Comparator Data Characteristics and Testing Procedures for the Clinical Performance Evaluation of Continuous Glucose Monitoring Systems

Comparing the performance of different continuous glucose monitoring (CGM) systems is challenging due to the lack of comprehensive guidelines for clinical study design. In particular, the absence of concise requirements for the distribution of comparator (reference) blood glucose (BG) concentrations and their rate of change (RoC) that are used to evaluate CGM performance, impairs comparability. For this article, several experts in the field of CGM performance testing have collaborated to propose characteristics of the distribution of comparator measurements that should be collected during CGM performance testing. Specifically, it is proposed that at least 7.5% of comparator BG concentrations are <70 mg/dL (3.9 mmol/L) and >300 mg/dL (16.7 mmol/L), respectively, and that at least 7.5% of BG-RoC combinations indicate fast BG changes with impending hypo- or hyperglycemia, respectively. These proposed characteristics of the comparator data can facilitate the harmonization of testing conditions across different studies and CGM systems and ensure that the most relevant scenarios representing real-life situations are established during performance testing. In addition, a study protocol and testing procedure for the manipulation of glucose levels are suggested that enable the collection of comparator data with these characteristics. This work is an important step toward establishing a future standard for the performance evaluation of CGM systems.

A sub-analysis of the SAGE study in Italy indicates good glycemic control in type 1 diabetes

BACKGROUND AND AIMS

Intensive glycemic control minimizes the risk of micro- and macrovascular complications in patients with type 1 diabetes (T1D). We report glycemic control in Italian participants (age groups: 26-44, 45-64, and ≥65 years) of the global SAGE study.

METHODS AND RESULTS

The primary endpoint was proportion of participants who achieved an HbA_1c <7% in predefined age groups. In the 523 patients with T1D, mean age was 44.6 years and mean body mass index (BMI) was 25 kg/m². Mean HbA_1c was 7.5% and 29.4% had HbA_1c <7.0%, with the highest percentage in those 26-45 years (31.7%) and the lowest in those ≥65 years (20%). Altogether, 22.9% of patients achieved their physician-established individualized HbA_1c target. Most patients had ≥1 symptomatic hypoglycemic episode in the previous 3 months (≤70 mg/dL 82.5%; ≤54 mg/dL 61%). Severe hypo- and hyperglycemia were experienced by 16.3% and 12% of patients, of which 7.1 and 9.5%, respectively, required hospitalization/emergency visits. More patients achieved HbA_1c <7% with CSII (30%) than with multiple daily insulin injections (27.9%). In multivariate analysis, BMI (OR 0.94, 95% CI 0.89-0.99, p = 0.032) and adherence to diet (OR 0.36, 95% CI 0.18-0.70, p = 0.0028) were significantly associated with HbA_1c <7.0%.

CONCLUSIONS

Glycemic control can be considered good in the Italian SAGE cohort, especially in younger patients, who more frequently use pumps/continuous glucose monitoring. Greater patient education and use of technology may further support this achievement. Patients should be encouraged to maintain a low BMI and adhere to their diet.

Methods for Insulin Bolus Adjustment Based on the Continuous Glucose Monitoring Trend Arrows in Type 1 Diabetes: Performance and Safety Assessment in an In Silico Clinical Trial

BACKGROUND

Providing real-time magnitude and direction of glucose rate-of-change (ROC) via trend arrows represents one of the major strengths of continuous glucose monitoring (CGM) sensors in managing type 1 diabetes (T1D). Several literature methods were proposed to adjust the standard formula (SF) used for insulin bolus calculation by accounting for glucose ROC, but each of them provides different suggestions, making it difficult to understand which should be applied in practice. This work aims at performing an extensive in-silico assessment of their performance and safety.

METHODS

The methods of Buckingham (BU), Scheiner (SC), Pettus/Edelman (PE), Klonoff/Kerr (KL), Aleppo/Laffel (AL), Ziegler (ZI), and Bruttomesso (BR) were evaluated using the UVa/Padova T1D simulator, in single-meal scenarios, where ROC and glucose at mealtime varied between [-2,+2] mg/dL/min and [80,200] mg/dL, respectively. Efficacy of postprandial glucose control was quantitatively assessed by time in, above and below range (TIR, TAR, and TBR, respectively).

RESULTS

For negative ROCs, all methods proved to increase TIR and decrease TAR and TBR vs SF, with KL, PE, and BR being the most effective. For positive ROCs, a general worsening of the performances is present, only BR improved the glycemic control when mealtime glucose was close to hypoglycemia, while SC resulted the safest in the other conditions.

CONCLUSIONS

Insulin bolus adjustment methods are effective for negative ROCs, but they generally appear to overdose for positive ROCs, calling for safer strategies in such a scenario. These results can be useful in outlining guidelines to identify which adjustment to apply based on the mealtime condition.

Automated insulin delivery: benefits, challenges, and recommendations. A Consensus Report of the Joint Diabetes Technology Working Group of the European Association for the Study of Diabetes and the American Diabetes Association

A technological solution for the management of diabetes in people who require intensive insulin therapy has been sought for decades. The last 10 years have seen substantial growth in devices that can be integrated into clinical care. Driven by the availability of reliable systems for continuous glucose monitoring, we have entered an era in which insulin delivery through insulin pumps can be modulated based on sensor glucose data. Over the past few years, regulatory approval of the first automated insulin delivery (AID) systems has been granted, and these systems have been adopted into clinical care. Additionally, a community of people living with type 1 diabetes has created its own systems using a do-it-yourself approach by using products commercialised for independent use. With several AID systems in development, some of which are anticipated to be granted regulatory approval in the near future, the joint Diabetes Technology Working Group of the European Association for the Study of Diabetes and the American Diabetes Association has created this consensus report. We provide a review of the current landscape of AID systems, with a particular focus on their safety. We conclude with a series of recommended targeted actions. This is the fourth in a series of reports issued by this working group. The working group was jointly commissioned by the executives of both organisations to write the first statement on insulin pumps, which was published in 2015. The original authoring group was comprised by three nominated members of the American Diabetes Association and three nominated members of the European Association for the Study of Diabetes. Additional authors have been added to the group to increase diversity and range of expertise. Each organisation has provided a similar internal review process for each manuscript prior to submission for editorial review by the two journals. Harmonisation of editorial and substantial modifications has occurred at both levels. The members of the group have selected the subject of each statement and submitted the selection to both organisations for confirmation.

Automated Insulin Delivery: Benefits, Challenges, and Recommendations. A Consensus Report of the Joint Diabetes Technology Working Group of the European Association for the Study of Diabetes and the American Diabetes Association

A technological solution for the management of diabetes in people who require intensive insulin therapy has been sought for decades. The last 10 years have seen substantial growth in devices that can be integrated into clinical care. Driven by the availability of reliable systems for continuous glucose monitoring, we have entered an era in which insulin delivery through insulin pumps can be modulated based on sensor glucose data. Over the past few years, regulatory approval of the first automated insulin delivery (AID) systems has been granted, and these systems have been adopted into clinical care. Additionally, a community of people living with type 1 diabetes has created its own systems using a do-it-yourself approach by using products commercialized for independent use. With several AID systems in development, some of which are anticipated to be granted regulatory approval in the near future, the joint Diabetes Technology Working Group of the European Association for the Study of Diabetes and the American Diabetes Association has created this consensus report. We provide a review of the current landscape of AID systems, with a particular focus on their safety. We conclude with a series of recommended targeted actions. This is the fourth in a series of reports issued by this working group. The working group was jointly commissioned by the executives of both organizations to write the first statement on insulin pumps, which was published in 2015. The original authoring group was comprised by three nominated members of the American Diabetes Association and three nominated members of the European Association for the Study of Diabetes. Additional authors have been added to the group to increase diversity and range of expertise. Each organization has provided a similar internal review process for each manuscript prior to submission for editorial review by the two journals. Harmonization of editorial and substantial modifications has occurred at both levels. The members of the group have selected the subject of each statement and submitted the selection to both organizations for confirmation.

An Integrated Mobile Platform for Automated Data Collection and Real-Time Patient Monitoring in Diabetes Clinical Trials

We present a new mobile platform to be used in clinical trials aimed at both collecting data and assessing new technologies and treatments for diabetes care. The main components of the platform are a mobile app, that automatically collects data from continuous glucose monitoring sensors and activity trackers, and also allows users to manually log daily events; a cloud database for safe data storage; a web interface, which allows clinicians to monitor patients' status in real-time. The platform is modular and highly customizable for a multitude of purposes in clinical research. Preliminary tests performed for daily-life data gathering by both clinicians and users are extremely encouraging.

Effectiveness of adding alarms to flash glucose monitoring in adults with type 1 diabetes under routine care

AIM

Whether glucose sensor alarms improve metabolic control and are accepted by individuals with diabetes is unclear. Here, we investigated whether switching from a standard flash glucose monitoring system (FGM1) to a system equipped with hypo- and hyperglycemia alarms (FGM2) improves glycemic control and psychological outcomes in adults with type 1 diabetes (T1D).

METHODS

Subjects with T1D and > 4% of time in hypoglycemia or > 40% of time in hyperglycemia were studied while wearing FGM1 (4 weeks) and after switching to FGM2 for 8 weeks. The primary endpoint was the change in time in range (TIR 70-180 mg/dl [3.9-10.0 mmol/L]) after 4 weeks of FGM2 use. Time below range (TBR), time above range (TAR), mean glucose, coefficient of variation (CV), sensor scans, treatment satisfaction, and hypoglycemia fear were secondary outcomes.

