Effect of Dietary Macronutrient Composition

February 4, 2019 updated by: Elizabeth Parks, University of Texas Southwestern Medical Center

Effect of Dietary Macronutrient Composition on Liver Substrate Metabolism

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

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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

Enrollment (Actual)

24

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Dallas, Texas, United States, 75390-9052
        • Center for Human Nutrition

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: 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.
Other: 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
Change from Baseline in fatty acid synthesis at 5 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Change from Baseline in dietary fat clearance at 5 months
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.
Change from Baseline in adipose fat flux at 5 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Texas Southwestern Medical Center

Investigators

  • Principal Investigator: Elizabeth J Parks, PhD, UTSW Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2007

Primary Completion (Actual)

December 31, 2013

Study Completion (Actual)

December 31, 2013

Study Registration Dates

First Submitted

June 7, 2011

First Submitted That Met QC Criteria

June 9, 2011

First Posted (Estimate)

June 10, 2011

Study Record Updates

Last Update Posted (Actual)

February 6, 2019

Last Update Submitted That Met QC Criteria

February 4, 2019

Last Verified

February 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 5RL-1DK081187

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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