Threshold-based insulin-pump interruption for reduction of hypoglycemia

The Impact of Technology on Current Diabetes Management

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

Minimizing Hypoglycemia in Diabetes

Hypoglycemia caused by treatment with a sulfonylurea, a glinide, or insulin coupled with compromised defenses against the resulting falling plasma glucose concentrations is a problem for many people with diabetes. It is often recurrent, causes significant morbidity and occasional mortality, limits maintenance of euglycemia, and impairs physiological and behavioral defenses against subsequent hypoglycemia. Minimizing hypoglycemia includes acknowledging the problem; considering each risk factor; and applying the principles of intensive glycemic therapy, including drug selection and selective application of diabetes treatment technologies. For diabetes health-care providers treating most people with diabetes who are at risk for or are suffering from iatrogenic hypoglycemia, these principles include selecting appropriate individualized glycemic goals and providing structured patient education to reduce the incidence of hypoglycemia. This is typically combined with short-term scrupulous avoidance of hypoglycemia, which often will reverse impaired awareness of hypoglycemia. Clearly, the risk of hypoglycemia is modifiable.

Nocturnal Glucose Metabolism in Type 1 Diabetes: A Study Comparing Single Versus Dual Tracer Approaches

BACKGROUND

Understanding the effect size, variability, and underlying physiology of the dawn phenomenon is important for next-generation closed-loop control algorithms for type 1 diabetes (T1D).

SUBJECTS AND METHODS

We used an iterative protocol design to study 16 subjects with T1D on individualized insulin pump therapy for two successive nights. Endogenous glucose production (EGP) rates at 3 a.m. and 7 a.m. were measured with [6,6-(2)H(2)]glucose as a single tracer, infused from midnight to 7 a.m. in all subjects. To explore possibility of tracer recycling due to prolonged [6,6-(2)H(2)]glucose infusion, which was highly probable after preplanned interim data analyses, we infused a second tracer, [6-(3)H]glucose, from 4 a.m. to 7 a.m. in the last seven subjects to measure EGP at 7 a.m.

RESULTS

Cortisol concentrations increased during both nights, but changes in glucagon and insulin concentration were inconsistent. Although the plasma glucose concentrations rose from midnight to 7 a.m. during both nights, EGP measured with [6,6-(2)H(2)]glucose between 3 a.m. and 7 a.m. did not differ during Night 1 but fell in Night 2. However, EGP measured with [6-(3)H]glucose at 7 a.m. was higher than that measured with [6,6-(2)H(2)]glucose during both nights, thereby suggesting tracer recycling probably underestimating EGP calculated at 7 a.m. with [6,6-(2)H(2)]glucose. Likewise, EGP was higher at 7 a.m. with [6-(3)H]glucose than at 3 a.m. with [6,6-(2)H(2)]glucose during both nights.

CONCLUSIONS

The data demonstrate a consistent overnight rise in glucose concentrations through increased EGP, mediated likely by rising cortisol concentrations. The observations with the dual tracer approach imply significant tracer recycling leading to underestimation of EGP measured by longer-duration tracer infusion.

Predictive Low-Glucose Insulin Suspension Reduces Duration of Nocturnal Hypoglycemia in Children Without Increasing Ketosis

OBJECTIVE

Nocturnal hypoglycemia can cause seizures and is a major impediment to tight glycemic control, especially in young children with type 1 diabetes. We conducted an in-home randomized trial to assess the efficacy and safety of a continuous glucose monitor-based overnight predictive low-glucose suspend (PLGS) system.

RESEARCH DESIGN AND METHODS

In two age-groups of children with type 1 diabetes (11-14 and 4-10 years of age), a 42-night trial for each child was conducted wherein each night was assigned randomly to either having the PLGS system active (intervention night) or inactive (control night). The primary outcome was percent time <70 mg/dL overnight.

RESULTS

Median time at <70 mg/dL was reduced by 54% from 10.1% on control nights to 4.6% on intervention nights (P < 0.001) in 11-14-year-olds (n = 45) and by 50% from 6.2% to 3.1% (P < 0.001) in 4-10-year-olds (n = 36). Mean overnight glucose was lower on control versus intervention nights in both age-groups (144 ± 18 vs. 152 ± 19 mg/dL [P < 0.001] and 153 ± 14 vs. 160 ± 16 mg/dL [P = 0.004], respectively). Mean morning blood glucose was 159 ± 29 vs. 176 ± 28 mg/dL (P < 0.001) in the 11-14-year-olds and 154 ± 25 vs. 158 ± 22 mg/dL (P = 0.11) in the 4-10-year-olds, respectively. No differences were found between intervention and control in either age-group in morning blood ketosis.

CONCLUSIONS

In 4-14-year-olds, use of a nocturnal PLGS system can substantially reduce overnight hypoglycemia without an increase in morning ketosis, although overnight mean glucose is slightly higher.

Technology to Reduce Hypoglycemia

Hypoglycemia is a major barrier toward achieving glycemic targets and is associated with significant morbidity (both psychological and physical) and mortality. This article reviews technological strategies, from simple to more advanced technologies, which may help prevent or mitigate exposure to hypoglycemia. More efficient insulin delivery systems, bolus advisor calculators, data downloads providing information on glucose trends, continuous glucose monitoring with alarms warning of hypoglycemia, predictive algorithms, and finally closed loop insulin delivery systems are reviewed. The building blocks to correct use and interpretation of this range of available technology require patient education and appropriate patient selection.

Evidence-informed clinical practice recommendations for treatment of type 1 diabetes complicated by problematic hypoglycemia

Problematic hypoglycemia, defined as two or more episodes per year of severe hypoglycemia or as one episode associated with impaired awareness of hypoglycemia, extreme glycemic lability, or major fear and maladaptive behavior, is a challenge, especially for patients with long-standing type 1 diabetes. Individualized therapy for such patients should include a composite target: optimal glucose control without problematic hypoglycemia. Therefore, we propose a tiered, four-stage algorithm based on evidence of efficacy given the limitations of educational, technological, and transplant interventions. All patients with problematic hypoglycemia should undergo structured or hypoglycemia-specific education programs (stage 1). Glycemic and hypoglycemia treatment targets should be individualized and reassessed every 3-6 months. If targets are not met, one diabetes technology-continuous subcutaneous insulin infusion or continuous glucose monitoring-should be added (stage 2). For patients with continued problematic hypoglycemia despite education (stage 1) and one diabetes technology (stage 2), sensor-augmented insulin pumps preferably with an automated low-glucose suspend feature and/or very frequent contact with a specialized hypoglycemia service can reduce hypoglycemia (stage 3). For patients whose problematic hypoglycemia persists, islet or pancreas transplant should be considered (stage 4). This algorithm provides an evidence-informed approach to resolving problematic hypoglycemia; it should be used as a guide, with individual patient circumstances directing suitability and acceptability to ensure the prudent use of technology and scarce transplant resources. Standardized reporting of hypoglycemia outcomes and inclusion of patients with problematic hypoglycemia in studies of new interventions may help to guide future therapeutic strategies.

