The Effect of Prior Continuous Glucose Monitoring Use on Glycemic Outcomes in the Pivotal Trial of the MiniMed™ 670G Hybrid Closed-Loop System

Closed-loop therapy: recent advancements and potential predictors of glycemic outcomes

INTRODUCTION

Hybrid closed-loop systems have become the standard of care for managing type 1 diabetes (T1D). Both clinical trials and real-world data have demonstrated that these systems improve glycemic control without increasing the risk of hypoglycemia, while also reducing the overall burden of T1D management. A systematic literature search was conducted using PubMed for studies including individuals with T1D that were published until the end of 2024.

AREAS COVERED

In this review, we summarize the safety and efficacy of currently available hybrid closed-loop systems, drawing from key clinical trials and real-world data analyses. We also highlight recent advancements in closed-loop systems, discuss their limitations and barriers to access, and explore future directions for automated insulin delivery. Finally, we explore potential predictors of outcomes for people with T1D to better understand why some individuals respond better to closed-loop systems than others.

EXPERT OPINION

Closed-loop systems are advancing rapidly, with a growing focus on enhancing automation through fully closed-loop systems to improve glycemic control and further reduce the burden of management. Identifying the predictors that influence how individuals respond to closed-loop therapy will enable these systems to be optimized. It is crucial to ensure widespread and equitable access to this advanced technology.

Evaluation of hybrid closed-loop insulin delivery system in type 1 diabetes in real-world clinical practice: One-year observational study

BACKGROUND

In 2016, the Food and Drug Administration approved the first hybrid closed-loop (HCL) insulin delivery system for adults with type 1 diabetes (T1D). There is limited information on the impact of using HCL systems on patient-reported outcomes (PROs) in patients with T1D in real-world clinical practice. In this independent study, we evaluated glycemic parameters and PROs over one year of continuous use of Medtronic's 670G HCL in real-world clinical practice.

AIM

To assess the effects of hybrid closed loop system on glycemic control and quality of life in adults with T1D.

METHODS

We evaluated 71 patients with T1D (mean age: 45.5 ± 12.1 years; 59% females; body weight: 83.8 ± 18.7 kg, body mass index: 28.7 ± 5.6 kg/m2, A1C: 7.6% ± 0.8%) who were treated with HCL at Joslin Clinic from 2017 to 2019. We measured A1C and percent of glucose time-in-range (%TIR) at baseline and 12 months. We measured percent time in auto mode (%TiAM) for the last two weeks preceding the final visit and assessed PROs through several validated quality-of-life surveys related to general health and diabetes management.

RESULTS

At 12 mo, A1C decreased by 0.3% ± 0.1% (P = 0.001) and %TIR increased by 8.1% ± 2.5% (P = 0.002). The average %TiAM was only 64.3% ± 32.8% and was not associated with A1C, %TIR or PROs. PROs, provided at baseline and at the end of the study, showed that the physical functioning submodule of 36Item Short-Form Health Survey increased significantly by 22.9% (P < 0.001). Hypoglycemia fear survey/worry scale decreased significantly by 24.9% (P < 0.000); Problem Areas In Diabetes reduced significantly by -17.2% (P = 0.002). The emotional burden submodules of dietary diversity score reduced significantly by -44.7% (P = 0.001). Furthermore, analysis of Clarke questionnaire showed no increase in awareness of hypoglycemic episodes. WHO-5 showed no improvements in subject's wellbeing among participants after starting the 670G HCL system. Finally, analysis of Pittsburgh Sleep Quality Index showed no difference in sleep quality, sleep latency, or duration of sleep from baseline to 12 mo.

CONCLUSION

The use of HCL in real-world clinical practice for one year was associated with significant improvements in A1C, %TIR, physical functioning, hypoglycemia fear, emotional distress, and emotional burden related to diabetes management. However, these changes were not associated with time in auto mode.

Long-Term Benefits of an Integrated Continuous Glucose Monitoring and Insulin Pump System for Emergency Admissions, Hospitalization, and Metabolic Control in a Cohort of People With Diabetes: Retrospective Cohort Study

BACKGROUND

There is evidence in the literature that the use of sensor-augmented insulin pumps in patients with high-complexity diabetes improves metabolic control. However, there is no long-term information on clinical outcomes such as hospitalization or admission to the emergency room. This study describes outcomes for metabolic control, incidence of hospitalizations, and emergency room visits in a specific population using this technology.