RESULTS

We included 38 subjects aged 33.7 ± 12.6 year. During 4 weeks of FGM2 use, TIR increased from 52.8 to 57.0% (p = 0.001), TBR decreased from 6.2 to 3.4% (p < 0.0001) as did time < 54 mg/dl (from 1.4 to 0.3%, p < 0.0001) and CV (from 39.6% to 36.1%, p < 0.0001). These changes were confirmed after 8 weeks of FGM2 use. Treatment satisfaction improved and fear of hypoglycemia decreased. Subjects who had > 4% of time in hypoglycemia at baseline showed the greatest improvements in glucose control and treatment satisfaction.

CONCLUSION

Switching from FGM1 to FGM2 improved TIR and treatment satisfaction and reduced fear of hypoglycemia. Participants who benefited most from switching from FGM1 to FGM2 were those prone to hypoglycemia.

Glycemic control after switching to faster aspart in adults with type 1 diabetes

AIMS

Post-prandial hyperglycemia remains an unmet need in the management of type 1 diabetes (T1D). In randomized trials, faster insulin aspart (FIA) showed modest but significant reductions of glycemic spikes after meals. Whether such benefit is evident in routine clinical practice is unclear.

METHODS

We analyzed data of patients with T1D at the time they switched from a prior bolus insulin to FIA and at the first available follow-up. The primary endpoint was the change in the time spent in hyperglycemia > 250 mg/dl during daytime from flash glucose monitoring (FGM). Secondary outcomes included the change in HbA1c, body weight, insulin dose and other FGM metrics.

RESULTS

We included 117 patients with T1D on multiple daily injections who switched to FIA, 57 of whom had data from FGM. Patients were 41-year-old, 51.3% men, with 19.3 years diabetes duration and a baseline HbA1c of 7.7% (60 mmol/mol). Mean observation time was 4.3 months. After switching to FIA, HbA1c declined by 0.1% (1 mmol/mol) only in patients with baseline HbA1c > 7.0% (53 mmol/mol). Time spent in hyperglycemia > 250 mg/dl during daytime was significantly reduced from 14.8 to 11.9% (p = 0.006). Time in range improved from 48.3 to 51.0% (p = 0.028). Results were consistent across various patient characteristics.

CONCLUSIONS

Under routine care, patients with T1D who switched to FIA experienced a reduction in the time spent in hyperglycemia > 250 mg/dl during daytime and an increase in time in range. These improvements may be due to better control of post-prandial hyperglycemia, as observed in trials.

Switching from predictive low glucose suspend to advanced hybrid closed loop control: Effects on glucose control and patient reported outcomes

AIMS

Automated insulin delivery improves glucose control. Aim of this study was to compare in real life the effects on glucose control and patient reported outcomes of an advanced hybrid closed loop system (Control-IQ), versus a simpler system with predictive low glucose suspend function (Basal-IQ).

METHODS

Thirty-one type 1 diabetic subjects were studied during Basal-IQ and after switching to Control-IQ. Variables analyzed were time spent in range (70-180 mg/dL), in tight range (70-140 mg/dL), above range (>180 mg/dL), below range (<70 mg/dL), mean glucose, coefficient of variation and glycated hemoglobin. Questionnaires were administered regarding therapy satisfaction (Diabetes Treatment Satisfaction Questionnaire in status/change form), fear of hypoglycemia (Hypoglycemia Fear Survey), quality of sleep (Pittsburgh Sleep Quality Index).

RESULTS

After 12 weeks of Control-IQ, time in range increased from 62.7 to 74.0%, p < 0.0001, time in tight range increased from 37.1 to 44.6 %, p < 0.001, time above range decreased from 35.6 to 24.4% p < 0.0001. Improvements were observed in mean glucose and glucose variability. Glycated hemoglobin decreased from 7.0% (53 mmol/mol) to 6.6% (49 mmol/mol), p < 0.0001. Subjects using Control-IQ manifested greater satisfaction and less fear of hypoglycemia.

CONCLUSION

Compared to Basal-IQ, Control-IQ improves glucose control and therapy satisfaction.

Performance of intermittently scanned continuous glucose monitoring systems in people with type 1 diabetes: A pooled analysis

AIMS

To conduct a pooled analysis to assess the performance of intermittently scanned continuous glucose monitoring (isCGM) in association with the rate of change in sensor glucose in a cohort of children, adolescents, and adults with type 1 diabetes.

MATERIAL AND METHODS

In this pooled analysis, isCGM system accuracy was assessed depending on the rate of change in sensor glucose. Clinical studies that have been investigating isCGM accuracy against blood glucose, accompanied with collection time points were included in this analysis. isCGM performance was assessed by means of median absolute relative difference (MedARD), Parkes error grid (PEG) and Bland-Altman plot analyses.

RESULTS

Twelve studies comprising 311 participants were included, with a total of 15 837 paired measurements. The overall MedARD (interquartile range) was 12.7% (5.9-23.5) and MedARD differed significantly based on the rate of change in glucose (P < 0.001). An absolute difference of -22 mg/dL (-1.2 mmol/L) (95% limits of agreement [LoA] 60 mg/dL (3.3 mmol/L), -103 mg/dL (-5.7 mmol/L)) was found when glucose was rapidly increasing (isCGM glucose minus reference blood glucose), while a -32 mg/dL (1.8 mmol/L) (95% LoA 116 mg/dL (6.4 mmol/L), -51 mg/dL (-2.8 mmol/L)) absolute difference was observed in periods of rapidly decreasing glucose.

CONCLUSIONS

The performance of isCGM was good when compared to reference blood glucose measurements. The rate of change in glucose for both increasing and decreasing glucose levels diminished isCGM performance, showing lower accuracy during high rates of glucose change.

Implantable and transcutaneous continuous glucose monitoring system: a randomized cross over trial comparing accuracy, efficacy and acceptance

AIM

To compare accuracy, efficacy and acceptance of implantable and transcutaneous continuous glucose monitoring (CGM) systems.

METHODS

In a randomized crossover trial we compared 12 weeks with Eversense implantable sensor (EVS) and 12 weeks with Dexcom G5 transcutaneous sensor (DG5) in terms of accuracy, evaluated as Mean Absolute Relative Difference (MARD) vs capillary glucose (SMBG), time of CGM use, adverse events, efficacy (as HbA1c, time in range, time above and below range) and psychological outcomes evaluated with Diabetes Treatment Satisfaction Questionnaire (DTSQ), Glucose Monitoring Satisfaction Survey (GMSS), Hypoglycemia Fear Survey (HFS2), Diabetes Distress Scale (DDS).

RESULTS

16 subjects (13 males, 48.8 ± 10.1 years, HbA1c 55.8 ± 7.9 mmol/mol, mean ± SD) completed the study. DG5 was used more than EVS [percentage of use 95.7 ± 3.6% vs 93.5 ± 4.3% (p = 0.02)]. MARD was better with EVS (12.2 ± 11.5% vs. 13.1 ± 14.7%, p< 0.001). No differences were found in HbA1c. While using EVS time spent in range increased and time spent in hyperglycemia decreased, but these data were not confirmed by analysis of retrofitted data based on SMBG values. EVS reduced perceived distress, without significant changes in other psychological outcomes.

CONCLUSIONS

CGM features may affect glycemic control and device acceptance.

Tryptophan Metabolites, Cytokines, and Fatty Acid Binding Protein 2 in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) differ for triggers, mode of start, associated symptoms, evolution, and biochemical traits. Therefore, serious attempts are underway to partition them into subgroups useful for a personalized medicine approach to the disease. Here, we investigated clinical and biochemical traits in 40 ME/CFS patients and 40 sex- and age-matched healthy controls. Particularly, we analyzed serum levels of some cytokines, Fatty Acid Binding Protein 2 (FAPB-2), tryptophan, and some of its metabolites via serotonin and kynurenine. ME/CFS patients were heterogeneous for genetic background, trigger, start mode, symptoms, and evolution. ME/CFS patients had higher levels of IL-17A (p = 0.018), FABP-2 (p = 0.002), and 3-hydroxykynurenine (p = 0.037) and lower levels of kynurenine (p = 0.012) and serotonin (p = 0.045) than controls. Changes in kynurenine and 3-hydroxykynurenine were associated with increased kynurenic acid/kynurenine and 3-hydroxykynurenine/kynurenine ratios, indirect measures of kynurenine aminotransferases and kynurenine 3-monooxygenase enzymatic activities, respectively. No correlation was found among cytokines, FABP-2, and tryptophan metabolites, suggesting that inflammation, anomalies of the intestinal barrier, and changes of tryptophan metabolism may be independently associated with the pathogenesis of the disease. Interestingly, patients with the start of the disease after infection showed lower levels of kynurenine (p = 0.034) than those not starting after an infection. Changes in tryptophan metabolites and increased IL-17A levels in ME/CFS could both be compatible with anomalies in the sphere of energy metabolism. Overall, clinical traits together with serum biomarkers related to inflammation, intestine function, and tryptophan metabolism deserve to be further considered for the development of personalized medicine strategies for ME/CFS.

Patient-reported outcomes in adults with type 1 diabetes in global real-world clinical practice: The SAGE study

AIMS

To conduct a secondary analysis of the SAGE study to evaluate the association between glycaemic control and patient-reported outcomes (PROs), in adults with type 1 diabetes (T1DM) across different age groups and regions.

MATERIALS AND METHODS

SAGE was a multinational, cross-sectional, observational study in adults with T1DM. Data were collected at a single visit, analysed according to predefined age groups (26-44, 45-64, and ≥65 years), and reported across different regions. PRO questionnaires were applied to assess hypoglycaemia fear (Hypoglycemia Fear Survey-II), diabetes-related distress (Problem Areas In Diabetes questionnaire), insulin treatment satisfaction (Insulin Treatment Satisfaction Questionnaire), and diabetes-specific quality of life (QoL; Audit of Diabetes-Dependent Quality of Life). Multivariable analysis was performed to evaluate the relationship between glycated haemoglobin (HbA1c) target achievement (<7% and individualised targets) with PRO scores.