Pathway to artificial pancreas systems revisited: moving downstream

Artificial pancreas (AP) systems, a long-sought quest to replicate mechanically islet physiology that is lost in diabetes, are reaching the clinic, and the potential of automating insulin delivery is about to be realized. Significant progress has been made, and the safety and feasibility of AP systems have been demonstrated in the clinical research center and more recently in outpatient "real-world" environments. An iterative road map to AP system development has guided AP research since 2009, but progress in the field indicates that it needs updating. While it is now clear that AP systems are technically feasible, it remains much less certain that they will be widely adopted by clinicians and patients. Ultimately, the true success of AP systems will be defined by successful integration into the diabetes health care system and by the ultimate metric: improved diabetes outcomes.

[Clinical recommendations for sport practice in diabetic patients (RECORD Guide). Diabetes Mellitus Working Group of the Spanish Society of Endocrinology and Nutrition (SEEN)]

Sporting activity is becoming a common practice in patients with diabetes mellitus (DM). This situation requires both a preliminary medical assessment and a wide range of changes in treatment which have scarcely been addressed in medical literature.

OBJECTIVE

To prepare a clinical guideline on the medical approach to patients with diabetes who practice sport regularly.

METHODS

An expert panel from the Diabetes Mellitus Working Group of the Spanish Society of Endocrinology and Nutrition (SEEN) reviewed the most relevant literature in each of the sections. Based both on this review and on data from the experience of a number of athletes with DM, a number of recommendations were agreed within each section. Finally, the Working Group and representatives of the SEEN jointly discussed all these recommendations.

CONCLUSION

The guideline provides recommendations ranging from medical assessment before patients with DM start to practice sport to actions during and after physical activity. Recommendations are also given on aspects such as the impact of sport on blood glucose control, training schemes, or special risk situations.

Closed loop insulin delivery in diabetes

The primary goal of type 1 diabetes treatment is attaining near-normal glucose values. This currently remains out of reach for most people with type 1 diabetes despite intensified insulin treatment in the form of insulin analogues, educational interventions, continuous glucose monitoring, and sensor augmented insulin pump. The main remaining problem is risk of hypoglycaemia, which cannot be sufficiently reduced in all patient groups. Additionally, patients' burn-out often develops with years of tedious day-to-day diabetes management, rendering available diabetes-related technology less efficient. Over the past 40 years, several attempts have been made towards computer-programmed insulin delivery in the form of closed loop, with faster developments especially in the past decade. Automated insulin delivery has reduced human error in glycaemic control and considerably lessened the burden of routine self-management. In this chapter, data from randomized controlled trials with closed-loop insulin delivery that included type 1 diabetes population are summarized, and an evidence-based vision for possible routine utilization of closed loop is provided.

Predictors of Hypoglycemia in the ASPIRE In-Home Study and Effects of Automatic Suspension of Insulin Delivery

BACKGROUND

Hypoglycemia varies between patients with type 1 diabetes and is the main obstacle to therapy intensification. We investigated known and potential risk factors for hypoglycemia in subjects with type 1 diabetes.

METHOD

In the ASPIRE In-Home study (NCT01497938), a randomized trial of the threshold suspend (TS) feature of sensor-augmented insulin pump (SAP) therapy, subjects' propensity to nocturnal hypoglycemia (NH) was established in a 2-week run-in phase and assessed in a 3-month study phase via continuous glucose monitoring. Categorical variables were tested for association with NH rates in both phases.

RESULTS

Elevated rates of NH were significantly associated with baseline A1C ≤7%, with bolus insulin deliveries unassisted by the bolus estimation calculator, and with assignment to the control group during the study phase.

CONCLUSIONS

Routine use of the TS feature and the bolus estimation calculator are strategies that may reduce the risk of NH.

HypoDE: Research Design and Methods of a Randomized Controlled Study Evaluating the Impact of Real-Time CGM Usage on the Frequency of CGM Glucose Values <55 mg/dl in Patients With Type 1 Diabetes and Problematic Hypoglycemia Treated With Multiple Daily Injections

Systems for continuous glucose monitoring (CGM) have been available for a number of years, and numerous clinical studies have been performed with them. Interestingly, in many of these studies patients with an increased risk of hypoglycemic events were excluded. In addition, in most studies subjects were using a pump for insulin delivery. Therefore our knowledge about the benefit of CGM in patients employing multiple daily injections (MDI) of insulin is limited, especially when it comes to a reduction in the risk of low glucose events in high-risk individuals. We are planning to run a 26-week randomized controlled study in Germany (HypoDE, Hypoglycemia in Deutschland) that is focused on evaluating if such a reduction can be observed in patients on MDI with an increased risk of low glucose events. In all, 160 patients will participate in the study, randomized into the intervention group and control group. Ideally one would study if the frequency of severe hypoglycemic events is different between both groups. However, this would require such a large sample size and study duration, so for pragmatic reasons we will use low glucose levels <55 mg/dl (measured by CGM) for at least 20 minutes as a risk marker for severe hypoglycemic events. The results from the HypoDE study shall help determine the advantage of using CGM in subjects with type 1 diabetes with an increased risk of low glucose events treated with MDI.

Multicenter outpatient dinner/overnight reduction of hypoglycemia and increased time of glucose in target with a wearable artificial pancreas using modular model predictive control in adults with type 1 diabetes

AIMS

To test in an outpatient setting the safety and efficacy of continuous subcutaneous insulin infusion (CSII) driven by a modular model predictive control (MMPC) algorithm informed by continuous glucose monitoring (CGM) measurement.

