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Trial record 1 of 1 for:    20644946 [PUBMED-IDS]
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Full-fat Yogurt and Glucose Tolerance

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ClinicalTrials.gov Identifier: NCT03577119
Recruitment Status : Recruiting
First Posted : July 4, 2018
Last Update Posted : July 4, 2018
Sponsor:
Collaborator:
National Dairy Council
Information provided by (Responsible Party):
Jana Kraft, University of Vermont Medical Center

Brief Summary:
This study determines if substituting full-fat yogurt (i.e., whole, 3.25% fat) for non-fat yogurt in the diet can reduce the risk of type 2 diabetes and inflammation in association with changes in the composition of the gastrointestinal bacteria prediabetic male and female volunteers. The central hypothesis is that dairy fat impacts whole body glucose handling and insulin sensitivity as well as inflammation both directly, and indirectly via influencing the gut microbiota composition.

Condition or disease Intervention/treatment Phase
Pre-Diabetes Dietary Supplement: Full-fat yogurt Dietary Supplement: Non-fat yogurt Not Applicable

Detailed Description:

The overall objective of this study is to determine if substituting full-fat yogurt (i.e., whole, 3.25% fat) for non-fat yogurt in the diet can i) improve whole body glucose handling and insulin sensitivity, ii) modulate systemic inflammation, and iii) induce putatively beneficial changes in the composition of the colonic microbiota in prediabetic men and women. By comparing a diet containing non-fat yogurt with a diet comprising of full-fat yogurt, the investigators will address the following specific hypotheses and aims:

Hypothesis 1: Dietary intake of full-fat yogurt will improve fasting and postprandial markers of glucose homeostasis, insulin sensitivity, and pancreatic cell function. Aim 1: Evaluating the diet-induced changes in blood glucose and endogenous insulin secretion. This will be assessed through a mixed meal tolerance test and oral glucose tolerance test.

Hypothesis 2: Dietary intake of full-fat yogurt will relatively reduce systemic inflammation. Aim 2: Examine diet-induced changes in inflammatory tone. This will be assessed through measurements of circulating (plasma) pro- and anti-inflammatory cytokines, cytokine production assays from in vitro-stimulated peripheral blood mononuclear cells, and plasma stimulated cytokine production in immortalized human cell lines.

Hypothesis 3: A diet containing full-fat yogurt will alter the colonic bacteria structure (e.g. decrease the Firmicutes/Bacteroidetes ratio). Aim 3: Characterize diet-induced alterations in colonic bacteria structure (composition and density) via next-generation sequencing and real-time Polymerase Chain Reaction Assays (PCR).

This study recruits 32 pre-diabetic female and male volunteers (50:50) aged 50-65 using a double-blinded, randomized crossover design to compare two experimental diets, 1) a low-fat diet containing fat-free yogurt (total fat: 28% energy), and 2) a higher fat diet consisting of whole 3.25% fat yogurt (total fat: 38% energy). Fat in the whole yogurt accounts entirely for the arithmetic difference in fat of 10% energy between the two diets. The study will consist of two 21-day experimental diet periods preceded by a 7-day control diet. The total length of study will be 8 weeks. The diet during the control diet periods will be an average U.S. diet to establish a normalized fatty acid intake among the subjects and to standardize the subject's physiologic state before each experimental diet. At the end of the first control period ("run-in") and at the end of each of the experimental diets, a mixed meal tolerance test and an oral glucose test will be performed to assess diet-induced changes in whole-body glucose handling and insulin sensitivity. In addition, blood and stool samples will be collected to examine diet-induced alterations in inflammatory tone and gastrointestinal microflora.


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 32 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: This study will employ a controlled, randomized, double-blinded crossover trial comparing two diets.
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Full-fat Yogurt and Glucose Tolerance
Actual Study Start Date : June 1, 2018
Estimated Primary Completion Date : June 1, 2020
Estimated Study Completion Date : June 1, 2021

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Prediabetes

Arm Intervention/treatment
Experimental: Full-fat yogurt
Participants will receive a 21-day controlled diet that includes three daily servings of whole (3.25% fat) yogurt (38% of energy from fat, 44% of energy from carbohydrates, and 18% of energy from protein).
Dietary Supplement: Full-fat yogurt
Controlled diet that includes three daily servings of whole (3.25% fat) yogurt.

