Study Compares MiniMed 780G and MiniMed 670G Algorithms

This content originally appeared on diaTribe. Republished with permission.

By Albert Cai

A new study in adolescents and young adults with type 1 diabetes directly compared two automated insulin delivery algorithms. Medtronic’s newer Advanced Hybrid Closed Loop (built into the MiniMed 780G system) improved glucose management more than the MiniMed 670G, though both systems showed impressive increases in Time in Range for this population. Ultimately, the 670G gave users over an hour and a half more time in range each day, while the 780G gave wearers over two hours every day in range!

Two Medtronic automated insulin delivery algorithms, the Advanced Hybrid Closed Loop and the MiniMed 670G, were recently compared in a cross-over study, allowing 113 participants to use both algorithms. Results from the study were published in the medical journal The Lancet. Notably, the study tested this technology in adolescents and young adults with type 1 diabetes ­– a group for which diabetes management is notoriously challenging. View our resources for adolescents with diabetes here.

For an introduction to automated insulin delivery (AID), check out our piece on current and coming-soon AID systems in 2021.

What is the MiniMed 670G?

The MiniMed 670G is an AID system that has been available since spring 2017 – it was the first system ever to “close the loop.” The system includes the MiniMed 670G pump, the Guardian Sensor 3 continuous glucose monitor (CGM), and an automated insulin adjustment algorithm. The algorithm adjusts basal insulin delivery every five minutes based on CGM readings, and a target of 120 mg/dl.

What is Advanced Hybrid Closed Loop?

Advanced Hybrid Closed Loop (AHCL) is Medtronic’s next-generation AID algorithm. The AHCL algorithm is used in Medtronic’s MiniMed 780G system, which is currently available in at least twelve countries in Europe. While it is not yet available in the US, Medtronic hopes to launch the 780G in the US this spring. In addition to automatic basal rate adjustments, the AHCL algorithm can also deliver automatic correction boluses and has an adjustable glucose target that goes down to 100 mg/dl. This is big news because many people using closed loop do not want to target the higher 120 mg/dl, even as a safety measure. The 780G algorithm is designed to have fewer alarms and even simpler operation than the MiniMed 670G system.

What was the study?

The newly published FLAIR (Fuzzy Logic Automated Insulin Regulation) study was conducted over six months across seven diabetes centers (four in the US, two in Europe, and one in Israel). The study enrolled 113 adolescents and young adults (ages 14-29) with type 1 diabetes. The study sample is notable, because teens and young adults with type 1 diabetes have the highest average A1C levels of any age group.

At the beginning of the study, participants performed their usual diabetes management routine for two weeks to establish their baseline glucose levels. Half of the group was then randomly assigned to use the MiniMed 670G system, while the other half of the group used the same pump and CGM, but with the new AHCL algorithm. After three months – the halfway point of the study – the two groups “crossed over,” switching to the opposite technology.

What were the results?

Nearly every measure of glucose management favored the AHCL period over the MiniMed 670G:

  • Compared to baseline, participants reduced time spent above 180 mg/dl by 1.2 hours per day when using MiniMed 670G and 1.9 hours per day when using AHCL.
  • Time in Range (TIR, time between 70-180 mg/dl) improved from a baseline of 57% to 63% using Minimed 670G and to 67% using AHCL.
  • Time spent below 70 mg/dl fell 0.2% of the time. While those 28 minutes a day may not be statistically significant – and time in severe hypoglycemia, or below 54 mg/dl, did not increase from baseline when using either algorithm – many people with diabetes would benefit from that additional half hour in range.

The graph below shows the time spent in glucose ranges during baseline, MiniMed 670G, and AHCL periods. For both algorithms, the Time in Range increase from baseline was significant – use of either AID system led to at least 14 hours more each week spent in range. Nevertheless, we also point out, of course, that the group (again, the group that has the most challenges of any age group managing diabetes) still experienced a fair amount of time above 250 mg/dl. This is  another reason for healthcare professionals and people with diabetes to think about the “whole person” when considering diabetes management, and another reason why we always recommend Adam Brown’s Bright Spots and Landmines for ways to improve diabetes management in terms of food, exercise, mindset, and sleep – it includes many strategies for people, especially teens and young adults, to use each day.

AID comparison

Image source: diaTribe

  • The biggest Time in Range improvement came overnight (between midnight to 6am). During this six-hour overnight period, AHCL users spent an average of 4.4 hours in range (74% TIR), compared to 4.2 hours (70% TIR) for 670G, and 3.5 hours (58% TIR) during baseline. While the overnight Time in Range difference between AHCL and 670G may not seem large, it added up to nearly a 22-hour difference over the three-month the AHCL period.
  • With daytime numbers, the average AHCL user spent 63 more hours (about 2.6 days) in range than the average 670G user in each three-month study period.

The graph below shows daytime and nighttime differences in time spent in range (70-180 mg/dl), and the data is included in a table at the end of this article. Better sleep the night before can also make diabetes management more effective during the day.

Comparison

Image source: diaTribe

  • Using MiniMed 670G drove an average A1C improvement from 7.9% to 7.6%, while AHCL use improved A1C from 7.9% to 7.4%.