METHODS

13 patients affected by type 1 diabetes participated to a non-randomized outpatient 42-h experiment that included two evening meals and overnight periods (in short, dinner & night periods). CSII was patient-driven during dinner & night period 1 and MMPC-driven during dinner&night period 2. The study was conducted in hotels, where patients could move around freely. A CGM system (G4 Platinum; Dexcom Inc., San Diego, CA, USA) and insulin pump (AccuChek Combo; Roche Diagnostics, Mannheim, Germany) were connected wirelessly to a smartphone-based platform (DiAs, Diabetes Assistant; University of Virginia, Charlottesville, VA, USA) during both periods.

RESULTS

A significantly lower percentage of time spent with glucose levels <3.9 mmol/l was achieved in period 2 compared with period 1: 1.96 ± 4.56% vs 12.76 ± 15.84% (mean ± standard deviation, p < 0.01), together with a greater percentage of time spent in the 3.9-10 mmol/l target range: 83.56 ± 14.02% vs 62.43 ± 29.03% (p = 0.04). In addition, restricting the analysis to the overnight phases, a lower percentage of time spent with glucose levels <3.9 mmol/l (1.92 ± 4.89% vs 12.7 ± 19.75%; p = 0.03) was combined with a greater percentage of time spent in 3.9-10 mmol/l target range in period 2 compared with period 1 (92.16 ± 8.03% vs 63.97 ± 2.73%; p = 0.01). Average glucose levels were similar during both periods.

CONCLUSIONS

The results suggest that MMPC managed by a wearable system is safe and effective during evening meal and overnight. Its sustained use during this period is currently being tested in an ongoing randomized 2-month study.

Unsupervised home use of an overnight closed-loop system over 3-4 weeks: a pooled analysis of randomized controlled studies in adults and adolescents with type 1 diabetes

AIMS

To compare overnight closed-loop and sensor-augmented pump therapy in patients with type 1 diabetes by combining data collected during free-living unsupervised randomized crossover home studies.

METHODS

A total of 40 participants with type 1 diabetes, of whom 24 were adults [mean ± standard deviation (s.d.) age 43 ± 12 years and glycated haemoglobin (HbA1c) 8.0 ± 0.9%] and 16 were adolescents (mean ± s.d. age 15.6 ± 3.6 years and HbA1c 8.1 ± 0.8%), underwent two periods of sensor-augmented pump therapy in the home setting, in combination with or without an overnight closed-loop insulin delivery system that uses a model predictive control algorithm to direct insulin delivery. The order of the two interventions was random; each period lasted 4 weeks in adults and 3 weeks in adolescents. The primary outcome was time during which sensor glucose readings were in the target range of 3.9-8.0 mmol/l.

RESULTS

The proportion of time when sensor glucose was in the target range (3.9-8.0 mmol/l) overnight (between 24:00 and 08:00 hours) was 18.5% greater during closed-loop insulin delivery than during sensor-augmented therapy (p < 0.001). Closed-loop therapy significantly reduced mean overnight glucose levels by 0.9 mmol/l (p < 0.001), with no difference in glycaemic variability, as measured by the standard deviation of sensor glucose. Time spent above the target range was reduced (p = 0.001), as was time spent in hypoglycaemia (<3.9 mmol/l; p = 0.014) during closed-loop therapy. Lower mean overnight glucose levels during closed-loop therapy were brought about by increased overnight insulin delivery (p < 0.001) without changes to the total daily delivery (p = 0.84).

CONCLUSION

Overnight closed-loop insulin therapy at home in adults and adolescents with type 1 diabetes is feasible, showing improvements in glucose control and reducing the risk of nocturnal hypoglycaemia.

Retrospective analysis of the real-world use of the threshold suspend feature of sensor-augmented insulin pumps

BACKGROUND

The automatic Threshold Suspend (TS) feature of the MiniMed 530G system (Medtronic MiniMed, Inc., Northridge, CA), when enabled, suspends insulin delivery for up to 2 h when the sensor glucose (SG) value reaches a preset threshold.

MATERIALS AND METHODS

SG data from 20,973 patients who enabled the TS feature at their discretion and uploaded pump and sensor data to CareLink(®) (Medtronic MiniMed, Inc.) from October 15, 2013 to July 21, 2014 were analyzed. Comparisons between 758,382 patient-days wherein the TS feature was enabled at any time and 166,791 patient-days in which it was not enabled were made. Further comparisons were made between data collected during daytime (8:00 a.m. to 10:00 p.m.) and nighttime (10:00 p.m. to 8:00 a.m.) hours. Data from subsets of patients who enabled the TS feature all of the time (n=14,673) versus those who never enabled the TS feature (n=2,249) were also compared. Recovery from hypoglycemia during and after 2-h pump suspension events was also assessed.

RESULTS

The TS feature was enabled on 82% of patient-days. Patient-days in which the TS feature was enabled, compared with patient-days in which it was not, had 69% fewer SG values ≤50 mg/dL (0.64% vs. 2.09%, respectively; P<0.001). The reduction in hypoglycemia seen on TS-enabled days was more pronounced during nighttime than during daytime hours. SG data from full-time users of the TS feature reflected a 62% reduction in values ≤50 mg/dL and a 5.6% reduction in values ≥300 mg/dL compared with data from nonusers (P<0.001 for each). The median SG value at the start of 2-h suspensions was 60 (interquartile range [IQR], 57-66) mg/dL, immediately after was 87 (IQR, 63-123) mg/dL, and 4 h later was 164 (IQR, 117-220) mg/dL.

CONCLUSIONS

The TS feature, when enabled consistently, reduced hypoglycemic exposure, and for those who had it enabled 100% of the time, hyperglycemia was also reduced.

