Implantable insulin pumps. A position statement about their clinical use

The management of type 1 diabetes in adults. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) convened a writing group to develop a consensus statement on the management of type 1 diabetes in adults. The writing group has considered the rapid development of new treatments and technologies and addressed the following topics: diagnosis, aims of management, schedule of care, diabetes self-management education and support, glucose monitoring, insulin therapy, hypoglycaemia, behavioural considerations, psychosocial care, diabetic ketoacidosis, pancreas and islet transplantation, adjunctive therapies, special populations, inpatient management and future perspectives. Although we discuss the schedule for follow-up examinations and testing, we have not included the evaluation and treatment of the chronic microvascular and macrovascular complications of diabetes as these are well-reviewed and discussed elsewhere. The writing group was aware of both national and international guidance on type 1 diabetes and did not seek to replicate this but rather aimed to highlight the major areas that healthcare professionals should consider when managing adults with type 1 diabetes. Though evidence-based where possible, the recommendations in the report represent the consensus opinion of the authors. Graphical abstract.

The Management of Type 1 Diabetes in Adults. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) convened a writing group to develop a consensus statement on the management of type 1 diabetes in adults. The writing group has considered the rapid development of new treatments and technologies and addressed the following topics: diagnosis, aims of management, schedule of care, diabetes self-management education and support, glucose monitoring, insulin therapy, hypoglycemia, behavioral considerations, psychosocial care, diabetic ketoacidosis, pancreas and islet transplantation, adjunctive therapies, special populations, inpatient management, and future perspectives. Although we discuss the schedule for follow-up examinations and testing, we have not included the evaluation and treatment of the chronic microvascular and macrovascular complications of diabetes as these are well-reviewed and discussed elsewhere. The writing group was aware of both national and international guidance on type 1 diabetes and did not seek to replicate this but rather aimed to highlight the major areas that health care professionals should consider when managing adults with type 1 diabetes. Though evidence-based where possible, the recommendations in the report represent the consensus opinion of the authors.

Insulin Pump Therapy

BACKGROUND

Advances in pump technology have increased the popularity of this treatment modality among patients with type 1 diabetes and recently also among patients with type 2 diabetes.

AREAS OF UNCERTAINTY

Four decades after the incorporation of the insulin pump in clinical use, questions regarding its efficacy, occurrence rate of short-term complications as hypoglycemia and diabetes ketoacidosis, timing of pump initiation, and selected populations for use remain unanswered.

DATA SOURCES

A review of the literature was performed using the PubMed database to identify all articles published up till December 2018, with the search terms including insulin pump therapy/continuous subcutaneous insulin delivery. The Cochrane database was searched for meta-analysis evaluating controlled randomized trials. Consensuses guidelines published by the International Society for Pediatric and Adolescent Diabetes, American Diabetes Association, and Advanced Technologies and Treatments for Diabetes year books were additionally reviewed for relevant cited articles.

THERAPEUTIC ADVANCES

Insulin pump therapy offers flexible management of diabetes. It enables adjustment of basal insulin to daily requirements and circadian needs, offers more precise treatment for meals and physical activity, and, when integrated with continuous glucose monitoring, allows glucose responsive insulin delivery. The ability to download and transmit data for analysis allow for treatment optimization. Newer pumps are simple to operate and increase user experience. Studies support the efficacy of pump therapy in improving glycemic control and reducing the occurrence of hypoglycemia without increasing episodes of diabetes ketoacidosis. They also improve quality of life. Recent evidence suggests a role for pump therapy in reducing microvascular and macrovascular diabetes-related complications.

CONCLUSIONS

Insulin pump therapy appears to be effective and safe in people with T1D regardless of age. Future advancements will include incorporation of closed loop and various decision support systems to aid and improve metabolic control and quality of life.

Molecular Mechanisms of Glucose Fluctuations on Diabetic Complications

Accumulating evidence indicates the occurrence and development of diabetic complications relates to not only constant high plasma glucose, but also glucose fluctuations which affect various kinds of molecular mechanisms in various target cells and tissues. In this review, we detail reactive oxygen species and their potentially damaging effects upon glucose fluctuations and resultant downstream regulation of protein signaling pathways, including protein kinase C, protein kinase B, nuclear factor-κB, and the mitogen-activated protein kinase signaling pathway. A deeper understanding of glucose-fluctuation-related molecular mechanisms in the development of diabetic complications may enable more potential target therapies in future.

High drug-loading gold nanoclusters for responsive glucose control in type 1 diabetes

BACKGROUND

Diabetes is one of the biggest medical challenges worldwide. The key to efficiently treat type 1 diabetes is to accurately inject insulin according to the blood glucose levels. In this study, we aimed to develop an intelligent insulin-releasing gold nanocluster system that responds to environmental glucose concentrations.

