Understanding Fatty Liver Disease: A Guide to Recent Updates
by Dr. Megan Taylor
Fatty liver disease, previously known as Non-Alcoholic Fatty Liver Disease (NAFLD), has always been a confusing condition for my patients to understand. This has been made even more complicated over the last couple of years, with recent publications that have provided updates in nomenclature, prevalence insights, risk factors, and diagnostic approaches. So, to help clarify things, let’s explore these changes and what they mean for individuals and public health.
A New Name: MASLD
In an effort to better align the disease with its underlying metabolic causes, NAFLD has been renamed to Metabolic-dysfunction Associated Steatotic Liver Disease (MASLD). This name change is an attempt to reflects the condition's strong links to metabolic health, such as insulin resistance, rather than merely stating that alcohol is not the cause of the condition. i
Why It Matters
Fatty liver disease is the most common liver disorder worldwide. Fatty liver disease affects upwards of 30% of the global population and up to 37% of adults in the U.S. The prevalence of this condition rises further to 70% among those with type 2 diabetes (Kanwal, et al. 2021).
While this disease often initially presents without symptoms, it can progress over years and decades to more severe liver damage, including fibrosis (reversible scarring) or cirrhosis (an advanced stage of scaring that is irreversible). Ultimately, this scarring can put patients at risk of developing liver cancer and/or liver failure.
Risk Factors
Key contributors to MASLD include:
Metabolic Issues: high triglycerides, low HDL (“good”) cholesterol, hypertension, prediabetes or diabetes, insulin resistance, or high amounts of abdominal visceral fat (fat stored deep within the abdominal cavity, surrounding vital organs like the liver, intestines, and stomach)
Lifestyle: limited physical activity, low intake of dietary fiber and high intake of sugar-sweetened snacks and beverages
Genetics: genetic predisposition can also exacerbate the risk in some individuals
Diagnostic Challenges
Diagnosing MASLD has historically relied on liver biopsies, an invasive and costly test that requires a physician to take a sample of your liver tissue. However, the focus in the new guidelines has shifted to the use of non-invasive testing tools that minimize both risks and costs. These include:
Abdominal ultrasound: to look for evidence of steatosis (fat accumulation) in the liver, however this technique can miss more early stages.
Liver enzymes: to look for hepatocyte (liver cell) damage and death, however many patients with MASLD will have normal liver enzymes.
Blood-Based Risk Calculations: use markers found in your blood to assess risk for fibrosis, and include Fibrosis-4 (FIB-4) index and the Enhanced Liver Fibrosis (ELF) test among others
Liver stiffness measurements (using ultrasound or MRI): fat stored deep within the abdominal cavity, surrounding vital organs like the liver, intestines, and stomach provides insights into liver stiffness, indicating potential fibrosis.
Focus on Fibrosis
Among the greatest concerns in MASLD is advanced fibrosis which predicts long-term outcomes more reliably than steatosis (fat accumulation) alone. Patients with metabolic risk factors listed above, or imaging evidence of steatosis, should undergo regular fibrosis risk evaluations to prevent progression. These could include blood based risk calculators and/or liver stiffness measurements discussed above, in addition to checking liver enzymes.
Use of FibroScan (tm) technology at Neighborhood Naturopathic & Primary Care
Given the high prevalence of MASLD, and difficulties faced in diagnosing this condition, we have decided to offer a non-invasive, low cost screening tool called FibroScan in our office. Utilizing vibration-controlled transit elastography, this test measures the stiffness of your liver which can indicate the degree of scarring or fibrosis of the liver tissue. A stiffer liver will indicate a greater risk of fibrosis and need for more detailed evaluation and aggressive treatment, and may include a referral to a liver specialist.
This testing takes < 30 min and involves a simple, non-painful procedure using an ultrasound device placed on the right side of your body at your ribcage. You need to fast for 3 hours prior to the test, and wear comfortable, loose fitting clothing (shirt & pants/skirt/shorts) that would allow easy access to your abdomen.
You can learn more about this procedure, which is used to evaluate liver health for multiple conditions beyond MASLD, at the Memorial Sloan Kettering website here.
If you have been diagnosed with fatty liver, or have risk factors for such, talk to your provider about whether you’d be a candidate for FibroScan.
Have additional questions about fatty liver and if you should be screened?
See you in clinic,
Dr. Megan
Citations:
Kanwal F, Shubrook JH, Adams LA, Pfotenhauer K, Wai-Sun Wong V, Wright E, Abdelmalek MF, Harrison SA, Loomba R, Mantzoros CS, Bugianesi E, Eckel RH, Kaplan LM, El-Serag HB, Cusi K. Clinical Care Pathway for the Risk Stratification and Management of Patients With Nonalcoholic Fatty Liver Disease. Gastroenterology. 2021 Nov;161(5):1657-1669. doi: 10.1053/j.gastro.2021.07.049. Epub 2021 Sep 20. PMID: 34602251; PMCID: PMC8819923.