OBJECTIVE

We aimed to assess long-term glycemic and clinical outcomes after the use of continuous subcutaneous insulin infusion and continuous glucose monitoring in people with diabetes.

METHODS

A retrospective cohort study was carried out in patients with diabetes previously treated with an intensive insulin regimen at a specialized diabetes treatment center who required a sensor-augmented insulin pump due to nonoptimal glycemic control. Glycated hemoglobin, severe hypoglycemic episodes, nonsevere hypoglycemic episodes, perception of hypoglycemia, and the incidence of emergency room visits and hospitalizations before and after treatment were evaluated.

RESULTS

Between January 2013 and August 2020, 74 patients with a median age of 36 (IQR 27-46) years were included in the study with a median 4 (IQR 2-7) years of follow-up. We found a statistically significant reduction in glycated hemoglobin (8.35% vs 7%; P<.001), nonsevere hypoglycemic episodes (71/74, 96% vs 62/74, 84%; P=.01), emergency room visits (42/73, 58% vs 4/62, 6%; P<.001), and hospitalizations (36/72, 50% vs 10/72, 14%; P<.001) after use of continuous subcutaneous insulin infusion.

CONCLUSIONS

The use of a sensor-augmented insulin pump associated with a strict follow-up program for patients with high-complexity diabetes led to a significant and sustained reduction in glycated hemoglobin and hypoglycemic episodes, as well as in the rate of emergency room visits and hospitalizations. These results encourage the adoption of this technology in patients who do not achieve metabolic control with optimal management of diabetes.

Safety, metabolic and psychological outcomes of Medtronic MiniMed 670G in children, adolescents and young adults: a systematic review

Hybrid closed loop (HCL) systems are the combination of a pump for insulin delivery and a glucose sensor for continuous glucose monitoring. These systems are managed by an algorithm, which delivers insulin on the basis of the interstitial glucose levels. The MiniMed™ 670G system was the first HCL system available for clinical purpose. In this paper, we reviewed the literature about metabolic and psychological outcomes in children, adolescents and young adults with type 1 diabetes treated with MiniMed™ 670G. Only 30 papers responded to the inclusion criteria and thus were considered. All the papers show that the system is safe and effective in managing glucose control. Metabolic outcomes are available up to 12 months of follow-up; longer study period are lacking. This HCL system may improve HbA1c up to 7.1% and time in range up to 73%. The time spent in hypoglycaemia is almost neglectable. Better improvement in blood glucose control is observed in patients with higher HbA1c at HCL system start and larger daily use of auto-mode functionality.     Conclusion: The Medtronic MiniMed™ 670G is safe and well accepted, without any increase in the burden for patients. Some papers report an improvement in the psychological outcomes, but other papers do not confirm this finding. So far, it significantly improves the management of diabetes mellitus in children, adolescents and young adults. Proper training and support by the diabetes team are mandatory. Studies for a period longer than 1 year would be appreciated to better understand the potentiality of this system. What is Known: • The Medtronic MiniMed^TM 670G is a hybrid closed loop system which combines a continuous glucose monitoring sensor with an insulin pump. • It has been the first hybrid closed loop system available for clinical purpose. Adequate training and patients support play a key role in diabetes management. What is New: • The Medtronic MiniMed^TM 670G may improve HbA1c and CGM metrics up to 1-year of follow-up, but the improvement appears lower than advanced hybrid closed loop systems. This system is effective to prevent hypoglycaemia. • The psychosocial effects remain less understood in terms of improvement of psychosocial outcomes. The system has been considered to provide flexibility and independence by the patients and their caregivers. The workload required to use this system is perceived as a burden by the patients who decrease the use of auto-mode functionality over time.

Transitioning of People With Type 1 Diabetes From Multiple Daily Injections and Self-Monitoring of Blood Glucose Directly to MiniMed 780G Advanced Hybrid Closed-Loop System: A Two-Center, Randomized, Controlled Study

OBJECTIVE

The aim of this study was to evaluate the outcomes of transitioning to the MiniMed 780G advanced hybrid closed-loop (AHCL) system in adult individuals with type 1 diabetes mellitus (T1DM) naive to continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) technologies.