RESULTS

We employed gold nanoclusters (AuNCs) as a novel carrier nanomaterial by taking advantage of their high drug-loading capacity. We prepared AuNCs in the protection of bovine serum albumin, and we decorated AuNCs with 3-aminophenylboronic acid (PBA) as a glucose-responsive factor. Then we grafted insulin onto the surface to obtain the glucose-responsive insulin-releasing system, AuNC-PBA-Ins complex. The AuNC-PBA-Ins complex exhibited high sensitivity to glucose concentration, and rapidly released insulin in high glucose concentration in vitro. In the type 1 diabetic mouse model in vivo, the AuNC-PBA-Ins complex effectively released insulin and regulated blood glucose level in the normoglycemic state for up to 3 days.

CONCLUSIONS

We successfully developed a phenylboronic acid-functionalized gold nanocluster system (AuNC-PBA-Ins) for responsive insulin release and glucose regulation in type 1 diabetes. This nanocluster system mimics the function of blood glucose regulation of pancreas in the body and may have potential applications in the theranostics of diabetes.

Closed-loop insulin delivery: current status of diabetes technologies and future prospects

INTRODUCTION

Type 1 diabetes is characterised by destruction of pancreatic beta cells, leading to insulin deficiency and hyperglycaemia. The mainstay of treatment remains lifelong insulin therapy as a sustainable cure has as yet proven elusive. The burden of daily management of type 1 diabetes has contributed to suboptimal outcomes for people living with the condition. Innovative technological approaches have been shown to improve glycaemic and patient-related outcomes.

AREAS COVERED

We discuss recent advances in technologies in type 1 diabetes including closed-loop systems, also known as the 'artificial pancreas. Its various components, technical aspects and limitations are reviewed. We also discuss its advent into clinical practice, and other systems in development. Evidence from clinical studies are summarised.

EXPERT COMMENTARY

The recent approval of a hybrid closed-loop system for clinical use highlights the significant progress made in this field. Results from clinical studies have shown safety and glycaemic benefit, however challenges remain around improving performance and acceptability. More data is required to establish long-term clinical efficacy and cost-effectiveness, to fulfil the expectations of people with type 1 diabetes.

Finding the right route for insulin delivery - an overview of implantable pump therapy

INTRODUCTION

Implantable pump therapy adopting the intraperitoneal route of insulin delivery has been available for the past three decades. The key rationale for implantable pump therapy is the restoration of the portal-peripheral insulin gradient of the normal physiology. Uptake in clinical practice is limited to specialized centers and selected patient populations. Areas covered: Implantable pump therapy is discussed, including technical aspects, rationale for its use, and glycemic and non-glycemic effects. Target populations, summaries of clinical studies and issues related to implantable pump therapy are highlighted. Limitations of implantable pump therapy and its future outlook in clinical practice are presented. Expert opinion: Although intraperitoneal insulin delivery appears closer to the normal physiology, technical, pharmacological, and costs barriers prevent a wider adoption. Evidence from clinical studies remains scarce and inconclusive. As a consequence, the use of implantable pump therapy will be confined to a small population unless considerable technological progress is made and well-conducted studies can demonstrate glycemic and/or non-glycemic benefits justifying wider application.

9th Annual Symposium on Self-Monitoring of Blood Glucose, April 28-30, 2016, Madrid, Spain

International experts in the field of diabetes and diabetes technology met in Madrid, Spain, for the 9th Annual Symposium on Self-Monitoring of Blood Glucose. The goal of these meetings is to establish a global network of experts, thus facilitating new collaborations and research projects to improve the lives of people with diabetes. The 2016 meeting comprised a comprehensive scientific program, parallel interactive workshops, and two keynote lectures.

[Technology in the nurse-patient relationship in diabetology, a true metronome?]

Technology is evolving to keep pace with patients' and caregivers' needs and advances in research. In diabetology, this progress concerns administration systems, the devices for monitoring blood sugar levels, accessories and technical support, and provides hope for tomorrow. In this context, it is essential that the patient remains at the centre of the nurse-patient relationship and that technology remains simply a source of reference points and comfort.

Continuous intraperitoneal insulin infusion versus subcutaneous insulin therapy in the treatment of type 1 diabetes: effects on glycemic variability

INTRODUCTION

As continuous intraperitoneal insulin infusion (CIPII) results in a more physiologic action of insulin than subcutaneous (SC) insulin administration, we hypothesized that CIPII would result in less glycemic variability (GV) than SC insulin therapy among type 1 diabetes mellitus (T1DM) patients.

