Fatty Liver
Hepatic steatosis is the pathological accumulation of fat in the liver that impairs its proper function. Contrary to common belief, it is not always associated with excessive alcohol consumption.
Symptoms and Causes
Fatty liver disease, known as hepatic steatosis, is the accumulation of triglycerides and fatty acids in liver cells (hepatocytes). The presence of fat alone does not usually cause organ dysfunction; however, over time it leads to inflammation, fibrosis (tissue scarring), and structural deformity, at which point the liver ceases to function properly. For this reason, it is essential to treat fatty liver disease as soon as it is detected.
Fatty liver disease may progress through four stages, although not all patients go through all of them:
- Simple fatty liver: Fat accumulates in more than 10% of hepatocytes, but there is no inflammation or significant liver damage. It is usually reversible.
- Steatohepatitis: In addition to the presence of fat, there is inflammation and cellular damage.
- Fibrosis: Scar tissue (fibrous tissue) forms in the liver and nearby blood vessels as a result of chronic inflammation. The liver structure becomes altered, reducing its regenerative capacity and function.
- Cirrhosis: Scarring is widespread, and the damage is severe and irreversible. In most cases, it leads to liver failure.
Hepatic steatosis is currently the most common liver disease. As a general rule, fatty liver is a benign condition that can be reversed through healthy lifestyle habits when it is not associated with excessive alcohol consumption. In alcohol-related cases, however, close medical follow-up is recommended because liver damage may be irreversible.
Symptoms
Fatty liver disease is usually asymptomatic in its early stages. When symptoms occur, the most common are:
- Excessive tiredness.
- Fatigue.
- General malaise.
- Pain in the upper right quadrant of the abdomen.
- Nausea and loss of appetite.
As steatosis worsens or when it is caused by excessive alcohol consumption, it may present with:
- Pruritus.
- Abdominal swelling.
- Leg edema.
- Dyspnea: shortness of breath.
- Spider angiomas.
- Mild redness of the palms.
- Jaundice: yellow discoloration of the skin, eyes, and mucous membranes.
- Unexplained weight loss.
Causes
Fatty liver disease may occur due to two main causes:
- Non-alcoholic fatty liver disease: Currently referred to as metabolic dysfunction-associated steatotic liver disease (MASLD). Although the exact reasons for its development remain unknown, it is usually associated with:
- Genetic predisposition.
- Overweight.
- Insulin resistance.
- Alcohol-related fatty liver disease: Alcohol metabolism produces toxic substances that impair the liver’s ability to process fats.
Risk Factors
The main factors that increase the risk of fat accumulation in the liver are:
- Non-alcoholic fatty liver disease:
- Obesity, especially abdominal obesity.
- Hypercholesterolemia.
- Elevated blood triglyceride levels.
- Metabolic syndrome: obesity, hypertension, and elevated cholesterol and triglyceride levels occurring simultaneously.
- Type 2 diabetes.
- Hypothyroidism: insufficient thyroid hormone levels impair lipid metabolism, leading to increased cholesterol and triglycerides.
- Polycystic ovary syndrome: most patients with this condition develop insulin resistance.
- Hypopituitarism: the pituitary gland does not produce normal levels of hormones (cortisol, growth hormone, TSH), thereby affecting metabolism.
- Alcohol-related fatty liver disease: Alcohol consumption, even if occasional, can cause liver damage. However, the risk increases with greater alcohol intake.
Complications
The most significant complications of fatty liver disease include:
- Cirrhosis: formation of scar tissue in the liver as a consequence of inflammation.
- Ascites: accumulation of fluid in the abdomen.
- Esophageal varices: dilation of the esophageal veins.
- Hypersplenism: an enlarged and overactive spleen that destroys red blood cells, white blood cells, and platelets.
- Hepatitis: inflammation of the liver.
- Liver cancer: chronic inflammation alters cellular characteristics, making cells more prone to mutations.
- Liver failure: loss of liver function.