RESEARCH DESIGN AND METHODS

This was a two-center, randomized, controlled, parallel-group trial with evaluation of individuals with T1DM aged 26-60 years managed with multiple daily injections (MDI) and self-monitoring of blood glucose (BGM) with HbA1c <10%.

RESULTS

A total of 41 participants were recruited and randomized to either the AHCL (n = 20) or the MDI+BGM (n = 21) group, and 37 participants (mean ± SD age 40.3 ± 8.0 years, duration of diabetes 17.3 ± 12.1 years, BMI 25.1 ± 3.1 kg/m2, HbA1c 7.2 ± 1.0%) completed the study. Time spent with glucose levels in target range increased from 69.3 ± 12.3% at baseline to 85.0 ± 6.3% at 3 months in the AHCL group, while remaining unchanged in the control group (treatment effect 21.5% [95% CI 15.7, 27.3]; P < 0.001). The time with levels below range (<70 mg/dL) decreased from 8.7 ± 7.3% to 2.1 ± 1.7% in the AHCL group and remained unchanged in the MDI+BGM group (treatment effect -4.4% [95% CI -7.4, -2.1]; P < 0.001). Participants from the AHCL group also had significant improvements in HbA1c levels (treatment effect -0.6% [95% CI -0.9, -0.2]; P = 0.005) and in quality of life (QoL) in specific subscales compared with the MDI+BGM group.

CONCLUSIONS

People with T1DM naive to CSII and CGM technologies initiating AHCL significantly and safely improved their glycemic control, as well as their QoL and psychological well-being.

Real-world evidence on clinical outcomes of people with type 1 diabetes using open-source and commercial automated insulin dosing systems: A systematic review

AIMS

Several commercial and open-source automated insulin dosing (AID) systems have recently been developed and are now used by an increasing number of people with diabetes (PwD). This systematic review explored the current status of real-world evidence on the latest available AID systems in helping to understand their safety and effectiveness.

METHODS

A systematic review of real-world studies on the effect of commercial and open-source AID system use on clinical outcomes was conducted employing a devised protocol (PROSPERO ID 257354).

RESULTS

Of 441 initially identified studies, 21 published 2018-2021 were included: 12 for Medtronic 670G; one for Tandem Control-IQ; one for Diabeloop DBLG1; two for AndroidAPS; one for OpenAPS; one for Loop; three comparing various types of AID systems. These studies found that several types of AID systems improve Time-in-Range and haemoglobin A_1c (HbA_1c ) with minimal concerns around severe hypoglycaemia. These improvements were observed in open-source and commercially developed AID systems alike.

CONCLUSIONS

Commercially developed and open-source AID systems represent effective and safe treatment options for PwD of several age groups and genders. Alongside evidence from randomized clinical trials, real-world studies on AID systems and their effects on glycaemic outcomes are a helpful method for evaluating their safety and effectiveness.

An analysis of Medtronic MiniMed 670G insulin pump use in clinical practice and the impact on glycemic control, quality of life, and compliance

AIMS

This study evaluated the use of the Medtronic MiniMed 670G system in adults with type 1 diabetes mellitus from a large endocrinology practice and its impact on glycemic control, quality of life (QoL), compliance and safety.

METHODS

84 participants completed one site visit for data collection. Percentage of time in range (TIR: 70-180 mg/dL), hyperglycemia or time above range (TAB) (>180 mg/dL), hypoglycemia or time below range (TBR) (<70 mg/dL), HbA1c, average blood glucose (ABG), and other metrics were evaluated at the last visit using the system (LVMM) and compared between the last visit on previous insulin therapy (LVPT).

RESULTS

The mean percentage of TIR at the LVMM was 74.0 ± 12.1%, with an increase of 27.1% (p < 0.001) in TIR from the LVPT. The mean percentage of TAR was 22.9 ± 11.8% and the mean percentage of TBR was 3.2 ± 5.1%.

CONCLUSIONS

The use of the Medtronic MiniMed 670G system in our practice resulted in a TIR above the recommended target with a high degree of treatment satisfaction and compliance in adults with type 1 diabetes. Furthermore, the system may be a reasonable choice for patients struggling with significant amounts of hypoglycemia.

