and cardiovascular events and affecting quality of life, mood and work performance the following day. It may induce impaired awareness of hypoglycaemia. Cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke dangerous arrhythmias. Treatment strategies are discussed that may help to minimise the frequency of nocturnal hypoglycaemia.

Cost-Effectiveness Analysis of Sensor-Augmented Insulin Pump Therapy with Automated Insulin Suspension Versus Standard Insulin Pump Therapy in Patients with Type 1 Diabetes in Sweden

INTRODUCTION

In Sweden an estimated 10,000 people with type 1 diabetes use continuous subcutaneous insulin infusion (CSII). Sensor-augmented pump therapy (SAP) is associated with higher acquisition costs but provides additional clinical benefits (e.g. reduced rate of hypoglycemic events) over and above that of CSII alone. The aim of the analysis was to assess the cost-effectiveness of SAP with automated insulin suspension relative to CSII alone in two different groups of patients with type 1 diabetes in Sweden.

METHODS

Cost-effectiveness analyses were performed using the QuintilesIMS CORE Diabetes Model, with clinical and economic input data derived from published literature. Separate analyses were performed for patients at increased risk of hypoglycemia and for patients with uncontrolled glycated hemoglobin (HbA1c) at baseline. Analyses were performed from a societal perspective over a lifetime time horizon. Future costs and clinical outcomes were discounted at 3% per annum.

RESULTS

SAP with automated insulin suspension was associated with an incremental gain in quality-adjusted life expectancy versus the CSII of 1.88 quality-adjusted life years (QALYs) in patients at high risk of hypoglycemia and of 1.07 QALYs in patients with uncontrolled HbA1c at baseline. Higher lifetime costs for SAP with automated insulin suspension resulted in projected incremental cost-effectiveness ratios for the SAP with automated insulin suspension versus CSII of Swedish Krona (SEK) 139,795 [euros (EUR) 14,648] per QALY gained for patients at increased risk for hypoglycemia and SEK 251,896 (EUR 26,395) per QALY gained for patients with uncontrolled HbA1c. In both groups, SAP with automated insulin suspension also reduced the incidence of diabetes-related complications relative to CSII.

CONCLUSIONS

In Sweden, SAP with automated insulin suspension likely represents a cost-effective treatment option relative to CSII for the management of patients with type 1 diabetes with a history of severe hypoglycemic events or patients who struggle to achieve good glycemic control despite the use of CSII.

FUNDING

Medtronic International Trading Sàrl.

Evaluation of a Predictive Low-Glucose Management System In-Clinic

BACKGROUND

Predictions based on continuous glucose monitoring (CGM) data are the basis for automatic suspension and resumption of insulin delivery by a predictive low-glucose management feature termed "suspend before low," which is part of the Medtronic MiniMed^® 640G combined insulin pump and CGM system. This study assessed the safety and performance characteristics of the system in an in-clinic setting at eight sites.

MATERIALS AND METHODS

In-clinic standardized increases in basal insulin delivery rates were used to induce nocturnal hypoglycemia in subjects (14-75 years) with type 1 diabetes wearing the MiniMed 640G system. The "suspend before low" feature was set at 65 mg/dL, and as a result, the predictive algorithm suspended insulin delivery when the forecasted glucose was predicted to be ≤85 mg/dL in 30 min (a 20 mg/dL safety buffer). Reference plasma glucose values (Yellow Springs Instruments [YSI], Yellow Springs, OH) were used to establish hypoglycemia and were defined as ≥2 consecutive values ≤65 mg/dL.

RESULTS

Eighty subjects were screened. Among the 69 successful completers, 27 experienced a hypoglycemic event and 42 did not, a prevention rate of 60%. The mean (±standard deviation) YSI value at the time of pump suspension was 101 ± 18.5 mg/dL, and the mean duration of the 68 "suspend before low" events was 105 ± 27 min. At 120 min after the start of the pump suspension events, the mean YSI value was 102 ± 34.6 mg/dL.

CONCLUSION

The MiniMed 640G "suspend before low" feature prevented 60% of induced predicted hypoglycemic events without significant rebound hyperglycemia.

