Feasibility Study of a Hybrid Closed-Loop System with Automated Insulin Correction Boluses

Sustained Effectiveness of an Advanced Hybrid Closed-Loop System in a Cohort of Children and Adolescents With Type 1 Diabetes: A 1-Year Real-World Study

OBJECTIVE

To investigate glucose metrics and identify potential predictors of the achievement of glycemic outcomes in children and adolescents during their first 12 months of MiniMed 780G use.

RESEARCH DESIGN AND METHODS

This multicenter, longitudinal, real-world study recruited 368 children and adolescents with type 1 diabetes (T1D) starting SmartGuard technology between June 2020 and June 2022. Ambulatory glucose profile data were collected during a 15-day run-in period (baseline), 2 weeks after automatic mode activation, and every 3 months. The influence of covariates on glycemic outcomes after 1 year of MiniMed 780G use was assessed.

RESULTS

After 15 days of automatic mode use, all glucose metrics improved compared with baseline (P < 0.001), except for time below range (P = 0.113) and coefficient of variation (P = 0.330). After 1 year, time in range (TIR) remained significantly higher than at baseline (75.3% vs. 62.8%, P < 0.001). The mean glycated hemoglobin (HbA1c) over the study duration was lower than the previous year (6.9 ± 0.6% vs. 7.4 ± 0.9%, P < 0.001). Time spent in tight range (70-140 mg/dL) was 51.1%, and the glycemia risk index was 27.6. Higher TIR levels were associated with a reduced number of automatic correction boluses (P < 0.001), fewer SmartGuard exits (P = 0.021), and longer time in automatic mode (P = 0.030). Individuals with baseline HbA1c >8% showed more relevant improvement in TIR levels (from 54.3% to 72.3%).

CONCLUSIONS

Our study highlights the sustained effectiveness of MiniMed 780G among youth with T1D. Findings suggest that even children and adolescents with low therapeutic engagement may benefit from SmartGuard technology.

Safety, Metabolic and Psychological Outcomes of Medtronic MiniMed 780G™ in Children, Adolescents and Young Adults: A Systematic Review

The MiniMed™ 780G is a second-generation automated insulin delivery system that implements a modified proportional-integral-derivative algorithm with some features of an MD-Logic artificial pancreas algorithm. The system may deliver automatic correction boluses up to every 5 min, and it allows the user to choose between three glucose target setpoints (100, 110 and 120 mg/dL). We aimed to review the current evidence on this device in children, adolescents, and young adults living with type 1 diabetes. We screened 783 papers, but only 31 manuscripts were included in this review. Data on metabolic outcomes show that this system is safe as regards severe hypoglycaemia and diabetic ketoacidosis. The glycated haemoglobin may drop to levels about 7%, with CGM reports showing a time in range of 75-80%. The time above range and the time below range are within the recommended target in most of the subjects. Few studies evaluated the psychological outcomes. This system seems to be more effective than the first-generation automated insulin delivery systems. The MiniMed™ 780G has been associated with an improvement in sleep quality in subjects living with diabetes and their caregivers, along with an improvement in treatment satisfaction. Psychological distress is as reduced as the glucose control is improved. We also discuss some case reports describing particular situations in clinical practice. Finally, we think that data show that this system is a further step towards the improvement of the treatment of diabetes as concerns both metabolic and psychological outcomes.

Real-World Performance of First- Versus Second-Generation Automated Insulin Delivery Systems on a Pediatric Population With Type 1 Diabetes: A One-Year Observational Study

BACKGROUND

The aim of this single-center observational study was to assess the real-world performance of first- and second-generation automated insulin delivery (AID) systems in a cohort of children and adolescents with type 1 diabetes over a one-year follow-up.

METHODS

Demographic, anamnestic, and clinical data of the study cohort were collected at the start of automatic mode. Data on continuous glucose monitoring metrics, system settings, insulin requirements, and anthropometric parameters at three different time points (start period, six months, 12 months) were retrospectively gathered and statistically analyzed.

RESULTS

Fifty-four individuals (55.6% of females) aged 7 to 18 years switching to AID therapy were included in the analysis. Two weeks after starting automatic mode, subjects using advanced hybrid closed-loop (AHCL) showed a better response than hybrid closed-loop (HCL) users in terms of time in range (P = .016), time above range 180 to 250 mg/dl (P = .022), sensor mean glucose (P = .047), and glycemia risk index (P = .012). After 12 months, AHCL group maintained better mean sensor glucose (P = .021) and glucose management indicator (P = .027). Noteworthy, both HCL and AHCL users achieved the recommended clinical targets over the entire study period. The second-generation AID system registered longer time spent with automatic mode activated and fewer shifts to manual mode at every time point (P < .001).