MATERIALS AND METHODS

Data from 5-day blind continuous glucose monitoring (CGM) measurements performed during a 26-week, prospective, observational case-control study were analyzed. The coefficient of variation (CV) was the primary measure of GV. In addition, the SD of the mean glucose level, mean of daily differences, and mean amplitude of glycemic excursions were calculated.

RESULTS

In total, 176 patients (36% male; mean age, 49 [SD 13] years; median diabetes duration, 24 [interquartile range, 17, 35] years; glycated hemoglobin level, 63 [10] mmol/mmol), of which 37 used CIPII and 139 SC insulin therapy, were analyzed. CGM data were available for 169 patients at baseline (CIPII, n=35; SC, n=134) and for 164 patients at 26 weeks (CIPII, n=35; SC, n=129). After adjustment for baseline differences, the CV was 4.9% (95% confidence interval, 1.0, 8.8) lower with CIPII- compared with SC-treated patients, irrespective of the use of multiple daily injections or continuous SC insulin infusion. There were no differences in other indices of GV between groups.

CONCLUSIONS

Despite higher blood glucose, the CV was slightly lower with CIPII compared with SC insulin therapy in T1DM patients, and other measures of GV were identical. Future studies are needed to confirm these findings and investigate whether this results in prevention of hypoglycemia and even perhaps (less) microvascular complications.

7(th) Annual Symposium on Self-Monitoring of Blood Glucose (SMBG), May 8-10, 2014, Helsinki, Finland

International experts in the fields of diabetes, diabetes technology, endocrinology, mobile health, sport science, and regulatory issues gathered for the 7(th) Annual Symposium on Self-Monitoring of Blood Glucose (SMBG). The aim of this meeting was to facilitate new collaborations and research projects to improve the lives of people with diabetes. The 2014 meeting comprised a comprehensive scientific program, parallel interactive workshops, and two keynote lectures.

Assessment of a new insulin preparation for implanted pumps used in the treatment of type 1 diabetes

BACKGROUND

Implanted insulin pumps using the peritoneal route provide long-term improvement of glucose control compared with subcutaneous insulin therapy in type 1 diabetes (T1D) patients. The stability of insulin preparation is critical for a safe use in implanted pumps. Insuman implantable(®) (400 IU/mL) (Sanofi-Aventis Deutschland GmbH, Frankfurt am Main, Germany), a recombinant human insulin, has been developed as a replacement for Insuplant(®) (Aventis Pharma, Frankfurt am Main, Germany), a semisynthetic insulin, the only one used so far. The aim of the study was to demonstrate the noninferiority of Insuman versus Insuplant, in terms of safety and effectiveness when used in implanted pumps.

SUBJECTS AND METHODS

The patients enrolled, currently treated for T1D by the Medtronic MiniMed (Northridge, CA) implantable pump model 2007 with Insuplant, were randomized into two study arms and received either Insuman or Insuplant for four pump refill cycles. Each pump refill cycle was 40±5 days. The co-primary end points included glycated hemoglobin (HbA1c) change from baseline and pump infusion accuracy.

RESULTS

In total, 169 patients were randomized. Noninferiority of Insuman versus Insuplant was demonstrated both for the HbA1c change from baseline (as a percentage) with intergroup difference of 95% confidence interval (-0.36;+0.11) and for the infusion accuracy assessed by the measured percentage of error at pump refill, as shown by intergroup difference of 95% confidence interval (-5.81; -0.50), in per-protocol populations, although the insulin daily dose was similar. Severe hypoglycemia occurred at least once in 12 versus 11 patients, respectively, and metabolic or technical adverse events were comparable.

CONCLUSIONS

Findings suggest that Insuman can safely and effectively replace Insuplant in implanted pumps.

Use of the continuous glucose monitoring system to treat insulin autoimmune syndrome: quantification of glucose excursions and evaluation of treatment efficacy

BACKGROUND

Autoimmune hypoglycaemia, based on the presence of autoantibodies directed against endogenous insulin (insulin autoimmune syndrome or Hirata's disease), is a rare cause of hypoglycaemia. Treatment of the disease is not standardized and various therapeutic options have been proposed. We wondered whether using a continuous glucose-monitoring system could help quantify precisely glucose excursions and allow evaluation of treatment efficacy.

CASE REPORT

A 44-year-old Caucasian patient with insulin autoimmune syndrome was studied for 7 days using a continuous glucose monitoring system under various treatment regimens, i.e. diet modification, high-dose corticosteroids, alpha-glucosidase inhibitors, and plasmapheresis.