Clinical Use of Continuous Glucose Monitoring in Adults with Type 1 Diabetes

With the emphasis on intensive management of type 1 diabetes, data from studies support frequent monitoring of glucose levels to improve glycemic control and reduce glucose variability, which can be related to an increase in macro and microvascular complications. However, few perform capillary blood glucose that frequently. There are currently two available alternatives that this review will discuss, continuous glucose monitoring (CGM) and flash glucose monitoring. CGM has become an important diagnostic and therapeutic option in optimizing diabetes management. CGM systems are now more accurate, smaller, and easier to use compared to original models. Randomized controlled trials (RCTs) have demonstrated that CGM can improve Hemoglobin A1c (HbA1C) and reduce glucose variability in both continuous subcutaneous insulin infusion and multiple daily injection users. When used in an automated "insulin-suspend" system, reduced frequency of hypoglycemia and shorter time spent in hypoglycemic range have been demonstrated. Despite the potential benefits CGM has to offer in clinical practice, concerns exist on the accuracy of these devices and patient compliance with therapy, which may prevent the true clinical benefit of CGM being achieved, as observed in RCTs. Flash glucose monitoring systems FreeStyle® Libre™ (Abbott Diabetes Care, Alameda, CA) are as accurate as many CGM systems available and have the added benefit of being factory calibrated. Studies have shown that flash glucose monitoring systems are very well tolerated by patients and effectively reduce glucose variability, increasing time in range.

Who Should Be Considered for Islet Transplantation Alone?

PURPOSE OF REVIEW

Episodic hypoglycemia is an almost inevitable consequence of exogenous insulin treatment of type 1 diabetes, and in up to 30% of patients, this can lead to impaired awareness of hypoglycemia. This predisposes to recurrent severe hypoglycemia and has a huge impact on quality of life. Although many patients can get resolution of severe hypoglycemia through novel education and technology, some patients continue to have ongoing life-threatening hypoglycemia. Islet transplantation offers an alternative therapeutic option for these patients, in whom these conventional approaches have been unsuccessful. This review discusses the selection process of identifying suitable candidates based on recent clinical data.

RECENT FINDINGS

Results from studies of islet transplantation suggest the optimal recipient characteristics for successful islet transplantation include age >35 years, insulin requirements <1.0/kg, and weight < 85 kg. Islet transplantation can completely resolve hypoglycemia and near-normalize glucose levels, achieving insulin independence for a limited period of time in up to 40% of patients. The selection of appropriate candidates, optimizing donor selection, the use of an optimized protocol for islet cell extraction, and immunosuppression therapy have been proved to be the key criteria for a favorable outcome in islet transplantation.

"Let the Algorithm Do the Work": Reduction of Hypoglycemia Using Sensor-Augmented Pump Therapy with Predictive Insulin Suspension (SmartGuard) in Pediatric Type 1 Diabetes Patients

BACKGROUND

A sensor-augmented insulin pump (SAP) using the MiniMed^® 640G system with SmartGuard™ technology allows an automatic stop of insulin delivery based on prediction of low glucose levels. Since pediatric patients are particularly prone to hypoglycemia, this device may offer additional protection beyond conventional sensor-augmented therapy.

METHODS

This prospective, pediatric multicenter user evaluation assessed 6 weeks of SAP with SmartGuard (threshold setting for hypoglycemia: 70 mg/dL) compared to a preceding period of 2 weeks with SAP only. The primary outcome was the potential reduction in the frequency of hypoglycemic episodes and hypoglycemic intensity (area under the curve [AUC] and time <70 mg/dL).

RESULTS

The study included 24 patients with at least 3 months of insulin pump use (average age: 11.6 ± 5.1 years, 15 female, average type 1 diabetes duration: 7.5 ± 4.2 years, mean ± SD) who had on average 3.2 ± 1.0 predictive suspensions/patient/day. The mean sensor glucose minimum during suspension was 78 ± 6 mg/dL and the average suspension time was 155 ± 47 min/day. Use of SmartGuard in patients treated as per the protocol (n = 18) reduced the number of instances in which the glucose level was <70 mg/dL (1.02 ± 0.52 to 0.72 ± 0.36; P = 0.027), as well as AUC <70 mg/dL (0.76 ± 0.73 to 0.38 ± 0.24; P = 0.027) and the time/day the level fell below 70 mg/dL (73 ± 56 to 31 ± 22 min). The reduction of hypoglycemia was not associated with a significant change in mean glucose concentration (171 ± 26 to 180 ± 19 mg/dL, P = 0.111) and HbA1c (7.5% ± 0.5% to 7.6% ± 0.7%, (P = 0.329). Manual resumption of insulin delivery followed by carbohydrate intake resulted in significantly higher glucose levels 1 h after suspension compared to SmartGuard suspensions with automatic resume (190.8 ± 26.5 vs. 138.7 ± 10.3 mg/dL; P < 0.001).

