Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with an estimated prevalence of 20-30% in the general population.
These figures are based on a systematic review that included studies involving more than 8 million people in 22 countries, in which the presence of the disease was analyzed using imaging studies such as ultrasound or computed tomography.
In addition, the frequency increases associated with an increase in the prevalence of overweight/obesity, metabolic syndrome and diabetes worldwide.
Fatty liver and its causes
Eduardo Fassio (MN 63.149), specialist in hepatology and gastroenterology and head of the gastroenterology service at the Prof. Alejandro Posadas National Hospital, explained that fatty liver disease is a condition in which fat accumulates in the liver. There are two main types:
- Non-alcoholic fatty liver disease.
- Alcoholic fatty liver disease, also called alcoholic fatty liver disease.
In this sense, the specialist argued that the cause of the disease is multifactorial and plays a very important role. “genetic factors and overeating leading to central obesity and adipose tissue dysfunction leading to increased delivery of fatty acids to the liver.”
“This is due to insulin resistance (with subsequent increased risk of developing diabetes) and changes in the microbiota (populations of bacteria that inhabit the intestines of people). A sedentary lifestyle also contributes“, he warned.
The clinical spectrum and prognosis of the disease is wide. “The majority of patients present with so-called simple steatosis, which is usually benign in evolution and generally does not lead to consequences associated with liver disease, but a smaller percentage presents with non-alcoholic steatohepatitis, which can progress to cirrhosis of the liver and all its complications. . Although only a small proportion of patients with NAFLD progress to cirrhosis, given the huge number of people affected worldwide, this is believed to be the main reason for the need for liver transplantation in the future.“, accurate.
Fatty liver symptoms
As is common with all chronic liver diseases, affected patients usually do not show symptoms, and diagnosis begins with the detection of abnormal blood tests (hepatogram enzymes) or ultrasound at routine examinations.
“It is highly recommended that physicians caring for patients with diabetes, obesity, or metabolic syndrome investigate this condition. because it does not cause symptoms in the transition from early stages to later stages, such as cirrhosis of the liver,” said.
The specialist explained that to distinguish between the two mentioned variants (simple steatosis and steatohepatitis) is still possible only by examining a liver biopsy, which is an invasive procedure. However, it is known that the prognosis of liver disease will be determined by what is called fibrosis, which is the “scarring” of liver tissue that can occur with all chronic liver diseases, the maximum degree of which is cirrhosis.
Fortunately, there are some non-invasive methods that a doctor can use to periodically assess whether his patient’s liver fibrosis is increasing. These include scoring systems (scores) based on commonly available tests such as liver enzymes, platelet count, patient age, and others; and various types of elastography, which are tests that assess the stiffness of the liver. (as a surrogate for fibrosis).
“If these non-invasive methods give poor results (below certain levels known from previous studies), the attending physician can advise the patient that liver complications are very unlikely in the short/medium term and focus on trying to correct comorbidities that usually co-exist, such as obesity or lipid changes (cholesterol, triglycerides), or preventing diabetes“, kept.
On the other hand, if non-invasive tests show results above certain levels, increases the risk of severe liver fibrosis/cirrhosis, and a hepatologist should be consulted to assess therapeutic options and prevent complications.
The patient has fatty liver with no or mild fibrosis (low risk of liver complications) or severe/cirrhosis of the liver (high risk of liver complications), “You should be aware that because you are a person who usually has signs of the metabolic syndrome (diabetes, obesity, hypertension, lipid changes), you tend to suffer from arterial atherosclerosis and vascular problems such as myocardial infarction or stroke. Therefore, an interdisciplinary approach and correction of these multiple changes, which are almost always asymptomatic, are very important.”
Treatment of fatty degeneration of the liver
While many drugs are under investigation that affect disease mechanisms at various levels, none have yet been approved for clinical use by regulatory agencies such as the FDA (in the US) or the EMA (in the US). Europe).
“On the other hand, there is a lot of scientific evidence that sustained weight loss over time is associated with significant improvement in liver health. Upon reaching a decrease in body weight by 5% (in relation to the initial level), a decrease in the amount of fat in the liver is observed; while with a reduction of 7-10%, a reduction in inflammation and even fibrosis is achieved, which is the most important discovery. Unfortunately, it is known that patients find it difficult to maintain weight loss over time. Even within scientific studies where patients are better controlled, the proportion of individuals who achieve weight loss equal to or greater than 10% of their base weight is only 10%, ”the specialist said.
Several studies have compared different types of diet (e.g. low-fat or low-carb, etc.) and none has been found to be better than the other. The so-called Mediterranean diet, which is high in fruits, vegetables, whole grains, monounsaturated fats (olive oil) and polyunsaturated fats (fish) and low in saturated fats (red meat) and processed foods (trans fats). attractive in that it not only reduces fatty deposits in the liver, but can also prevent cardiovascular complications.”. Combining a low-calorie diet with moderate exercise, both aerobic and strength-based, is recommended by major scientific societies.
Finally, the specialist concluded: “In morbidly obese patients undergoing bariatric surgery (to lose weight), this is usually associated with a significant improvement in liver health during follow-up. But until now, fatty degeneration of the liver in itself is not considered an indication for bariatric surgery. There are some drugs that are approved for the treatment of diabetes that cause significant weight loss in patients (eg, semaglutide) and have shown promising results in fatty liver in phase 2 trials.
Meanwhile, numerous trials, known as phase 3 trials, are currently underway to analyze the efficacy and safety of these and various other types of drugs in patients with non-alcoholic fatty liver disease.