CONCLUSION

Continuous glucose monitoring system data confirmed that insulin autoimmune syndrome alternated between periods of prandial hyperglycaemia and interprandial hypoglycaemia. Alpha glucosidase inhibitors and plasmapheresis were more potent in limiting glucose excursions than corticosteroid or diet-only treatments. The continuous glucose monitoring system appears to be a useful tool in the management of insulin autoimmune syndrome.

Continuous intraperitoneal insulin infusion in type 1 diabetes: a 6-year post-trial follow-up

BACKGROUND

Continuous intraperitoneal insulin infusion (CIPII) with an implantable pump is a treatment option for patients with type 1 diabetes mellitus (T1DM). Aim of the present study was to describe the long-term course of glycaemic control, complications, health related quality of life (HRQOL) and treatment satisfaction among T1DM patients treated with CIPII.

METHODS

Nineteen patients that participated in a randomized cross-over trial comparing CIPII and subcutaneous (SC) therapy in 2006 were followed until 2012. Laboratory, continuous glucose monitoring, HRQOL and treatment satisfaction measurements were performed at the start of the study, the end of the SC-, the end of the CIPII treatment phase in 2006 and during CIPII therapy in 2012. Linear mixed models were used to calculate estimated values and to test differences between the moments in time.

RESULTS

In 2012, more time was spent in hyperglycaemia than after the CIPII treatment phase in 2006: 37% (95% CI 29, 44) vs. 55% (95% CI 48, 63), mean difference 19.8% (95% CI 3.0, 36.6). HbA1c was 65 mmol/mol (95% CI 60, 71) at the end of the SC treatment phase in 2006, 58 mmol/mol (95% CI 53, 64) at the end of the CIPII treatment phase and 65 mmol/mol (95% CI 60, 71) in 2012, respectively (p > 0.05). In 2012, the median number of grade 2 hypoglycaemic events per week (1 (95% CI 0, 2)) was still significantly lower than during prior SC therapy (3 (95% CI 2, 4)): mean change -1.8 (95% CI -3.4, -0.4). Treatment satisfaction with CIPII was better than with SC insulin therapy and HRQOL remained stable. Pump or catheter dysfunction of the necessitated re-operation in 7 patients. No mortality was reported.

CONCLUSIONS

After 6 years of CIPII treatment, glycaemic regulation is stable and the number of hypoglycaemic events decreased compared to SC insulin therapy. Treatment satisfaction with CIPII is superior to SC insulin therapy, HRQOL is stable and complications are scarce. CIPII is a safe and effective treatment option for selected patients with T1DM, also on longer term.

Systematic review: continuous intraperitoneal insulin infusion with implantable insulin pumps for diabetes mellitus

Continuous intraperitoneal insulin infusion (CIPII) with implantable insulin pumps (IIPs) is a treatment option for diabetes, which is not widely utilized nor freely accessible in clinical practice. The aim of this study was to summarize available evidence on use of IIPs for CIPII for diabetes treatment, since its introduction to clinical use on the following outcomes: HbA1c, hypoglycaemic events, and complications of treatment.

SECONDARY OUTCOMES

complications of diabetes and treatment satisfaction. Following the procedure for a systematic review this paper may contribute to a balanced evaluation of the need and effectiveness of IIPs. A pre-specified, registered protocol (CRD42012002150) was followed. Studies investigating all diabetes populations and types of IIPs were considered eligible. The sensitive search strategy was developed in collaboration with a clinical librarian and contents experts. PUBMED, MEDLINE, CENTRAL EMBASE, trial registries, and other databases were searched. References were screened independently by two authors, and decisions on study selection were recorded. Of the 1,703 references screened, 362 were assessed as potentially eligible. Ninety-four were identified as studies using IIPs. Fifteen papers, together reporting on four-randomized trials, and eight cohorts were included. Narrative analysis is provided, and data tables are available. CIPII by way of IIPs is effective in lowering HbA1c levels and reducing hypoglycaemic events. Superiority of IIP treatment is likely related to patient characteristics, one subgroup being patients unable to acquire satisfactory glycaemic control with subcutaneous insulin treatment. Higher treatment satisfaction was also reported for this subgroup. For these patients, risk of morbidity may be considered acceptable. Patients' perspectives, influence on quality of life, and possible other outcomes should also be considered important factors in weighing individual benefits and risks. A more uniform method of reporting would help strengthen the evidence base.

