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Effect of Dietary Macronutrient Composition

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ClinicalTrials.gov Identifier: NCT01371396
Recruitment Status : Unknown
Verified April 2012 by Elizabeth Parks, University of Texas Southwestern Medical Center.
Recruitment status was:  Active, not recruiting
First Posted : June 10, 2011
Last Update Posted : April 23, 2012
Sponsor:
Information provided by (Responsible Party):
Elizabeth Parks, University of Texas Southwestern Medical Center

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

Condition or disease Intervention/treatment Phase
Metabolic Syndrome Non-alcoholic Fatty Liver Disease Obesity Other: Low-fat diet Other: Low-carbohydrate diet Not Applicable

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.


Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 24 participants
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Effect of Dietary Macronutrient Composition on Liver Substrate Metabolism
Study Start Date : September 2007
Estimated Primary Completion Date : June 2012
Estimated Study Completion Date : June 2014


Arm Intervention/treatment
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.




Primary Outcome Measures :
  1. de novo lipogenesis [ Time Frame: Change from Baseline in fatty acid synthesis at 5 months ]
    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 :
  1. Dietary fatty acid clearance to liver [ Time Frame: Change from Baseline in dietary fat clearance at 5 months ]
    Using a dietary stable isotope we will quantitate fat absorption and recycling of fat through the liver.

  2. Adipose fatty acid flux [ Time Frame: Change from Baseline in adipose fat flux at 5 months ]
    A stable isotope is infused and the rate of adipose fatty acid release is calculated after analyzing blood samples.



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Ages Eligible for Study:   20 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
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

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): 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

Publications of Results:
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
First Posted: June 10, 2011    Key Record Dates
Last Update Posted: April 23, 2012
Last Verified: April 2012

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

Additional relevant MeSH terms:
Metabolic Syndrome X
Liver Diseases
Fatty Liver
Non-alcoholic Fatty Liver Disease
Insulin Resistance
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Digestive System Diseases