A digital twin-enhanced decision support system improves time-in-range in type 1 diabetes: a randomized clinical trial.

Most individuals with type 1 diabetes (T1D) worldwide continue to be managed with multiple daily injections or sensor-augmented pumps. Decision-support systems (DSSs) have emerged as cost-effective tools to enhance treatment adherence and glucose control. We conducted a randomized, open-label, parallel-group study to evaluate STUDIA, a DSS incorporating a digital twin-enabled simulation-assisted bolus calculator. Twenty-eight participants with T1D used either the simulation-assisted calculator or traditional carbohydrate counting for prandial insulin dosing, with glucose monitored using Freestyle Libre. After four weeks, the group using the simulation-assisted calculator showed a 7% increase in time in the target glucose range (70-180 mg/dL) compared to the control (p < 0.001), along with a lower hypoglycemia incidence rate (RR 0.31, p = 0.022). Model performance yielded a mean absolute percentage error at 60 min of 19.2 ± 6.7%, increasing at longer horizons, with most discrepancies between simulation and sensor falling into no-risk or slight-risk zones. These findings support the safety, feasibility, and potential clinical utility of the STUDIA system in people with T1D.