Utilizing Non-Invasive Fibroscan® Technology to Identify Genetic Markers for Fatty Liver Progression

Overview

Non-alcoholic fatty liver disease (NAFLD) is a common disorder, affecting \~30% of people in the general population and up to 96% of obese individuals. Variations in several genes have been found to be associated with fatty liver, but these associations only explain a small percentage of the risk, and further studies are needed. In many cases NAFLD does not cause serious side effects, but in some individuals it progresses to scarring or hardening of the liver, liver failure, and cancer. The purpose of this research study is to determine if individuals who carry certain genetic variations in a gene related to bile and choline metabolism have an increased risk of fatty liver progressing to fibrosis, or scarring of the liver. This study will also use a new, non-invasive method called the FibroScan® to measure liver fat and liver stiffness. The FibroScan® device is FDA approved for use to measure liver stiffness, but not for the liver fat measurement. However, the FibroScan® instrument is considered a non-significant risk device. Since its induction in Europe and worldwide in 2003, there have been no adverse effects reported with this device.

Purpose: ABCB4 is a gene that intersects choline and bile metabolism, two processes that are highly relevant for liver disease. The investigators have identified a pattern of genetic variation that is associated with fatty liver burden and potentially, risk for liver disease. One of the most prominent genes in this pattern is ABCB4. This data needs to be replicated in the general population. This study will test the hypothesis that aberrant function of ABCB4 due to genetic variations will increase the risk of fatty liver progression to fibrosis. It will also implement innovative, non-invasive technology to measure liver fat and fibrosis utilizing the FibroScan® instrument. As additional proof of principle that the measurements we are making correlate with genetics, the investigators will also measure two genetic variants that have been shown in many studies to correlate with liver fat and fibrosis by their research team and others: PNPLA3 rs738409 and rs2281135. Finally, the investigators will calculate a NAFLD-Fibrosis score as an additional correlate to liver disease status. Participants: To test this hypothesis, 50 ethnically diverse, overweight or obese male and female adults will be recruited from the general population. Procedures: Genotyping to correlate variation in the ABCB4 and PNPLA3 genes with level of fatty liver and progression to fibrosis with the FibroScan®. Calculation of NAFLD-Fibrosis score.