CONCLUSIONS

Both systems showed sustained and successful glycemic outcomes in the first year of use. However, AHCL users achieved tighter glycemic targets, without an increase of hypoglycemia risk. Improved usability of the device may also have contributed to optimal glycemic outcomes by ensuring better continuity of the automatic mode activation.

Emerging Diabetes Technologies: Continuous Glucose Monitors/Artificial Pancreases

Over the past decade there have been many advances in diabetes technologies, such as continuous glucose monitors (CGM s), insulin-delivery devices, and hybrid closed loop systems . Now most CGMs (Medtronic-Guardian, Dexcom-G6, and Abbott-Libre-2) have MARD values of < 10%, in contrast to two decades ago when the MARD used to be > 20%. In addition, the majority of the new CGMs do not require calibrations, and the latest CGMs last for 10-14 days. An implantable 6-months CGM by Eversense-3 is now approved in the USA and Europe. Recently, the FDA approved Libre 3 which provides real-time glucose values every minute. Even though it is approved as an iCGM it is not interoperable with automatic-insulin-delivery (AID) systems. The newer CGMs that are likely to be launched in the next few months in the USA include the 10-11 days Dexcom G7 (60% smaller than the existing G6), and the 7-days Medtronic Guardian 4. Most of the newer CGM have several features like automatic initialization, easy insertion, predictive alarms, and alerts. It has also been noticed that an arm insertion site might have better accuracy than abdomen or other sites, like the buttock for kids. Lag time between YSI and different sensors have been reported differently, sometimes it is down to 2-3 min; however, in many instances, it is still 15-20 min, especially when the rate of change of glucose is > 2 mg/min. We believe that in the next decade there will be a significant increase in the number of people who use CGM for their day-to-day diabetes care.

One-year follow-up comparison of two hybrid closed-loop systems in Italian children and adults with type 1 diabetes

BACKGROUND AND AIMS

Tandem Control-IQ and MiniMed 780G are the main Advanced Hybrid Closed Loop (AHCL) systems currently available in pediatric and adult patients with Type 1 Diabetes (T1D). The aim of our study was to evaluate glycemic control after 1-year of follow-up extending our previous study of 1-month comparison between the two systems.

METHODS

We retrospectively compared clinical and continuous glucose monitoring (CGM) data from the patients included in the previous study which have completed 1-year observation period. The study population consisted of 74 patients, 42 Minimed 780G users and 32 Tandem Control-IQ users. Linear mixed models with random intercept were performed to study the variations over time and the interaction between time and system; Mann-Whitney or T-test were used to compare systems at 1-year.

RESULTS

Both systems have been shown to be effective in maintaining the glycemic improvement achieved one month after starting AHCL. Significant changes over time were observed for TIR, TAR, TAR>250mg/dl, average glucose levels and SD (p<0.001). At 1-year follow-up Minimed 780G obtained better improvement in TIR (p<0.001), TAR (p=0.002), TAR>250mg/dl (p=0.001), average glucose levels (p<0.001). The comparison of the glycemic parameters at 1-year showed a significant superiority of Minimed 780G in terms of TIR (71% vs 68%; p=0.001), TAR (p=0.001), TAR>250 (p=0.009), average glucose levels(p=0.001) and SD (p=0.031).

CONCLUSIONS

The use of AHCL systems led to a significant improvement of glycemic control at 1-month, which is maintained at 1-year follow-up. MiniMed is more effective than Tandem in reaching the International recommended glycemic targets. Continuous training and education in the use of technology is essential to get the best out of the most advanced technological tools.

Evaluation of blood glucose level control in type 1 diabetic patients using deep reinforcement learning

Diabetes mellitus is a disease associated with abnormally high levels of blood glucose due to a lack of insulin. Combining an insulin pump and continuous glucose monitor with a control algorithm to deliver insulin is an alternative to patient self-management of insulin doses to control blood glucose levels in diabetes mellitus patients. In this work, we propose a closed-loop control for blood glucose levels based on deep reinforcement learning. We describe the initial evaluation of several alternatives conducted on a realistic simulator of the glucoregulatory system and propose a particular implementation strategy based on reducing the frequency of the observations and rewards passed to the agent, and using a simple reward function. We train agents with that strategy for three groups of patient classes, evaluate and compare it with alternative control baselines. Our results show that our method is able to outperform baselines as well as similar recent proposals, by achieving longer periods of safe glycemic state and low risk.

Glycemic control during Ramadan fasting in adolescents and young adults with type 1 diabetes on MiniMed™ 780G advanced hybrid closed‑loop system: A randomized controlled trial

BACKGROUND

MiniMed^TM 780G is the most advanced insulin pump system approved for the treatment of type 1 diabetes mellitus (T1DM). Hypoglycemic events are a serious complication associated with T1DM management during Ramadan fasting.