CONCLUSIONS

SmartGuard technology significantly reduced the risk for hypoglycemia in pediatric type 1 diabetes patients without increasing HbA1c. Patients must be educated that when using combining predictive low-glucose insulin suspension technology, extra carbohydrate intake in response to an alarm combined with manual resumption is likely to cause rebound hyperglycemia. The best results were achieved when the user did not interfere with pump operation.

An Expert Opinion on Advanced Insulin Pump Use in Youth with Type 1 Diabetes

Among children and adolescents with type 1 diabetes mellitus, the use of insulin pump therapy has increased since its introduction in the early 1980s. Optimal management of type 1 diabetes mellitus depends on sufficient understanding by patients, their families, and healthcare providers on how to use pump technology. The goal for the use of insulin pump therapy should be to advance proficiency over time from the basics taught at the initiation of pump therapy to utilizing advanced settings to obtain optimal glycemic control. However, this goal is often not met, and appropriate understanding of the full features of pump technology can be lacking. The objective of this review is to provide an expert perspective on the advanced features and use of insulin pump therapy, including practical guidelines for the successful use of insulin pump technology, and other considerations specific to patients and healthcare providers.

H2O2-Responsive Vesicles Integrated with Transcutaneous Patches for Glucose-Mediated Insulin Delivery

A self-regulated "smart" insulin administration system would be highly desirable for diabetes management. Here, a glucose-responsive insulin delivery device, which integrates H₂O₂-responsive polymeric vesicles (PVs) with a transcutaneous microneedle-array patch was prepared to achieve a fast response, excellent biocompatibility, and painless administration. The PVs are self-assembled from block copolymer incorporated with polyethylene glycol (PEG) and phenylboronic ester (PBE)-conjugated polyserine (designated mPEG-b-P(Ser-PBE)) and loaded with glucose oxidase (GOx) and insulin. The polymeric vesicles function as both moieties of the glucose sensing element (GOx) and the insulin release actuator to provide basal insulin release as well as promote insulin release in response to hyperglycemic states. In the current study, insulin release responds quickly to elevated glucose and its kinetics can be modulated by adjusting the concentration of GOx loaded into the microneedles. In vivo testing indicates that a single patch can regulate glucose levels effectively with reduced risk of hypoglycemia.

Sensor-Augmented Insulin Pumps and Hypoglycemia Prevention in Type 1 Diabetes

Hypoglycemia can lead to seizures, unconsciousness, or death. Insulin pump treatment reduces the frequency of severe hypoglycemia compared with multiple daily injections treatment. The addition of a continuous glucose monitor, so-called sensor-augmented pump (SAP) treatment, has the potential to further limit the duration and severity of hypoglycemia as the system can detect and in some systems act on impending and prevailing low blood glucose levels. In this narrative review we summarize the available knowledge on SAPs with and without automated insulin suspension, in relation to hypoglycemia prevention. We present evidence from randomized trials, observational studies, and meta-analyses including nonpregnant individuals with type 1 diabetes mellitus. We also outline concerns regarding SAPs with and without automated insulin suspension. There is evidence that SAP treatment reduces episodes of moderate and severe hypoglycemia compared with multiple daily injections plus self-monitoring of blood glucose. There is some evidence that SAPs both with and without automated suspension reduces the frequency of severe hypoglycemic events compared with insulin pumps without continuous glucose monitoring.

Integrated sensor-augmented pump therapy systems [the MiniMed® Paradigm™ Veo system and the Vibe™ and G4® PLATINUM CGM (continuous glucose monitoring) system] for managing blood glucose levels in type 1 diabetes: a systematic review and economic evaluation

BACKGROUND

In recent years, meters for continuous monitoring of interstitial fluid glucose have been introduced to help people with type 1 diabetes mellitus (T1DM) to achieve better control of their disease.

OBJECTIVE

The objective of this project was to summarise the evidence on the clinical effectiveness and cost-effectiveness of the MiniMed(®) Paradigm™ Veo system (Medtronic Inc., Northridge, CA, USA) and the Vibe™ (Animas(®) Corporation, West Chester, PA, USA) and G4(®) PLATINUM CGM (continuous glucose monitoring) system (Dexcom Inc., San Diego, CA, USA) in comparison with multiple daily insulin injections (MDIs) or continuous subcutaneous insulin infusion (CSII), both with either self-monitoring of blood glucose (SMBG) or CGM, for the management of T1DM in adults and children.

DATA SOURCES

A systematic review was conducted in accordance with the principles of the Centre for Reviews and Dissemination guidance and the National Institute for Health and Care Excellence Diagnostic Assessment Programme manual. We searched 14 databases, three trial registries and two conference proceedings from study inception up to September 2014. In addition, reference lists of relevant systematic reviews were checked. In the absence of randomised controlled trials directly comparing Veo or an integrated CSII + CGM system, such as Vibe, with comparator interventions, indirect treatment comparisons were performed if possible.

METHODS

A commercially available cost-effectiveness model, the IMS Centre for Outcomes Research and Effectiveness diabetes model version 8.5 (IMS Health, Danbury, CT, USA), was used for this assessment. This model is an internet-based, interactive simulation model that predicts the long-term health outcomes and costs associated with the management of T1DM and type 2 diabetes. The model consists of 15 submodels designed to simulate diabetes-related complications, non-specific mortality and costs over time. As the model simulates individual patients over time, it updates risk factors and complications to account for disease progression.

RESULTS

Fifty-four publications resulting from 19 studies were included in the review. Overall, the evidence suggests that the Veo system reduces hypoglycaemic events more than other treatments, without any differences in other outcomes, including glycated haemoglobin (HbA1c) levels. We also found significant results in favour of the integrated CSII + CGM system over MDIs with SMBG with regard to HbA1c levels and quality of life. However, the evidence base was poor. The quality of the included studies was generally low, often with only one study comparing treatments in a specific population at a specific follow-up time. In particular, there was only one study comparing Veo with an integrated CSII + CGM system and only one study comparing Veo with a CSII + SMBG system in a mixed population. Cost-effectiveness analyses indicated that MDI + SMBG is the option most likely to be cost-effective, given the current threshold of £30,000 per quality-adjusted life-year gained, whereas integrated CSII + CGM systems and Veo are dominated and extendedly dominated, respectively, by stand-alone, non-integrated CSII with CGM. Scenario analyses did not alter these conclusions. No cost-effectiveness modelling was conducted for children or pregnant women.

CONCLUSIONS

The Veo system does appear to be better than the other systems considered at reducing hypoglycaemic events. However, in adults, it is unlikely to be cost-effective. Integrated systems are also generally unlikely to be cost-effective given that stand-alone systems are cheaper and, possibly, no less effective. However, evidence in this regard is generally lacking, in particular for children. Future trials in specific child, adolescent and adult populations should include longer term follow-up and ratings on the European Quality of Life-5 Dimensions scale at various time points with a view to informing improved cost-effectiveness modelling.

STUDY REGISTRATION

PROSPERO Registration Number CRD42014013764.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Continuous Glucose Monitoring: Impact on Hypoglycemia

The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia.

Effectiveness of Automated Insulin Management Features of the MiniMed® 640G Sensor-Augmented Insulin Pump

BACKGROUND

Automated insulin management features of the MiniMed® 640G sensor-augmented pump system include suspension in response to predicted low sensor glucose (SG) values ("suspend before low"), suspension in response to existing low SG values ("suspend on low"), and automatic restarting of basal insulin delivery upon SG recovery. The effectiveness of these features was evaluated using CareLink® software data.

METHODS

Anonymized data from MiniMed 640G system users (n = 4818), MiniMed 530G system users (n = 39,219), and MiniMed Paradigm® Veo™ system users (n = 43,193) who voluntarily uploaded pump and sensor data were retrospectively analyzed. Comparisons were made between days in which system features were enabled at any time and those in which they were not. Comparisons were also made between pump suspension events for which insulin delivery was automatically or manually resumed and between glycemic parameters of users who switched from the MiniMed Paradigm Veo system to the MiniMed 640G system.

RESULTS

Days in which the MiniMed 640G "suspend before low" feature was enabled had lower percentages of SG readings ≤70 mg/dL (3.9 mmol/L) or ≥240 mg/dL (13.3 mmol/L) than days when it was not enabled (P < 0.001 for each). Users who switched from the MiniMed Paradigm Veo system to the MiniMed 640G system had fewer excursions below ≤70 mg/dL (P < 0.001) and ≥240 mg/dL (P < 0.001). SG values following automatically resumed pump suspension events recovered more rapidly and had a more stabilized endpoint than following manually resumed events.

CONCLUSIONS

Automated insulin management features of the MiniMed 640G system can reduce the frequency of both high and low SG values and help stabilize SG after resumption of insulin delivery.

