Hybrid Closed-Loop Systems Help People Spend More Time in Healthy Blood Sugar Range

Researchers in Australia and the United Kingdom wanted to understand how well hybrid closed-loop systems—also called automated insulin delivery systems—help people manage their blood sugar. They studied two groups: 86 people in Australia and 288 people in the UK who started using hybrid closed-loop therapy.

The team tracked two key measures: how much time people spent in their target blood sugar range (between 70-180 mg/dL, known as time in range or TIR), and how much insulin they were actually using each day.

In the Australian group, time in range jumped from about 53% to 70%—a meaningful improvement. Importantly, the average daily insulin dose stayed nearly the same, going from 53.3 to 52.0 units per day.

The UK group saw similar results. Their time in range increased from a median of 54% to 66%. Average daily insulin doses actually stayed stable, rising slightly from 44.1 to 46.3 units per day but not significantly.

These improvements suggest that hybrid closed-loop systems are helping people's bodies use insulin more effectively, rather than requiring them to take more medication.

Time in range is an important measure of diabetes management. The higher the percentage, the more time someone spends in the healthy blood sugar zone where they're less likely to experience highs or lows that can affect how they feel and their long-term health.

This study included real people managing Type 1 diabetes in everyday life—not just those in controlled research settings. That makes the results especially relevant for understanding how hybrid closed-loop systems perform when people actually use them at home.

Researchers also created a new measurement called dose-normalized time in range (dn-TIR). This accounts for the fact that different people take different amounts of insulin. By dividing time in range by the total daily insulin dose, the measurement shows how well someone's blood sugar control is working relative to how much insulin they're using.

This new measure is not meant to replace standard blood sugar metrics that doctors already use. Instead, it offers another way to look at whether someone's diabetes management is improving in a way that takes their individual insulin needs into account.

Source: Diabetes, obesity & metabolism. 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.