Insulin pump risks and benefits: a clinical appraisal of pump safety standards, adverse event reporting and research needs. A joint statement of the European Association for the Study of Diabetes and the American Diabetes Association Diabetes Technology Working Group

Insulin pump therapy, also known as continuous subcutaneous insulin infusion (CSII), is an important and evolving form of insulin delivery, which is mainly used for people with type 1 diabetes. However, even with modern insulin pumps, errors of insulin infusion can occur due to pump failure, insulin infusion set (IIS) blockage, infusion site problems, insulin stability issues, user error or a combination of these. Users are therefore exposed to significant and potentially fatal hazards: interruption of insulin infusion can result in hyperglycaemia and ketoacidosis; conversely, delivery of excessive insulin can cause severe hypoglycaemia. Nevertheless, the available evidence on the safety and efficacy of CSII remains limited. The European Association for the Study of Diabetes (EASD) and American Diabetes Association (ADA) have therefore joined forces to review the systems in place for evaluating the safety of pumps from a clinical perspective. We found that useful information held by the manufacturing companies is not currently shared in a sufficiently transparent manner. Public availability of adverse event (AE) reports on the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database is potentially a rich source of safety information but is insufficiently utilised due to the current configuration of the system; the comparable database in Europe (European Databank on Medical Devices, EUDAMED) is not publicly accessible. Many AEs appear to be attributable to human factors and/or user error, but the extent to which manufacturing companies are required by regulators to consider the interactions of users with the technical features of their products is limited. The clinical studies required by regulators prior to marketing are small and over-reliant on bench testing in relation to 'predicate' products. Once a pump is available on the market, insufficient data are made publicly available on its long-term use in a real-world setting; such data could provide vital information to help healthcare teams to educate and support users, and thereby prevent AEs. As well as requiring more from the manufacturing companies, we call for public funding of more research addressing clinically important questions in relation to pump therapy: both observational studies and clinical trials. At present there are significant differences in the regulatory systems between the USA and European Union at both pre- and post-marketing stages; improvements in the European system are more urgently required. This statement concludes with a series of recommended specific actions for 'meknovigilance' (i.e. a standardised safety approach to technology) which could be implemented to address the shortcomings we highlight.

Hypo- and Hyperglycemic Alarms: Devices and Algorithms

Soon after the discovery that insulin regulates blood glucose by Banting and Best in 1922, the symptoms and risks associated with hypoglycemia became widely recognized. This article reviews devices to warn individuals of impending hypo- and hyperglycemia; biosignals used by these devices include electroencephalography, electrocardiography, skin galvanic resistance, diabetes alert dogs, and continuous glucose monitors (CGMs). While systems based on other technology are increasing in performance and decreasing in size, CGM technology remains the best method for both reactive and predictive alarming of hypo- or hyperglycemia.

Analysis: The Accuracy and Efficacy of the Dexcom G4 Platinum Continuous Glucose Monitoring System

In this issue of Journal of Diabetes Science and Technology, Nakamura and Balo report on accuracy and efficacy of the Dexcom G4 Platinum Continuous Glucose Monitoring System. The authors demonstrate good overall performance of this real-time continuous glucose monitoring (RT-CGM) system, although accuracy data of the next generation RT-CGM system, the G4AP, is already available. Also, now that MARDs seem to move to single-digit numbers, the question comes up how low we need to go with accuracy. Results of the study also showed a reduction in time spent in hypoglycemia, although the clinical relevance should be questioned. To date, few trials have demonstrated a reduction of severe hypoglycemia. Conventional RT-CGM, without threshold suspension or closing the loop, might be insufficient in preventing severe hypoglycemia.

The rise of multiple imputation: a review of the reporting and implementation of the method in medical research

Background

Missing data are common in medical research, which can lead to a loss in statistical power and potentially biased results if not handled appropriately. Multiple imputation (MI) is a statistical method, widely adopted in practice, for dealing with missing data. Many academic journals now emphasise the importance of reporting information regarding missing data and proposed guidelines for documenting the application of MI have been published. This review evaluated the reporting of missing data, the application of MI including the details provided regarding the imputation model, and the frequency of sensitivity analyses within the MI framework in medical research articles.

Methods

A systematic review of articles published in the Lancet and New England Journal of Medicine between January 2008 and December 2013 in which MI was implemented was carried out.

Results

We identified 103 papers that used MI, with the number of papers increasing from 11 in 2008 to 26 in 2013. Nearly half of the papers specified the proportion of complete cases or the proportion with missing data by each variable. In the majority of the articles (86%) the imputed variables were specified. Of the 38 papers (37%) that stated the method of imputation, 20 used chained equations, 8 used multivariate normal imputation, and 10 used alternative methods. Very few articles (9%) detailed how they handled non-normally distributed variables during imputation. Thirty-nine papers (38%) stated the variables included in the imputation model. Less than half of the papers (46%) reported the number of imputations, and only two papers compared the distribution of imputed and observed data. Sixty-six papers presented the results from MI as a secondary analysis. Only three articles carried out a sensitivity analysis following MI to assess departures from the missing at random assumption, with details of the sensitivity analyses only provided by one article.

Conclusions

This review outlined deficiencies in the documenting of missing data and the details provided about imputation. Furthermore, only a few articles performed sensitivity analyses following MI even though this is strongly recommended in guidelines. Authors are encouraged to follow the available guidelines and provide information on missing data and the imputation process.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-015-0022-1) contains supplementary material, which is available to authorized users.

Diabetes Complications in Childhood Diabetes-New Biomarkers and Technologies

A major challenge in preventing vascular complications in diabetes is the inability to identify high-risk patients at an early stage, emphasizing the importance of discovering new risk factors, technologies and therapeutic targets to reduce the development and progression of complications. Promising biomarkers which may improve risk stratification and serve as therapeutic targets, include: uric acid, insulin sensitivity, copeptin, SGLT-2 and Klotho/FGF-23. Non-invasive measures of macrovasuclar disease in youth, include: 1) pulse wave velocity to examine arterial stiffness; 2) carotid intima-media thickness to evaluate arterial thickness; 3) cardiac MRI to investigate cardiac function and structure. Novel microvascular measures include: GFR by iohexol clearance using filter paper to directly measure GFR, retinal vascular geometry to predict early retinal changes and corneal confocal microscopy to improve detection of early nerve loss to better predict diabetic neuropathy. Herein we will review technologies, novel biomarkers, and therapeutic targets in relation to vascular complications of diabetes.

Evaluation of a clinical tool to test and adjust the programmed overnight basal profiles for insulin pump therapy: a pilot study

OBJECTIVE

Clinical protocols for basal rate testing and adjustment are needed for effective insulin pump therapy. We evaluated the effects of a continuous glucose monitoring (CGM)-based semiautomated basal algorithm on glycemia.

METHODS

We developed and piloted a basal rate analyzer that interpreted CGM data from overnight fasts and recommended dose changes for subsequent nights. Subjects uploaded data online using sensor-augmented pumps for evaluation by the analyzer after each of 5 overnight fasts conducted over 2 to 8 weeks. It was designed to be conservative and iterative, making changes that did not exceed 10% at each iteration. The standard deviation and interquartile range of CGM values from midnight to 7 am (SD12-7am and IQR12-7am) over 3 baseline and 3 postintervention nights, hypoglycemia incidence (CGM values <4.0 mmol/L), and glycated hemoglobin (A1C) were compared.