RESULTS

The PRO scores showed relatively low levels of diabetes-related emotional distress and fear of hypoglycaemia, moderate to high treatment satisfaction, and low diabetes-related impact on QoL. Results were generally comparable across age groups with some regional variability. Achievement of the HbA1c <7% target was associated with less worry about hypoglycaemia, lower diabetes-related emotional distress, higher insulin treatment satisfaction, and higher QoL. Achievement of individualised HbA1c targets was associated with lower diabetes-related emotional distress and higher insulin treatment satisfaction.

CONCLUSIONS

Better glycaemic control was most closely associated with low emotional distress due to diabetes and high patient-reported insulin treatment satisfaction.

A "Slide Rule" to Adjust Insulin Dose Using Trend Arrows in Adults with Type 1 Diabetes: Test in Silico and in Real Life

INTRODUCTION

In persons with type 1 diabetes (T1D) insulin dosing can be adjusted based on trend arrows derived from continuous glucose monitoring (CGM). We propose a slide rule with narrower blood glucose intervals and more classes of insulin sensitivity than are available in current models.

METHODS

The slide rule was tested in silico, in which a meal was simulated in 100 virtual subjects and the insulin bolus was calculated either in the standard way based on the insulin-to-carbohydrate ratio and the correction factor or according to the slide rule, following which the percentage time spent in range (70-180 mg/dl; %T_IR), hypoglycemia (< 70 mg/dl; %T_HYPO), and hyperglycemia (> 180 mg/dl; %T_HYPER) was compared between the methods during the 4 h after the meal. Slide rule performance was also tested in real life by analyzing the same variables at during the 4 h postprandial period in 27 individuals with T1D. Only meals starting while the rate of change was at least 1 mg/dl per minute (increasing or decreasing) were considered for analysis.

RESULTS

In silico, when the preprandial trend arrow was increasing, our slide rule reduced %T_HYPER and increased %T_IR (p < 0.05), whereas when the preprandial trend arrow was decreasing, it reduced %T_HYPO and slightly increased %T_HYPER (p < 0.05). In real life, our slide rule kept subjects on target for 70.8 and 91.6% of postprandial time when preprandial trend arrows were increasing or decreasing, respectively.

CONCLUSION

The proposed slide rule performed well both in silico and in real life, suggesting that it could be safely adopted by individuals with T1D to improve glucose control.

Assessment of the effect of pregnancy planning in women with type 1 diabetes treated by insulin pump

BACKGROUND

Pregnant women with type 1 diabetes (T1D) have high risk of complications despite improved care based on technology advancements.

OBJECTIVE

To assess the effects of pregnancy planning on fetal and maternal outcomes in T1D women treated with continuous subcutaneous insulin infusion (CSII).

STUDY DESIGN

We retrospectively assessed maternal and neonatal outcomes in T1D women using CSII who had planned or unplanned pregnancies between 2002 and 2018. The study was done in two European countries with similar sustained programs for pregnancy planning over the study period.

RESULTS

Data from 107 pregnancies and newborn babies were collected. Seventy-nine pregnancies (73.8%) had been planned. HbA1c was lower in planned versus unplanned pregnancy before and during all three trimesters of pregnancy (p < 0.0001). Pregnancy planning was associated with a reduction in the occurrence of iatrogenic preterm delivery (RR 0.44, 95% CI 0.23-0.95; p = 0.01). Risk reduction persisted after adjustments for mother's age above 40 years and preeclampsia. High HbA1c before or during pregnancy was associated with an increased risk of iatrogenic preterm delivery (RR 3.05, 95% CI 1.78-5.22, p < 0.0001). Premature newborns needed intensive care more often than those at term (RR 3.10, 95% CI 1.53-4.31; p = 0.002).

CONCLUSIONS

Pregnancy planning in T1D women using CSII was associated with better glucose control and decreased risk of iatrogenic preterm delivery. Hence preconception care also improves pregnancy outcome in patients using an advanced mode of insulin delivery. Planned pregnancies could further benefit from the use of new metrics of glucose control.

Comparing the accuracy of transcutaneous sensor and 90-day implantable glucose sensor

BACKGROUND AND AIMS

Continuous glucose monitoring improves glycemic control in diabetes. This study compared the accuracy of the Dexcom G5 Mobile (Dexcom, San Diego, CA) transcutaneous sensor (DG5) and the first version of Eversense (Senseonics,Inc., Germantown, MD) implantable sensor (EVS).

METHODS AND RESULTS

Subjects with type 1 diabetes (T1D) and using EVS wore simultaneously DG5 for seven days. At day 3, patients were admitted to a clinical research center (CRC) to receive breakfast with delayed and increased insulin bolus to induce glucose excursions. At CRC, venous glucose was monitored every 15 min (or 5 min during hypoglycemia) for 6 h by YSI 2300 STAT PLUS™ glucose and lactate analyzer. At home patients were requested to perform 4 fingerstick glucose measurements per day. Eleven patients (9 males, age 47.4 ± 11.3 years, M±SD) were enrolled. During home-stay the median [25th-75th percentile] absolute relative difference (ARD) over all CGM-fingerstick matched-pairs was 11.64% [5.38-20.65]% for the DG5 and 10.75% [5.15-19.74]% for the EVS (p-value = 0.58). At CRC, considering all the CGM-YSI matched-pairs, the DG5 showed overall smaller median ARD than EVS, 7.91% [4.14-14.30]% vs 11.4% [5.04-18.54]% (p-value<0.001). Considering accuracy during blood glucose swings, DG5 performed better than EVS when glucose rate-of-change was -0.5 to -1.5 mg/dL/min, with median ARD of 7.34% [3.71-12.76]% vs 13.59% [4.53-20.78]% (p-value<0.001), and for rate-of-change < -1.5 mg/dl/min, with median ARD of 5.23% [2.09-15.29]% vs 12.73% [4.14-20.82]% (p-value = 0.02).

CONCLUSIONS

DG5 was more accurate than EVS at CRC, especially when glucose decreased. No differences were found at home.

Comparative Effectiveness of Switching From First-Generation Basal Insulin to Glargine 300 U/ml or Degludec 100 U/ml in Type 1 Diabetes: The RESTORE-1 Study

INTRODUCTION

Following pivotal trials, real-world evidence is important to assess the impact of new drugs in everyday clinical practice. The RESTORE-1 study aimed to compare effectiveness and safety of the second-generation basal insulins (2BI), i.e., insulin glargine 300 U/ml (Gla-300) vs. degludec 100 U/ml (IDeg-100), in type 1 diabetes (T1D).

METHODS

Retrospective, non-inferiority, multicenter study, based on electronic medical records. All patients switching to Gla-300 or IDeg-100 from first-generation basal insulins (1BI) were 1:1 propensity score matched (PSM). Changes during 6 months in HbA1c (primary endpoint), fasting plasma glucose (FPG), body weight, and insulin doses were assessed using linear mixed models for repeated measures. Incidence rates (IR) of hypoglycemic events were assessed.

RESULTS

Overall, 19 centers provided data on 585 patients in each PSM cohort. For both groups, statistically significant reductions in HbA1c from baseline to 6 months were documented: - 0.20%; (95% CI - 0.32; - 0.08) in the Gla-300 group and - 0.14%; (95% CI - 0.24; - 0.04) in the IDeg-100 group. The non-inferiority of Gla-300 vs. IDeg-100 was confirmed (non-inferiority margin of 0.30%; upper 95% CI at 6 months, 0.09%). No statistically significant between-group differences emerged in FPG and body weight. Dose changes of basal and short-acting insulin were small in both groups, but higher in the Gla-300 group than in the Deg-100 group (p < 0.006). Incidence rates (IR) of hypoglycemia (blood glucose ≤ 70 mg/dl and < 54 mg/dl) during the 6-month follow-up by treatment were slightly lower in the Gla-300 group than in the Deg-100 group [IR ratios 0.82 (95% CI 0.55; 1.22) and 0.83; (95% CI 0.38; 1.83), respectively]. Hypoglycemic events (blood glucose < 54 mg/dl) decreased at 6 months in both groups (p = 0.01 for Gla-300 and p < 0.001 for IDeg-100). There were no severe hypoglycemic events for Gla-300 and seven events for IDeg-100 (p = 0.02).

CONCLUSIONS

Switching from 1BI to 2BI in adults with T1D was associated with similar improvements in glycemic control and overall significant decrease in hypoglycemia, with no severe events with Gla-300. Effectiveness of both insulins was limited by under-titration.

Efficacy of telemedicine for persons with type 1 diabetes during Covid19 lockdown

BACKGROUND

Starting March 2020 the Italian Government imposed a lockdown to limit the spread of SARS-CoV-2. During lockdown outpatient visits were limited and telemedicine (TM) was encouraged.

METHODS

We retrospectively analyzed data from continuous or flash glucose monitoring systems shared through different cloud systems during the lockdown by subjects with type 1 diabetes and compared data obtained 4 weeks before and 4 weeks after structured telephonic visit. Variables considered were mean glucose, time spent in target (70-180 mg/dl), hypoglycemia (<70 mg/dl) and hyperglycemia (>180 mg/dl), coefficient of variation, and length of sensor use.

RESULTS

During the 4 weeks following the telephonic visit there was an improvement of glycemic control, with a significant reduction of mean glucose values (161.1 before vs 156.3 mg/dl after, p = 0.001), an increase of the time spent in target (63.6 vs 66.3, p = 0.0009) and a reduction of time spent in hyperglycemia (33.4 vs 30.5, p = 0.002). No changes were observed regarding glucose variability, time spent in hypoglycemia, and length of sensor use. Similar results were observed in subjects treated with multiple daily injections or continuous subcutaneous insulin infusion.

CONCLUSIONS

A structured telephonic visit appears to be an effective way to replace or integrate routine visits in particular conditions.

