Low Carbohydrate Diet vs. High Carbohydrate Diet in Type 1 Diabetes

Study Overview
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Brief Summary
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The aim of the study is to investigate glycemic control during a low carbohydrate diet compared with during a high carbohydrate diet in adults with insulin pump treated type 1 diabetes.

Official Title
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Low Carbohydrate Diet vs. High Carbohydrate Diet in Type 1 Diabetes: A Randomized Crossover Study

Conditions
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Type 1 Diabetes

Intervention / Treatment
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* Other: Low carbohydrate diet
* Other: High carbohydrate diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Type 1 diabetes ≥3 years Insulin pump use ≥1 year HbA1c ≥53 mmol/mol (7.0%) BMI 20-27 kg/m2 Willingness to count carbohydrates and use the insulin pump bolus calculator for all boluses during the intervention periods Willingness to use continuous glucose monitoring consistently during the intervention periods Exclusion Criteria: Females of childbearing potential who are pregnant, breast-feeding or intend to become pregnant or are not using adequate contraceptive methods Use of SGLT-2-inhibitors Use of corticosteroids during or within 30 days prior to the intervention periods Celiac disease Inflammatory bowel disease Macroalbuminuria Active proliferative retinopathy combined with an HbA1c ≥ 75 mmol/mol (9.0%) Known or suspected alcohol or drug abuse Other concomitant medical or psychological condition that according to the investigator's assessment makes the patient unsuitable for study participation

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low Carbohydrate Diet<br>< 100 grams of carbohydrate per day | Other: Low carbohydrate diet<br> <br> |
| Experimental: High Carbohydrate Diet<br>> 250 grams of carbohydrate per day | Other: High carbohydrate diet<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Time Spent in Euglycemia | Time spent with glucose values 4.0-10.0 mmol/l assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Glucose | Mean glucose value assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Standard Deviation of Glucose | Standard deviation of glucose values assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Coefficient of Variation of Glucose | Coefficient of variation of glucose values assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Mean Amplitude of Glycemic Excursions | Mean amplitude of glycemic excursions (MAGE) assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Time Spent in Hypoglycemia | Percentage of time spent with glucose values ≤ 3.9 mmol/l assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Time Spent in Hyperglycemia | Time spent with glucose values > 10.0 mmol/l assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Change in A1c | Change in hemoglobin A1c | From baseline to 12 weeks | 
| AUC Low | Difference in area under the curve <4.0 mmol/l assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| AUC High | Difference in area under the curve >10.0 mmol/l assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Post Breakfast Glucose Excursion | Difference in post breakfast glucose excursion assessed by continuous glucose monitoring | 12 weeks - from baseline to end of study | 
| Severe Hypoglycemia | Number of severe hypoglycemia episodes (glucagon or intravenous glucose administration) | From baseline to 12 weeks | 
| Total Daily Dose | Total daily insulin dose | 12 weeks - from baseline to end of study | 
| Total Daily Basal Insulin 24 Hour | Total daily basal insulin dose in the time range 00:00-24:00 | 12 weeks - from baseline to end of study | 
| Total Nightime Basal Insulin | Total nighttime basal insulin in the time range 00:00-06:00 | From baseline to 12 weeks | 
| Total Daytime Basal Insulin | Total daytime basal insulin in the time range 06:00-24:00 | 12 weeks - from baseline to end of study | 
| Total Daily Bolus Insulin | Difference in total daily bolus insulin | 12 weeks - from baseline to end of study | 
| Blood Glucose Readings | Number of blood glucose readings | 12 weeks - from baseline to end of study | 
| Carbohydrate Servings | Number of daily carbohydrate servings (one serving ≥ 15 grams) | 12 weeks - from baseline to end of study | 
| Body Composition | Change in fat mass (% of total body weight) assessed by Dual-energy X-ray Absorptiometry | 12 weeks - from baseline to end of study | 
| Weight | Change in weight | 12 weeks - from baseline to end of study | 
| Hip Circumference | Change in hip circumference | 12 weeks - from baseline to end of study | 
| Waist Circumference | Change in waist circumference | From baseline to 12 weeks | 
| Systolic Blood Pressure | Change in systolic blood pressure | 12 weeks - from baseline to end of study | 
| Diastolic Blood Pressure | Change in diastolic blood pressure | 12 weeks - from baseline to end of study | 
| Heart Rate | Change in heart rate | 12 weeks - from baseline to end of study | 
| Diabetes Treatment Satisfaction | Change in Diabetes Treatment Satisfaction Questionnaire score. Score range: 0-36, with higher values representing higher degrees of treatment satisfaction. | 12 weeks - from baseline to end of study | 
| Hypoglycemia Fear | Change in Hypoglycemia Fear Survey score. Score range: 0-52, with higher scores indicating higher degrees of fear of hypoglycemia. | 12 weeks - from baseline to end of study | 
| Cholesterol | Change in total cholesterol | 12 weeks - from baseline to end of study | 
| HDL | Change in HDL | 12 weeks - from baseline to end of study | 
| LDL | Change in LDL | 12 weeks - from baseline to end of study | 
| Triglycerides | Change in triglycerides | 12 weeks - from baseline to end of study | 
| Free Fatty Acids | Change in free fatty acids | 12 weeks - from baseline to end of study | 
| Sodium | Change in sodium | 12 weeks - from baseline to end of study | 
| Potassium | Change in potassium | 12 weeks - from baseline to end of study | 
| Creatinine | Change in creatinine | 12 weeks - from baseline to end of study | 
| Urate | Change in urate | 12 weeks - from baseline to end of study | 
| Albumin | Change in albumin | 12 weeks - from baseline to end of study | 
| Hemoglobin | Change in hemoglobin | 12 weeks - from baseline to end of study | 
| Leucocytes | Change in leucocytes | 12 weeks - from baseline to end of study | 
| Thrombocytes | Change in thrombocytes | 12 weeks - from baseline to end of study | 
| Iron | Change in iron | 12 weeks - from baseline to end of study | 
| Transferrin | Change in transferrin | 12 weeks - from baseline to end of study | 
| Ferritin | Change in ferritin | 12 weeks - from baseline to end of study | 
| Folate | Change in folate | 12 weeks - from baseline to end of study | 
| Vitamin B-12 | Change in vitamin B-12 | 12 weeks - from baseline to end of study | 
| Magnesium | Change in magnesium | 12 weeks - from baseline to end of study | 
| Zinc | Change in zinc | 12 weeks - from baseline to end of study | 
| U-alb-crea Ratio | Change in urine albumin-creatinine ratio | 12 weeks - from baseline to end of study | 
| Supar | Change in Supar | 12 weeks - from baseline to end of study | 
| CRP | Change in CRP | 12 weeks - from baseline to end of study | 
| IL-1 | Change in IL-1 | 12 weeks - from baseline to end of study | 
| IL-6 | Change in IL-6 | 12 weeks - from baseline to end of study | 
| IL-8 | Change in IL-8 | 12 weeks - from baseline to end of study | 
| TNF-alpha | Change in TNF-alpha | 12 weeks - from baseline to end of study |