The Impact of a Moderate Carbohydrate Diet in Children With Type 1 Diabetes on Hybrid Closed-loop Therapy
NCT Number: NCT06567158
Acronym: COMBINE1
Status: RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Diabetes Mellitus, Type 1
Interventions: OTHER: Moderate carbohydrate diet|OTHER: Traditional diet
Sponsor: Universitaire Ziekenhuizen KU Leuven
Sex: ALL
Age: CHILD
Enrollment: 28
Study Design: Allocation: RANDOMIZED|Intervention Model: CROSSOVER|Masking: NONE|Primary Purpose: TREATMENT
Start Date: 2024-05-15
Completion Date: 2025-12-31
Locations: UZ Leuven, Leuven, Vlaams-Brabant, 3000, Belgium

Summary:
In the past, carbohydrate restriction was indicated as a treatment for people with type 1 diabetes when exogenous insulin was not available. Now it is mainly used as an added treatment for people with type 1 diabetes on top of standard insulin administration and glucose monitoring. Despite previous studies, the impact of carbohydrate restriction on glycemic control and quality of life is still not clear. Furthermore, few studies exist on carbohydrate restriction in children with type 1 diabetes and combined with the use of hybrid closed-loop insulin delivery. Therefore this study will determine the impact on glycemic control and the feasability of a moderate carbohydrate diet compared to a traditional diet in children (7-17 years) with type 1 diabetes on top of using a hybrid closed-loop system. In this randomized, crossover study, 28 children will follow a moderate carbohydrate diet (four weeks) and a traditional diet (four weeks) in randomized order. With a run-in period (two weeks) prior to the first diet and a wash-out period (six weeks) between the two diets, the children will participate in the study for a total of 16 weeks. The primary endpoint is the difference of time spent in target range (defined as a sensor glucose value between 70 and 180 mg/dL) between the four-week moderate carbohydrate diet and the four-week traditional diet.

Primary Outcome Measures: Time in range, Difference of time spent in range (70-180 mg/dL) between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Secondary Outcome Measures: Time in tight range, Difference of time spent in range (70-140 mg/dL) between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Time below range, Difference of time spent below range (\<70 mg/dL) between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Time in level 2 hypoglycemia, Difference of time spent below range of 54 mg/dL between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Time above range, Difference of time spent above range (\>180 mg/dL) between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Time in level 2 hyperglycemia, Difference of time spent above range of 250 mg/dL between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Hemoglobin A1c, Difference of hemoglobin A1c between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Mean blood glucose, Difference of mean blood glucose between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Glycemic variability: standard deviation and coefficient of variation, Difference of glycemic variability, in terms of standard deviation (SD) and coefficient of variation (CV) of blood glucose levels between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Daily insulin dose, Difference of insulin doses (total, basal and bolus) between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Number of severe hypoglycemic events, Difference in the frequency of severe hypoglycemic events between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Number of diabetic ketoacidosis, Difference in the frequence of diabetic ketoacidosis between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Body weight, Difference in body weight between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Body mass index, Difference in body mass index between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Blood lipids (total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein concentrations), Difference in blood lipids (total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein concentrations) between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Satisfaction with the diet in the context of diabetes treatment, Difference in the satisfaction with the diet (Diabetes treatment satisfaction questionnaire - DTSQs) between the moderate carbohydrate diet and the traditional diet. The DTSQs has a scale of 0-48 and a higher score is associated with a higher treatment satifaction., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Bioelectrical impedance analysis, Difference in bioelectrical impedance analysis between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Carb ratio, Difference in carb ratio between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Active insulin time, Difference in active insulin time between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Number of people who use glucose target 100 mg/dL, 110 mg/dL and 120 mg/dL, Difference in umber of people who use glucose target 100 mg/dL, 110 mg/dL and 120 mg/dL between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Consumed carbohydrates, Difference in consumed carbohydrates between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet|Meal composition, Difference in meal composition a between the moderate carbohydrate diet and the traditional diet., 4 weeks moderate carbohydrate diet and 4 weeks traditional diet