Effects of glucose variability on hematopoietic stem/progenitor cells in patients with type 1 diabetes

BACKGROUND AND PURPOSE

Diabetes reduces the levels of hematopoietic stem/progenitor cells (HSPCs), which can contribute to organ and tissue homeostasis. Among patients with diabetes, lower HSPC levels predict the development or worsening of micro- and macro-angiopathy. High glucose variability is also associated with diabetic complications and we have previously shown that acute hypoglycaemia can stimulate stem/progenitor cells. Thus, we evaluated the relationship between glucose variability or time in hypoglycaemia and HSPCs in patients with type 1 diabetes (T1D).

METHODS

Patients with T1D were compared to healthy subjects. HSPCs (CD34⁺, CD133⁺, CD34⁺CD133⁺, CD34 + CD45^dim) were quantified by flow cytometry. Using flash glucose monitoring system for 90 days, we calculated several measures of glucose variability and time in hypoglycaemia.

RESULTS

Forty-four patients with T1D and 44 healthy subjects were enrolled. Compared to healthy controls, T1D patients had significantly lower levels of HSPCs and duration of diabetes was inversely correlated with HSPC levels. Significant direct correlations were found between HSPC levels and the coefficient of variation of glucose levels or time in hypoglycaemia, which were stronger in patients with short-term than in those with long-standing diabetes.

CONCLUSION

This study confirms the pauperization of HSPCs in T1D patients and demonstrates a potential HSPC-stimulatory effect of hypoglycaemia, which mitigates with long-lasting diabetes. These data are consistent with a model whereby disease chronicity progressively blunts the release of HSPCs in response to adrenergic triggers, like hypoglycaemic events.

Diabetic ketoacidosis: A consensus statement of the Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology and Pediatric Diabetoloy (SIEDP)

BACKGROUND AND AIM

Diabetic ketoacidosis (DKA) is a serious medical emergency once considered typical of type 1 diabetes (T1DM), but now reported to occur in type 2 and GDM patients as well. DKA can cause severe complications and even prove fatal. The aim of our study was to review recent international and national guidelines on diagnosis, clinical presentation and treatment of diabetic ketoacidosis, to provide practical clinical recommendations.

METHODS AND RESULTS

Electronic databases (MEDLINE (via PUB Med), Scopus, Cochrane library were searched for relevant literature. Most international and national guidelines indicate the same accurate flow chart to diagnose, to evaluate from clinical and laboratory point of view, and treat diabetic ketoacidosis.

CONCLUSION

Prompt diagnosis, rapid execution of laboratory analysis and correct treatment are imperative to reduce the mortality related to diabetic ketoacidosis. These recommendations are designed to help healthcare professionals reduce the frequency and burden of DKA.

Performance of the Steno type 1 risk engine for cardiovascular disease prediction in Italian patients with type 1 diabetes

BACKGROUND AND AIMS

Premature cardiovascular disease cause excess mortality in type 1 diabetes (T1D). The Steno T1D Risk Engine was developed and validated in northern European countries but its validity in other populations is unknown. We evaluated the performance of the Steno T1D Risk Engine in Italian patients with T1D.

MATERIALS AND METHODS

We included patients with T1D with a baseline visit between July 2013 and April 2014, who were free of cardiovascular disease and had complete information to estimate risk. The estimated cardiovascular risk score was compared with the 5-year rate of cardiovascular events by means of logistic regression.

RESULTS

Among 223 patients (mean age 43 ± 13 years, 34.5% male, mean duration of diabetes 22 ± 12 years) the mean estimated cardiovascular risk at 5 years was 5.9% (95% C.I. 5.2-6.5%). At baseline, high estimated risk discriminated the presence of asymptomatic atherosclerosis better than microangiopathy, and was not associated with markers of inflammation or endothelial activation. After a mean follow-up of 4.7 ± 0.5 years, only 3 cardiovascular events were observed and nonetheless the risk score was significantly associated with their incidence (OR 1.22; 95% C.I. 1.08-1.39, p = 0.001). However, the observed event rate was significantly lower than the estimated one (3 vs 13; 95% C.I. 12-14; p < 0.001).

CONCLUSION

The Steno T1D Risk Score identified subjects with subclinical atherosclerosis and high cardiovascular risk in an Italian T1D population. However, the absolute risk was significantly overestimated. Further studies in larger population are needed to confirm these results.

Glycaemic Control Among People with Type 1 Diabetes During Lockdown for the SARS-CoV-2 Outbreak in Italy

INTRODUCTION

In late February 2020, due to the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the Italian Government closed down all educational and sport activities. In March, it introduced further measures to stop the spread of coronavirus disease (COVID-19), placing the country in a state of almost complete lockdown. We report the impact of these restrictions on glucose control among people with type 1 diabetes (T1D).

METHODS

Data were collected on 33 individuals with T1D who were monitoring their glucose levels using a flash glucose monitoring device and remotely connected to the diabetes clinic on a cloud platform. We retrieved information on average glucose, standard deviation and percentage time in hypoglycaemia (< 70 mg/dl), glucose range (70-180 mg/dl) and hyperglycaemia (> 180 mg/dl). We compared glycaemic measures collected during lockdown to those collected before the SARS-CoV-2 epidemic and to the periods immediately before lockdown.

RESULTS

In 20 patients who had stopped working and were at home as a result of the lockdown, overall glycaemic control improved during the first 7 days of the lockdown as compared to the weeks before the spread of SARS-CoV-2. Average glucose declined from 177 ± 45 mg/dl (week before lockdown) to 160 ± 40 mg/dl (lockdown; p = 0.005) and the standard deviation improved significantly. Time in range increased from 54.4 to 65.2% (p = 0.010), and time in hyperglycaemia decreased from 42.3 to 31.6% (p = 0.016). The number of scans per day remained unchanged. In 13 patients who continued working, none of the measures of glycaemic control changed during lockdown.

CONCLUSION

Despite the limited possibility to exercise and the incumbent psychologic stress, glycaemic control improved in patients with T1D who stopped working during the lockdown, suggesting that slowing down routine daily activities can have beneficial effects on T1D management, at least in the short term.

Vitamin D status and non-alcoholic fatty liver disease in patients with type 1 diabetes

PURPOSE

In patients with type 1 diabetes (T1D), the prevalence of non-alcoholic fatty liver disease (NAFLD) ranges from 10 to 53% and contrasting evidence suggests that vitamin D deficiency may favor liver fat accumulation. Here, we investigated the association between vitamin D status and NAFLD in adults with T1D.

METHODS

220 consecutive adult T1D patients on multiple daily injections or continuous subcutaneous insulin infusion and not taking calcium or vitamin D supplements were included. Patient characteristics, 25(OH)D serum levels, and metabolic parameters were analyzed. Vitamin D status was defined as sufficiency ( ≥ 75 nmol/L; 30 ng/ml), insufficiency (50-75 nmol/L; 20-30 ng/ml), or deficiency ( < 50 nmol/L; 20 ng/ml). NAFLD was diagnosed at ultrasound examination and graded 0-3.

RESULTS

NAFLD was present in 57 patients (29.5%): 51 grade 1, 5 grade 2, and 1 grade 3. Median 25(OH)D levels were 53 nmol/L (IQR 38-70) in patients with NAFLD and 50 nmol/L (34-69) in patients without (p = 0.46). At multivariable analysis, NAFLD was not associated with 25(OH)D levels (p = 0.42) or vitamin D deficiency (p = 0.55), while BMI (OR 1.16, 95% CI 1.07-1.27) and serum triglycerides (OR 1.02, 95% CI 1.01-1.03) were independently associated with NAFLD.

CONCLUSIONS

Vitamin D status appears to have no link with low-grade NAFLD in patients with type 1 diabetes.

The use of real time continuous glucose monitoring or flash glucose monitoring in the management of diabetes: A consensus view of Italian diabetes experts using the Delphi method

Until recently, in Italy, the use of continuous glucose monitoring (CGM) systems has been limited, but is now rapidly increasing, including the so-called real-time CGM (rtCGM) and the intermittently viewed CGM (iCGM), also called Flash Glucose Monitoring (FGM). These technologies overcome many of the limitations of self-monitoring of blood glucose (SMBG) by fingerprick and allow to go beyond HbA1c to check glucose control in diabetes. However, standardized protocols for applying and interpreting rtCGM and FGM data are lacking. In this paper, we delineate a consensus amongst Italian diabetes physicians on the attributes of rtCGM and FGM technologies, and introduce a consistent approach for their use by Italian healthcare professionals. Most experts consider rtCGM and FGM as two separate categories of interstitial subcutaneous fluid (ISF) sensing technologies, and see them as superior to SMBG. Furthermore, there is strong consensus that rtCGM and FGM reduce hypoglycemia risk, increase the amount of time in the target glucose range and augment treatment satisfaction. However, there is still no agreement on the indication of the FGM for subjects who suffer asymptomatic hypoglycemia. Consensus on the role of education in initiating and optimizing use of rtCGM/FGM and about the interpretation of glucose trends was near unanimous, whereas no consensus was reached on the statement that there are no disadvantages/risks of rtCGM/FGM. Some issues remain in rtCGM/FGM management: a) risk of excessive correction of high or low glucose; b) risk of alert fatigue leading to alert silencing or rtCGM termination; c) allergic reaction to the adhesive keeping rtCGM or FGM sensors in place. The panel almost unanimously agreed that sensor accuracy depends on multiple variables, that alarm setting should be individualized, and that global glycemic profile represent an useful tool in interpreting glucose data. More clinical studies and a wider use of these devices will increase the efficacy and effectiveness of continuous glucose monitoring in Italy.