Effectiveness of the low-glucose suspend feature of insulin pump during fasting during Ramadan in type 1 diabetes mellitus

BACKGROUND

Severe hypoglycaemia during the daytime of Ramadan fasting is a highly feared complication. In a prospective study, we investigated the effect of the low-glucose suspend (LGS) algorithm on the frequency of hypoglycaemia in adolescents with T1DM who wished to fast during Ramadan.

SUBJECTS AND METHODS

Sixty patients (19 males and 41 females, 15.6 ± 2.7 years, duration of diabetes 5.8 ± 2.9 years, pump therapy for 1.73 ± 0.99 years, used the Paradigm(®) Veo(™) System (Medtronic) and were divided into two groups: first (n=25), those who used the sensor with low-glucose suspend (LGS) feature and second (n = 35), those who used the sensor but turned off low-glucose suspend (LGS) feature.

RESULTS

A total of 2716 LGS alerts occurred, and 48.6% began in the afternoon between 4pm and 7pm. The mean duration of LGS events was 26.5 min, 38% lasted for <5 min and 5.3% lasted for 120 min. Among these episodes, the mean sensor glucose was 62.3 ± 5.96 mg/dL at LGS activation, rose to 129.8 ± 11.6 mg/dL by the end of the LGS episode (when insulin delivery was automatically resumed) and was 155.6 ± 11.1 mg/dL at 240 min. LGS usage significantly reduced area under the curve (AUC) <70, AUC <60 mg/dL (p = 0.0001) and >240 mg/dL (p = 0.006). None of the LGS-on group broke their fast versus 15 in the second group (p = 0.001). No episodes of severe hyperglycaemia or DKA were noticed in either groups.

CONCLUSIONS

Usage of low-glucose suspend (LGS) significantly reduced exposure to hypoglycaemia without compromising safety. Copyright © 2016 John Wiley & Sons, Ltd.

Effectiveness of a Predictive Algorithm in the Prevention of Exercise-Induced Hypoglycemia in Type 1 Diabetes

BACKGROUND

Sensor-augmented pump therapy (SAPT) with a predictive algorithm to suspend insulin delivery has the potential to reduce hypoglycemia, a known obstacle in improving physical activity in patients with type 1 diabetes. The predictive low glucose management (PLGM) system employs a predictive algorithm that suspends basal insulin when hypoglycemia is predicted. The aim of this study was to determine the efficacy of this algorithm in the prevention of exercise-induced hypoglycemia under in-clinic conditions.

METHODS

This was a randomized, controlled cross-over study in which 25 participants performed 2 consecutive sessions of 30 min of moderate-intensity exercise while on basal continuous subcutaneous insulin infusion on 2 study days: a control day with SAPT alone and an intervention day with SAPT and PLGM. The predictive algorithm suspended basal insulin when sensor glucose was predicted to be below the preset hypoglycemic threshold in 30 min. We tested preset hypoglycemic thresholds of 70 and 80 mg/dL. The primary outcome was the requirement for hypoglycemia treatment (symptomatic hypoglycemia with plasma glucose <63 mg/dL or plasma glucose <50 mg/dL) and was compared in both control and intervention arms.

RESULTS

Results were analyzed in 19 participants. In the intervention arm with both thresholds, only 6 participants (32%) required treatment for hypoglycemia compared with 17 participants (89%) in the control arm (P = 0.003). In participants with a 2-h pump suspension on intervention days, the plasma glucose was 84 ± 12 and 99 ± 24 mg/dL at thresholds of 70 and 80 mg/dL, respectively.

CONCLUSIONS

SAPT with PLGM reduced the need for hypoglycemia treatment after moderate-intensity exercise in an in-clinic setting.

Prevention of Insulin-Induced Hypoglycemia in Type 1 Diabetes with Predictive Low Glucose Management System

BACKGROUND

Sensor-augmented pump therapy (SAPT) with algorithms to predict impending low blood glucose and suspend insulin delivery has the potential to reduce hypoglycemia exposure. The aim of this study was to determine whether predictive low glucose management (PLGM) system is effective in preventing insulin-induced hypoglycemia in controlled experiments.

METHODS

Two protocols were used to induce hypoglycemia in an in-clinic environment. (A) Insulin bolus: Insulin was administered as a manual bolus through the pump. (B) Increased basal insulin: Hypoglycemia was induced by increasing basal rates overnight to 180%. For both protocols, participants were randomized and studied on 2 separate days; a control day with SAPT alone and an intervention day with SAPT and PLGM activated. The predictive algorithm was programmed to suspend basal insulin infusion when sensor glucose was predicted to be <80 mg/dL in 30 min. The primary outcome was the requirement for hypoglycemia treatment (symptomatic hypoglycemia or plasma glucose <50 mg/dL) and was compared in both control and intervention arms.