RESULTS

Twenty subjects with mean ages of 38±13 years and A1C 7.6%±0.8% (60±8.7 mmol/mol) underwent the 5 iterations of basal assessments over 5±3 weeks. SD12-7am and IQR12-7am did not change from baseline to postintervention (1.57±0.8 to 1.63±0.8 mmol/L; p=0.35; 3.66±2.07 to 3.47±2.26 mmol/L; p=0.90). However, mean glucose values were lower between 2 to 3 am at baseline compared to postintervention; 3-night hypoglycemia incidence declined from 1.6±1.8 to 0.5±0.7 episodes (p=0.01), and A1C improved from 7.6%±0.8% to 7.4%±0.9% (60%±8.7% to 57%±9.8% mmol/mol; p=0.03).

CONCLUSIONS

The use of a basal rate analyzer was associated with reduced hypoglycemia and improved A1C. However, overnight glycemic stability was not improved. Further research into the efficacy of the CGM-based semiautomated algorithm is warranted.

Progress of artificial pancreas devices towards clinical use: the first outpatient studies

PURPOSE OF REVIEW

This article describes recent progress in the automated control of glycemia in type 1 diabetes with artificial pancreas devices that combine continuous glucose monitoring with automated decision-making and insulin delivery.

RECENT FINDINGS

After a gestation period of closely supervised feasibility studies in research centers, the last 2 years have seen publication of studies testing these devices in outpatient environments, and many more such studies are ongoing. The most basic form of automation, suspension of insulin delivery for actual or predicted hypoglycemia, has been shown to be effective and well tolerated, and a first-generation device has actually reached the market. Artificial pancreas devices that actively dose insulin fall into two categories, those that dose insulin alone and those that also use glucagon to prevent and treat hypoglycemia (bihormonal artificial pancreas). Initial outpatient clinical trials have shown that both strategies can improve glycemic management in comparison with patient-controlled insulin pump therapy, but only the bihormonal strategy has been tested without restrictions on exercise.

SUMMARY

Artificial pancreas technology has the potential to reduce acute and chronic complications of diabetes and mitigate the burden of diabetes self-management. Successful outpatient studies bring these technologies one step closer to availability for patients.

Real-time continuous glucose monitoring in type 1 diabetes: a qualitative framework analysis of patient narratives

OBJECTIVE

This study analyzed narratives about experiences of real-time continuous glucose monitoring (CGM) in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

People with type 1 diabetes using CGM and caregivers completed an online survey. Questions included duration of CGM, frequency of sensor wear, funding, and a free narrative about experiences or views about CGM. We used qualitative framework analysis to analyze 100 responses; 50% of participants were aged ≥ 18 years.

RESULTS

Most participants (87%) used CGM with insulin pump therapy, 71% used sensors ≥ 75% of the time, and 66% received funding for CGM from the National Health Service. Four themes were identified: 1) metabolic control, 2) living with CGM (work and school, sleep, exercise, nutrition, frequency of self-monitoring of blood glucose [SMBG]), 3) psychological issues and patient/caregiver attitudes, and 4) barriers to CGM use (technical issues, financial issues, attitudes of healthcare professionals toward CGM). Despite some hassles, experiences were overwhelmingly positive, with improved glycemic control, diet and exercise management, quality of life, and physical and psychological well-being, as well as reduced frequency of SMBG. Technical problems included sensor inaccuracy and unreliability, and "alarm fatigue." The advantages of CGM used with an insulin pump with automatic suspension of insulin delivery during hypoglycemia were recorded by several participants, noting reduced hypoglycemia frequency and fear of nocturnal hypoglycemia.

CONCLUSIONS

Patient and caregiver narratives indicate that CGM is a valuable addition to diabetes care for many with type 1 diabetes.

Insulin pump risks and benefits: a clinical appraisal of pump safety standards, adverse event reporting, and research needs: a joint statement of the European Association for the Study of Diabetes and the American Diabetes Association Diabetes Technology Working Group

Insulin pump therapy, also known as continuous subcutaneous insulin infusion (CSII), is an important and evolving form of insulin delivery, which is mainly used for people with type 1 diabetes. However, even with modern insulin pumps, errors of insulin infusion can occur due to pump failure, insulin infusion set (IIS) blockage, infusion site problems, insulin stability issues, user error, or a combination of these. Users are therefore exposed to significant and potentially fatal hazards: interruption of insulin infusion can result in hyperglycemia and ketoacidosis; conversely, delivery of excessive insulin can cause severe hypoglycemia. Nevertheless, the available evidence on the safety and efficacy of CSII remains limited. The European Association for the Study of Diabetes (EASD) and the American Diabetes Association (ADA) have therefore joined forces to review the systems in place for evaluating the safety of pumps from a clinical perspective. We found that useful information held by the manufacturing companies is not currently shared in a sufficiently transparent manner. Public availability of adverse event (AE) reports on the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database is potentially a rich source of safety information but is insufficiently utilized due to the current configuration of the system; the comparable database in Europe (European Databank on Medical Devices [EUDAMED]) is not publicly accessible. Many AEs appear to be attributable to human factors and/or user error, but the extent to which manufacturing companies are required by regulators to consider the interactions of users with the technical features of their products is limited. The clinical studies required by regulators prior to marketing are small and over-reliant on bench testing in relation to "predicate" products. Once a pump is available on the market, insufficient data are made publicly available on its long-term use in a real-world setting; such data could provide vital information to help health care teams to educate and support users and thereby prevent AEs. As well as requiring more from the manufacturing companies, we call for public funding of more research addressing clinically important questions in relation to pump therapy: both observational studies and clinical trials. At present, there are significant differences in the regulatory systems between the US and European Union at both pre- and postmarketing stages; improvements in the European system are more urgently required. This statement concludes with a series of recommended specific actions for "meknovigilance" (i.e., a standardized safety approach to technology) that could be implemented to address the shortcomings we highlight.

The Accuracy and Efficacy of the Dexcom G4 Platinum Continuous Glucose Monitoring System

BACKGROUND

The purpose of this study was to evaluate the accuracy and efficacy of Dexcom G4 Platinum CGM System.