A High-Fiber Diet Decreases Postabsorptive Protein Turnover but Does Not Alter Insulin Sensitivity in Men with Type 1 Diabetes Mellitus

BACKGROUND

High-fiber diets (HFDs) are recommended in the diet of persons with diabetes, yet such diets can impair macronutrient digestion and/or absorption, modify insulin sensitivity, and reset metabolism.

OBJECTIVES

We studied the effects of a HFD on the kinetics of whole-body protein, a macronutrient that could be affected by dietary fiber, in type 1 diabetes mellitus (T1DM), under both basal-low insulinemic and hyperinsulinemic conditions.

METHODS

Eight men with T1DM (body mass index range: 21.8-27.8 kg/m2) were studied twice - before and after the addition of guar gum (∼15 g/d) to their usual diet for ∼4 mo. Whole-body protein degradation (i.e., the rate of appearance [Ra] of endogenous leucine), leucine disposal to protein synthesis (PS), deamination, and reamination, were determined before and after the HFD, both in the postabsorptive state and following a euglycemic, hyperinsulinemic, hyperaminoacidemic clamp, using isotope dilution methods.

RESULTS

After the HFD, mean values (± SEs) for postabsorptive leucine Ra decreased by ∼20%: from 2.52 (0.15) to 2.03 (0.16) μmol x kg-1 x min-1, P < 0.049, after vs. before the HFD respectively. PS also decreased, by ∼25%: from 2.03 (0.15) to 1.57 (0.15), P < 0.045. Leucine concentration (P = 0.1) and reamination (P = 0.095) decreased moderately, whereas deamination was unchanged. Following the clamp, plasma amino acid concentrations (P < 0.001), leucine deamination (+ ∼50%, P < 0.00002), reamination (+ ∼30%, P < 0.0007), and PS (+ ∼35%, P < 0.00001) were all increased compared with postabsorptive state values, whereas endogenous leucine Ra was suppressed (by 15%, P < 0.00001, and by 25%, P < 0.001, with the primary or the reciprocal pool models, respectively). No significant differences in these insulin effects before compared with after the HFD were observed. Metabolic control (glycated hemoglobin), daily insulin requirement, and insulin-mediated glucose disposal were unchanged after the HFD.

CONCLUSIONS

A HFD downregulates postabsorptive protein turnover in men with T1DM, by decreasing both protein degradation and synthesis, possibly due to a subtle decrease and/or delay in amino acid absorption. It does not significantly affect the insulin (and amino acid sensitivity) to protein turnover, glucose disposal, and metabolic control.

Metabolic control and complications in Italian people with diabetes treated with continuous subcutaneous insulin infusion

BACKGROUND AND AIM

The objective of this cross-sectional study was to evaluate the degree of glycaemic control and the frequency of diabetic complications in Italian people with diabetes who were treated with continuous subcutaneous insulin infusion (CSII).

METHODS AND RESULTS

Questionnaires investigating the organisation of diabetes care centres, individuals' clinical and metabolic features and pump technology and its management were sent to adult and paediatric diabetes centres that use CSII for treatment in Italy. Information on standard clinical variables, demographic data and acute and chronic diabetic complications was derived from local clinical management systems. The sample consisted of 6623 people with diabetes, which was obtained from 93 centres. Of them, 98.8% had type 1 diabetes mellitus, 57.2% were female, 64% used a conventional insulin pump and 36% used a sensor-augmented insulin pump. The median glycated haemoglobin (HbA_1c) level was 60 mmol/mol (7.6%). The HbA_1c target (i.e. <58 mmol/mol for age <18 years and <53 mmol/mol for age >18 years) was achieved in 43.4% of paediatric and 23% of adult participants. Factors such as advanced pump functions, higher rate of sensor use, pregnancy in the year before the study and longer duration of diabetes were associated with lower HbA_1c levels. The most common chronic complications occurring in diabetes were retinopathy, microalbuminuria and hypertension. In the year before the study, 5% of participants reported ≥1 episode of severe hypoglycaemic (SH) episodes (SH) and 2.6% reported ≥1 episode of ketoacidosis.

CONCLUSIONS

Advanced personal skills and use of sensor-based pump are associated with better metabolic control outcomes in Italian people with diabetes who were treated with CSII. The reduction in SH episodes confirms the positive effect of CSII on hypoglycaemia.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 02620917 (ClinicalTrials.gov).

Effects of Hypoglycemia on Circulating Stem and Progenitor Cells in Diabetic Patients

CONTEXT

Iatrogenic hypoglycemia is the most common acute diabetic complication, and it significantly increases morbidity. In people with diabetes, reduction in the levels of circulating stem and progenitor cells predicts adverse outcomes.

OBJECTIVE

To evaluate whether hypoglycemia in diabetes affects circulating stem cells and endothelial progenitor cells (EPCs).

DESIGN

We performed an experimental hypoglycemia study (Study 1) and a case-control study (Study 2).

SETTING

Tertiary referral inpatient clinic.

PATIENTS AND OTHER PARTICIPANTS

Type 1 diabetic patients (Study 1, n = 19); diabetic patients hospitalized for severe iatrogenic hypoglycemia, matched inpatient and outpatient controls (Study 2, n = 22/group).

INTERVENTIONS

Type 1 diabetic patients underwent two in-hospital sessions of glucose monitoring during a breakfast meal with or without induction of hypoglycemia in random order. In Study 2, patients hospitalized for hypoglycemia and matched controls were compared.

MAIN OUTCOME MEASURE

Circulating stem cells and EPCs were measured by flow cytometry based on the expression of CD34 and kinase insert domain receptor (KDR).

RESULTS

In Study 1, the physiologic decline of CD34+KDR+ EPCs from 8 am to 2 pm was abolished by insulin-induced hypoglycemia in type 1 diabetic patients. In Study 2, diabetic patients hospitalized for severe iatrogenic hypoglycemia had significantly lower levels of CD34+ stem cells and CD34+KDR+ EPCs compared with diabetic inpatients or outpatient controls.

CONCLUSIONS

In diabetic patients, a single mild hypoglycemic episode can compromise the physiologic EPC fluctuation, whereas severe hypoglycemia is associated with a marked reduction in stem cells and EPCs. These data provide a possible link between hypoglycemia and adverse outcomes of diabetes.

FreeStyle Libre and Dexcom G4 Platinum sensors: Accuracy comparisons during two weeks of home use and use during experimentally induced glucose excursions

BACKGROUND AND AIMS

This study compared the accuracy of the FreeStyle Libre (Abbott, Alameda, CA) and Dexcom G4 Platinum (DG4P, Dexcom, San Diego, CA) CGM sensors.

METHODS AND RESULTS

Twenty-two adults with type 1 diabetes wore the two sensors simultaneously for 2 weeks. Libre was used according to manufacturer-specified lifetime (MSL); DG4P was used 7 days beyond MSL. At a clinical research center (CRC), subjects were randomized to receive the same breakfast with standard insulin bolus (standard) or a delayed and increased (delayed & increased) bolus to induce large glucose swings during weeks 1 and 2; venous glucose was checked every 5-15 min for 6 h. Subjects performed ≥4 reference fingersticks/day at home. Accuracy was assessed by differences in mean absolute relative difference (%MARD) in glucose levels compared with fingerstick test (home use) and YSI reference (CRC). During home-stay the Libre MARD was 13.7 ± 3.6% and the DG4P MARD 12.9 ± 2.5% (difference not significant [NS]). With both systems MARD increased during hypoglycaemia and decreased during hyperglycaemia, without significant difference between sensors. In the euglycaemic range MARD was smaller with DG4P [12.0 ± 2.4% vs 14.0 ± 3.6%, p = 0.026]. MARD increased in both sensors following delayed & increased vs. standard bolus (Libre: 14.9 ± 5.5% vs. 10.9 ± 4.1%, p = 0.008; DG4P: 18.1 ± 8.1% vs. 13.1 ± 4.6%, p = 0.026); between-sensor differences were not significant (p = 0.062). Libre was more accurate during moderate and rapid glucose changes.

CONCLUSIONS

DG4P and Libre performed similarly up to 7 days beyond DG4P MSL. Both sensors performed less well during hypoglycaemia but Libre was more accurate during glucose swings.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov (NCT02734745) April 12, 2016.

The GesTIO protocol experience: safety of a standardized order set for subcutaneous insulin regimen in elderly hospitalized patients

BACKGROUNDS

In non-critical hospitalized patients with diabetes mellitus, guidelines suggest subcutaneous insulin therapy with basal-bolus regimen, even in old and vulnerable inpatients.

AIM

To evaluate safety, efficacy, and benefit on clinical management of the GesTIO protocol, a set of subcutaneous insulin administration rules, in old and vulnerable non-ICU inpatients.

METHODS

Retrospective, observational study. Patients admitted to Geriatric Clinic of Padua were studied. 88 patients matched the inclusion criteria: type 2 diabetes or hospital-related hyperglycemia, ≥65 years, regular measurements of capillary glycemia, and basal-bolus subcutaneous insulin regimen managed by "GesTIO protocol" for five consecutive days.

MAIN OUTCOME MEASURES

ratio of patients with blood glucose (BG) <3.9 mmol/l; number of BG per patient in target range (5-11.1 mmol/l); daily mean BG; and calls to physicians for adjusting insulin therapy.

RESULTS

Mean age was 82 ± 7 years. 9.1% patients experienced mild hypoglycaemia, and no severe hypoglycaemia was reported. The median number of BG per patients in target range increased from 2.0 ± 2 to 3.0 ± 2 (p < 0.001). The daily mean BG decreased from 11.06 ± 3.03 to 9.64 ± 2.58 mmol/l (-12.8%, p < 0.005). The mean number of calls to physicians per patient decreased from 0.83 to 0.45 (p < 0.05).

CONCLUSIONS

Treatment with GesTIO protocol allows a safe and effective treatment even in very old and vulnerable inpatients with a faster management insulin therapy.