RESULTS

With insulin bolus, 24/28 participants required hypoglycemia treatment with SAPT alone compared to 5/28 participants when PLGM was activated (P ≤ 0.001). With increased basal rates, all the eight SAPT-alone participants required treatment for hypoglycemia compared to only one with SAPT and PLGM. There was no post pump-suspend hyperglycemia with insulin bolus (P = 0.4) or increased basal rates (P = 0.69) in participants with 2-h pump suspension on intervention days.

CONCLUSIONS

SAPT with PLGM reduced the requirement for hypoglycemia treatment following insulin-induced hypoglycemia in an in-clinic setting.

Oral delivery of insulin for treatment of diabetes: status quo, challenges and opportunities

Objectives

Diabetes mellitus is characterised by progressive β-cell destruction and loss of function, or loss of ability of tissues to respond to insulin. Daily subcutaneous insulin injection is standard management for people with diabetes, although patient compliance is hard to achieve due to the inconvenience of injections, so other forms of delivery are being tested, including oral administration. This review summarises the developments in oral insulin administration.

Methods

The PubMed database was consulted to compile this review comparing conventional subcutaneous injection of insulin to the desired oral delivery.

Key findings

Oral administration of insulin has potential benefits in reducing pain and chances of skin infection, improving the portal levels of insulin and avoiding side effects such as hyperinsulinemia, weight gain and hypoglycaemia. Although oral delivery of insulin is an ideal administration route for patients with diabetes, several physiological barriers have to be overcome. An expected low oral bioavailability can be attributed to its high molecular weight, susceptibility to enzymatic proteolysis and low diffusion rate across the mucin barrier.

Conclusions

Strategies for increasing the bioavailability of oral insulin include the use of enzyme inhibitors, absorption enhancers, mucoadhesive polymers and chemical modification for endogenous receptor-mediated absorption. These may help significantly increase patient compliance and disease management.

Hypoglycemia Prevention and User Acceptance of an Insulin Pump System with Predictive Low Glucose Management

BACKGROUND

The MiniMed 640G sensor-augmented insulin pump system (Medtronic, Inc., Northridge, CA) can automatically suspend insulin delivery in advance of predicted hypoglycemia and restart it upon recovery. The aims of this analysis were to determine the rate at which predicted hypoglycemia was avoided with this strategy, as well as to assess user acceptance of the system and its insulin management features.

SUBJECTS AND METHODS

Forty subjects with type 1 diabetes used the system for 4 weeks. We retrospectively evaluated performance of the system, using downloaded pump and sensor data, and evaluated user acceptance via questionnaires.

RESULTS

There were 2,322 suspend before low events (2.1 per subject-day). The mean (± SD) duration of pump suspension events was 56.4 ± 9.6 min, and the mean subsequent sensor glucose (SG) nadir was 71.8 ± 5.2 mg/dL. SG values following 1,930 (83.1%) of the predictive suspensions did not reach the preset low limit. Nadir SG values of ≤50 and ≤60 mg/dL were seen in 207 (8.9%) and 356 (15.3%) of the predictive suspensions, respectively. Blood glucose (BG) and SG values before and during the study were comparable (P > 0.05). The mean absolute relative difference between paired SG and BG values was 10.9 ± 13.8%. Subjects felt confident using the system, agreed that it helped protect them from hypoglycemia, and wished to continue using it.

CONCLUSIONS

Automatic insulin pump suspension as implemented in the MiniMed 640G system can help patients avoid hypoglycemia, without significantly increasing hyperglycemia.

Safety and efficacy of the predictive low glucose management system in the prevention of hypoglycaemia: protocol for randomised controlled home trial to evaluate the Suspend before low function

INTRODUCTION

Innovations with sensor-augmented pump therapy (SAPT) to reduce hypoglycaemia in patients with type 1 diabetes are an ongoing area of research. The predictive low glucose management (PLGM) system incorporates continuous glucose sensor data into an algorithm and suspends basal insulin before the occurrence of hypoglycaemia. The system was evaluated in in-clinic studies, and has informed the parameters of a larger home trial to study its efficacy and safety in real life.