Both systems showed extremely positive results and were found to be safe for use in young people with type 1 diabetes. The AID algorithms led to dramatic increases in Time in Range in a population that stands to benefit – over the course of a year, adolescents and young adults could spend more than ten additional days in range. The direct comparison between these two AID algorithms is highly informative – we hope to see similar trials in the future.

Comparison

Image source: diaTribe

Source: diabetesdaily.com

Tandem’s Control-IQ Cleared for Ages 6-13: Automated Insulin Delivery for Children!

This content originally appeared on diaTribe. Republished with permission.

By Divya Gopisetty, Hanna Gutow, and Albert Cai

In exciting news, Tandem announced expanded clearance for the hybrid closed loop Control-IQ. The system is now available for children ages 6-13

The FDA cleared Tandem’s automated insulin delivery (AID) system, Control-IQ, for children ages 6-13, last week in the US. This system is designed to increase time in range for users and it does – see below for the data!

To date, the only other hybrid closed loop system available for children is Medtronic’s MiniMed 670G, which is approved for children seven years and older. Control-IQ is the first system with automatic correction boluses and no fingerstick calibration (thanks to the Dexcom G6 sensor that it uses).

Control-IQ launched in January of this year for people 14 years and older. Since then, more than 40,000 t:slim X2 pump users have upgraded their pump software to Control-IQ. We saw very positive real-world data presented at ADA this year – in the first 30 days using Control-IQ, users’ time in range increased by 2.4 hours per day, and individuals were in active closed loop 96% of the time.

At the ATTD conference in February, the trial for Control-IQ in children presented strong results. Results from that trial were used to get this week’s FDA clearance. In that trial, we learned that:

  • Children using Control-IQ spent 67% time in range, compared to 55% for children using a sensor-augmented pump. This is a massive difference that equals nearly three more hours in range each day.
  • Children using Control-IQ reached 80% time in range overnight, compared to 54% in the control group – similarly, this change is even bigger, at over six hours more daily time in range.

Control-IQ still should not be used in children under the age of six, in people who require less than ten units of insulin per day, and in children who weigh less than 55 pounds.

For more information on the system, check out Kerri Sparling’s Test Drive of Control-IQ where her time in range improvement was quite impressive! You can also Katie Bacon’s piece on one family’s takeaways (her own!) from the first month of their teenage daughter using Control-IQ.

Source: diabetesdaily.com

New Research: Hybrid Closed-Loop System Outcomes (ADA 2020)

Technology is truly changing the lives of many people with diabetes across the world. Advancements continue in many areas, including the development and testing of various automated insulin delivery systems.

The MiniMed 670G insulin pump system is the first of it’s kind in providing automatic insulin delivery adjustments based on continuous glucose monitoring (CGM) data. Now, two recent research studies, the results of which were just presented this weekend at the American Diabetes Association (ADA) 80th Scientific Sessions, are highlighting the positive outcomes of the system for young and adults patients.

Outcomes in Adult Patients

Dr. Stephanie Kim, MD, MPH, from the University of San Francisco, CA, presented the results of a single-center research study in adult patients with type 1 diabetes. The researchers enrolled 52 patients (47% female, average age 46 +/-12 years, average diabetes duration of 27 +/- 15 years) utilizing the Medtronic 670G system and started “Automode” delivery of insulin between 2017 and 2019, in an effort to evaluate the impact of automatic delivery on glycemic outcomes.

The study subjects were stratified into two groups, depending on baseline blood glucose levels (defined as A1c level of higher than 7.6% or lower than or equal to 7.5%). The A1c levels were evaluated at baseline (before starting Automode) and again approximately 17 months after starting Automode.

The data revelated that while the A1c level did not change significantly in patients in the lower A1c cohort, there was improvement in the group with baseline A1c>7.6%. These patients improved their A1c, on average, from 8.3% to 7.8% using this system.

Outcomes in Youth

Dr. Goran Petrovski, MD, PhD, of Sidra Medicine in Qatar, reported on the results of an observational study of children and young adults with type 1 diabetes who used multiple daily insulin injections (MDI) and switched to the MiniMed 670G hybrid closed-loop system. A total of 42 patients (ages 7-18, mean age 12 years) were enrolled in the study.

Excitingly, the study outcomes demonstrated considerable improvements to the average A1c levels (8.4% at baseline to 6.7% at 3-months follow-up, and 6.9% at 6-months follow-up) after initiating the hybrid closed-loop system therapy. Also, the time-in-range (defined in this study as blood glucose levels between 70-180 mg/dL) improved considerably with the use of this technology. Notably, no instances of diabetic ketoacidosis (DKA) or severe hypoglycemia were reported. The authors declared no conflict of interest and concluded that “children and adolescents with T1D can successfully initiate the HCL system, achieve and maintain better glycemic control than previous MDI regimen.”

Petrovski et. al. (Presented at ADA 2020)

Conclusions

Technology that can help people with diabetes better manage their blood glucose levels continues to improve. Notably, while the glycemic improvement in youth who transitioned from MDI to the automated system were considerable, the improvements were much more modest in the study on adults using this system who switched to Automode. Altogether, the data highlight the potential of technology to improve outcomes, while also revealing that technology use (at least as it stands today) is generally not enough on its own, to achieve optimal results. Patient education regarding diet, exercise, and the numerous intricacies of dosing insulin remain central to optimizing outcomes.

Source: diabetesdaily.com

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