Short sleep duration measured by wrist actimetry is associated with deteriorated glycemic control in type 1 diabetes

OBJECTIVE

Sleep restriction has been associated with deteriorated insulin sensitivity. The effects of short sleep duration have been explored little in patients with type 1 diabetes. This study addresses the question of whether sleep curtailment affects HbA1c levels in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Seventy-nine adult patients with type 1 diabetes (median age 40 years [IQR 23-49]; 47% men) were recruited to wear a wrist actimetry sensor during 3 consecutive days to assess mean sleep duration during normal daily life. A subsample of 37 patients also performed 24-h ambulatory blood pressure monitoring (ABPM). Medical history, sleep questionnaires, and diabetes-related quality of life (DQOL) were assessed.

RESULTS

Patients having shorter sleep duration--less than 6.5 h (n=21)--had higher levels of HbA1c (P=0.01) than patients with longer sleep duration, above 6.5 h (n=58). In a multivariable regression model including shorter versus longer sleep duration, diabetes duration, DQOL score, and daily activity, sleep duration was the only variable independently associated with HbA1c (R2=10%). In patients who performed 24-h ABPM, patients with a nondipping pattern of blood pressure exhibited shorter sleep duration than patients with a dipping pattern of blood pressure.

CONCLUSIONS

Shorter sleep duration is associated with higher HbA1c levels in patients with type 1 diabetes, as well as with a nondipping pattern of blood pressure, anticipating a long-term deleterious impact on the risk of microvascular complications. Further studies should test whether extending the duration of sleep may improve both HbA1c and blood pressure in type 1 diabetes.

Complications of continuous intraperitoneal insulin infusion with an implantable pump

AIM: To monitor the course of continuous intraperitoneal insulin infusion (CIPII) and to gain more insight into possible complications.

METHODS: A retrospective, longitudinal observational cohort study in patients with type 1 diabetes mellitus (T1DM) was performed. Only patients with “brittle” T1DM who started CIPII between January 1, 2000 and June 1, 2011, and were treated in the only centre in The Netherlands providing CIPII treatment (Isala clinics, Zwolle) were eligible for inclusion. Outcomes were defined as operation-free period (OFP), rate and type of complications. Subanalyses were made between patients starting CIPII from 2000 to 2007 and from 2007 onwards in order to study possible changes over time in complications and/or OFP. The OFP was calculated as the time from initial implantation to the date of first documented re-operation. If patients had not experienced an operation, their data were recorded at the date of last follow up or death. Kaplan-Meier curves were constructed to visualize the OFP. A (two-sided) P value of less than 0.05 was considered statistically significant.

RESULTS: Fifty-seven patients were treated with CIPII, although one patient was excluded from analyses because of self-induced complications. In the remaining 56 patients, 70 complications occurred during 283 patient years. Catheter occlusion (32.9%), pump dysfunction (17.1%), pain at the pump site (15.7%) and infections (10.0%) were the most frequent complications. This resulted in a median OFP of 4.5 years (95% confidence interval 4.1-4.8 years) without any difference between the time periods. Fifty re-operations were performed because of complications, one per 5.6 patient years, with a decrease in pump dysfunction (P = 0.04) and pump explantations (P = 0.02) after 2007. In total, 9 episodes of ketoacidosis occurred during follow up and there were 69 hospital re-admissions, with a median duration of 6 d. CIPII was ceased in five patients due to recurrent infections (n = 2), pain (n = 1), inadequate glycaemic control (n = 1) or by own choice (n = 1). No CIPII related mortality was reported.

CONCLUSION: The OFP has been stable over the last decade. No CIPII related mortality was reported. A significant decrease in pump dysfunction and explantation was seen after 2007 compared to the period 2000-2007. CIPII remains a safe treatment modality for specific patient groups.

Advances in pump technology: insulin patch pumps, combined pumps and glucose sensors, and implanted pumps

This review discusses the most recent developments in insulin pump technology. The benefits of the insulin pump to patients with type 1 diabetes are recognized both for its metabolic effectiveness and its positive effects on quality of life. The current pumps are reliable, small and light, and are becoming more and more sophisticated. Nevertheless, there remain practical and psychological constraints for the patient. However, recent patch-pump advances should simplify the technical aspects of pump treatment and enhance patient comfort. Another advance combines the insulin pump with a glucose sensor. Such a combination is logical for optimizing pump use and, to that end, developing an automated or 'closed-loop'system that permits the delivery of subcutaneous insulin adjusted according to measured levels of subcutaneous glucose. Finally, implanted insulin pumps have proven their worth not only because of their simple use, but also for their contribution in the artificial pancreas project. Indeed, the prompt response with intraperitoneal administration of insulin makes it of interest for use in a closed-loop system.

Evolution of devices in diabetes management

Recent technological advancements in insulin administration and glucose monitoring have allowed patients with diabetes to become increasingly involved in their own care. Devices replacing the traditional vial and syringe, such as insulin pens, are gaining popularity and offer simple and convenient insulin administration. Pen devices are associated with improved dose accuracy, reducing the risk of hypo- or hyperglycemia, and are continually being updated with new safety features in order to optimize their performance. In patients for whom glucose variability remains a problem, continuous subcutaneous insulin infusion via an implanted canula or continuous intraperitoneal insulin infusion via an implanted pump is safe and effective when used correctly, although cost can be a limitation. More accurate retrospective and real-time continuous monitoring devices, which can better detect blood glucose excursions, have become standard components of modern-day diabetes management. The most recent devices have sensor-signaling capabilities with wireless data transmission, leading to reduced time delay and more accurate alerts. Ultimately, though, while self-management remains a critical factor in improving glycemic control at present, human error may undermine even the most accurate treatment interventions. A key long-term goal in diabetes management is, therefore, to develop an automated and accurate closed-loop system for blood glucose monitoring and insulin delivery to better reflect the physiological mechanisms of glucose homeostasis and remove the "human" element. This "artificial pancreas" would offer the most innovative intervention for diabetes management and has the potential to considerably reduce the patient's burden of self-care.

A recent survey confirms the efficacy and the safety of implanted insulin pumps during long-term use in poorly controlled type 1 diabetes patients

BACKGROUND

This article reports a prolonged trial with insulin pumps implanted in patients with type 1 diabetes showing poor glucose control and a high rate of complications.

METHODS

We reviewed data from 181 patients undergoing implanted insulin pump therapy. Analysis included hemoglobin A1c (HbA1c) values, body weight, and diabetes complications status.

RESULTS

At implantation, the mean age was 43 (range, 19-72) years, mean duration of diabetes was 22.2 (2-52) years, and mean body weight was 68.6 (43-104) kg. The complication status involved retinopathy (62% of patients), neuropathy (34.6%), nephropathy (26%), and cardiovascular disease (14%). Patients' previous insulin treatment regimen was multiple daily injections (17.1%) or continuous subcutaneous insulin infusion (82.9%). HbA1c levels significantly dropped from 7.9 ± 1.2% to 7.6 ± 1.2% after 1 year (P < 0.01) and remained within the range of 7.5-7.6% for up to 5 years. No significant variation of body weight or complications status occurred.

CONCLUSIONS

Implanted insulin pump therapy demonstrates long-term benefits in type 1 diabetes patients who have poor prognosis under intensive subcutaneous treatment.

Using a fuzzy controller optimized by a genetic algorithm to regulate blood glucose level in type 1 diabetes

In this paper a closed-loop control algorithm for blood glucose regulation in type 1 diabetic patients is proposed by using the Mamdani-type fuzzy method. Because of the presence of high-pass proportional derivatives in fuzzy designing, optimal values are applied for two inputs and one output membership functions in order to prevent the fluctuations due to derivatives in fuzzy design. Therefore, 19 values which are related to membership functions of the two inputs and one output are obtained by using a genetic algorithm (GA). The new model, termed the Augmented Minimal Model (AMM), is used in simulations. This controller is capable of stabilizing the blood glucose concentration at a normoglycaemic level of 90 mg dl(-1). The operation of the controller under various situations including multiple meal disturbances, and noise due to inaccurate effects of measuring blood glucose level are considered. Uncertainties in the meal disturbance function and variations of model parameters were also taken into consideration in simulations and the controller was found to be robust to such uncertainties.

A novel strategy for long-term implantable artificial pancreas

Technology has recently changed type 1 diabetes treatment by introducing several advancements able to improve patients' quality of life. However, despite of several decades of research efforts, the dream of a fully-automated implanted artificial pancreas is quite far from its realization. The need for periodically restoring the implanted battery charge and refilling the implanted insulin reservoir are the main issues, for which invasive surgery, transcutaneous catheters or external portable devices are presently the only solutions. In this paper we propose a novel approach to these issues, describing a totally implanted closed-loop artificial pancreas with a wireless battery charger and a non-invasive strategy for insulin refilling, based on sensorized swallowable "insulin carrier" capsules. Such system has the potential to represent a final solution for diabetes treatment, by fully restoring patients' quality of life.

Assessing glycaemic variability with continuous glucose monitoring system before and after continuous subcutaneous insulin infusion in people with Type 1 diabetes

We evaluated glycaemic variability with continuous glucose monitoring system in 31 people with Type 1 diabetes mellitus using multiple daily injections initially and after switching to continuous subcutaneous insulin infusion. There was a significant improvement in HbA1c, mean glucose, standard deviation of mean glucose and in hyperglycaemic excursions with CSII.

