Our proposed study aims to build upon the existing findings by conducting a first-of-its-kind randomized controlled trial (RCT) that directly compares Advanced Hybrid Closed Loop (AHCL) and open-loop insulin delivery (OLID) systems during Ramadan. This comparison is crucial for understanding the nuanced benefits and potential limitations of each system in the context of Ramadan fasting, a topic not yet explored in RCT settings. By undertaking this study, we intend to bridge this gap in research, providing valuable insights into the effectiveness of these contrasting insulin delivery methods. The outcomes of this research could significantly inform clinical recommendations for T1DM management during Ramadan, emphasizing the importance of personalized treatment approaches that are aligned with patient needs and technological advancements.

A Multi-center, randomized controlled trial will be conducted at King Fahad Medical City and Prince Sultan Military Medical City

Participants were randomly assigned to either the control group (OLID) or one of the intervention groups (AHCL). Stratified randomization will be used according to age (<18 and ≥18 years) and HbA1c (<8.5% and ≥8.5%) to avoid overrepresentation of certain age or glycemic control groups.

All groups will receive comprehensive diabetes education and extensive carbohydrate counting training. Continuous glucose monitoring (CGM) will be conducted using the Guardian 4 sensor or Dexcom G6 for the intervention group depending on the type of pump used. The control group will continue using their current CGM device. Data on glycemic control, hypoglycemic events, and patient satisfaction will be collected before and throughout Ramadan. Additionally, fructosamine levels for all patients will be checked both before and after Ramadan to provide a more immediate assessment of glycemic control.

The investigators compared between groups in terms of the number of fasting days out of the entire month and the number of days in which participants break their fast due to diabetes-related reasons. Days when female participants do not fast due to their menstrual period will not be counted as days of fasting break for the purposes of this analysis.

Sociodemographic data, laboratory investigations, and relevant clinical data will be collected from the Electronic Health Record (EHR). CGM metrics including Time in Range (TIR), Time Above Range (TAR), Time Below Range (TBR), Glucose Management Indicator (GMI), and Coefficient of Variation (COV) will be gathered. Fructosamine levels will also be measured to assess the immediate past 2 weeks' glycemic control. A survey for diabetes distress and quality of life will be filled by the participants prior to the study.

The same CGM metrics will be collected. Insulin data including total daily dose (TDD) and percentage of basal insulin and meal boluses will be obtained. Fructosamine levels will be measured again at the end of the study to compare with the baseline measurements. This will provide a detailed assessment of the glycemic control changes specifically during Ramadan. The quality of life and diabetes distress surveys will be refilled at the end of the study. HbA1c levels will also be collected at the end of the study for a comprehensive assessment of the glycemic control during Ramadan.

Statistical Analysis:

The sample size was calculated using the confidence interval method. Statistical analyses will include comparative evaluations of HbA1c levels, hypoglycemia incidence, and patient-reported outcomes. Assuming change in time of range by 12%, power: 80% and alpha error of 5%, sample size was calculated at 25 for each group. However, we are planning to include the maximum patients we could recruit to account for the possible patients drop out.

Inclusion Criteria:

• Type 1 diabetes as per the American Diabetes Association classification for at least 1 year.
• Age 14 to 70.
• OLID therapy for at least 6 months.
• Willingness and ability to adhere to the study protocol.

Exclusion Criteria:

• Pregnancy.
• Using medications that affect blood glucose like steroids.
• Patients who are not able to fast for the entire month of Ramadan due to medical or non-medical reasons.