Type 1 Diabetes Management Using a Very Low Carbohydrate Versus Standard Diet

Not Applicable

Recruiting

• Conditions: Type1diabetes
• Interventions: Other: standard carbohydrate diet; Other: very low carbohydrate diet

• Registration Number: NCT03710928
• Lead Sponsor: Boston Children's Hospital

Brief Summary

Despite major technological advances, management of type one diabetes mellitus (T1D) remains suboptimal, putting millions of people at risk for immediate and long-term complications. After meals, a mismatch between carbohydrate absorption rate and insulin action typically leads to alternating periods of hyper- and hypoglycemia. A conceptually promising approach to control both problems is dietary carbohydrate restriction to reduce postprandial blood glucose changes and insulin needs. In a prior survey study, the investigators documented exceptional glycemic control (HbA1c 5.67%) and low acute complication rates among 316 children and adults with T1D consuming a very-low-carbohydrate diet.

To test the feasibility of this approach, the investigators will conduct a randomized-controlled feeding study involving 32 adults and adolescents with T1D. Participants will be randomized to receive a very low carbohydrate vs. standard carbohydrate diet. Participants will be in the study for 12 weeks and receive all their meals by meal delivery.They will share continuous glucose monitoring data with the study team and be in close communication to adjust insulin doses as needed. All participants will have a screening visit, an individual or group education session, and 3 study visits to evaluate diabetes control and metabolic health. Some of these visits will have a fasting blood draw. Two of the visits will also comprise additional metabolic studies to assess glucagon response and brain function during hypoglycemia by magnetic resonance imaging (MRI). Participants will have IV catheters placed and receive IV insulin to drop blood glucose levels to 50 mg/dl for up to 30 minutes. The primary outcome will be HbA1c change from baseline. Secondary outcomes include detailed measures of glycemic variability, metabolic health, and quality of life.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2018-10-16
• Study First Submitted QC: 2018-10-17
• Study First Posted: 2018-10-18
• Study Start: 2020-01-03
• Status Verified: 2024-12
• Last Update Submitted: 2024-12-16
• Last Update Posted: 2024-12-18
• Primary Completion: 2026-07-31
• Study Completion: 2026-07-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 32

Inclusion Criteria

• Males and females with T1D for at least 1 year
• Age 18 to 40 years
• Tanner stage ≥ IV
• BMI 18.5-35 kg/m2
• Stable glycemic control (HbA1c 6.5-9%)
• Use of a continuous glucose monitor (CGM)
• Use of an insulin pump
• Attendance of at least 1 diabetes care visit over the past 12 months (including virtual)

Exclusion Criteria

• Ketoacidosis or severe hypoglycemia with seizure or coma in the past 6 months

• Dietary restrictions or intolerances that are incompatible with the planned food deliveries, e.g. celiac disease, gastroparesis, certain food allergies

• Following a weight-loss or otherwise restrictive diet

• Vigorous exercise >2 hours on >3 days a week

• History of an eating disorder or at risk for eating disorder, assessed by the Eating Disorders Diagnostic Scale (EDDS)

• Major medical illness or use of medications other than insulin and metformin that could interfere with metabolic or glycemic variables

• Significant psychiatric illness

• Smoking, use of recreational drugs, or excessive alcohol consumption

• Pregnancy or breastfeeding

• Anemia

• For participants who undergo MRI:

  1. Standard MRI exclusion criteria
  2. Irregular menses
  3. Use of psychotropic medication other than SSRIs or other mild antidepressant or anxiety medications (unless these medications are safe to be held for several days to allow for the acquisition of MRI data)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
standard diet	standard carbohydrate diet	Dietary Intervention, food delivery
very low carbohydrate diet	very low carbohydrate diet	Dietary Intervention, food delivery

Primary Outcome Measures

Name	Time	Method
Hemoglobin A1C change	12 weeks - baseline	HbA1C change from baseline at 12 weeks will be compared between the 2 interventions

Secondary Outcome Measures

Name	Time	Method
percent time spent in hyperglycemia	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
blood glucose average	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
total daily insulin dose	week 0 and 12	average daily insulin dose over 1 week will be calculated
percent time spent below the glycemic target of 70 mg/dl	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
percent time spent in the glycemic target range of 70-140 mg/dl	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
fasting low density lipoprotein cholesterol	week 0 and 12	from venous blood
Self-reported quality of life assessed per self-report by The Problem Areas in Diabetes Scale (PAID)	week 0, 6, and 12	The scores for each item are summed, then multiplied by 1.25 to generate a total score out of 100.
Becks Depression Inventory II (BDI II) less suicidality	week 0, 6, and 12	BDI-II less suicidality is a 20-item self-report inventory that measures assesses for presence and severity of depression depressive symptoms. Each item is scored between 0-3. Item scores are added up to a total score (max. 60) and reported.
Yale Food Addiction Scale 2.0 (YFAS 2.0)	week 0, 6, and 12	Assesses indicators of addictive-like eating.The YFAS includes two scoring options: 1) a "symptom count" that reflects the number of addiction-like criteria endorsed and 2) a dichotomous "diagnosis" that indicates whether a threshold of three or more "symptoms" plus clinically significant impairment or distress has been met. The diagnosis score will be calculated at baseline and used as an effect modifier. Symptom counts will be reported separately as a longitudinal measure.
percent time in hypoglycemia below 54 mg/dl	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
percent time spent above the glycemic target of 140 mg/dl	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
blood glucose standard deviation	week 0 and 12	will be calculated from 1-week continuous glucose monitoring data
Mean Amplitude of Glycemic Excursions (MAGE), a measure for postprandial glycemic variability	week 0 and 12	will be calculated by dividing blood glucose standard deviation by blood glucose average
fasting high density lipoprotein cholesterol	week 0 and 12	from venous blood
fasting beta hydroxybutyrate	weeks 0, 1, 2, 4, 6, 9, 12	from venous blood and/or point-of-care testing
Glycemic Variability Index, a measure for glycemic variability normalized to mean blood glucose level	week 0 and 12	will be calculated by dividing blood glucose standard deviation by blood glucose average
fasting total cholesterol	week 0 and 12	from venous blood
fasting triglycerides	week 0 and 12	from venous blood
fasting high-sensitivity c-reactive protein	week 0 and 12	from venous blood
Highly Processed Food Withdrawal Scale (ProWS)	Baseline, daily on days 1-7, then weekly; primary focus on change from baseline to day 7	Assesses withdrawal-type symptoms that may occur when individuals cut down on rewarding foods.

Trial Locations

Locations (1)

Boston Children's Hospital; 🇺🇸 Boston, Massachusetts, United States