Clinical trial NCT04082884: Very Low Carbohydrate Diet as an Adjunctive Therapy for Youth Type 1 Diabetes
Official title: Very Low Carbohydrate Diet as an Adjunctive Therapy for Youth Type 1 Diabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Type 1 Diabetes
Keywords: very low carbohydrate diet
Lead sponsor: Yale University
Sponsor class: OTHER
Collaborators: name: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
First posted: 2019-09-09
Enrollment: 6
Sex: ALL
Minimum age (years): 13
Maximum age (years): 25
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SEQUENTIAL
Intervention model description: Following enrollment, participants will follow a standard carbohydrate diet for 2 weeks. They will then undergo a 1 week transition followed by 2 weeks on a higher protein very low carbohydrate diet that is then followed by 2 weeks on a higher fat very low carbohydrate diet.
Primary purpose: TREATMENT

Brief summary: This prospective, open-label pilot/feasibility study of 10 youth with T1D is to evaluate glycemic and metabolic changes taking place with a very low carbohydrate diet.

Detailed description: First, to evaluate the feasibility of following each type of VLCD (high protein or high fat), participants will follow a standard carbohydrate diet for 2 weeks, followed by a 1 week transition to a VLCD, and then follow the a high protein VLCD for 2 weeks followed by a high fat VLCD for 2 weeks. The study will consist of 4 in person or virtual visits which will take place over \~7 weeks. All participants will be initially studied for 2 weeks while ingesting a standard diet recommended by the American Diabetes Association, followed by a 1-week transition to a VLCD, and followed by 2 weeks on each type of VLCD (high protein, high fat). During the first (baseline) period fasting β-hydroxybutyrate levels will be measured 2-3 times per week. During the VLCD study periods, fasting β-hydroxybutyrate levels will be measured daily in the morning using a blood ketone meter; insulin doses will be collected using insulin pump downloads and continuous glucose monitoring (CGM) profiles will be used to assess glycemic excursions on each diet, as well as the time in hypo-, eu- and hyperglycemic ranges. The purpose of this study is to examine changes in sensor glucose levels, basal and bolus insulin doses, and metabolic factors following implementation of a very low carbohydrate diet (VLCD). Sensor-derived time glucose ranges will serve as a surrogate marker of hemoglobin A1c given the short duration of the study. Safety measures of the diet will also be assessed, including daily fasting ketone levels.

The first hypothesis of the study is that use of a VLCD with strict monitoring of ketosis will reduce glycemic variability and increase time in target range, defined as 70-180 mg/dL by reducing the time in the hyperglycemic (\>180 mg/dL) and hypoglycemic ranges (\<70 mg/dL). Decreased carbohydrate intake will lead to less postprandial hyperglycemia. Lower insulin doses for meals and snacks as a result of decreased carbohydrate intake will lessen postprandial hypoglycemia as well.

Eligibility criteria: Inclusion Criteria:

* BMI 19-30 m2 for individuals at least 18 years old or BMI \< 95 percentile for individuals less than 18 years old
* Participants 18 years of age must be able to read and provide written consent
* Participants under 18 years of age must be able to read and provide written assent
* Participants are managed using an insulin pump or injections
* Participant has or is willing to wear a CGM for the duration of the study
* Participant is willing to complete diet logging procedures stated above

Exclusion Criteria:

* A1c \< 6.5% or \> 10%
* Recent history of more than 1 of diabetic ketoacidosis (DKA) in the past 6 months
* Treatment with glucose-lowering drugs other than insulin
* Unstable psychiatric disorders, including eating disorders (DSM-V criteria)
* Weight loss medications within the last 6 months
* Females who are pregnant, lactating or planning to become pregnant in the next 6 months
* Another medical condition that precludes participation in the study

Primary outcomes:
measure: Percentage of Time in Target Range of 70-180 mg/dL.
timeFrame: 2 weeks per intervention, up to 7 weeks
Secondary outcomes:
measure: Percentage of Time Spent > 180 mg/dL to 250 mg/dl
timeFrame: 2 weeks per intervention, up to 7 weeks
measure: Percent Time Spent > 250 mg/dL Based on Sensor-derived Glucose Values
timeFrame: 2 weeks per intervention, up to 7 weeks
measure: Percent of Time Spent > = 55 to < 70 mg/dL Based on Sensor-derived Glucose Values
timeFrame: 2 weeks per intervention, up to 7 weeks
measure: Percent Time Spent < 55 mg/dL Based on Sensor-derived Glucose Values
timeFrame: 2 weeks per intervention, up to 7 weeks
measure: Total Daily Insulin Dose
timeFrame: 2 weeks per intervention, up to 7 weeks
measure: Average Sensor Glucose Level
timeFrame: 2 weeks per intervention, up to 7 weeks
Other outcomes:
Locations:
city: New Haven
country: United States
facility: Yale-New Haven Hospital
state: Connecticut
Study officials:
References: