What is steatotic (fatty) liver disease?
Steatotic liver disease (SLD), also known as fatty liver disease (FLD), encompasses a range of conditions where fat accumulates in the liver. This excess fat can lead to inflammation and liver damage over time if not addressed. It’s essential to manage risk factors like obesity, diabetes, and high cholesterol to prevent or manage this condition. A healthy, high-functioning liver contains a small amount of fat. Fat accumulation becomes an issue when it reaches over 5% of your liver’s weight.
What are the types of steatotic (fatty) liver disease?
The type of fatty liver is based on its causes and the conditions associated with it. There are mainly two causes which are either Alcohol related and non-alcohol related liver disease.
Alcoholic liver disease (ALD)
Alcoholic liver disease (ALD): excessive alcohol consumption is a leading cause of steatotic liver disease, known as alcoholic fatty liver disease (AFLD). When alcohol is metabolised by the liver, it can lead to the accumulation of fat within liver cells, leading to steatosis. Over time, chronic alcohol consumption can overwhelm the liver’s ability to regenerate and repair itself, resulting in inflammation, scarring (cirrhosis), and potentially liver failure.
The liver has a remarkable ability to regenerate and repair itself. However, excessive alcohol consumption can overwhelm this regenerative capacity. When alcohol is metabolised in the liver, it generates harmful byproducts that can damage liver cells. With chronic alcohol abuse, the liver’s ability to regenerate new cells becomes compromised, leading to the accumulation of fat (steatosis) and eventually to more severe liver damage. That’s why moderation or cessation of alcohol consumption is crucial for preventing and managing alcoholic liver disease.
Non-alcoholic fatty liver disease (NAFLD)
Non-alcoholic fatty liver disease (NAFLD): is a liver problem that affects people who drink little to no alcohol. In NAFLD, too much fat builds up in the liver. It is seen most often in people who are overweight or obese.
NAFLD is increasingly prevalent worldwide, particularly in Middle Eastern and Western countries, paralleling the rise in obesity rates. It stands as the most widespread form of chronic liver disease, affecting roughly 25% of the global population. In Australia there are almost 6 million people affected by NAFLD.
Within NAFLD, some individuals may progress to a condition called non-alcoholic steatohepatitis (NASH), which represents a severe manifestation of fatty liver disease. NASH induces liver inflammation and swelling due to fat accumulation, potentially leading to advanced liver scarring, known as cirrhosis, and even liver cancer. The liver damage seen in NASH mirrors that of heavy alcohol consumption.
Efforts are currently underway to rename non-alcoholic fatty liver disease to metabolic dysfunction-associated steatotic liver disease (MASLD). Similarly, there are recommendations to rename non-alcoholic steatohepatitis to metabolic dysfunction-associated steatohepatitis (MASH).
NAFLD often manifests without noticeable symptoms. However, when symptoms do arise, they may include fatigue, malaise, and discomfort in the upper right abdomen. Advanced stages of NASH and cirrhosis may present symptoms such as itchy skin, abdominal swelling (ascites), shortness of breath, leg swelling, spider-like blood vessels on the skin’s surface, an enlarged spleen, red palms, and jaundice (yellowing of the skin and eyes).
Metabolic dysfunction-associated fatty liver disease (MAFLD)
Metabolic dysfunction-associated fatty liver disease (MAFLD): previously known as non-alcohol related fatty liver disease (NAFLD) because the fat buildup in the liver isn’t linked to heavy alcohol consumption. However, experts revised the name to better reflect the underlying causes of the condition. In MAFLD, the primary factors contributing to fat accumulation in the liver are cardio-metabolic risk factors, which encompass various conditions and characteristics posing risks to heart health.
Risk factors associated with MAFLD include obesity, type 2 diabetes, high blood pressure, Lipid abnormalities.
It’s worth noting that MAFLD can also occur in individuals who consume small amounts of alcohol weekly. “Small amounts” are defined as less than 140 grams per week for individuals assigned female at birth (AFAB) and less than 210 grams per week for individuals assigned male at birth (AMAB).
Metabolic-associated steatohepatitis (MASH)
Metabolic-associated steatohepatitis (MASH): represents a severe manifestation of metabolic dysfunction-associated fatty liver disease (MAFLD). In MASH, the accumulation of fat in the liver progresses to inflammation, followed by tissue damage and scarring (fibrosis). Previously, healthcare providers referred to MASH as non-alcohol related steatohepatitis (NASH).
Metabolic alcoholic liver disease (MetALD)
Metabolic alcoholic liver disease (MetALD): Occurs when a person has both MAFLD and increased alcohol intake. The interplay between metabolic risk factors and alcohol consumption can contribute differently to fat buildup in the liver for each person with MetALD (metabolic-associated alcoholic liver disease). In MetALD, both factors play a significant role in the accumulation of fat in the liver.
For individuals with MetALD, having both a cardiometabolic risk factor (such as obesity, type 2 diabetes, high blood pressure, or lipid abnormalities) and consuming alcohol above certain thresholds (more than 140 grams per week for individuals assigned female at birth, or more than 210 grams per week for individuals assigned male at birth) can exacerbate liver damage.
