Grains Reduce Adiposity and Improve Nutrition Study (GRAIN)

This study has been completed.
Sponsor:
Collaborator:
General Mills Inc.
Information provided by (Responsible Party):
Penny Kris-Etherton, Penn State University
ClinicalTrials.gov Identifier:
NCT00924521
First received: June 18, 2009
Last updated: November 29, 2012
Last verified: November 2012
  Purpose

Whole grain intake beneficially affects body weight, body fat and glucose metabolism, and the investigators' previous work has shown that a high whole grain intake significantly reduced body fat in the abdominal region as measured by dual energy X-ray absorptiometry (DEXA) compared to a refined grain intake. Additional research is needed with regard to the mechanisms by which whole grains may affect visceral adiposity and the adipokines, which have been associated with risk for insulin resistance and type 2 diabetes. Therefore the proposed study aims to address these issues and in addition, includes exploratory work with adipocytes in cell culture to evaluate the effects of whole grains on adipocyte function.

Hypothesis:

There will be a greater reduction in visceral adiposity, indicators of insulin resistance (HOMA score), improvement in inflammatory status and improvement in adipokine levels after six weeks of a weight stable period and after six weeks of weight loss in subjects consuming 6-9 servings compared to 0 servings of whole grains per day.


Condition Intervention
Metabolic Syndrome
Insulin Resistance
Dietary Supplement: Whole grain diet
Dietary Supplement: Refined grain

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Grains Reduce Adiposity and Improve Nutrition Study (GRAINS) Increased Whole Grain Intake - Beneficial Effects on Visceral Adiposity, Vascular Function and Glucose Metabolism/Insulin Resistance

Resource links provided by NLM:


Further study details as provided by Penn State University:

Primary Outcome Measures:
  • Body Composition [ Time Frame: Week 6 and 12 - End of diet period 1 and 2 ] [ Designated as safety issue: No ]
    To assess regional changes in body fat deposition, subjects will undergo a dual energy X-ray absorptiometry (DXA) scan at baseline (beginning of study) and end of each intervention period. Waist circumference measurements also will be taken at this time to track how much fat is lost from the abdominal area of the body.


Secondary Outcome Measures:
  • Fasting glucose [ Time Frame: Time 0, week 6 and week 14 - Baseline end of each diet period ] [ Designated as safety issue: No ]
    Twelve-hour fasting blood samples (30ml) will be collected for analyses of plasma glucose levels.

  • Plasma cytokines [ Time Frame: Week 0, week 6 and week 14 - Baseline end of each diet period ] [ Designated as safety issue: No ]
    Twelve-hour fasting blood samples (30ml) will be collected for analyses of plasma C-reactive protein and inflammatory cytokines. Blood samples obtained at baseline will be used to measure baseline values for study endpoints, whereas blood samples obtained at the end of each diet period will measure final endpoint values.

  • Endothelial Health [ Time Frame: Week 0, week 6 and week 14 - Baseline end of each diet period ] [ Designated as safety issue: No ]
    Study subjects will undergo endothelial health assessment by EndoPAT analysis. The EndoPat procedure will occur while the subject is lying down in a relaxed state. Throughout the study, the inflation pressure of the EndoPAT device will be electronically set to 10mm Hg below diastolic BP. Testing begins with 10 min of rest. Following rest, baseline pulse amplitude is measured from each fingertip for 5 min. Next, arterial flow is interrupted for 5 min by a cuff placed on the forearm at an occlusion pressure of 250 mmHg. Following occlusion release, pulse amplitude recording continues for 5 min.

  • Resting Metabolic Rate [ Time Frame: Week 0 and week 14 - Baseline and end of diet period 2 ] [ Designated as safety issue: No ]
    The COSMED Fitmate is a state-of-the-art resting metabolic rate machine that takes accurate, quick readings of your oxygen use. Participants will lie quietly without moving for 30 minutes upon arrival. A mask will be placed around the nose and mouth and participant will be asked to remain still for another 15 min will resting metabolic rate is measured. The test provides valuable information about how much energy (calories) an individual burns in a 24-hour period. The test will take ~15 min to complete.

  • Appetite Hormones [ Time Frame: Week 0, week 6 and week 14 - Baseline end of each diet period ] [ Designated as safety issue: No ]
    Twelve-hour fasting blood samples (30ml) will be collected to assess changes in plasma appetite hormones across the two diet periods.

