The TANGO study is a 12-month study involving 120 children and adolescents with Type 1 Diabetes (T1D) across the Czech Republic, Israel, and Poland who use automated insulin delivery (AID) systems.

Currently, the global standard for diabetes management is "Time in Range" (TIR), which aims to keep blood sugar levels between 70-180 mg/dL. However, newer technologies like AID systems may now allow for a tighter, more physiological goal called "Time in Normal Glycemia" (TING), which targets a range of 70-140 mg/dL.

This study will randomly assign participants to follow either the standard TIR target or the tighter TING target to see if the narrower range improves overall blood sugar control and HbA1c without increasing the risk of hypoglycemia, family stress, or daily treatment burden.

By comparing these two approaches, researchers hope to determine if clinical guidelines should be updated to reflect a more precise glucose target for children and adolescents worldwide

This multinational, multicenter, randomized controlled trial aims to evaluate the clinical impact of targeting Time in Normal Glycemia (TING; 70-140 mg/dL) compared to the current standard, Time in Range (TIR; 70-180 mg/dL), in children and adolescents with Type 1 Diabetes (T1D).

Background and Rationale Managing glucose levels in pediatric T1D is essential for preventing long-term complications. While the international consensus currently recommends maintaining a TIR >70%, recent technological advances-such as automated insulin delivery (AID) systems and next-generation continuous glucose monitors (CGM)-now make it feasible to target narrower, more physiological glucose ranges. TING (70-140 mg/dL) has emerged as a potential new clinical metric for improved metabolic compensation. However, there is no definitive evidence yet that aiming for this tighter range leads to better long-term outcomes than the standard TIR without increasing treatment burden or psychological stress.

Study Objectives The primary objective is to determine if setting TING as the glycemic target improves CGM-derived glycemic metrics compared to the standard TIR approach.

Secondary objectives include:

Evaluating changes in HbA1c. Assessing differences in Quality of Life (QoL) and treatment burden using standardized patient and caregiver questionnaires.

Monitoring the safety and incidence of acute complications, such as severe hypoglycemia and diabetic ketoacidosis (DKA).

Study Design and Population The study will enroll 120 children and adolescents (ages 5.0-17.99) across three tertiary pediatric diabetes centers in the Czech Republic, Israel, and Poland. All participants must be using AID systems and have used a CGM for at least 70% of the time in the month prior to enrollment.

From the target population, we aim to recruit 25% of individuals newly diagnosed.

Intervention and Methods

Participants will be randomized 1:1 into two groups:

TING Group (Intervention): Will follow a target glucose range of 70-140 mg/dL (3.9-7.8 mmol/L).

TIR Group (Control): Will follow the standard target range of 70-180 mg/dL (3.9-10.0 mmol/L).

Both groups will receive structured education from a multidisciplinary team regarding CGM interpretation, glycemic targets, and self-management. In the TING group, CGM hyperglycemia targets will be lowered by at least 10% from baseline.

Timeline and Endpoints The study duration is 12 months. Data collection includes CGM metrics, insulin dose data, and HbA1c at 3-month intervals (Months 0, 3, 6, 9, and 12). A telephone check-up will occur 6 weeks after baseline to assess early adherence and treatment satisfaction.

Primary Endpoint: Change in TIR (70-180 mg/dL) between baseline and 12 months.

Secondary/Exploratory Endpoints: Percentage of time in TING, time in hypoglycemia (Levels 1 and 2), glycemic variability, and various QoL scores (PAID, INSPIRE, Hypoglycemia/Hyperglycemia Fear Surveys) .

Impact If targeting TING is proven beneficial and acceptable, the results of this trial could inform future clinical guidelines and redefine optimal glycemic targets for pediatric diabetes care globally.

Inclusion Criteria:

• Diagnosis of T1D per ADA criteria
• Age 5.0-17.99 at the start of study
• CGM use >70% of the time during the month prior to enrollment
• Maximum HbA1c of 86mmol/mol (10% in DCCT)

Exclusion Criteria:

• No concurrent illnesses impacting glycemia
• No treatments impacting glycemia
• Severe hypoglycemia documented in the 60 day period leading up to patient recruitment
• Current participation in any other interventional study
• Any significant diseases / conditions including psychiatric disorders and substance abuse that in the opinion of the investigator is likely to affect the subject's ability to complete the study or compromise participant's safety
• Female subject who is pregnant or lactating or planning to become pregnant within the planned study duration

We plan to share the anonymised participants' data on individual request