Prevention
The best way to prevent fatty liver disease is to adopt a healthy lifestyle:
- Follow a balanced diet rich in fruits, vegetables, healthy fats, and fiber.
- Avoid alcohol, sugars, and processed foods.
- Drink between 1.5 and 2 liters of water daily to maintain hydration and help the liver eliminate toxins.
- Maintain a healthy body weight.
- Exercise regularly.
- Do not smoke.
- Monitor blood glucose, cholesterol, and triglyceride levels.
- Ensure appropriate management of diabetes.
Which specialist treats fatty liver disease?
Fatty liver disease is managed within the field of Digestive Diseases, usually by physicians specializing in Hepatology.
Diagnosis
Fatty liver disease is often detected during tests performed to evaluate other liver disorders because, as mentioned previously, it usually does not cause symptoms until advanced stages. Common diagnostic procedures include:
- Blood tests: Liver function tests and metabolic markers allow the specialist to assess possible abnormalities in liver function.
- ALT and AST transaminases: Elevated levels are usually indicative of inflammation.
- Gamma-glutamyl transferase (GGT): An enzyme involved in amino acid transport and toxin metabolism. Elevated GGT levels are associated with liver inflammation and damage.
- Lipid profile: Measures blood cholesterol and triglyceride levels. Elevated values are a clear indicator of fatty liver disease.
- Blood glucose level: Blood sugar levels increase when fat accumulates in the liver.
- Ultrasound: Ultrasound waves are used to obtain images of the liver when liver disease is suspected. Findings are classified as follows:
- Mild hepatic steatosis: Liver images appear slightly brighter than normal, although the diaphragm and blood vessel margins remain clearly visible.
- Moderate hepatic steatosis: The liver appears brighter, and the veins and diaphragm are less clearly defined.
- Severe hepatic steatosis: The organ appears markedly hyperechoic, and neither the diaphragm nor blood vessels are clearly visible because ultrasound waves do not adequately penetrate the tissue due to fibrosis.
- Magnetic Resonance Imaging (MRI) or Computed Tomography (CT): These techniques provide more detailed images using radiofrequency waves and a magnetic field (MRI) or X-rays obtained from multiple angles (CT). They are effective for evaluating the internal structure of the liver and facilitate the diagnosis of fatty liver disease and cirrhosis.
- Liver Elastography: Measures the speed at which waves emitted by the device travel through liver tissue. The faster the waves propagate, the greater the liver stiffness.
- Transient elastography (FibroScan®): Performed similarly to an ultrasound examination by moving the ultrasound probe across the abdominal surface. Software calculates wave propagation speed.
- MRI elastography: Radiofrequency waves and a magnetic field are used to create images showing how waves pass through the liver. Results are displayed as a color map indicating the degree of tissue stiffness:
- Blue or green: Represents a healthy liver with elastic, soft tissue.
- Yellow or red: Indicates stiff tissue due to fibrosis or cirrhosis.
- Liver biopsy: A sample of liver tissue is obtained, usually using a needle inserted through the abdomen, and analyzed microscopically in the laboratory. Cellular abnormalities may reveal:
- Inflammation: Increased presence of white blood cells.
- Steatosis: Accumulation of fat cells within hepatocytes.
- Fibrosis or cirrhosis: Presence of scar tissue.
- Structural changes: Alterations in cellular characteristics.
- Presence of cysts or tumors.
- Abnormal iron or copper deposits.
Treatment
Current treatment of fatty liver disease focuses on lifestyle modifications aimed at achieving a healthy weight, improving dietary habits, and controlling blood glucose, cholesterol, and triglyceride levels.
When steatosis is alcohol-related, alcoholic beverages must be completely avoided. If necessary, patients should undergo psychological therapy (individual and group) to overcome alcohol dependence.
To date, no medications have proven definitively effective for the treatment of fatty liver disease, although research remains ongoing. Recent advances indicate that semaglutide significantly reduces liver inflammation and may even improve fibrosis in advanced stages.