  • Abdominal obesity [ Time Frame: Week 14 - End of diet period 2 ] [ Designated as safety issue: No ]
    A subset of subjects will undergo magnetic resonance imaging (MRI) scans in the abdominal region by standard protocols. Subjects will be placed in a prone position in the magnet with their arms stretched above their head. A series of 40-47 T1-weighed axial spin echo images, will be taken in the abdominal region using established body landmarks. Body compartment volumes for total abdominal and visceral adipose tissue, as well as muscle, will then be obtained by tissue integration analysis.


Enrollment: 54
Study Start Date: March 2009
Study Completion Date: August 2011
Primary Completion Date: April 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Refined grain
Participants in this group will receive only refined grains as typically consumed in the average American diet.
Dietary Supplement: Refined grain
Participants in this group will receive only refined grains as typically consumed in the average American diet.
Experimental: Whole grain diet
Participants in this group will receive 6-9 servings of whole grain daily to replace the refined grains typically included in the average American diet. Number of servings will depend upon calorie assignment.
Dietary Supplement: Whole grain diet
Participants in this group will receive 6-9 servings of whole grain daily to replace the refined grains typically included in the average American diet. Number of servings will depend upon calorie assignment.

Detailed Description:

Including whole grains as part of a heart-healthy diet has been shown to be beneficial in decreasing body weight and body fat. The beneficial effects of whole grains on body weight may be explained by the larger volume and relatively low energy density of whole grain food thus leading to increased satiation. Reducing visceral fat is of particular importance as visceral adiposity has been associated with increased risk for metabolic diseases and cardiovascular disease.

The proposed study is a randomized, 2-parallel arm controlled feeding study. Subjects will be fed one of two weight maintenance diets (refined grain and whole grain) for 6 weeks, followed by a 6 week controlled weight loss period where subjects are fed the same diets, but at a reduced calorie level, designed to elicit weight loss (~2 lbs per week). Diets for both groups will have the same nutrient profile (percent of calories from fat, protein, carbohydrates, etc.); however, the whole grain (WG) group will substitute whole grains for refined grains in their grain intake (breads, tortillas, cereals, etc.). The WG group will be expected to take in 6-9 servings of whole grains per day on both diets. Plasma endpoints will be measured at baseline and at the end of the 6-week diet periods. Blood samples also will be taken at the mid-point of each period and held for analysis if deemed appropriate after initial data is reviewed. Endo-PAT will be conducted at baseline and at the end of each diet period as well as DEXA and MRI testing.

  Eligibility

Ages Eligible for Study:   35 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • BMI > 25 to < 42
  • Waist circumference of > 40 inches for males and > 35 inches for females and having one other of the criteria for metabolic syndrome will be recruited
  • In this population, we will also accept the following:

    • LDL-C < 175 mg/dL
    • HDL-C > 25 mg/dL
    • Triglycerides < 400 mg/dL
  • All subjects will be required to meet one specific criteria for metabolic syndrome beyond increased waist circumference

Exclusion Criteria:

  • Smokers
  • Have insulin-dependent diabetes
  • Are pregnant or expecting to be pregnant, lactating in the last 6 months
  • Are taking NSAIDS or other medications known to affect inflammatory markers or drugs affecting glucose metabolism

Blood pressure lowering medications are acceptable if the person has controlled BP at screening, <140/90 mmHg.

  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00924521

Locations
United States, Pennsylvania
Penn State University
University Park, Pennsylvania, United States, 16802
Sponsors and Collaborators
Penn State University
General Mills Inc.
Investigators
Principal Investigator: Penny M Kris-Etherton, PhD Penn State University
  More Information

Publications:
Responsible Party: Penny Kris-Etherton, Distinguished Professor of Nutrition, Penn State University
ClinicalTrials.gov Identifier: NCT00924521     History of Changes
Other Study ID Numbers: PKE GRAIN
Study First Received: June 18, 2009
Last Updated: November 29, 2012
Health Authority: United States: Institutional Review Board

Keywords provided by Penn State University:
grains
fiber
metabolic syndrome
insulin

Additional relevant MeSH terms:
Metabolic Syndrome X
Insulin Resistance
Syndrome
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Disease
Pathologic Processes

ClinicalTrials.gov processed this record on September 22, 2014