METHODS

Seventy-two subjects enrolled at 4 US centers; 61% were male; 83% had T1DM and17% had T2DM. Subjects wore at least 1 system for up to 7 days. Subjects participated in a total of 36 hours in the clinic to contribute YSI reference glucose measurements with venous blood draws every 15 minutes on study Day 1, Day 4, and Day 7.

RESULTS

The overall mean absolute relative difference (ARD) versus YSI was 13% with a median of 10%. Precision ARD was 9% ± 4% between 2 sensors with a 7% coefficient of variation. The mean ARD versus SMBG was 14% with a median of 11%. One hundred two (94%) sensors lasted 7 days and the systems displayed 97% of their expected glucose readings in average. The time spent in low CGM readings during nighttime hours decreased from the first night use to the 6th night (P < .001) with a small difference in average CGM glucose from 147 ± 40 mg/dL to 166 ± 62 mg/dL. There were no serious adverse events or infectious complications reported.

CONCLUSIONS

The study showed the Dexcom G4 Platinum CGM System is one of the most accurate CGMs. The significant reduction in nocturnal time spent in a hypoglycemic state observed during this study suggests that a longer term study of CGM use, especially nocturnal use, could be beneficial for patients with hypoglycemia unawareness.

Evaluation of short-term predictors of glucose concentration in type 1 diabetes combining feature ranking with regression models

Glucose concentration in type 1 diabetes is a function of biological and environmental factors which present high inter-patient variability. The objective of this study is to evaluate a number of features, which are extracted from medical and lifestyle self-monitoring data, with respect to their ability to predict the short-term subcutaneous (s.c.) glucose concentration of an individual. Random forests (RF) and RReliefF algorithms are first employed to rank the candidate feature set. Then, a forward selection procedure follows to build a glucose predictive model, where features are sequentially added to it in decreasing order of importance. Predictions are performed using support vector regression or Gaussian processes. The proposed method is validated on a dataset of 15 type diabetics in real-life conditions. The s.c. glucose profile along with time of the day and plasma insulin concentration are systematically highly ranked, while the effect of food intake and physical activity varies considerably among patients. Moreover, the average prediction error converges in less than d/2 iterations (d is the number of features). Our results suggest that RF and RReliefF can find the most informative features and can be successfully used to customize the input of glucose models.

Assessing sensor accuracy for non-adjunct use of continuous glucose monitoring

BACKGROUND

The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the level of accuracy permitting non-adjunct CGM use) is a topic of ongoing debate. Assessment of this level in clinical experiments is virtually impossible because the magnitude of CGM errors cannot be manipulated and related prospectively to clinical outcomes.

MATERIALS AND METHODS

A combination of archival data (parallel CGM, insulin pump, self-monitoring of blood glucose [SMBG] records, and meals for 56 pump users with type 1 diabetes) and in silico experiments was used to "replay" real-life treatment scenarios and relate sensor error to glycemic outcomes. Nominal blood glucose (BG) traces were extracted using a mathematical model, yielding 2,082 BG segments each initiated by insulin bolus and confirmed by SMBG. These segments were replayed at seven sensor accuracy levels (mean absolute relative differences [MARDs] of 3-22%) testing six scenarios: insulin dosing using sensor values, threshold, and predictive alarms, each without or with considering CGM trend arrows.

RESULTS

In all six scenarios, the occurrence of hypoglycemia (frequency of BG levels ≤50 mg/dL and BG levels ≤39 mg/dL) increased with sensor error, displaying an abrupt slope change at MARD =10%. Similarly, hyperglycemia (frequency of BG levels ≥250 mg/dL and BG levels ≥400 mg/dL) increased and displayed an abrupt slope change at MARD=10%. When added to insulin dosing decisions, information from CGM trend arrows, threshold, and predictive alarms resulted in improvement in average glycemia by 1.86, 8.17, and 8.88 mg/dL, respectively.

CONCLUSIONS

Using CGM for insulin dosing decisions is feasible below a certain level of sensor error, estimated in silico at MARD=10%. In our experiments, further accuracy improvement did not contribute substantively to better glycemic outcomes.

The benefits, limitations, and cost-effectiveness of advanced technologies in the management of patients with diabetes mellitus

Hypoglycemia mitigation is critical for appropriately managing patients with diabetes. Advanced technologies are becoming more prevalent in diabetes management, but their benefits have been primarily judged on the basis of hemoglobin A1c. A critical appraisal of the effectiveness and limitations of advanced technologies in reducing both A1c and hypoglycemia rates has not been previously performed. The cost of hypoglycemia was estimated using literature rates of hypoglycemia events resulting in hospitalizations. A literature search was conducted on the effect on A1c and hypoglycemia of advanced technologies. The cost-effectiveness of continuous subcutaneous insulin infusion (CSII) and real-time continuous glucose monitors (RT-CGM) was reviewed. Severe hypoglycemia in insulin-using patients with diabetes costs $4.9-$12.7 billion. CSII reduces A1c in some but not all studies. CSII improves hypoglycemia in patients with high baseline rates. Bolus calculators improve A1c and improve the fear of hypoglycemia but not hypoglycemia rates. RT-CGM alone and when combined with CSII improve A1c with a neutral effect on hypoglycemia rates. Low-glucose threshold suspend systems reduce hypoglycemia with a neutral effect on A1c, and low-glucose predictive suspend systems reduce hypoglycemia with a small increase in plasma glucose levels. In short-term studies, artificial pancreas systems reduce both hypoglycemia rates and plasma glucose levels. CSII and RT-CGM are cost-effective technologies, but their wide adoption is limited by cost, psychosocial, and educational factors. Most currently available technologies improve A1c with a neutral or improved rate of hypoglycemia. Advanced technologies appear to be cost-effective in diabetes management, especially when including the underlying cost of hypoglycemia.

Management of diabetes in the elderly

Management of diabetes in the elderly necessitates careful consideration of concomitant geriatric syndromes and comorbid conditions that increase the risk of complications, including severe hypoglycemia. Whereas healthy older adults can use therapeutic approaches recommended for their younger counterparts, treatment plans for frail elderly patients need to be simplified and A1c and blood pressure goals relaxed with the development of impairments in function, cognition, vision, and dexterity. The goals of diabetes management in the elderly should be to maintain quality of life and minimize symptomatic hyperglycemia and drug side effects, including hypoglycemia.