Prospective Analysis of the Impact of Commercialized Hybrid Closed-Loop System on Glycemic Control, Glycemic Variability, and Patient-Related Outcomes in Children and Adults: A Focus on Superiority Over Predictive Low-Glucose Suspend Technology

Background: Automatization of insulin delivery by closed-loop systems represents a major step in type 1 diabetes management. The aim of this study was to analyze the effect of the commercialized hybrid closed-loop system, the MiniMed 670G system, on glycemic control, glycemic variability, and patient satisfaction. Methods: A prospective study, including type 1 diabetes patients consecutively starting on the 670G system in one adult and two pediatric hospitals, was performed. Baseline and 3-month visits were documented. Two weeks of data from the system were downloaded. Glycemic variability measures were calculated. Adults and adolescents completed a set of questionnaires (Gold and Clarke scores, Hypoglycemia Fear Survey, Diabetes Quality of Life [DQoL], Diabetes Treatment Satisfaction [DTS], Diabetes Distress Scale, Pittsburgh Sleep Quality Index). Results: Fifty-eight patients were included (age: 28 ± 15 years [7-63], <18 years old: 38% [n = 22], 59% [n = 34] females, previous use of SAP-PLGS [predictive low-glucose suspend]: 60% [n = 35]). HbA1c was reduced from 57 ± 10 to 53 ± 7 mmol/L (7.4% ± 0.9% to 7.0% ± 0.6%) (P < 0.001) and time in range 70-180 mg/dL was increased from 63.0% ± 11.4% to 72.7% ± 8.7% (P < 0.001). In patients with high baseline hypoglycemia risk, time <54 and <70 mg/dL were reduced from 0.9% ± 1.1% to 0.45% ± 0.7% (P = 0.021) and from 3.3% ± 2.8% to 2.1% ± 2.1% (P = 0.019), respectively. Glycemic variability measures improved. Time in auto mode was 85% ± 17%, the number of auto mode exits was 0.6 ± 0.3 per day, and the number of alarms was 8.5 ± 3.7 per day. Fear of hypoglycemia, DQoL, DTS, and diabetes distress improved, while the percentage of patients with poor sleep quality was reduced. The discontinuation rate was 3%. Conclusion: The commercialized hybrid closed-loop system improves glycemic control and glycemic variability in children and adults, reducing the burden of living with type 1 diabetes.

10-Day structured initiation protocol from multiple daily injection to hybrid closed-loop system in children and adolescents with type 1 diabetes

AIM

The aim of this study was to evaluate the 10-day initiation protocol for MiniMed 670G hybrid closed-loop (HCL) system in individuals with type 1 diabetes on multiple daily injection (MDI) in achieving desirable glycemic control.

METHODS

An open-label single-arm, single-center, clinical investigation in children aged 7-18 years on MDI following a structured protocol: 2 days, HCL system assessment; 5 days, HCL system training (2-h sessions on 5 consecutive days with groups of 3-5 participants and families); 3 days, Manual Mode use of HCL system; 84 days, Auto Mode use of the HCL system, cumulating in 10 days from MDI to Auto Mode activation.

RESULTS

A total of 30 children (age 10.24 ± 2.6 years) were enrolled in the study, and all completed the planned 84 days on Auto Mode. The participants used the sensor for a median of 92% of the time and spent a median of 89% in Auto Mode. The mean HbA1c decreased from 8.2 ± 1.4% (66 ± 15.3 mmol/mol) at baseline to 6.7 ± 0.5% (50 ± 5.5 mmol/mol) at the end of the study (p = 0.017). Time in range (70-180 mg/dL) increased from 46.9 ± 18.5% at baseline to 75.6 ± 6.9% in Auto Mode (p < 0.001). This was achieved while spending 2.8% of the time below 70 mg/dL and without any severe hypoglycemia or DKA.

CONCLUSION

Children and adolescents with type 1 diabetes on MDI therapy can successfully initiate the HCL system, using a concise structured 10-day protocol.

Switching from Suspend-Before-Low Insulin Pump Technology to a Hybrid Closed-Loop System Improves Glucose Control and Reduces Glucose Variability: A Retrospective Observational Case-Control Study

