Liver Positron Emission Tomography (PET) Study of Non Alcoholic Fatty Liver Disease
The purpose of this study is to evaluate how the liver receives and uses fats for energy. This will help the investigators further understand the physical and chemical processes responsible for Non-Alcoholic Fatty Liver Disease (NAFLD) in overweight females with or without NAFLD who are scheduled to undergo gastric bypass surgery.
|Study Design:||Observational Model: Case-Only
Time Perspective: Prospective
|Official Title:||An Interdisciplinary Approach to the Study of Non-alcoholic Fatty Liver Disease|
- Hepatic Fatty Acid Uptake [ Time Frame: 3 hours ] [ Designated as safety issue: No ]Liver fatty acid uptake as determined by 1-11C-palmitate PET imaging.
- Hepatic Fatty Acid Oxidation [ Time Frame: 3 hours ] [ Designated as safety issue: No ]Liver fatty acid oxidation as determined by 1-11C-palmitate PET imaging.
- Hepatic DNL [ Time Frame: 3 hours ] [ Designated as safety issue: No ]DNL (de-novo lipogenesis) as determined by 13C-acetate PET imaging.
Biospecimen Retention: Samples With DNA
|Study Start Date:||July 2010|
|Estimated Study Completion Date:||July 2014|
|Estimated Primary Completion Date:||July 2014 (Final data collection date for primary outcome measure)|
Obese Females (pre-bariatric surgery)
Twenty obese females (18-45 years of age, BMI > or equal to 45) who are scheduled to undergo bariatric surgery at Barnes-Jewish Hospital will be screened for enrollment over 2 years.
This study involves a multidisciplinary approach that will address the metabolic mechanisms responsible for Non-alcoholic Fatty Liver Disease (NAFLD) in humans. Nonalcoholic fatty liver disease (NAFLD) has become an important public health problem in many industrialized countries because of its high prevalence, potential progression to severe liver disease, and association with cardiometabolic abnormalities, including diabetes, the metabolic syndrome, dilated cardiomyopathy, and coronary heart disease. Although obesity is an important risk factor for NAFLD many obese persons have minimal or no steatosis. The mechanism responsible for the pathogenesis of steatosis is not known, but must involve one or more of the following:
- Increased hepatic fatty acid (FA) delivery
- Decreased hepatic FA oxidation
- Increased de novo lipogenesis (DNL)
- Inadequate hepatic triglyceride secretion
We hypothesize that alterations in all of these metabolic processes are involved in the pathogenesis of NAFLD. However, a comprehensive evaluation of these factors in individual cohorts of subjects has never been performed, and the ability to measure hepatic FA oxidation in vivo in human subjects has not been available.
The following Specific Aims will be evaluated in obese women with and without NAFLD, who are scheduled for bariatric surgery:
- Determine hepatic FA uptake and oxidation by using novel PET techniques in combination with measurements of DNL using stable isotope tracers and by assessing liver tissue FA oxidative capacity by evaluating gene expression of FA oxidative enzymes and mitochondrial content.
- Determine hepatic fatty acid delivery by using stable isotope tracers to assess the rate of free FA (FFA) release into plasma and cellular biology methods to determine the expression and protein content of the major tissue FA transporter (CD36).
- Determine hepatic very-low-density lipoprotein TG (VLDL-TG) secretion rate by using stable isotope tracers.
- Determine liver histology and factors involved in inflammation and fibrosis by using routine staining and immunohistochemistry.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00949403
|United States, Missouri|
|St. Louis, Missouri, United States, 63110|
|Washington University School of Medicine|
|St.Louis, Missouri, United States, 63110|
|Principal Investigator:||Robert J Gropler, MD||Washington University School of Medicine|