Accuracy of a CGM Sensor in Pediatric Subjects With Type 1 Diabetes. Comparison of Three Insertion Sites: Arm, Abdomen, and Gluteus

BACKGROUND

Patients with diabetes, especially pediatric ones, sometimes use continuous glucose monitoring (CGM) sensor in different positions from the approved ones. Here we compare the accuracy of Dexcom® G5 CGM sensor in three different sites: abdomen, gluteus (both approved) and arm (off-label).

METHOD

Thirty youths, 5-9 years old, with type 1 diabetes (T1D) wore the sensor during a clinical trial where frequent self-monitoring of blood glucose (SMBG) measurements were obtained. Sensor was inserted in different sites according to the patient habit. Accuracy metrics include absolute relative difference (ARD) and absolute difference (AD) of CGM with respect to SMBG. The three sites were compared with ANOVA. If the test detected a difference, an additional pair-wise comparison was performed.

RESULTS

Overall, no accuracy difference was detected: the mean ARD was 13.3% (SD = 13.5%) for abdomen, 13.4% (12.9%) for arm and 12.9% (20.2%) for gluteus ( P value = .83); the mean AD was 17.0 mg/dl (17.2 mg/dl) for abdomen, 17.2 mg/dl (17.1 mg/dl) for arm and 18.3 mg/dl (18.5 mg/dl) for gluteus ( P value = .30). In hypo- and euglycemia ARD ( P value = .87 and .15, respectively), and AD ( P value = .68 and .37, respectively) were not statistically different. At variance, in hyperglycemia, a significant difference was detected between the two approved sites, abdomen and gluteus (ΔARD = -2.2% [CI = -4.2%, -0.1%], P value = .04), whereas the comparisons with the off-label location, arm-abdomen, and arm-gluteus were not significant.

CONCLUSIONS

These results suggest that the accuracy of the sensor placed on the arm was not significantly different with respect to the two approved insertion sites (abdomen and gluteus). Larger, randomized trials are needed to draw final conclusions.

Overnight Closed-Loop Control Improves Glycemic Control in a Multicenter Study of Adults With Type 1 Diabetes

CONTEXT

Closed-loop control (CLC) for the management of type 1 diabetes (T1D) is a novel method for optimizing glucose control, and strategies for individualized implementation are being developed.

OBJECTIVE

To analyze glycemic control in an overnight CLC system designed to "reset" the patient to near-normal glycemic targets every morning.

DESIGN

Randomized, crossover, multicenter clinical trial.

PARTICIPANTS

Forty-four subjects with T1D requiring insulin pump therapy.

INTERVENTION

Sensor-augmented pump therapy (SAP) at home vs 5 nights of CLC (active from 23:00 to 07:00) in a supervised outpatient setting (research house or hotel), with a substudy of 5 nights of CLC subsequently at home.

MAIN OUTCOME MEASURE

The percentage of time spent in the target range (70 to 180 mg/dL measured using a continuous glucose monitor).

RESULTS

Forty subjects (age, 45.5 ± 9.5 years; hemoglobin A1c, 7.4% ± 0.8%) completed the study. The time in the target range (70 to 180 mg/dL) significantly improved in CLC vs SAP over 24 hours (78.3% vs 71.4%; P = 0.003) and overnight (85.7% vs 67.6%; P < 0.001). The time spent in a hypoglycemic range (<70 mg/dL) decreased significantly in the CLC vs SAP group over 24 hours (2.5% vs 4.3%; P = 0.002) and overnight (0.9% vs 3.2%; P < 0.001). The mean glucose level at 07:00 was lower with CLC than with SAP (123.7 vs 145.3 mg/dL; P < 0.001). The substudy at home, involving 10 T1D subjects, showed similar trends with an increased time in target (70 to 180 mg/dL) overnight (75.2% vs 62.2%; P = 0.07) and decreased time spent in the hypoglycemic range (<70 mg/dL) overnight in CLC vs SAP (0.6% vs 3.7%; P = 0.03).

CONCLUSION

Overnight-only CLC increased the time in the target range over 24 hours and decreased the time in hypoglycemic range over 24 hours in a supervised outpatient setting. A pilot extension study at home showed a similar nonsignificant trend.

Fertilizing a Patient Engagement Ecosystem to Innovate Healthcare: Toward the First Italian Consensus Conference on Patient Engagement

Currently we observe a gap between theory and practices of patient engagement. If both scholars and health practitioners do agree on the urgency to realize patient engagement, no shared guidelines exist so far to orient clinical practice. Despite a supportive policy context, progress to achieve greater patient engagement is patchy and slow and often concentrated at the level of policy regulation without dialoguing with practitioners from the clinical field as well as patients and families. Though individual clinicians, care teams and health organizations may be interested and deeply committed to engage patients and family members in the medical course, they may lack clarity about how to achieve this goal. This contributes to a wide "system" inertia-really difficult to be overcome-and put at risk any form of innovation in this filed. As a result, patient engagement risk today to be a buzz words, rather than a real guidance for practice. To make the field clearer, we promoted an Italian Consensus Conference on Patient Engagement (ICCPE) in order to set the ground for drafting recommendations for the provision of effective patient engagement interventions. The ICCPE will conclude in June 2017. This document reports on the preliminary phases of this process. In the paper, we advise the importance of "fertilizing a patient engagement ecosystem": an oversimplifying approach to patient engagement promotion appears the result of a common illusion. Patient "disengagement" is a symptom that needs a more holistic and complex approach to solve its underlined causes. Preliminary principles to promote a patient engagement ecosystem are provided in the paper.

Influence of health locus of control and fear of hypoglycaemia on glycaemic control and treatment satisfaction in people with Type 1 diabetes on insulin pump therapy

AIM

To assess the influence of health locus of control and fear of hypoglycaemia on metabolic control and treatment satisfaction in people with Type 1 diabetes mellitus on continuous subcutaneous insulin infusion.

METHODS

People with Type 1 diabetes on continuous subcutaneous insulin infusion for at least 1 year, sub-classified as an 'acceptable glucose control' group [HbA_1c ≤ 58 mmol/mol (7.5%)] and a 'suboptimum glucose control' group [HbA_1c > 58 mmol/mol (7.5%)], were consecutively enrolled in a multicentre cross-sectional study. Questionnaires were administered to assess health locus of control [Multidimensional Health Locus of Control (MHLC) scale, with internal and external subscales], fear of hypoglycaemia [Hypoglycaemia Fear Survey II (HFS-II)] and treatment satisfaction [Diabetes Treatment Satisfaction Questionnaire (DTSQ)].

RESULTS

We enrolled 214 participants (mean ± sd age 43.4 ± 12.1 years). The suboptimum glucose control group (n = 127) had lower mean ± sd internal MHLC and DTSQ scores than the acceptable glucose control group (19.6 ± 5.2 vs 21.0 ± 5.0, P = 0.04 and 28.8 ± 4.8 vs 30.9 ± 4.5, P < 0.001). HFS-II scores did not differ between the two groups. Internal MHLC score was negatively associated with HbA_1c (r = -0.15, P < 0.05) and positively associated with the number of mild and severe hypoglycaemic episodes (r = 0.16, P < 0.05 and r = 0.18, P < 0.001, respectively) and with DTSQ score (r = 0.17, P < 0.05). HFS-II score was negatively associated with DTSQ score (r = -0.18, P < 0.05) and positively with number of severe hypoglycaemic episodes (r = 0.16, P < 0.5).

CONCLUSIONS

In adults with Type 1 diabetes receiving continuous subcutaneous insulin infusion, high internal locus represents the most important locus of control pattern for achieving good metabolic control.

Parental evaluation of a telemonitoring service for children with Type 1 Diabetes

Introduction In the past years, we developed a telemonitoring service for young patients affected by Type 1 Diabetes. The service provides data to the clinical staff and offers an important tool to the parents, that are able to oversee in real time their children. The aim of this work was to analyze the parents' perceived usefulness of the service. Methods The service was tested by the parents of 31 children enrolled in a seven-day clinical trial during a summer camp. To study the parents' perception we proposed and analyzed two questionnaires. A baseline questionnaire focused on the daily management and implications of their children's diabetes, while a post-study one measured the perceived benefits of telemonitoring. Questionnaires also included free text comment spaces. Results Analysis of the baseline questionnaires underlined the parents' suffering and fatigue: 51% of total responses showed a negative tendency and the mean value of the perceived quality of life was 64.13 in a 0-100 scale. In the post-study questionnaires about half of the parents believed in a possible improvement adopting telemonitoring. Moreover, the foreseen improvement in quality of life was significant, increasing from 64.13 to 78.39 ( p-value = 0.0001). The analysis of free text comments highlighted an improvement in mood, and parents' commitment was also proved by their willingness to pay for the service (median = 200 euro/year). Discussion A high number of parents appreciated the telemonitoring service and were confident that it could improve communication with physicians as well as the family's own peace of mind.

Psychological outcomes of evening and night closed-loop insulin delivery under free living conditions in people with Type 1 diabetes: a 2-month randomized crossover trial

AIM

To assess the impact on fear of hypoglycaemia and treatment satisfaction with an artificial pancreas system used for 2 consecutive months, as well as participant acceptance of the artificial pancreas system.

METHODS

In a randomized crossover trial patient-related outcomes associated with an evening-and-night artificial pancreas and sensor-augmented pump therapy were compared. Both intervention periods lasted 8 weeks. The artificial pancreas acceptance questionnaire (range 0-90, higher scores better), Hypoglycaemia Fear Survey II (range 0-72, higher scores worse) and Diabetes Treatment Satisfaction Questionnaire (range 0-36, higher scores better) were completed by 32 participants. Semi-structured interviews were conducted after study completion in a subset of six participants. Outcomes were compared using a repeated-measures anova model or paired t-test when appropriate.

RESULTS

The total artificial pancreas acceptance questionnaire score at the end of the artificial pancreas period was 69.1 (sd 14.7; 95% CI 63.5, 74.7), indicating a positive attitude towards the artificial pancreas. No significant differences were found among the scores at baseline, end of sensor-augmented pump therapy period or end of the artificial pancreas period with regard to fear of hypoglycaemia [28.2 (sd 17.5), 23.5 (sd 16.6) and 23.5 (sd 16.7), respectively; P = 0.099] or diabetes treatment satisfaction [29.0 (sd 3.9), 28.2 (sd 5.2) and 28.0 (sd 7.1), respectively; P = 0.43]. Themes frequently mentioned in the interviews were 'positive effects at work', 'improved blood glucose', 'fewer worries about blood glucose', but also 'frequent alarms', 'technological issues' and 'demand for an all-in-one device'.

CONCLUSIONS

The psychological outcomes of artificial pancreas and sensor-augmented pump therapy were similar. Current artificial pancreas technology is promising but user concerns should be taken into account to ensure utility of these systems.

Feasibility of Long-Term Closed-Loop Control: A Multicenter 6-Month Trial of 24/7 Automated Insulin Delivery

BACKGROUND

In the past few years, the artificial pancreas-the commonly accepted term for closed-loop control (CLC) of blood glucose in diabetes-has become a hot topic in research and technology development. In the summer of 2014, we initiated a 6-month trial evaluating the safety of 24/7 CLC during free-living conditions.

RESEARCH DESIGN AND METHODS

Following an initial 1-month Phase 1, 14 individuals (10 males/4 females) with type 1 diabetes at three clinical centers in the United States and one in Italy continued with a 5-month Phase 2, which included 24/7 CLC using the wireless portable Diabetes Assistant (DiAs) developed at the University of Virginia Center for Diabetes Technology. Median subject characteristics were age 45 years, duration of diabetes 27 years, total daily insulin 0.53 U/kg/day, and baseline HbA1c 7.2% (55 mmol/mol).

RESULTS

Compared with the baseline observation period, the frequency of hypoglycemia below 3.9 mmol/L during the last 3 months of CLC was lower: 4.1% versus 1.3%, P < 0.001. This was accompanied by a downward trend in HbA1c from 7.2% (55 mmol/mol) to 7.0% (53 mmol/mol) at 6 months. HbA1c improvement was correlated with system use (Spearman r = 0.55). The user experience was favorable with identified benefit particularly at night and overall trust in the system. There were no serious adverse events, severe hypoglycemia, or diabetic ketoacidosis.

CONCLUSION

We conclude that CLC technology has matured and is safe for prolonged use in patients' natural environment. Based on these promising results, a large randomized trial is warranted to assess long-term CLC efficacy and safety.

Switching from twice-daily glargine or detemir to once-daily degludec improves glucose control in type 1 diabetes. An observational study

BACKGROUND AND AIMS

Degludec is an ultralong-acting insulin analogue with a flat and reproducible pharmacodynamic profile. As some patients with type 1 diabetes (T1D) fail to achieve 24-h coverage with glargine or detemir despite twice-daily injections, we studied the effect of switching T1D patients from twice-daily glargine or detemir to degludec.

METHODS AND RESULTS

In this prospective observational study, T1D patients on twice-daily glargine or detemir were enrolled. At baseline and 12 weeks after switching to degludec, we recorded HbA1c, insulin dose, 30-day blood glucose self monitoring (SMBG) or 14-day continuous glucose monitoring (CGM), treatment satisfaction (DTSQ), fear of hypoglycemia (FHS). We included 29 patients (mean age 34 ± 11 years; diabetes duration 18 ± 10 years). After switching to degludec, HbA1c decreased from 7.9 ± 0.6% (63 ± 6 mmol/mol) to 7.7 ± 0.6% (61 ± 6 mmol/mol; p = 0.028). SMBG showed significant reductions in the percent and number of blood glucose values <70 mg/dl and in the low blood glucose index (LBGI) during nighttime. CGM showed a significant reduction of time spent in hypoglycemia, an increase in daytime spent in target 70-180 mg/dl, and a reduction in glucose variability. Total insulin dose declined by 17% (p < 0.001), with 24% reduction in basal and 10% reduction in prandial insulin. DTSQ and FHS significantly improved.

CONCLUSION

Switching from twice-daily glargine or detemir to once daily degludec improved HbA1c, glucose profile, hypoglycemia risk and treatment satisfaction, while insulin doses decreased. ClinicalTrials.govNCT02360254.

Evaluating the Experience of Children With Type 1 Diabetes and Their Parents Taking Part in an Artificial Pancreas Clinical Trial Over Multiple Days in a Diabetes Camp Setting

OBJECTIVE

To explore the experiences of children with type 1 diabetes and their parents taking part in an artificial pancreas (AP) clinical trial during a 7-day summer camp.

RESEARCH DESIGN AND METHODS

A semistructured interview, composed of 14 questions based on the Technology Acceptance Model, was conducted at the end of the clinical trial. Participants also completed the Diabetes Treatment Satisfaction Questionnaire (DTSQ, parent version) and the AP Acceptance Questionnaire.

RESULTS

Thirty children, aged 5-9 years, and their parents completed the study. A content analysis of the interviews showed that parents were focused on understanding the mechanisms, risks, and benefits of the new device, whereas the children were focused on the novelty of the new system. The parents' main concerns about adopting the new system seemed related to the quality of glucose control. The mean scores of DTSQ subscales indicated general parents' satisfaction (44.24 ± 5.99, range 32-53) and trustful views of diabetes control provided by the new system (7.8 ± 2.2, range 3-12). The AP Acceptance Questionnaire revealed that most parents considered the AP easy to use (70.5%), intended to use it long term (94.0%), and felt that it was apt to improve glucose control (67.0%).

CONCLUSIONS

Participants manifested a positive attitude toward the AP. Further studies are required to explore participants' perceptions early in the AP development to individualize the new treatment as much as possible, and to tailor it to respond to their needs and values.

Randomized Summer Camp Crossover Trial in 5- to 9-Year-Old Children: Outpatient Wearable Artificial Pancreas Is Feasible and Safe

OBJECTIVE

The Pediatric Artificial Pancreas (PedArPan) project tested a children-specific version of the modular model predictive control (MMPC) algorithm in 5- to 9-year-old children during a camp.

RESEARCH DESIGN AND METHODS

A total of 30 children, 5- to 9-years old, with type 1 diabetes completed an outpatient, open-label, randomized, crossover trial. Three days with an artificial pancreas (AP) were compared with three days of parent-managed sensor-augmented pump (SAP).

RESULTS

Overnight time-in-hypoglycemia was reduced with the AP versus SAP, median (25(th)-75(th) percentiles): 0.0% (0.0-2.2) vs. 2.2% (0.0-12.3) (P = 0.002), without a significant change of time-in-target, mean: 56.0% (SD 22.5) vs. 59.7% (21.2) (P = 0.430), but with increased mean glucose 173 mg/dL (36) vs. 150 mg/dL (39) (P = 0.002). Overall, the AP granted a threefold reduction of time-in-hypoglycemia (P < 0.001) at the cost of decreased time-in-target, 56.8% (13.5) vs. 63.1% (11.0) (P = 0.022) and increased mean glucose 169 mg/dL (23) vs. 147 mg/dL (23) (P < 0.001).

CONCLUSIONS

This trial, the first outpatient single-hormone AP trial in a population of this age, shows feasibility and safety of MMPC in young children. Algorithm retuning will be performed to improve efficacy.

Day-and-Night Closed-Loop Glucose Control in Patients With Type 1 Diabetes Under Free-Living Conditions: Results of a Single-Arm 1-Month Experience Compared With a Previously Reported Feasibility Study of Evening and Night at Home

OBJECTIVE

After testing of a wearable artificial pancreas (AP) during evening and night (E/N-AP) under free-living conditions in patients with type 1 diabetes (T1D), we investigated AP during day and night (D/N-AP) for 1 month.

RESEARCH DESIGN AND METHODS

Twenty adult patients with T1D who completed a previous randomized crossover study comparing 2-month E/N-AP versus 2-month sensor augmented pump (SAP) volunteered for 1-month D/N-AP nonrandomized extension. AP was executed by a model predictive control algorithm run by a modified smartphone wirelessly connected to a continuous glucose monitor (CGM) and insulin pump. CGM data were analyzed by intention-to-treat with percentage time-in-target (3.9-10 mmol/L) over 24 h as the primary end point.

RESULTS

Time-in-target (mean ± SD, %) was similar over 24 h with D/N-AP versus E/N-AP: 64.7 ± 7.6 vs. 63.6 ± 9.9 (P = 0.79), and both were higher than with SAP: 59.7 ± 9.6 (P = 0.01 and P = 0.06, respectively). Time below 3.9 mmol/L was similarly and significantly reduced by D/N-AP and E/N-AP versus SAP (both P < 0.001). SD of blood glucose concentration (mmol/L) was lower with D/N-AP versus E/N-AP during whole daytime: 3.2 ± 0.6 vs. 3.4 ± 0.7 (P = 0.003), morning: 2.7 ± 0.5 vs. 3.1 ± 0.5 (P = 0.02), and afternoon: 3.3 ± 0.6 vs. 3.5 ± 0.8 (P = 0.07), and was lower with D/N-AP versus SAP over 24 h: 3.1 ± 0.5 vs. 3.3 ± 0.6 (P = 0.049). Insulin delivery (IU) over 24 h was higher with D/N-AP and SAP than with E/N-AP: 40.6 ± 15.5 and 42.3 ± 15.5 vs. 36.6 ± 11.6 (P = 0.03 and P = 0.0004, respectively).

