Prediabetes (Insulin Resistance, Impaired Glucose Tolerance)
Conditions
Brief summary
The primary purpose of this study is to determine the sex-specific metabolic and molecular response, among adults with prediabetes, when moving from a Western Diet to plant-based diet.
Detailed description
Plant-based diets that are abundant in myoinsitol and D-chiro inositol (MI and DCI) increase insulin sensitivity by promotion of insulin signaling lowering serum insulin and improving insulin resistance. The Western diet contributes to chronic metabolic inflammation often leading to the development of metabolic diseases. There is known metabolic improvement among men compared to women when following a plant-based diet or intensive lifestyle modifications. Through this study we look to identify the pathways in which plant-based diet impact skeletal muscle inositol metabolites among sexes (men vs. women) and improve insulin sensitivity.
Interventions
OTHERPlant-based diet
Standard plant-based meals will be provided directly to participants. The dietary intervention will begin with a one-week Western diet run-in; hereafter, participants will consume plant-based meals for approximately 5 weeks. Total energy provided will be equal to REE X 1.4 to account for light physical activity to support weight maintenance. High-inositol snacks will be provided to meet energy needs. Meals and snacks combined will provide a minimum of 20mg total inositol/kg body weight. For example, a 200lb participant will consume 1.8g daily, which is consistent with doses used in prior studies.
Sponsors
Jean L. Fry
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
30 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
* Body mass index greater than or equal to 27 * High waist circumference (women greater than or equal to 35; men greater than or equal to 40) * Prediabetes (based on fasting glucose 100-125 mg/dL, HbA1c 5.7-6.4, or 2-hr post-oral glucose tolerance test glucose screen between 140-199mg/dL) * Physical activity below national guidelines * Aged 30-55 (premenopausal for women) * Following a Western diet
Exclusion criteria
* Diabetes diagnosis * Take medications that may affect insulin sensitivity * More than 5% weight change within 6 months of screening * History of bariatric surgery * Report any dietary supplement, medication, or medical condition known to significantly affect weight or metabolism * Take hormone replacement therapy * Consume 3 or more servings of combined fruit and vegetables daily and/or 3 or more servings of whole grains daily * Any food allergy more severe than grade 1 on the CoFAR Grading Scale for Systemic Allergic Reactions, Version 3.0 or allergy to lidocaine
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin sensitivity (glucose infusion rate) | The first measure is taken immediately after the run-in and the final measure will be taken immediately after the completion of the plant-based diet intervention five weeks later. | This gold standard test for IS will be performed at baseline and post-intervention with support of the COBRE Phenotyping core. After ≥8 hour fast, participants will be admitted to our Center for Clinical and Translational Science (CCTS) and two IVs inserted; one for infusion, the other for blood draws (see Phenotyping core). The primary outcome is the glucose infusion rate (GIR), a direct measure of whole body IS, which will enable us to detect even small changes in IS in response to the intervention. COBRE mentor Dr. Kern is proficient in use of these methods The primary clinical outcome is the change in GIR from post run-in to post intervention. |
| Skeletal muscle d-chiroinositol content | The first measure is taken immediately after the run-in and the final measure will be taken immediately after the completion of the plant-based diet intervention five weeks later. | Muscle samples will be homogenized, then inositol compounds will be extracted using solvents. In the prepared samples, D-chiroinositol content will be assessed by a commercial service using LC-MS/MS. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Phosphorylation status of insulin signaling molecules in skeletal muscle | The first measure is taken immediately after the run-in and the final measure will be taken immediately after the completion of the plant-based diet intervention five weeks later. | Upon insulin stimulation, insulin-responsive signaling proteins are phosphorylated to initiate downstream effects. The ratio of phosphorylated and unphosphorylated, as well as total protein, per standard unit of skeletal muscle will be determined. |
| Absolute change in visceral fat (g) | The first measure is taken immediately after the run-in and the final measure will be taken immediately after the completion of the plant-based diet intervention five weeks later. | Computed tomography will be used to measure visceral fat |
| Fasting blood glucose | The first measure is taken immediately after the run-in and the final measure will be taken immediately after the completion of the plant-based diet intervention five weeks later. | Baseline measure of fasting blood glucose are measured via YSI before the start of the OGTT |
Countries
United States
Outcome results
None listed