Insulin pump use in Europe

Although European groups have initiated innovative clinical research in the field of insulin pump therapy, insulin pump use remains currently limited in many European countries, and well behind that in the United States. The main reason is the late approval of cost coverage by most national healthcare insurance systems, which is still lacking in some countries. Partly in connection with this delay, the number of trained physicians to pump therapy is low in many countries, while diabetes educators do not exist as an acknowledged entity in many European countries, and pump manufacturers are excluded from the education process of patients in most of them. Pump use in pediatric-age populations has strongly increased during the last years, following the evidence-based demonstrations of the benefits of pump therapy in these patients leading to an international consensus on pump indications and practice. Failure to control type 1 diabetes to target and frequent hypoglycemia under multiple daily insulin injections are consensus-based but restrictive indications for pump therapy in adults in most countries. The economic burden on healthcare insurance systems does not facilitate wider use of insulin pumps, but a significant expansion of pump therapy according to consensus-based indications is still expected thanks to the growing knowledge of physicians in technologies and because of the increasing interest of patients to use technology to improve their control of diabetes and health-related quality of life. More sophisticated technologies connected to pump therapy, such as continuous glucose monitoring or telemedicine, will need specific cost coverage for a true implementation in diabetes care in Europe.

Closed-loop insulin delivery using a subcutaneous glucose sensor and intraperitoneal insulin delivery: feasibility study testing a new model for the artificial pancreas

OBJECTIVE

Attempts to build an artificial pancreas by using subcutaneous insulin delivery from a portable pump guided by an subcutaneous glucose sensor have encountered delays and variability of insulin absorption. We tested closed-loop intraperitoneal insulin infusion from an implanted pump driven by an subcutaneous glucose sensor via a proportional-integral-derivative (PID) algorithm.

RESEARCH DESIGN AND METHODS

Two-day closed-loop therapy (except for a 15-min pre-meal manual bolus) was compared with a 1-day control phase with intraperitoneal open-loop insulin delivery, according to randomized order, in a hospital setting in eight type 1 diabetic patients treated by implanted pumps. The percentage of time spent with blood glucose in the 4.4-6.6 mmol/l range was the primary end point. RESULTS During the closed-loop phases, the mean +/- SEM percentage of time spent with blood glucose in the 4.4-6.6 mmol/l range was significantly higher (39.1 +/- 4.5 vs. 27.7 +/- 6.2%, P = 0.05), and overall dispersion of blood glucose values was reduced among patients. Better closed-loop glucose control came from the time periods excluding the two early postprandial hours with a higher percentage of time in the 4.4-6.6 mmol/l range (46.3 +/- 5.3 vs. 28.6 +/- 7.4, P = 0.025) and lower mean blood glucose levels (6.9 +/- 0.3 vs. 7.9 +/- 0.6 mmol/l, P = 0.036). Time spent with blood glucose <3.3 mmol/l was low and similar for both investigational phases.

CONCLUSIONS

Our results demonstrate the feasibility of intraperitoneal insulin delivery for an artificial beta-cell and support the need for further study. Moreover, according to a semiautomated mode, the features of the pre-meal bolus in terms of timing and amount warrant further research.

Circulating insulin antibodies: influence of continuous subcutaneous or intraperitoneal insulin infusion, and impact on glucose control

The purification of animal insulin preparations and the use of human recombinant insulin have markedly reduced the incidence, but not completely suppressed, the development of anti-insulin antibodies (IAs). Advances in technologies concerning the mode of delivery of insulin, i.e. continuous subcutaneous insulin infusion (CSII), continuous peritoneal insulin infusion (CPII) and more recently inhaled insulin administration, appear to significantly increase circulating levels of immunoglobulin G (IgG) anti-IAs in diabetic patients. However, the increase is usually moderate and mostly transient as compared to previous observations with poorly purified animal insulin preparations. The clinical impact of these circulating anti-IAs remains unclear. Nevertheless, several studies have suggested that antibodies could retard insulin action, leading to a worsening of postprandial hyperglycaemia and/or serve as a carrier, thus leading to unexpected hypoglycaemia. CPII may be associated with more marked and sustained increase in IAs levels, possibly related to the use of an unstable insulin and the formation of immunogenic aggregates of insulin. The possible clinical consequences of these high levels of IAs remain to be evaluated because a low-glucose morning syndrome or severe insulin resistance with ketone bodies production have been reported in some cases. In conclusion, even if CSII and CPII may promote the development of circulating IAs, this increase does not lead to immunological insulin resistance, compared to that previously described with animal non-purified insulin preparations, and seems to have only marginal influence on blood glucose control or complications in most diabetic patients.