METHODS AND ANALYSIS

The aim of this report is to describe the study design and outcome measures for the trial. This is a 6-month, multicentre, randomised controlled home trial to test the PLGM system in children and adolescents with type 1 diabetes. The system is available in the Medtronic MiniMed 640G pump as the 'Suspend before low' feature. Following a run-in period, participants are randomised to either the control arm with SAPT alone or the intervention arm with SAPT and Suspend before low. The primary aim of this study is to evaluate the time spent hypoglycaemic (sensor glucose <3.5 mmol/L) with and without the system. The secondary aims are to determine the number of hypoglycaemic events, the time spent hyperglycaemic, and to evaluate safety with ketosis and changes in glycated haemoglobin. The study also aims to assess the changes in counter-regulatory hormone responses to hypoglycaemia evaluated by a hyperinsulinaemic hypoglycaemic clamp in a subgroup of patients with impaired awareness. Validated questionnaires are used to measure the fear of hypoglycaemia and the impact on the quality of life to assess burden of the disease.

ETHICS AND DISSEMINATION

Ethics committee permissions were gained from respective Institutional Review boards. The findings of the study will provide high quality evidence of the ability of the system in the prevention of hypoglycaemia in real life.

TRIAL REGISTRATION NUMBER

ACTRN12614000510640, Pre-results.

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Chapter 6: patient selection for pilot clinical trials of islet xenotransplantation

Patients in whom type 1 diabetes is complicated by impaired awareness of hypoglycemia and recurrent episodes of severe hypoglycemia are candidates for islet or pancreas transplantation if severe hypoglycemia persists after completion of a structured stepped care approach or a formalized medical optimization run-in period that provides access to hypoglycemia-specific education including behavioral therapies, insulin analogs, and diabetes technologies under the close supervision of a specialist hypoglycemia service. Patients with type 1 diabetes and end-stage renal failure who cannot meet clinically appropriate glycemic goals or continue to experience severe hypoglycemia after completion of a formalized medical optimization program under the guidance of an expert diabetes care team are candidates for islet or pancreas transplantation either simultaneously with or after a previous kidney transplant. Similarly, patients with type 2 diabetes and problematic hypoglycemia or renal failure who meet these criteria are considered candidates for islet replacement. Likewise, patients with pancreatectomy-induced diabetes in whom an islet autograft was not available or deemed inappropriate are candidates for islet or pancreas transplantation if extreme glycemic lability persists despite best medical therapy. To justify participation of these transplant candidates in early-phase trials of porcine islet cell products, lack of timely access to islet or pancreas allotransplantation due to allosensitization, high islet dose requirements, or other factors, or alternatively, a more favorable benefit-risk determination associated with the xenoislet than the alloislet or allopancreas transplant must be demonstrated. Additionally, in non-uremic xenoislet recipients, the risks associated with diabetes must be perceived to be more serious than the risks associated with the xenoislet product and the rejection prophylaxis, and in xenoislet recipients with renal failure, the xenoislet product and immunosuppression must not impact negatively on renal transplant outcomes. The most appropriate patient group for islet xenotransplantation trials will be defined by the specific characteristics of each investigational xenoislet product and related technologies applied for preventing rejection. Selecting recipients who are more likely to experience prolonged benefits associated with the islet xenograft will help these patients comply with lifelong monitoring and other public health measures.

Long-term health economic benefits of sensor-augmented pump therapy vs continuous subcutaneous insulin infusion alone in type 1 diabetes: a U.K. perspective

AIMS/HYPOTHESIS

Continuous subcutaneous insulin infusion (CSII) is an important treatment option for type 1 diabetes patients unable to achieve adequate glycemic control with multiple daily injections (MDI). Combining CSII with continuous glucose monitoring (CGM) in sensor-augmented pump therapy (SAP) with a low glucose-suspend (LGS) feature may further improve glycemic control and reduce the frequency of hypoglycemia. A cost-effectiveness analysis of SAP + LGS vs. CSII plus self-monitoring of blood glucose (SMBG) was performed to determine the health economic benefits of SAP + LGS in type 1 diabetes patients using CSII in the U.K.

METHODS

Cost-effectiveness analysis was performed using the CORE diabetes model. Treatment effects were sourced from the literature, where SAP + LGS was associated with a projected HbA1c reduction of -1.49% vs. -0.62% for CSII, and a reduced frequency of severe hypoglycemia. The time horizon was that of patient lifetimes; future costs and clinical outcomes were discounted at 3.5% and 1.5% per annum, respectively.