Experimental: Non-fat yogurt (Control)
Participants will receive a 21-day controlled diet that includes three daily servings of fat-free yogurt (28% of energy from fat, 54% of energy from carbohydrates, and 18% of energy from protein).
Dietary Supplement: Non-fat yogurt
Controlled diet that includes three daily servings of fat-free yogurt.




Primary Outcome Measures :
  1. Changes in insulin sensitivity and β-cell function: MMTT [ Time Frame: Baseline, 4 weeks, and 8 weeks ]
    Evaluated through mixed meal tolerance test (MMTT) prior to and post experimental diets. Tests will be quantified using the area under the curve (AUC) of the temporal changes in blood glucose, insulin, C-peptide, and incretins (GLP-1 and GIP) using fasting and serial postprandial blood samples. All measurements will be reported as mol/L.

  2. Changes in insulin sensitivity and β-cell function: OGTT [ Time Frame: Baseline, 4 weeks, and 8 weeks ]
    Evaluated through oral glucose tolerance test (OGTT) prior to and post experimental diets. Tests will be quantified using the area under the curve (AUC) of the temporal changes in blood glucose, insulin, C-peptide, and incretins (GLP-1 and GIP) using fasting and serial postprandial blood samples. All measurements will be reported as mol/L.


Secondary Outcome Measures :
  1. Changes in inflammatory markers [ Time Frame: Baseline, 4 weeks, and 8 weeks ]
    Evaluated through measurements of circulating (plasma) pro- and anti-inflammatory cytokines, cytokine production assays from in vitro-stimulated peripheral blood mononuclear cells, and plasma stimulated cytokine production in immortalized human cell lines prior to and post experimental diets. Inflammatory markers that will be measured are: interleukins 1beta, 6, 8, and 10 (IL-1beta, IL-6, IL-8, and IL-10), and tumor necrosis factor alpha (TNFalpha). All measurements will be reported as pg/mL.

  2. Changes to Colonic microbiota structure: density [ Time Frame: Baseline, 4 weeks, and 8 weeks ]
    Evaluated through analysis of colonic bacteria structure (composition and density) of specific colonic microbiota prior to and post experimental diets. Density of colonic bacteria will be measured in log copies/ug feces.

  3. Changes to Colonic microbiota structure: relative abundance [ Time Frame: Baseline, 4 weeks, and 8 weeks ]
    Evaluated through analysis of colonic bacteria structure (composition and density) of specific colonic microbiota prior to and post experimental diets. Relative abundance of Taxa of colonic bacteria will be reported as a percentage (%).



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   50 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Men and women and not expecting major lifestyle changes while on study
  • Age 50-65
  • Overweight and obesity (BMI 25-39.9 kg/m2)
  • Stable body weight for the last 6 months (no more than a +/- 5% change)
  • Diagnosis of prediabetes, defined as either impaired fasting glucose (fasting glucose: 100-125 mg/dL), impaired glucose tolerance (blood glucose levels of between: 140-199 mg/dL 2-hr post 75-g oral glucose tolerance test), and/or a hemoglobin A1C (HbA1C) level ranging from 5.7% to 6.4%
  • Women: Post-Menopausal: no menses previous 12 mos.; Follicular Stimulating Hormone (FSH) > 20 mIU/mL
  • Consuming at least 25% of calories from fat (screening will be based an online fat screener:

http://nutritionquest.com/wellness/free-assessment-tools-for-individuals/fat-intake-screener/

  • Normal cognition
  • Read and understand English
  • Have a telephone
  • Willing to follow the study coordinator's/manager's and dietitian's instructions

Exclusion Criteria:

