This article is the second in a series of four articles exploring the epidemic of liver disease called nonalcoholic fatty liver disease and its more severe form, nonalcoholic steatohepatitis.
Amreen Dinani, MD
Nonalcoholic fatty liver disease (NAFLD) and its more serious form, non-alcoholic steatohepatitis (NASH), is gaining world-wide attention. Patients with NASH are more likely to have obesity and type 2 diabetes—two conditions that are highly prevalent among the general population.
Obesity and type 2 diabetes mellitus is reportedly even higher in the US veteran population. Identifying NAFLD poses a serious challenge, due to the lack of specific signs of symptoms, making diagnosis, management and follow up in the general population and veteran population challenging.
The Veterans Health Administration (VHA) has implemented several innovative strategies to manage liver disease. This has been illustrated with success in identifying, treating and curing a significant portion of veterans with chronic hepatitis C infection. Now, major efforts are being undertaken to implement an effective population health management strategy for veterans with NAFLD that may present a path forward for the rest of country.
Liver biopsy remains the standard to diagnose NAFLD and identify the key features of NASH, (steatosis, inflammation, liver cell injury) and amount of liver scarring (liver fibrosis). However, liver biopsy is an impractical tool for NAFLD diagnosis. One in four Americans could be affected – meaning there are far too many people with NAFLD and NASH to biopsy.
The liver biopsy procedure is invasive, can be associated with patient discomfort or pain, and can result in complications such as bleeding. Additionally, there can be variation in interpretation of the biopsy results by pathologists, which is not ideal for disease monitoring and treatment decisions.
For these reasons, non-invasive tests (NITs) are being adopted more widely to avoid reliance on liver biopsies.
The Shift Toward NITs
A number of NITs are now available and canbe broadly categorized into blood and imaging-based tests or biomarkers. The two most commonly used blood tests are fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS). Both can be relatively easy to calculate by utilizing an application (App) or calculator, by inputting routine lab results (aspartate aminotransferase [AST], alanine aminotransferase [ALT], platelet count, albumin) and some standard patient information, such as age, BMI and presence or absence of diabetes.
Vibration controlled transient elastography (VCTE), or FibroScan, is an imaging-based technology, that is becoming more widely available to assess liver stiffness. FibroScan can assess liver stiffness which correlates with liver scarring, while simultaneously measuring degree of steatosis with controlled attenuated parameter (CAP).
FibroScan has been shown to be effective in detecting NAFLD and liver scarring. It also provides instantaneous results that are reproducible and has created excitement as a point-of-care test. FibroScan is covered by Medicare, Medicaid, and many insurance plans.
Both types of NITs described above can categorize patients into low, moderate or high risk of having liver scarring, with best performance in ruling out advanced liver scarring.
Primary care physicians and caregivers should be aware of the high prevalence of NAFLD, not only in the general population, but amongst veterans as well. The key message is that patients must be better informed about how their liver functions, the impact of their behavior on liver health, how lifestyle modification can prevent and reverse liver damage if caught in the early stages and the value of carefully managing liver disease to prevent progression into cirrhosis or cancer.
Part 3 of this series looks at current and future treatments for liver disease.
Amreen Dinani, MD, is an Assistant Professor in the Department of Medicine, Division of Liver Diseases. Dr. Dinani’s clinical and research interests are in nonalcoholic fatty liver disease (NAFLD). She is an investigator for many ongoing clinical trials in NALFD.
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