Escaping the Hemoglobin A1c-Centric World in Evaluating Diabetes Mellitus Interventions

Any intervention in patients with diabetes must consider its effect on both the incidence of hypoglycemia and hemoglobin A1c. Yet, there is no single metric that expresses these key factors simultaneously. Such a composite metric would permit clinicians, regulators, manufacturers, payers, and researchers to more easily evaluate the merits of an intervention as well as enable the comparison of qualitatively different interventions. This article proposes a composite metric, the hypoglycemia-A1c score (HAS), as the basis for a more comprehensive approach for the stakeholders in diabetes treatment to better understand how an intervention affects diabetes management. The article also demonstrates how additional parameters such as effects on weight, quality of life, and costs could be included in such a scoring system.

Factors associated with glycemic control in adult type 1 diabetes patients treated with insulin pump therapy

Continuous subcutaneous insulin infusion (CSII) by insulin pump seems to improve glycemia and quality of life as compared to conventional insulin therapy in type 1 diabetes (T1DM). However, while many T1DM subjects achieve excellent glycemic control, some others cannot reach recommended goals. In a retrospective analysis, we searched for factors associated with glycemic control in T1DM patients treated with insulin pump therapy. Data from 192 patients (133 women and 59 men) treated with personal insulin pumps at the Department of Metabolic Diseases, University Hospital, Krakow, Poland were analyzed. Sources of information included medical records, memory read-outs from insulin pumps and data from glucose meters. Univariate, multivariate linear and logistic regression analysis for the association with hemoglobin A1c (HbA1c) level were performed. The mean age of the subjects was 28.9 (±11.2) years, the mean duration of T1DM-14.6 (±7.6) years, mean body mass index-23.5 (±3.1) kg/m2. The mean HbA1c level in the entire study group was 7.4% (57 mmol/mol). In the multivariate linear regression analysis, HbA1c correlated with the mean number of daily blood glucose measurements, number of hypoglycemic episodes per 100 blood glucose measurements, age at the examination, and continuous glucose monitoring system use. Multivariate logistic regression analysis for reaching the therapeutic target of HbA1c<7.0% (53 mmol/mol) showed that the independent predictors of achieving this goal included the same four variables. In a large clinical observation, we identified that patient-related and technological factors associated with glycemic control in adult pump-treated T1DM subjects.

Comparison of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy for glycaemic control in patients with type 1 diabetes: an open-label randomised controlled crossover trial

BACKGROUND

The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system.

METHODS

We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337.

FINDINGS

The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target range between single-hormone artificial pancreas and conventional insulin pump therapy was 11% (17; p=0·002) and between dual-hormone artificial pancreas and conventional insulin pump therapy was 12% (21; p=0·00011). There was no difference (15; p=0·75) in the proportion of time spent in the target range between the single-hormone and dual-hormone artificial pancreas systems. There were 52 hypoglycaemic events with conventional insulin pump therapy (12 of which were symptomatic), 13 with the single-hormone artificial pancreas (five of which were symptomatic), and nine with the dual-hormone artificial pancreas (0 of which were symptomatic); the number of nocturnal hypoglycaemic events was 13 (0 symptomatic), 0, and 0, respectively.

INTERPRETATION

Single-hormone and dual-hormone artificial pancreas systems both provided better glycaemic control than did conventional insulin pump therapy. The single-hormone artificial pancreas might be sufficient for hypoglycaemia-free overnight glycaemic control.

FUNDING

Canadian Diabetes Association; Fondation J A De Sève; Juvenile Diabetes Research Foundation; and Medtronic.

Integrated insulin pump therapy with continuous glucose monitoring for improved adherence: technology update

Insulin pump therapy combined with real-time continuous glucose monitoring, known as sensor-augmented pump (SAP) therapy, has been shown to improve metabolic control and to reduce the rate of hypoglycemia in adults with type 1 diabetes compared to multiple daily injections or standard continuous subcutaneous insulin infusion. Glycemic variability is also reduced in patients on SAP therapy. This approach allows patients to monitor their glucose levels being informed of glycemic concentration and trend. Trained diabetic patients, therefore, can appropriately modify insulin infusion and/or carbohydrate intake in order to prevent hypo- or hyperglycemia. For these reasons, SAP therapy is now considered the gold standard for type 1 diabetes treatment. To be clinically effective, however, devices and techniques using advanced technology should not only have the potential to theoretically ameliorate metabolic control, but also be well accepted by patients in terms of satisfaction and health-related quality of life, because these factors will improve treatment adherence and consequently overall outcome. SAP therapy is generally well tolerated by patients; however, many clinical trials have identified significant noncompliance in the use of this device, most notably in the pediatric and adolescent populations. In this review we aim to analyze the main reasons for good or poor adherence to SAP therapy and to provide useful tips in order to fully benefit from this kind of novel therapeutic approach.

Factors affecting the success of glucagon delivered during an automated closed-loop system in type 1 diabetes

BACKGROUND

In bi-hormonal closed-loop systems for treatment of diabetes, glucagon sometimes fails to prevent hypoglycemia. We evaluated glucagon responses during several closed-loop studies to determine factors, such as gain factors, responsible for glucagon success and failure.

METHODS

We extracted data from four closed-loop studies, examining blood glucose excursions over the 50min after each glucagon dose and defining hypoglycemic failure as glucose values<60 mg/dl. Secondly, we evaluated hyperglycemic excursions within the same period, where glucose was>180 mg/dl. We evaluated several factors for association with rates of hypoglycemic failure or hyperglycemic excursion. These factors included age, weight, HbA1c, duration of diabetes, gender, automation of glucagon delivery, glucagon dose, proportional and derivative errors (PE and DE), insulin on board (IOB), night vs. day delivery, and point sensor accuracy.

RESULTS

We analyzed a total of 251 glucagon deliveries during 59 closed-loop experiments performed on 48 subjects. Glucagon successfully maintained glucose within target (60-180 mg/dl) in 195 (78%) of instances with 40 (16%) hypoglycemic failures and 16 (6%) hyperglycemic excursions. A multivariate logistic regression model identified PE (p<0.001), DE (p<0.001), and IOB (p<0.001) as significant determinants of success in terms of avoiding hypoglycemia. Using a model of glucagon absorption and action, simulations suggested that the success rate for glucagon would be improved by giving an additional 0.8μg/kg.