CONCLUSIONS

D/N-AP and E/N-AP both achieved better glucose control than SAP under free-living conditions. Although time in the different glycemic ranges was similar between D/N-AP and E/N-AP, D/N-AP further reduces glucose variability.

Multinational Home Use of Closed-Loop Control Is Safe and Effective

OBJECTIVE

To evaluate the efficacy of a portable, wearable, wireless artificial pancreas system (the Diabetes Assistant [DiAs] running the Unified Safety System) on glucose control at home in overnight-only and 24/7 closed-loop control (CLC) modes in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

At six clinical centers in four countries, 30 participants 18-66 years old with type 1 diabetes (43% female, 96% non-Hispanic white, median type 1 diabetes duration 19 years, median A1C 7.3%) completed the study. The protocol included a 2-week baseline sensor-augmented pump (SAP) period followed by 2 weeks of overnight-only CLC and 2 weeks of 24/7 CLC at home. Glucose control during CLC was compared with the baseline SAP.

RESULTS

Glycemic control parameters for overnight-only CLC were improved during the nighttime period compared with baseline for hypoglycemia (time <70 mg/dL, primary end point median 1.1% vs. 3.0%; P < 0.001), time in target (70-180 mg/dL: 75% vs. 61%; P < 0.001), and glucose variability (coefficient of variation: 30% vs. 36%; P < 0.001). Similar improvements for day/night combined were observed with 24/7 CLC compared with baseline: 1.7% vs. 4.1%, P < 0.001; 73% vs. 65%, P < 0.001; and 34% vs. 38%, P < 0.001, respectively.

CONCLUSIONS

CLC running on a smartphone (DiAs) in the home environment was safe and effective. Overnight-only CLC reduced hypoglycemia and increased time in range overnight and increased time in range during the day; 24/7 CLC reduced hypoglycemia and increased time in range both overnight and during the day. Compared with overnight-only CLC, 24/7 CLC provided additional hypoglycemia protection during the day.

Survey on the use of insulin pumps in Italy: comparison between pediatric and adult age groups (IMITA study)

AIMS

The aim of the study was to evaluate and compare continuous subcutaneous insulin infusion (CSII) use in pediatric and adult age groups.

METHODS

Data were collected with a questionnaire sent by e-mail to CSII-experienced Diabetes Centers. The questionnaire assessed: (1) number of CSII-treated patients; (2) patient demographic data and characteristics; (3) structure and organization of Diabetes Centers providing CSII therapy; (4) pump characteristics (conventional pump, sensor-augmented pump); and (5) CSII dropouts.

RESULTS

A total of 217 out of 1093 Italian centers participated: 51 pediatric (23.5 %) and 166 (76.5 %) adult centers (AP). Compared to a survey performed in 2005, there was a significant increase in the number of pediatric units when compared to adult units (112 vs 37 %, respectively, p < 0.05). Pediatric age is characterized by a greater concern for quality of life and injections, and a higher dropout rate (10.6 vs 8.9 %) mainly related to pump wearability and site reactions. A complete diabetes-care team is associated with a superior use of technology (fewer dropouts, increased CGM and advanced bolus use) which is, however, still used in a small percentage of patients.

CONCLUSIONS

In Italy, the number of CSII-treated pediatric patients (PP) is growing more significantly when compared to adults. Only 60 % of all patients are using advanced functions and 20 % are using CGMs continuously. This confirms the great interest in diabetes technology that is growing in pediatric diabetologists. However, much improvement is warranted in the organization and specialized training of pediatric, adult and transitional facilities.

2 month evening and night closed-loop glucose control in patients with type 1 diabetes under free-living conditions: a randomised crossover trial

BACKGROUND

An artificial pancreas (AP) that can be worn at home from dinner to waking up in the morning might be safe and efficient for first routine use in patients with type 1 diabetes. We assessed the effect on glucose control with use of an AP during the evening and night plus patient-managed sensor-augmented pump therapy (SAP) during the day, versus 24 h use of patient-managed SAP only, in free-living conditions.

METHODS

In a crossover study done in medical centres in France, Italy, and the Netherlands, patients aged 18-69 years with type 1 diabetes who used insulin pumps for continuous subcutaneous insulin infusion were randomly assigned to 2 months of AP use from dinner to waking up plus SAP use during the day versus 2 months of SAP use only under free-living conditions. Randomisation was achieved with a computer-generated allocation sequence with random block sizes of two, four, or six, masked to the investigator. Patients and investigators were not masked to the type of intervention. The AP consisted of a continuous glucose monitor (CGM) and insulin pump connected to a modified smartphone with a model predictive control algorithm. The primary endpoint was the percentage of time spent in the target glucose concentration range (3·9-10·0 mmol/L) from 2000 to 0800 h. CGM data for weeks 3-8 of the interventions were analysed on a modified intention-to-treat basis including patients who completed at least 6 weeks of each intervention period. The 2 month study period also allowed us to asses HbA1c as one of the secondary outcomes. This trial is registered with ClinicalTrials.gov, number NCT02153190.

FINDINGS

During 2000-0800 h, the mean time spent in the target range was higher with AP than with SAP use: 66·7% versus 58·1% (paired difference 8·6% [95% CI 5·8 to 11·4], p<0·0001), through a reduction in both mean time spent in hyperglycaemia (glucose concentration >10·0 mmol/L; 31·6% vs 38·5%; -6·9% [-9·8% to -3·9], p<0·0001) and in hypoglycaemia (glucose concentration <3·9 mmol/L; 1·7% vs 3·0%; -1·6% [-2·3 to -1·0], p<0·0001). Decrease in mean HbA1c during the AP period was significantly greater than during the control period (-0·3% vs -0·2%; paired difference -0·2 [95% CI -0·4 to -0·0], p=0·047), taking a period effect into account (p=0·0034). No serious adverse events occurred during this study, and none of the mild-to-moderate adverse events was related to the study intervention.

INTERPRETATION

Our results support the use of AP at home as a safe and beneficial option for patients with type 1 diabetes. The HbA1c results are encouraging but preliminary.

FUNDING

European Commission.

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.

Accuracy of two continuous glucose monitoring systems: a head-to-head comparison under clinical research centre and daily life conditions

AIMS

To assess the accuracy and reliability of the two most widely used continuous glucose monitoring (CGM) systems.

METHODS

We studied the Dexcom®G4 Platinum (DG4P; Dexcom, San Diego, CA, USA) and Medtronic Paradigm Veo Enlite system (ENL; Medtronic, Northridge, CA, USA) CGM systems, in 24 patients with type 1 diabetes. The CGM systems were tested during 6-day home use and a nested 6-h clinical research centre (CRC) visit. During the CRC visit, frequent venous blood glucose samples were used as reference while patients received a meal with an increased insulin bolus to induce an aggravated postprandial glucose nadir. At home, patients performed at least six reference capillary blood measurements per day. A Wilcoxon signed-rank test was performed using all data points ≥15 min apart.

RESULTS

The overall mean absolute relative difference (MARD) value [standard deviation (s.d.)] measured at the CRC was 13.6 (11.0)% for the DG4P and 16.6 (13.5)% for the ENL [p < 0.0002, confidence interval of difference (CI Δ) 1.7-4.3%, n = 530]. The overall MARD assessed at home was 12.2 (12.0)% for the DG4P and 19.9 (20.5)% for the ENL (p < 0.0001, CI Δ = 5.8-8.7%, n = 839). During the CRC visit, the MARD in the hypoglycaemic range [≤3.9 mmol/l (70 mg/dl)], was 17.6 (12.2)% for the DG4P and 24.6 (18.8)% for the ENL (p = 0.005, CI Δ 3.1-10.7%, n = 117). Both sensors showed higher MARD values during hypoglycaemia than during euglycaemia [3.9-10 mmol/l (70-180 mg/dl)]: for the DG4P 17.6 versus 13.0% and for the ENL 24.6 versus 14.2%.

CONCLUSIONS

During circumstances of intended use, including both a CRC and home phase, the ENL was noticeably less accurate than the DG4P sensor. Both sensors showed lower accuracy in the hypoglycaemic range. The DG4P was less affected by this negative effect of hypoglycaemia on sensor accuracy than was the ENL.

Multinight "bedside" closed-loop control for patients with type 1 diabetes

BACKGROUND

Studies of closed-loop control (CLC) systems have improved glucose levels in patients with type 1 diabetes. In this study we test a new CLC concept aiming to "reset" the patient overnight to near-normoglycemia each morning, for several consecutive nights.

SUBJECTS AND METHODS

Ten insulin pump users with type 1 diabetes (mean age, 46.4±8.5 years) were enrolled in a two-center (in the United States and Italy) randomized crossover trial comparing 5 consecutive nights of CLC (23:00-07:00 h) in an outpatient setting versus sensor-augmented insulin pump therapy of the same duration at home. Primary end points included time spent in 80-140 mg/dL as measured by continuous glucose monitoring overnight and fasting blood glucose distribution at 7:00 h.

RESULTS

Compared with sensor-augmented pump therapy, CLC improved significantly time spent between 80 and 140 mg/dL (54.5% vs. 32.2%; P<0.001) and between 70 and 180 mg/dL (85.4% vs. 59.1%; P<0.001); CLC reduced the mean glucose level at 07:00 h (119.3 vs. 152.9 mg/dL; P<0.001) and overnight mean glucose level (139.0 vs. 170.3 mg/dL; P<0.001) using a marginally lower amount of insulin (6.1 vs. 6.8 units; P=0.1). Tighter overnight control led to improved daytime control on the next day: the overnight/next-day control correlation was r=0.52, P<0.01.

CONCLUSIONS

Multinight CLC of insulin delivery (artificial pancreas) results in significant improvement in morning and overnight glucose levels and time in target range, with the potential to improve daytime control when glucose levels were "reset" to near-normoglycemia each morning.