The relative contribution of alcohol consumption versus metabolic risk factors can vary from person to person. Some individuals may be more susceptible to liver damage from alcohol consumption, while others may experience more significant effects from metabolic risk factors. This variability underscores the importance of personalised medical assessment and management for individuals with MetALD.
Other causes of fatty liver disease
Other causes of fatty liver disease: Fatty liver disease can stem from factors beyond alcohol use or cardiometabolic risk factors. Medications, certain diseases, and even unknown causes can lead to the development of steatosis in the liver. When healthcare providers cannot pinpoint a specific cause for FLD, it’s termed cryptogenic FLD. This designation underscores the complexity of liver diseases and the need for further research to better understand and manage these conditions.
How serious is fatty liver?
Understanding the progression of liver disease due to fat buildup highlights the importance of early detection and intervention. In most cases, fat accumulation in the liver doesn’t lead to serious issues or hinder its normal function. However, when the condition progresses, it typically advances through several stages:
- Hepatitis: The liver transitions from a state of fatty infiltration to inflammation, known as steatohepatitis. This inflammation damages liver tissue, marking the onset of liver disease. For example, MAFLD can progress to MASH during this stage.
- Fibrosis: As inflammation persists, bands of scar tissue form in the liver where tissue damage occurs, leading to stiffening of the live a process known as fibrosis.
- Cirrhosis: Extensive scarring replaces healthy liver tissue, resulting in cirrhosis of the liver. Without treatment, cirrhosis can culminate in severe conditions like liver failure and liver cancer. It's noteworthy that approximately 90% of individuals who develop hepatocellular carcinoma (HCC), a type of liver cancer, have underlying cirrhosis.
What are the signs and symptoms of fatty liver disease (FLD)?
The signs and symptoms of steatotic (fatty) liver disease (ASD) can vary depending on the stage of the condition:
When FLD is in its early stages and may not cause symptoms. However, when symptoms do occur, they can include abdominal pain or a feeling of fullness in the upper right side of your abdomen (belly) and extreme exhaustion or weakness (fatigue).
As FLD progresses to cirrhosis of the liver, symptoms may become more noticeable and can include nausea, loss of appetite, unexplained weight loss, yellowish skin and whites of the eyes (jaundice), swelling in your abdomen (ascites), swelling in your legs, feet, or hands (edema) and bleeding that your healthcare provider detects in your oesophagus, stomach, or rectum.
It’s important to note that not everyone with SLD will experience symptoms, and symptoms may not appear until the disease has advanced. Regular medical check-ups and screenings are essential for early detection and treatment of SLD.
How is fatty liver disease diagnosed?
Since fatty liver disease (FLD) often doesn’t present with noticeable symptoms, doctors may detect it through routine blood tests or investigations for other conditions. Elevated levels of liver enzymes found in blood tests can indicate liver injury and serve as a red flag for potential liver disease.
To diagnose FLD, healthcare providers may perform several diagnostic tests and procedures, including:
- Medical history: Your doctor will inquire about your medical history, including any underlying conditions, alcohol consumption habits, and medications you're taking.
- Physical exam: A physical examination may be conducted to assess for signs of liver inflammation (such as an enlarged liver) or signs of advanced liver disease, such as jaundice.
- Imaging procedures: Imaging tests like ultrasound, CT scan, or MRI may be ordered to evaluate the liver for signs of inflammation and scarring. A specialised ultrasound called Fibro Scan or liver elastography may be used to quantify the amount of fat and scar tissue in the liver.
- Liver biopsy: In some cases, a liver biopsy may be performed to obtain a tissue sample and determine the extent of liver disease. A liver biopsy is particularly valuable for distinguishing between metabolic-associated fatty liver disease (MAFLD) and metabolic-associated steatohepatitis (MASH), as it provides insight into the severity and progression of the condition.
These diagnostic tests and procedures are essential for accurately diagnosing SLD, assessing its severity, and guiding appropriate treatment and management strategies.
What is the management and treatment for fatty liver disease?
While there’s no specific medication to treat fatty liver disease (FLD), healthcare providers focus on managing the risk factors that contribute to the condition and promoting overall liver health. This typically involves making lifestyle changes that can improve your health and reduce the progression of liver disease.
Your hepatologist may recommend the following:
- Avoiding alcohol: It's crucial to abstain from alcohol consumption, even if your FLD isn't related to alcohol use, to prevent further liver damage.
- Weight management: Losing weight through a combination of dietary changes, exercise, and, in some cases, medications like GLP1RA can help improve liver health. Bariatric surgery or gastric balloon may be an option for individuals who qualify and struggle to lose weight through other methods.
- Managing metabolic conditions: Taking prescribed medications to manage conditions like diabetes, high cholesterol, and high triglycerides can help reduce the risk of liver disease progression.
- Vaccinations: Getting vaccinated for hepatitis A and hepatitis B is essential, especially for individuals with liver disease, as these viral infections can exacerbate liver damage.
By implementing these strategies and working closely with your doctor, you can help manage FLD and reduce the risk of complications. Regular monitoring and follow-up appointments are essential to track progress and adjust your treatment plan as needed.
Your specialist may consider adjusting your prescriptions. Some medications can have side effects that affect liver function or lead to hepatic steatosis. In such cases, Dr. Peerbaccus may recommend alternative medications with fewer hepatotoxic effects or adjust the dosage of current medications to minimise liver-related complications.
