C-Carbs: A CGM-guided Approach to Teaching Carb Awareness

The C-CARBS study is a randomized controlled study evaluating a patient-facing education program designed to help adults with diabetes use continuous glucose monitoring (CGM) data to guide mealtime insulin dosing. The study focuses on adults with diabetes who use CGM and multiple daily insulin injections (MDI) and who do not routinely use carbohydrate counting or have difficulty with carbohydrate counting. Participants will be randomly assigned to either the C-CARBS intervention or usual care. Participants assigned to the intervention will receive four weekly, one-hour education sessions with a Certified Diabetes Care and Education Specialist. The sessions will focus on using CGM information, including current glucose levels and glucose trends, to support mealtime insulin dosing without relying solely on traditional carbohydrate counting. Participants in both groups will complete study assessments throughout the study, including questionnaires and four 3-day meal and insulin logs. Meal and insulin information may be recorded manually or through the participant's Dexcom app. CGM data and laboratory measures, including hemoglobin A1c (HbA1c), will be collected to evaluate changes in glycemic outcomes. The study will also assess participants' insulin dosing behaviors, use of diabetes technology, and experience with the intervention. The primary goal of the study is to determine whether the C-CARBS education program can improve mealtime insulin dosing behaviors and glycemic outcomes among adults with diabetes who do not routinely use carbohydrate counting.