CONCLUSION

We conclude that glucagon fails to prevent hypoglycemia when it is given at a low glucose threshold and when glucose is falling steeply. We also confirm that high IOB significantly increases the risk for glucagon failures. Tuning of glucagon subsystem parameters may help reduce this risk.

Monitoring glycemia in diabetes

Monitoring of glycemic control is a key component of the diabetes treatment plan. Patients who are not meeting targets often require more intensive monitoring, ranging from frequent self-monitored glucose to continuous glucose monitoring in order to facilitate medication and lifestyle changes. However, more intensive monitoring demands more training and a structured plan for interpretation and use of the data. Better patient and provider tools to support decision-making and progress toward an artificial pancreas may help to alleviate this burden.

Insulin therapy in type 1 diabetes

Although not curable, type 1 diabetes is eminently controllable. IIT, as guided by the results of landmark studies such as the DCCT, provides primary care providers with a blueprint for reducing the frequency of the devastating complications of diabetes that were all too common in the recent past. Considering the remarkable advances in contemporary therapy, including MDI and CSII, the likelihood of even greater future improvements in quality of life and survivability can be anticipated. Success requires patient engagement and education, an informed primary care provider, and an interdisciplinary team to maximize the benefits of insulin therapy and avoid the risks of hypoglycemia.

Association between post-dinner dietary intakes and nocturnal hypoglycemic risk in adult patients with type 1 diabetes

AIMS

To describe (i) current bedtime nutritional practices and (ii) the association between post-dinner dietary intake and the occurrence of non-severe nocturnal hypoglycemia (NH) in real-life conditions among adult patients with type 1 diabetes using insulin analogs.

METHODS

One hundred adults (median [interquartile range]: age 46.4 [36.0-55.8] years, HbA1c 7.9 [7.3-8.6] % (63 [56-70] mmol/mol)) using multiple daily injections (n=67) or insulin pump (n=33) wore a blinded continuous glucose monitoring system and completed a food diary for 72-h.

RESULTS

NH occurred on 28% of 282 nights analyzed. (i) Patients reported post-dinner dietary intakes on 63% of the evenings. They injected rapid-acting insulin boluses on 64 occasions (23% of 282 evenings). These insulin boluses were mostly injected with (n=37) dietary intakes. (ii) Post-dinner dietary intake was not associated with NH occurrence in univariate analyses. In multivariate analyses, the injection of rapid-acting insulin modulated the association between post-dinner dietary intake and NH: with insulin, post-dinner carbohydrate intake was positively associated with NH (odds ratio (OR): 1.16 [95% confidence interval, CI: 1.04-1.29] per 5g increase, p=0.008); without insulin, post-dinner protein intake was inversely associated with NH occurrence (OR [95% CI]: 0.88 [0.78-1.00] per 2g increase, p=0.048).

CONCLUSIONS

NH remains frequent in adults with type 1 diabetes. There is a complex relationship between post-dinner dietary intake and NH occurrence, including the significant role of nutrient content and rapid-acting insulin injection that requires further investigation.

Hypoglycaemia in diabetes mellitus: epidemiology and clinical implications

Hypoglycaemia is a frequent adverse effect of treatment of diabetes mellitus with insulin and sulphonylureas. Fear of hypoglycaemia alters self-management of diabetes mellitus and prevents optimal glycaemic control. Mild (self-treated) and severe (requiring help) hypoglycaemia episodes are more common in type 1 diabetes mellitus but people with insulin-treated type 2 diabetes mellitus are also exposed to frequent hypoglycaemic events, many of which occur during sleep. Hypoglycaemia can disrupt many everyday activities such as driving, work performance and leisure pursuits. In addition to accidents and physical injury, the morbidity of hypoglycaemia involves the cardiovascular and central nervous systems. Whereas coma and seizures are well-recognized neurological sequelae of hypoglycaemia, much interest is currently focused on the potential for hypoglycaemia to cause dangerous and life-threatening cardiac complications, such as arrhythmias and myocardial ischaemia, and whether recurrent severe hypoglycaemia can cause permanent cognitive impairment or promote cognitive decline and accelerate the onset of dementia in middle-aged and elderly people with diabetes mellitus. Prevention of hypoglycaemia is an important part of diabetes mellitus management and strategies include patient education, glucose monitoring, appropriate adjustment of diet and medications in relation to everyday circumstances including physical exercise, and the application of new technologies such as real-time continuous glucose monitoring, modified insulin pumps and the artificial pancreas.

MD-Logic overnight control for 6 weeks of home use in patients with type 1 diabetes: randomized crossover trial

OBJECTIVE

We evaluated the effect of the MD-Logic system on overnight glycemic control at patients' homes.

RESEARCH DESIGN AND METHODS

Twenty-four patients (aged 12-43 years; average A1c 7.5 ± 0.8%, 58.1 ± 8.4 mmol/mol) were randomly assigned to participate in two overnight crossover periods, each including 6 weeks of consecutive nights: one under closed loop and the second under sensor-augmented pump (SAP) therapy at patients' homes in real-life conditions. The primary end point was time spent with sensor glucose levels below 70 mg/dL (3.9 mmol/L) overnight.

RESULTS

Closed-loop nights significantly reduced time spent in hypoglycemia (P = 0.02) and increased the percentage of time spent in the target range of 70-140 mg/dL (P = 0.003) compared with nights when the SAP therapy was used. The time spent in substantial hyperglycemia above 240 mg/dL was reduced by a median of 52.2% (interquartile range [IQR] 4.8, 72.9%; P = 0.001) under closed-loop control compared with SAP therapy. Overnight total insulin doses were lower in the closed-loop nights compared with the SAP nights (P = 0.04). The average daytime glucose levels after closed-loop operation were reduced by a median of 10.0 mg/dL (IQR -2.7, 19.2; P = 0.017) while lower total insulin doses were used (P = 0.038). No severe adverse events occurred during closed-loop control; there was a single event of severe hypoglycemia during a control night.

CONCLUSIONS

The long-term home use of automated overnight insulin delivery by the MD-Logic system was found to be a feasible, safe, and an effective tool to reduce nocturnal hypoglycemia and improve overnight glycemic control in subjects with type 1 diabetes.

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.

Update on the American Diabetes Association Standards of Medical Care

The diagnosis and management of diabetes in primary care has increased immensely over the past several years. The focus of this article is on the latest substantive revisions in the diagnosis, treatment, and management of diabetes, which was presented in the January 2014 issue of the ADA's journal Diabetes Care.