Fully Automated Insulin Delivery Helps Teens With Hard-to-Control T1D

What Was Studied and Why It Matters

Managing Type 1 diabetes (T1D) is hard for anyone, but teenagers face unique challenges — busy schedules, changing hormones, and the constant mental load of tracking meals and doses. As a result, many adolescents with T1D struggle to keep their HbA1c (a measure of average blood sugar over three months) within recommended targets.

Researchers wanted to know whether a fully closed-loop (FCL) insulin delivery system — one that automatically adjusts insulin around the clock without requiring the user to manually bolus for meals — could help this group. The study was published in Diabetes Technology & Therapeutics in 2025.

How the Study Worked

Twenty-four teenagers (ages 13–19) with above-target HbA1c levels took part in a carefully designed crossover study. That means each participant tried both approaches, in random order:

• Fully closed-loop system: The CamAPS HX app using fast-acting Fiasp insulin, which automatically controlled all insulin delivery with no mealtime boluses needed.
• Standard pump + CGM: Their usual insulin pump paired with a continuous glucose monitor (CGM), where they still had to manually dose for meals.

Each phase lasted 8 weeks of normal, unrestricted daily life. No special diets or clinical settings — just real-world conditions.

What the Researchers Found

The results were clear and significant:

• More time in target range: Teens using the FCL system spent 45% of the time with blood sugar in the healthy range, compared to just 32% with the standard pump — a difference of nearly 13 percentage points.
• Less time dangerously high: Time spent with very high blood sugar (above 250 mg/dL) dropped from about 40% to 29% with the FCL system.
• Lower average blood sugar: Mean glucose was meaningfully lower with FCL.
• No increase in lows: Time spent with low blood sugar was similar between both approaches — meaning better control didn't come at the cost of more hypoglycemia.
• No serious safety events: There were zero cases of severe hypoglycemia or diabetic ketoacidosis in either group.

The one area where the difference wasn't statistically significant was HbA1c after just 8 weeks — though levels did trend lower with FCL. Longer studies may show a bigger impact on this measure.

What This Means for Patients and Families

For teens and parents who feel like they're constantly battling blood sugar numbers, this research offers real hope. A fully automated system removes one of the biggest daily burdens — remembering to bolus for every meal — while still delivering safer, more stable glucose levels.

If your teen uses an insulin pump and CGM, having the right supplies consistently on hand is essential. MDS Diabetes makes it easy to stay stocked with CGM sensors, pump supplies, and other diabetes essentials, so technology like this can work without interruption.

Talk to your endocrinologist about whether a closed-loop system might be appropriate for your teen, especially if HbA1c has been difficult to manage.

Bottom Line

A fully closed-loop insulin system significantly improved blood sugar control in teenagers with hard-to-manage Type 1 diabetes — with no added risk of lows and no need to manually dose for meals. For families navigating the challenges of adolescent T1D, this technology represents a meaningful step forward in making diabetes management more automatic, more effective, and less stressful.