What is 'Time in Range' and why does it matter?

Time in Range (TIR) measures what percentage of the day your blood sugar stays between 70 and 180 mg/dL — the generally recommended healthy zone. More time in range is linked to lower risk of diabetes complications. Even a 5% improvement (about 1 extra hour per day in range) is considered clinically meaningful.

Can anyone with type 1 diabetes use an automated insulin delivery system?

AID systems are suitable for many people with type 1 diabetes, but eligibility depends on your individual health situation, insurance coverage, and your care team's guidance. Speak to your endocrinologist or diabetes nurse to find out if an AID system is a good fit for you.

Why did HbA1c improve similarly in both groups if the AID system was better?

HbA1c reflects your average blood sugar over 3 months and may not capture short-term improvements in glucose stability as sensitively as Time in Range does. Both groups were already reasonably well-controlled at the start, leaving less room for HbA1c to differ. TIR picks up on day-to-day fluctuations that HbA1c can miss.

Tubeless AID System vs Sensor Pump in Type 1 Diabetes

Key takeaways

✓AID system users spent 6.5% more time in healthy blood sugar range — about 1.5 extra hours per day
✓The AID system also reduced time spent too high or too low, and improved glucose stability
✓Both devices were safe with no severe hypoglycaemia or diabetic ketoacidosis in either group

Quick specs

Journal	Diabetologia
Year	2024
PMID	38634887

What Was This Study About?

Researchers in South Korea compared two types of wearable, tubeless insulin pumps in adults with type 1 diabetes. One was an automated insulin delivery (AID) system — sometimes called a "closed-loop" or "artificial pancreas" system — that automatically adjusts insulin based on continuous glucose readings. The other was a sensor-augmented pump (SAP), which shows glucose data but requires the user to make manual adjustments.

Who Was Studied?

104 adults aged 19–69 with type 1 diabetes took part across 13 hospitals in South Korea. Half used the AID system and half used the standard sensor pump for 12 weeks. All participants had reasonably controlled diabetes at the start (HbA1c below 10%).

What Did They Measure?

The main goal was Time in Range (TIR) — the percentage of the day blood sugar stayed in a healthy zone (70–180 mg/dL). More time in range means better, more stable glucose control with fewer highs and lows.

Key Results

The AID group spent significantly more time in the healthy blood sugar range:

AID system: TIR improved from 62.1% to 71.5% — a gain of nearly 10 percentage points
Standard pump: TIR improved only slightly, from 64.7% to 66.9%
The difference between groups was 6.5%, which is clinically meaningful (roughly 1.5 extra hours per day in range)

The AID group also had less time with blood sugar too high or too low, and more stable overall glucose levels.

What About HbA1c?

Both groups saw similar improvements in HbA1c (a 3-month blood sugar average), dropping to around 6.3–6.4% in both groups. The difference between the two groups was not statistically significant, suggesting both devices can support good long-term control.

Was It Safe?

Yes. There were no cases of diabetic ketoacidosis (DKA) or severe low blood sugar in either group throughout the 12-week trial.

What Does This Mean for Patients?

If you have type 1 diabetes and are considering an insulin pump, a tubeless AID system may offer better day-to-day glucose stability than a standard sensor pump — without the hassle of tubing. Talk to your diabetes care team about whether an AID system might be right for you.

References & Sources

Frequently asked questions

A tubeless AID system sticks directly to your skin with no tubing. It uses your continuous glucose monitor readings to automatically adjust insulin delivery — so it does much of the decision-making for you. A standard sensor pump also has no tubing and shows your glucose data, but you still need to manually decide when to give extra insulin.

Editorial note

This article is for educational purposes only and does not constitute medical advice. Always consult your healthcare provider before making changes to your diabetes management. Last reviewed: July 16, 2026 by the MDS Diabetes editorial team.

What to do next

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Tubeless AID System Beats Standard Pump in Type 1 Diabetes