RESULTS

Projected outcomes showed that SAP + LGS was associated with higher mean quality-adjusted life expectancy (17.9 vs. 14.9 quality-adjusted life years [QALYs], SAP + LGS vs. CSII), and higher life expectancy (23.8 vs. 21.9 years), but higher mean lifetime direct costs (GBP 125,559 vs. GBP 88,991), leading to an incremental cost-effectiveness ratio (ICER) of GBP 12,233 per QALY gained for SAP + LGS vs. CSII. Findings of the base-case analysis remained robust in sensitivity analyses.

CONCLUSIONS/INTERPRETATION

For UK-based type 1 diabetes patients with poor glycemic control, the use of SAP + LGS is likely to be cost-effective compared with CSII plus SMBG.

Automated insulin pump suspension for hypoglycaemia mitigation: development, implementation and implications

In type 1 diabetes (T1D), insulin replacement therapy should ideally replicate endogenous insulin secretion, but achieving this goal requires frequent adjustments to insulin delivery based on glucose levels and trends, carbohydrate intake and physical activity. An overriding concern for people taking insulin is hypoglycaemia, which remains the most feared consequence of insulin therapy and limits therapy intensification options. Although fully automated systems that achieve consistent euglycaemia in T1D remain an elusive goal, improvements in continuous glucose monitoring (CGM) sensors and control algorithms have enabled semi-automated systems that lower the risk of hypoglycaemia, especially nocturnal hypoglycaemia. The present review focuses on an important advance in insulin delivery systems: the use of CGM data to stop insulin delivery in the presence of hypoglycaemia. Although conceptually simple, this strategy represents a critical step in the journey toward a fully closed-loop artificial pancreas; the next steps in this journey are also discussed.

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.

Outpatient Management of Pediatric Type 1 Diabetes

The incidence of both type 1 and type 2 diabetes (T1DM and T2DM) continues to rise within the pediatric population. However, T1DM remains the most prevalent form diagnosed in children. It is critical that health-care professionals understand the types of diabetes diagnosed in pediatrics, especially the distinguishing features between T1DM and T2DM, to ensure proper treatment. Similar to all individuals with T1DM, lifelong administration of exogenous insulin is necessary for survival. However, children have very distinct needs and challenges compared to those in the adult diabetes population. Accordingly, treatment, goals, and age-appropriate requirements must be individually addressed. The main objectives for the treatment of pediatric T1DM include maintaining glucose levels as close to normal as possible, avoiding acute complications, and preventing long-term complications. In addition, unique to pediatrics, facilitating normal growth and development is important to comprehensive care. To achieve these goals, a careful balance of insulin therapy, medical nutrition therapy, and exercise or activity is necessary. Pharmacological treatment options consist of various insulin products aimed at mimicking prior endogenous insulin secretion while minimizing adverse effects. This review focuses on the management of pediatric T1DM in the outpatient environment, highlighting pharmacotherapy management strategies.

Inhaled Formoterol Diminishes Insulin-Induced Hypoglycemia in Type 1 Diabetes

OBJECTIVE

Hypoglycemia is one of the major factors limiting implementation of tight glycemic control in patients with type 1 diabetes and is associated with increased morbidity and mortality during intensive insulin treatment. β-2 Adrenergic receptor (AR) agonists have been reported to diminish nocturnal hypoglycemia; however, whether long-acting inhaled β-2 AR agonists could potentially be used to treat or prevent hypoglycemia has not been established.

RESEARCH DESIGN AND METHODS

Seven patients with type 1 diabetes and seven healthy control subjects received inhaled formoterol (48 μg), a highly specific β-2 AR agonist, or a placebo during a hyperinsulinemic-hypoglycemic clamp study to evaluate its capacity to antagonize the effect of insulin. In a second set of studies, five subjects with type 1 diabetes received inhaled formoterol to assess its effect as a preventive therapy for insulin-induced hypoglycemia.

RESULTS

During a hyperinsulinemic-hypoglycemic clamp, compared with placebo, inhaled formoterol decreased the glucose infusion rate required to maintain plasma glucose at a target level by 45-50% (P < 0.05). There was no significant effect on glucagon, epinephrine, cortisol, or growth hormone release (P = NS). Furthermore, in volunteers with type 1 diabetes 1 h after increasing basal insulin delivery twofold, glucose levels dropped to 58 ± 5 mg/dL, whereas hypoglycemia was prevented by inhaled formoterol (P < 0.001).

CONCLUSIONS

Inhalation of the β-2 AR-specific agonist formoterol may be useful in the prevention or treatment of acute hypoglycemia and thus may help patients with type 1 diabetes achieve optimal glucose control more safely.