Artificial pancreas: an emerging approach to treat Type 1 diabetes

Intensive insulin therapy aimed at achieving normal glucose levels significantly reduces the complications that are associated with diabetes but is also associated with an increased risk of low glucose levels (hypoglycemia). The growing use of continuous glucose monitors has stimulated the development of the artificial pancreas, a closed-loop insulin-delivery system aimed at restoring near-normal glucose levels while reducing the risk of hypoglycemia. The artificial pancreas comprises three components: a continuous glucose monitor, an insulin infusion pump and a control algorithm delivering insulin according to real-time glucose readings. In this article, we review closed-loop glucose control, including its components, development, testing and clinical application.

Use of short-term real-time continuous glucose monitoring in type 1 diabetes patients on continuous intraperitoneal insulin infusion: a feasibility study

BACKGROUND

In diabetes, strict glycemic control reduces risk of complications. One mode of therapy is continuous intraperitoneal insulin infusion (CIPII). With CIPII, like all intensified treatment strategies, frequent assessment of glucose levels is mandatory. Real-time (RT)-continuous glucose monitoring (CGM) gives RT information without the need for multiple invasive measurements. In theory, CIPII combined with RT-CGM could provide near normal glucose profiles. The objective of this study is to investigate effectiveness and safety of RT-CGM in patients treated with intraperitoneal insulin through an implanted pump.

METHODS

In an open-label, crossover, randomized study, effects of 6-day open RT-CGM use were studied in 12 type 1 diabetes patients on CIPII, with blinded RT-CGM used as a control. Primary outcome was time in euglycemia. Secondary outcomes included time in other glucose ranges, incidence of adverse events, and patient satisfaction. Agreement of self-measurement of blood glucose (SMBG) and RT-CGM measurements was assessed.

RESULTS

Median time spent in euglycemia was 68.2% (55.9-72.3%) with open RT-CGM and 64.9% (55.3-71.2%) with blinded RT-CGM (P = 0.25). Time spent in other glucose ranges did not differ (P > 0.05). There were no serious adverse events. Patient satisfaction was good. Median relative absolute difference of SMBG and RT-CGM values was 13.9%. Bland-Altman analysis showed a mean difference of -0.31 mg/dL with lower and upper limits of agreement of -77.0 and +76.4 mg/dL, respectively.

CONCLUSIONS

Short-term use of RT-CGM, although safe and with good patient satisfaction, does not result in more time spent in euglycemia, nor does it change time spent in other glucose ranges in our population of type 1 diabetes patients receiving CIPII.

Surgical aspects and complications of continuous intraperitoneal insulin infusion with an implantable pump

PURPOSE

Continuous intraperitoneal insulin infusion (CIPII) with an implantable pump is safe and effective in selected subjects with diabetes. Our aim was to assess surgical experience and complications with CIPII.

METHODS

We performed a retrospective longitudinal observational cohort study of patients that started with CIPII from 1990 to 2006. Operation free period and complication rate were compared between patients initiating CIPII before 2000 and from 2000 onwards.

RESULTS

In 63 patients, 166 re-operations were performed during 381 patient-years. Re-operations were pump replacement due to end-of-battery life (47%), laparoscopic catheter-related procedures (29%) and other interventions (24%). Median operation free period increased from 21 to 78 months from 2000 onwards (p = 0.039). Nineteen percent of patients developed complications. No operation-related mortality was reported.

CONCLUSIONS

Increased experience together with technical improvements has led to an increase of the operation free period. The absence of procedure-related mortality and a low complication rate makes CIPII feasible for selected patients with diabetes.

Clinical experience with an implanted closed-loop insulin delivery system

AIM: To report the first clinical experience with a prototype of implanted artificial beta-cell. METHODS: The Long-Term Sensor System® project assessed the feasibility of glucose control by the combined implantation of a pump for peritoneal insulin delivery and a central intravenous glucose sensor, connected physically by a subcutaneous lead and functionally by PID algorithms. It was performed in 10 type 1 diabetic patients from 2000 to 2007. RESULTS: No harmful complication related to implants occurred. Insulin delivery was affected by iterative but reversible pump slowdowns due to insulin precipitation. Glucose measurement by the intravenous sensors correlated well with meter values (r = 0.83-0.93, with a mean absolute deviation of 16.5%) for an average duration of 9 months. Uploading of pump electronics by PID algorithms designed for closed-loop insulin delivery allowed in-patient 48 hourtrials. CONCLUSION: Although the concept of a fully implantable artificial beta-cell has been shown as feasible, improvements in the sensor structure to increase its longevity and decrease sensor delay that affected closed-loop control at meal-times are expected.