What Predicts Success With Automated Insulin Delivery? New Data Points to Baseline Control

Researchers in France followed over 1,000 adults with type 1 diabetes who started using automated insulin delivery systems in 2022. These 'closed-loop' or 'hybrid closed-loop' systems automatically adjust insulin delivery based on continuous glucose monitor readings, removing some of the moment-to-moment decision-making from users.

The study tracked two widely used systems: the Medtronic MiniMed 780G and the Tandem Diabetes Control-IQ. Participants were monitored for 12 months to see who achieved the internationally recommended glucose targets: spending more than 70% of time in the 70–180 mg/dL range and less than 4% of time below 70 mg/dL.

Overall, 43% of participants met both target goals after a year. However, results differed between the two systems: 52% of MiniMed 780G users achieved targets, compared to 36% of Tandem Control-IQ users.

The researchers used statistical analysis to identify what predicted success. The strongest pattern they found was that people who started with better baseline blood sugar control—meaning higher time in range and lower HbA1c at the beginning—were significantly more likely to hit targets after 12 months on either system.

An important finding was that even participants who began with worse baseline control still showed meaningful improvement. Both systems reduced glucose variability (a measure of blood sugar swings) substantially over the 12 months. On the MiniMed 780G, the glucose risk indicator improved from 44.1 to 30.2; on the Tandem system, it improved from 49.4 to 36.7.

This suggests that automated insulin delivery helps stabilize blood sugar across the board, even though some patterns from baseline persist. In other words, the system is beneficial regardless of where you start—but starting with better control makes reaching the specific international targets more likely.

If you're considering automated insulin delivery or have recently started, this research reminds us that outcomes depend partly on where you're starting from. Your baseline glucose management—the control you have before using the system—plays a significant role in where you'll land after a year.

At the same time, the improvements seen even in people with poorer baseline control show that automated systems offer real benefits for everyone. The goal isn't to discourage anyone from exploring these technologies, but to set realistic expectations and understand that achieving tight glucose targets takes time and is influenced by factors beyond the device itself.

Source: Annales d'endocrinologie. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.