Effect of Dietary Macronutrient Composition

The recruitment status of this study is unknown because the information has not been verified recently.
Verified April 2012 by University of Texas Southwestern Medical Center.
Recruitment status was  Active, not recruiting
Sponsor:
Information provided by (Responsible Party):
Elizabeth Parks, University of Texas Southwestern Medical Center
ClinicalTrials.gov Identifier:
NCT01371396
First received: June 7, 2011
Last updated: April 20, 2012
Last verified: April 2012
  Purpose

The purpose of this study is to understand why Hispanics who are overweight have a higher incidence of fatty liver disease.


Condition Intervention
Metabolic Syndrome
Non-alcoholic Fatty Liver Disease
Obesity
Other: Low-fat diet
Other: Low-carbohydrate diet

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Effect of Dietary Macronutrient Composition on Liver Substrate Metabolism

Resource links provided by NLM:


Further study details as provided by University of Texas Southwestern Medical Center:

Primary Outcome Measures:
  • de novo lipogenesis [ Time Frame: Change from Baseline in fatty acid synthesis at 5 months ] [ Designated as safety issue: No ]
    In vivo measurement is made of liver fatty acid synthesis using stable isotope administration and analysis of plasma samples by GS/MS


Secondary Outcome Measures:
  • Dietary fatty acid clearance to liver [ Time Frame: Change from Baseline in dietary fat clearance at 5 months ] [ Designated as safety issue: No ]
    Using a dietary stable isotope we will quantitate fat absorption and recycling of fat through the liver.

  • Adipose fatty acid flux [ Time Frame: Change from Baseline in adipose fat flux at 5 months ] [ Designated as safety issue: No ]
    A stable isotope is infused and the rate of adipose fatty acid release is calculated after analyzing blood samples.


Estimated Enrollment: 24
Study Start Date: September 2007
Estimated Study Completion Date: June 2014
Estimated Primary Completion Date: June 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Hispanic subjects
Subjects will identify as Hispanic ethnicity.
Other: Low-fat diet
The subject will consume a diet that is calorically restricted to cause at least a 6% body weight loss over 4 months. Fat will make up less than 30% of dietary energy.
Other: Low-carbohydrate diet
The diet will be restricted in energy to cause at least a 6% loss of body weight over a 4 month period. Carbohydrate will provide less than 40% of total dietary energy.
African American subjects
Subjects will self-identify as African American in origin.
Other: Low-fat diet
The subject will consume a diet that is calorically restricted to cause at least a 6% body weight loss over 4 months. Fat will make up less than 30% of dietary energy.
Other: Low-carbohydrate diet
The diet will be restricted in energy to cause at least a 6% loss of body weight over a 4 month period. Carbohydrate will provide less than 40% of total dietary energy.

Detailed Description:

Obesity is a major factor driving the increased prevalence of hepatic steatosis in the US. However, little is known regarding the relationship between dietary intake and hepatic fat deposition or about the factors that promote loss of hepatic steatosis. Here, the investigators will determine how differences in dietary composition affect the development and regression of fatty liver. The investigators hypothesize that Hispanic subjects with metabolic syndrome will have higher liver fat synthesis rates compared to African American subjects.

Using detailed in vivo, serial measurements of fuel metabolism (GC/MS and NMR) fatty acid metabolism will be measured in the liver and periphery. This will be the first study in which these two methodologies are used together to assess both glucose and fatty acid metabolism in the same subjects. Subjects will be tested before and after a dietary weight-loss intervention producing 6% body weight loss over 5 months.

The specific aims are as follows:

AIM 1: Determine the contribution of peripheral and dietary fat to liver-TG in Hispanics and African Americans with metabolic syndrome.

Hypothesis: De novo lipogenesis will contribute to liver-TG in greater quantities compared to African Americans.

AIM 2: Determine the effects of low-CHO and low-fat diets on liver fat regression.

Hypothesis: Compared to a low-fat diet, a low-CHO diet will markedly decrease markers of inflammation coincident with greater improvements in insulin sensitivity as assessed by an intravenous glucose tolerance test.

  Eligibility

Ages Eligible for Study:   20 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Elevated serum ALT or metabolic syndrome
  • African American or Hispanic
  • Nondiabetic
  • Men or women
  • Smokers and nonsmokers
  • Pre- and post-menopausal (+/- HRT)
  • Stable body weight
  • Age 20-65 years
  • BMI between 25-45 kg/m2

Exclusion Criteria:

  • Diabetes or Pregnancy
  • Ethanol intake: males > 140 g/week, females > 70 g/week
  • Chronic hepatitis B or chronic hepatitis C
  • Hemochromatosis or Wilson's Disease
  • Autoimmune hepatitis or primary biliary cirrhosis
  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: NCT01371396

Locations
United States, Texas
Center for Human Nutrition
Dallas, Texas, United States, 75390-9052
Sponsors and Collaborators
University of Texas Southwestern Medical Center
Investigators
Principal Investigator: Elizabeth J Parks, PhD UTSW Medical Center
  More Information

Publications:
Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Elizabeth Parks, Associate Professor, University of Texas Southwestern Medical Center
ClinicalTrials.gov Identifier: NCT01371396     History of Changes
Other Study ID Numbers: 5RL-1DK081187
Study First Received: June 7, 2011
Last Updated: April 20, 2012
Health Authority: United States: Institutional Review Board

Keywords provided by University of Texas Southwestern Medical Center:
Metabolic syndrome
Non-alcoholic fatty liver disease
Obesity Metabolism
Stable isotopes
Dietary weight loss

Additional relevant MeSH terms:
Fatty Liver
Liver Diseases
Obesity
Metabolic Syndrome X
Digestive System Diseases
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Insulin Resistance
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases

ClinicalTrials.gov processed this record on August 28, 2014