AIM

This prospective study assessed the safety, effectiveness and optimization of advanced hybrid closed loop (AHCL) system on glycemic metrics and the level of hypoglycemia in T1DM patients who wished to fast Ramadan.

METHODS

Forty-two T1DM patients (mean age 15.2 ± 3.4 years) using AHCL system were divided into two groups (each n = 21): intervention group who adjusted AHCL settings and control group who kept the same settings as before Ramadan.

RESULTS

The most aggressive system settings among control group consisting of a 100 mg/dL glucose target, active insulin time of 2 h and bolus increment,maintained exceptional glycemia withtime in range reaching82.0 ± 10.2%, time above range >180 mg/dL of 12.1 ± 3.5% without an increase in hypoglycemia (time below range 3.0 ± 0.3%). All of which were non-significant in comparison to the intervention group. Overall time spent in closed loop (SmartGuard) by users averaged 98.7 ± 2.1% in Auto Mode and involved only 1.0 ± 0.7 exits per week indicating confidence in the system's performance. There were no severe hypoglycemic or diabetic ketoacidosis events during the study.

CONCLUSIONS

MiniMed™ 780G AHCL system assist in safe fasting with minimal user input and allows for achievement of recommended glycemic targets in people with T1DM during Ramadan fasting. The system demonstrated reduction in hypoglycemia exposure without compromising safety.

Safety and Glycemic Outcomes During the MiniMed™ Advanced Hybrid Closed-Loop System Pivotal Trial in Adolescents and Adults with Type 1 Diabetes

Introduction: This trial assessed safety and effectiveness of an advanced hybrid closed-loop (AHCL) system with automated basal (Auto Basal) and automated bolus correction (Auto Correction) in adolescents and adults with type 1 diabetes (T1D). Materials and Methods: This multicenter single-arm study involved an intent-to-treat population of 157 individuals (39 adolescents aged 14-21 years and 118 adults aged ≥22-75 years) with T1D. Study participants used the MiniMed™ AHCL system during a baseline run-in period in which sensor-augmented pump +/- predictive low glucose management or Auto Basal was enabled for ∼14 days. Thereafter, Auto Basal and Auto Correction were enabled for a study phase (∼90 days), with glucose target set to 100 or 120 mg/dL for ∼45 days, followed by the other target for ∼45 days. Study endpoints included safety events and change in mean A1C, time in range (TIR, 70-180 mg/dL) and time below range (TBR, <70 mg/dL). Run-in and study phase values were compared using Wilcoxon signed-rank test or paired t-test. Results: Overall group time spent in closed loop averaged 94.9% ± 5.4% and involved only 1.2 ± 0.8 exits per week. Compared with run-in, AHCL reduced A1C from 7.5% ± 0.8% to 7.0% ± 0.5% (<0.001, Wilcoxon signed-rank test, n = 155), TIR increased from 68.8% ± 10.5% to 74.5% ± 6.9% (<0.001, Wilcoxon signed-rank test), and TBR reduced from 3.3% ± 2.9% to 2.3% ± 1.7% (<0.001, Wilcoxon signed-rank test). Similar benefits to glycemia were observed for each age group and were more pronounced for the nighttime (12 AM-6 AM). The 100 mg/dL target increased TIR to 75.4% (n = 155), which was further optimized at a lower active insulin time (AIT) setting (i.e., 2 h), without increasing TBR. There were no severe hypoglycemic or diabetic ketoacidosis events during the study phase. Conclusions: These findings show that the MiniMed AHCL system is safe and allows for achievement of recommended glycemic targets in adolescents and adults with T1D. Adjustments in target and AIT settings may further optimize glycemia and improve user experience. Clinical Trial Registration number: NCT03959423.

Advanced technology for type 1 diabetes care in a deaf-mute patient

A 48-year-old deaf-mute man attending our outpatient clinic for long-term severely decompensated type 1 diabetes (mean glycated haemoglobin over 100 mmol/mol) has proved to be the best candidate for the beneficial implant of a next-generation closed loop insulin pump featuring a new refined auto-correction algorithm. The patient had already worn a stand-alone real-time continuous glucose monitoring (rt-CGM) device for 2 years, but his haemoglobin A1c (HbA1c) remained out of target with ample glucose variability. Then, we decided to use a novel advanced hybrid closed-loop insulin pump (the MiniMed 780G) coupled with his CGM device. After only 4 months this system led to a significant improvement in mean daily glucose levels (201±100 mg/dL vs 141±57 mg/dL), time in glucose range (43% vs 78%), percentage of time spent in hyperglycaemia (52% vs 20%), glucose variability (Coefficient of Variation 46% vs 38%), and HbA1c levels (121 mmol/mol vs 56 mmol/mol). The patient was highly satisfied.

Review of Automated Insulin Delivery Systems for Type 1 Diabetes and Associated Time in Range Outcomes

Automated insulin delivery (AID) systems play an important role in the management of type 1 diabetes mellitus (T1DM). These systems include three components: a continuous glucose monitor (CGM), an insulin pump and an algorithm that adjusts the pump based on the CGM sensor glucose readings. They are not fully automated and still require the user to administer bolus insulin doses for food. Some AID systems have automatic correction boluses, while others only have automatic basal or background insulin adjustments. As CGM has become more accurate and the technology has evolved, AID systems have demonstrated improved glycaemic outcomes. The clinical evaluation of AID systems in randomized controlled trials and real-world studies have shown their utility in helping glycaemic management. In this review, we compare AID systems that are commercially available in the US and summarize the literature, with a special focus on time in range in T1DM. The review also discusses new AID systems on the horizon and explores considerations for personalized care.

Can the AHCL System Be Used in T1D Patients with Borderline TDDI? A Case Report

(1) Background: Intensive insulin therapy using continuous subcutaneous insulin infusion (CSII) with continuous real-time glucose monitoring (rt CGM) is the best option for patients with T1D. The recent introduction of a technology called Advanced Hybrid Closed Loop (AHCL) represents a new era in the treatment of type 1 diabetes, the next step towards better care, as well as improving the effectiveness and safety of therapy. The aim is to present the case of a T1D patient with a borderline total daily dose of insulin being treated with the Medtronic AHCL system in automatic mode. (2) Materials and Methods: A 9-year-old boy, from October 2020, with type 1 diabetes in remission was connected to the Minimed™ 780G (AHCL) system in accordance with the manufacturer’s recommendations (daily insulin dose > 8 units, age > 7). Records of the patient’s history were collected from visits to The Department of Children’s Diabetology, as well as from the Medtronic CareLink™ software and the DPV SWEET program from October 2020 to April 2021. (3) Results: The patient’s total daily insulin requirement decreased in the first 6 weeks after the AHCL was connected, which may reflect the remission phase (tight glycemic control with a healthy lifestyle). The lowest daily insulin requirement of 5.7 units was also recorded. In a three-month follow-up of the patient treated with AHCL, it was found that for almost 38% of the days the insulin dose was less than 8 IU. (4) Conclusions: The AHCL system allows safe and effective insulin therapy in automatic mode, as well as in patients with a lower daily insulin requirement. The AHCL system should be considered a good therapeutic option for patients from the onset of T1D, as well in the remission phase.

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of advanced hybrid closed loop systems for the management of type 1 diabetes in children

Over the last years significant advances have been achieved in the development of technologies for diabetes management. Continuous subcutaneous insulin infusion (CSII), continuous glucose monitoring (CGM), predictive low glucose management (PLGM), hybrid closed loop (HCL) and advanced hybrid closed loop (AHCL) systems allow better diabetes management, thus reducing the burden of the disease and the risk of chronic complications. This review summarizes the main characteristics of the currently available HCL and AHCL systems and their primary effects in children and adolescents with type 1 diabetes (T1D). The findings of trials assessing the glucose control (time in range, HbA1c values, hypoglycemic events), the health-related quality of life and the existing limits of the use of these technologies are reported. The most recent data clearly confirm the ability of the HCL and AHCL insulin delivery systems to safely achieve a significant improvement of glucose control and quality of life in the pediatric population with T1D. Further studies are underway to overcame current barriers and future improvements in the usability of these technologies are awaited to facilitate their use in the routine clinical practice. The HCL and AHCL algorithms are the key features of today's insulin delivery systems that mark a crucial step towards fully automated closed loop systems.

A Comparison of Two Hybrid Closed-Loop Systems in Italian Children and Adults With Type 1 Diabetes

Tandem Control-IQ and Minimed 780G represent the most Advanced Hybrid Closed Loop (AHCL) systems currently available in pediatric and adult subjects with Type 1 Diabetes (T1D). We retrospectively compared clinical and continuous glucose monitoring data from 51 patients who upgraded to Minimed 780G system and have completed 1-month observation period with data from 39 patients who upgraded to Tandem Control-IQ. Inverse probability weighting was used to minimize the basal characteristics imbalances. Both AHCL systems showed a significant improvement in glycemic parameters. Minimed 780G group achieved higher TIR increase (p= 0.004) and greater reduction of blood glucose average (p= 0.001). Tandem Control-IQ system significantly reduced the occurrence of TBR (p= 0.010) and the Coefficient of Variation of glucose levels (p= 0.005). The use of ACHL systems led to a significant improvement of glycemic control substantially reaching the International recommended glycemic targets. Minimed 780G appears to be more effective in managing hyperglycemia, while Tandem Control-IQ seems to be more effective in reducing time in hypoglycemia.