  • History of type 1 or type 2 diabetes
  • Fasting blood glucose ≥126 mg/dL, HbA1C ≥6.5%
  • Subject with any chronic disease, inflammatory disease (e.g., asthma, rheumatoid arthritis, Crohn's disease or inflammatory bowel disease) and previous diagnosis of HIV or hepatitis C
  • Pregnant or breastfeeding women or women on hormone replacement therapy (for previous 3 months)
  • Intolerance to dairy foods (i.e., lactose intolerance or protein allergy), food allergies, or significant food preferences, dietary restrictions (vegetarian, vegan lifestyle), or food aversions that would interfere with diet adherence
  • History of a diagnosed eating disorder
  • Known/diagnosed gastrointestinal problems (e.g., inflammatory bowel disease, irritable bowel syndrome, etc.)
  • Antibiotics use during the past 6 months
  • Habitual use of tobacco or controlled substances, and dietary supplements during the study and 1 month prior to the study
  • On medically prescribed diets or following a diet (e.g., to lose weight) or use of obesity or weight-loss treatments such as dietary interventions or pharmacotherapy
  • Chronic anti-inflammatory medications, or frequent use (>25% of the time) of over-the-counter medication including laxatives and antacids (subjects with occasional use of allergy or cold medicine, NSAIDS, acetaminophen, or aspirin will be recruited, but these drugs will not be permitted during the study, except for acute administration up to 3 days prior to the outcome variables).
  • Waist circumference >40 inches in men and >35 inches in women
  • Current diagnosis of uncontrolled hypertension (systolic BP: >160mmHg, diastolic BP: >95mmHg), (may receive treatment for hypertension as long as 1) on a stable regime for the previous 6 wk, and 2) no anticipated change while on the study)
  • Untreated hyperlipidemia [may receive treatment for hyperlipidemia (statins) as long as 1) on a stable regime for the previous 6 wk, and 2) no anticipated change while on the study)
  • Participation on regular basis in competitive sports or habitual aerobic exercise training, which we will arbitrarily define a consisting of > 3 bouts/wk of aerobic exercise (unable to speak comfortably) for more than 20 min
  • Lifestyle or schedule incompatible with the study protocol
  • Psychiatric or behavioral conditions that in the view of the principal investigator may present a safety hazard to the participant or interfere with study participation or the ability to follow the intervention protocol

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03577119


Contacts
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Contact: Jana Kraft, PhD 802-656-5489 jana.kraft@uvm.edu
Contact: Dana E Bourne, B.S., MPH 802-656-9422 debourne@uvm.edu

Locations
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United States, Vermont
Clinical Research Center, University of Vermont Medical Center Recruiting
Burlington, Vermont, United States, 05401
Contact: Kimberly Luebbers, MSHS    802-656-8990    Kimberly.Luebbers@med.uvm.edu   
Contact: Joan Bertolet    (802) 847-4874    joan.bertolet@uvmhealth.org   
Sponsors and Collaborators
University of Vermont Medical Center
National Dairy Council
Investigators
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Principal Investigator: Jana Kraft, PhD University of Vermont

Publications:
Li, S., Field, A., Rimm, E. & Flint, A. Dairy consumption with onset of overweight and obesity among U.S. adolescents. FASEB J 28, 370.7 (2014).
Keeney, M. K., Katz, I. & Allison, M.J. On the probable origin of some milk fat acids in rumen microbial lipids. J Am Oil Chem Soc 39, 198-201 (1962).
Ferdinand, K. C. et al. Health economics of cardiovascular disease: Defining the research agenda. CVD Prev Control 6, 91-100 (2011).
Walsh, H. H., H.; Cersosimo, L.; Kien, C.L.; Kraft, J. Decreased abundance of firmicutes in the gut microbiota after consumption of a diet containing milk fats. FASEB J 30, 683.611 (2016).

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Responsible Party: Jana Kraft, Principal Investigator, University of Vermont Medical Center
ClinicalTrials.gov Identifier: NCT03577119     History of Changes
Other Study ID Numbers: 18-0295
First Posted: July 4, 2018    Key Record Dates
Last Update Posted: July 4, 2018
Last Verified: July 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Jana Kraft, University of Vermont Medical Center:
Prediabetes
Glucose Tolerance
Bioactive fatty acids
Insulin sensitivity
Diet
Milk fat
Lipid metabolism
Inflammation markers
Fecal microbiota composition
Dairy

Additional relevant MeSH terms:
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Prediabetic State
Glucose Intolerance
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hyperglycemia