Clinical trial NCT04944316: Effect of a Dietary Intervention on Insulin Requirements in Type 1 Diabetes
Official title: Physicians Committee for Responsible Medicine - a Randomized, Controlled Study of the Effect of a Low-fat, Plant-based Diet on Insulin Requirements in Individuals with Type 1 Diabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diabetes Mellitus, Type 1
Lead sponsor: Physicians Committee for Responsible Medicine
Sponsor class: OTHER
First posted: 2021-06-29
Enrollment: 35
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to compare the effects of a low-fat, plant-based dietary intervention and a portion-controlled dietary intervention (compliant with current American Diabetes Association (ADA) guidelines) on the management of type 1 diabetes in adults. The primary outcome measure of this study is insulin requirements (measured as the total daily dose (TDD) of insulin or basal and bolus insulin units injected per day). The study duration is 12 weeks.

Detailed description: Type 1 diabetes is a chronic autoimmune disorder characterized by loss of β-cell mass and function in the pancreas, leading to reduced secretion of insulin and hyperglycemia. The management of type 1 diabetes requires the administration of exogeneous insulin. Total daily dose (TDD) of insulin, a measure of the total amount of exogeneous insulin utilized per day, can be affected by multiple factors including insulin resistance, carbohydrate intake, body weight, and body composition. While the pathogenesis of type 1 diabetes and type 2 diabetes differ, a low-fat, plant-based diet has been shown to reduce insulin resistance, reduce body weight, improve body composition, and improve glycemic control in individuals with type 2 diabetes. A low-fat, plant-based diet has also been shown to improve β-cell function in individuals who are overweight. This finding is consistent with other research that shows that therapies that reduce body fat, or modify the distribution of body fat, improve β-cell function and glucose homeostasis. To date, a low-fat, plant-based diet has never been adequately tested in adults with type 1 diabetes. The purpose of this study is to compare the effects of low-fat, plant-based dietary intervention and a portion-controlled dietary intervention (compliant with current American Diabetes Association (ADA) guidelines) on insulin requirements in adults with type 1 diabetes.

Using a parallel group design, participants with type 1 diabetes will be randomly assigned to follow a low-fat, plant-based diet or a portion-controlled diet (compliant with current ADA guidelines) for 12 weeks. The principal dependent measures of this study are TDD of insulin, hemoglobin A1c (HbA1c), interstitial fluid glucose levels, and 24-hour carbohydrate: insulin ratio. Secondary and tertiary dependent measures include inflammatory biomarkers, blood lipids, body weight, diet quality, diet acceptability, and medication use.

The investigators hypothesize that both the low-fat, plant-based dietary intervention and the portion-controlled dietary intervention will elicit changes in insulin requirements, HbA1c, variability in interstitial glucose levels, insulin sensitivity, and body weight in participants with type 1 diabetes. The investigators further hypothesize that the low-fat, plant-based dietary intervention will confer a more substantial effect on changes in insulin requirements, HbA1c, insulin sensitivity, variability in interstitial glucose levels, and body weight in participants with type 1 diabetes.

Eligibility criteria: Inclusion criteria:

1. Type 1 diabetes
2. Men and women ≥ 18 years of age
3. Stable insulin regimen for past 3 months

Exclusion criteria:

1. Type 2 or gestational diabetes
2. Body mass index ≥ 40 kg/m2
3. HbA1c ≥ 12.0%
4. Smoking or drug abuse during the past six months
5. Alcohol consumption of more than 2 drinks per day or the equivalent, episodic increased drinking (e.g., more than 2 drinks per day on weekends), or a history of alcohol abuse or dependency followed by any current use
6. Unstable medical or psychiatric illness
7. Already following a low-fat vegan diet
8. Pregnant or breastfeeding, or plans of pregnancy within the study period
9. Lack of English fluency
10. Unable or unwilling to participate in all components of the study
11. Evidence of an eating disorder

Primary outcomes:
measure: Total Insulin Dose
timeFrame: Change from week 0 to week 12
measure: Glycemic Control
timeFrame: Change from week 0 to week 12
measure: Glycemic Variability
timeFrame: Change from week 0 to week 12
measure: 24-hour Carbohydrate to Insulin Ratio
timeFrame: Change from week 0 to week 12
Secondary outcomes:
measure: Body Weight
timeFrame: Change from week 0 to week 12
measure: Concentration of Plasma Lipids
timeFrame: Change from week 0 to week 12
measure: High-sensitivity C-reactive Protein (hs-CRP)
timeFrame: Change from week 0 to week 12
measure: Tumor necrosis factor - α (TNF-α)
timeFrame: Change from week 0 to week 12
measure: Interleukin (IL) - 1 (IL-1) and interleukin-6 (IL-6)
timeFrame: Change from week 0 to week 12
measure: Food costs
timeFrame: 12 weeks
measure: Insulin costs
timeFrame: 12 weeks
Other outcomes:
measure: Medication Use
timeFrame: Change from week 0 to week 12
measure: Diet Quality
timeFrame: Change from week 0 to week 12
measure: Diet Acceptability
timeFrame: Change from week 0 to week 12
Locations:
city: Washington
country: United States
facility: Physicians Committee for Responsible Medicine
state: District of Columbia
Study officials:
affiliation: Physicians Committee for Responsible Medicine
name: Hana Kahleova, MD, PhD
role: PRINCIPAL_INVESTIGATOR
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