There are no data whether hybrid closed-loop (HCL) systems are superior to sensor-augmented pump (SAP) therapy with predictive low glucose suspend (PLGS) feature in improving glucose control. Aim of our study was to evaluate the effect on metabolic control and glucose variability of the switch from SAP therapy with PLGS to a HCL system in type 1 diabetic individuals. Forty adults with type 1 diabetes, who had been using SAP therapy with PLGS feature (Minimed 640G; Medtronic, Northridge, CA) for at least 12 months were evaluated in a 6-month case-control observational retrospective study. Twenty subjects who consecutively switched from Minimed 640G to a HCL system (Minimed 670G; Medtronic) (670G group) were compared with a control group consisting of 20 subjects who continued with the MiniMed 640G pump (640G group) matched for age, gender, and HbA_1c. At the end of the study there was a significant reduction in average HbA_1c levels (-4.9 ± 6.4 mmol/mol [-0.4% ± 0.6%], P < 0.01), sensor glucose concentrations (-15.4 ± 17.7 mg/dL, P < 0.005), coefficient of variation of sensor glucose concentrations (-3.8% ± 3.6%, P < 0.01), percentage time spent in both hyperglycemic range 181-250 mg/dL (-5.1% ± 4.5%, P < 0.05), and >250 mg/dL (-6.1% ± 6.9%, P < 0.05) in the 670G group, whereas they remained unchanged in the 640G group. Percentage of time spent in euglycemic range significantly increased (11.6% ± 8.3%, P < 0.005) only in the 670G group. There was no change in time spent in hypoglycemic range in both groups. In adults with type 1 diabetes, switching from a 640G to a 670G system significantly improved glucose control and reduced glucose variability, thus reaching in most cases the recommended targets for time spent in euglycemic and hyperglycemic ranges without increasing the risk of hypoglycemia.

Technological advances shaping diabetes care

PURPOSE OF REVIEW

To emphasize the current unmet needs for patients with diabetes and evaluate the recent technological advances in the diabetes field and summarize upcoming technologies in diabetes care. This review highlights emerging diabetes technologies and patient-centered diabetes management.

RECENT FINDINGS

A review of the literature showed that there is a clear benefit of using diabetes technologies in diabetes care. Recently, the US Food and Drug Administration (FDA) created a new category of Class II integrated continuous glucose monitoring (iCGM) devices and announced new guidelines to accelerate the approval of future products. With the first-generation hybrid-closed loop, a new era opened in automated insulin delivery systems. Diabetes coaching, apps, and remote monitoring technologies eased access to the providers and increased patient's self-confidence for diabetes management.

SUMMARY

Improvements in diabetes technologies will hopefully overcome unmet needs for patients with diabetes and improve health outcomes. Patients will benefit from the upcoming technologies in their day-to-day diabetes management while providers may monitor patients remotely with ease and efficiently. These developments will decrease diabetes burden, improve quality of life, and open a new era of personalized diabetes care.

Cost-Effectiveness Analysis of the MiniMed 670G Hybrid Closed-Loop System Versus Continuous Subcutaneous Insulin Infusion for Treatment of Type 1 Diabetes

BACKGROUND

Hybrid closed-loop (HCL) systems combine continuous glucose monitoring with continuous subcutaneous insulin infusion (CSII) to continuously self-adjust basal insulin delivery. Relative to CSII, HCL improves glycemic control and reduces the risk of hypoglycemia but has higher acquisition costs. The aim of this analysis was to assess the cost-effectiveness of the MiniMed™ 670G HCL system versus CSII in people with type 1 diabetes (T1D) in Sweden.

METHODS

Cost-effectiveness analysis, from a societal perspective, was performed over patient lifetimes using the IQVIA CORE Diabetes Model. Clinical data were sourced from a study comparing the MiniMed 670G system with CSII in people with T1D. Cost data, expressed in 2018 Swedish krona (SEK), were obtained from Swedish reference prices and published literature.

RESULTS

The MiniMed 670G system was associated with a quality-adjusted life-year (QALY) gain of 1.90 but higher overall costs versus CSII, leading to an incremental cost-effectiveness ratio (ICER) of SEK 164,236 per QALY gained. Use of the HCL system resulted in a lower cumulative incidence of diabetes-related complications. Higher HCL system acquisition costs were partially offset by reduced complication costs and productivity losses. In people with T1D poorly controlled at baseline, the MiniMed 670G system was associated with 2.25 incremental QALYs versus CSII, yielding an ICER of SEK 15,830 per QALY gained.

CONCLUSIONS

The MiniMed 670G system was associated with clinical benefits and quality-of-life improvements in people with T1D relative to CSII. At a willingness-to-pay threshold of SEK 300,000 per QALY gained, this HCL system likely represents a cost-effective treatment option for people with T1D in Sweden.