Non-Alcoholic Fatty Liver Disease (FAT) is characterized by abnormal fat deposition in the hepatic parenchyma, which is not due to excessive alcohol consumption (≥30 g of alcohol on a daily basis in men and ≥20 g of alcohol in women), but in others factors such as obesity, hyperlipidemia, diabetes, hypothyroidism, etc.
Frequency of disease
MALNI is now the most common liver damage worldwide with an incidence of 25% and with ever-increasing incidence rates. It seems to be the hepatic manifestation of the metabolic syndrome, as it occurs in 47% of patients with type 2 diabetes and up to 80% of patients with obesity. Of course, there are cases where the disease occurs in patients with normal body weight and good BMI. Some genetic factors appear to contribute to the disease in slender patients, while the presence of localized abdominal obesity (increased waist circumference) in patients with otherwise normal body weight has also been implicated.
Forms and complications of the disease
“MALNI can occur as a simple fat deposition in the liver without co-occurring inflammation (simple steatosis) or take on the character of steathepatitis (NASH) which is characterized by inflammatory fat deposition and is the most aggressive form of the disease, as it can lead to fibrosis and cirrhosis of the liver in higher percentages compared to simple steatosis “, explains Dr. Dimitrios Karagiannakis MD, PhD Specialist-Hepatologist, Academic Fellow EKPA, Deputy Director of the 3rd General Hospital of the Metropolitan Clinic. He continues, “In the case of advanced fibrosis or cirrhosis, the patient is at greater risk for developing hepatocellular carcinoma (HCC), while in advanced, non-compensatory cirrhosis, there are complications of portal hypertension, ie ascites (presence of fluid in the abdomen cavity), hepatic encephalopathy (confusion, disorientation, instability, even coma) and varicose veins (rupture of dilated vessels in the esophagus called esophageal varices).
Unfortunately, MALNI not only causes liver problems, but also increases the risk of causing extra-hepatic complications. In particular, it seems to be associated with higher rates of adverse events from the cardiovascular system, such as coronary heart disease, hypertension and heart failure, while it also predisposes to cancers beyond the CKD, with colorectal and breast cancer more common.
Diagnosis
The diagnosis of the disease is usually made with a simple ultrasound of the upper abdomen, where the liver parenchyma appears as ultrasound (ie it is whiter, brighter) than normal (imprinted as gray).
Of course, the ultrasound is not able to distinguish mild fatty infiltration. In these cases, MRI is a more sensitive method for detecting intrahepatic fat, but is generally not recommended for this purpose due to its increased cost.
“It should be noted at this point that both MRI and CT may not be recommended for the diagnosis of fatty infiltration, but they are useful tools in the case of a pathological mass in the liver, in order to clarify whether it is CKD or not. .
“In recent years, a newer ultrasound technique called CAP has been used to diagnose MALNI, which seems to be able to distinguish even small deposits of intrahepatic fat and therefore excels at the discretion of simple ultrasound,” says the doctor.
In terms of laboratory tests, patients with MALNI may show an increase in transaminases (SGOT / SGPT) and / or γgt. It should be noted, however, that this is not necessary, as patients with simple steatosis usually do not have a hepatic biochemical test. Usually the presence of inflammation (NASH) and not just steatosis, is responsible for the increase of liver enzymes.
Distinguish between inflammation and simple steatosis
The distinction between simple steatosis and NASH is not always easy, as only with blood tests can not be extracted with absolute certainty. However, it is necessary to detect those patients who have NASH, as as already mentioned this entity leads more often to fibrosis and cirrhosis than simple steatosis. Absolute confirmation of the presence of NASH can only be achieved by performing a liver biopsy. However, as the latter is an invasive method and carries even small risks of complications, it is avoided in daily clinical practice. Thus, what stands out is not the control of the presence of inflammation, but of fibrosis, which is the evolution of NASH and is associated with an increased risk of liver cirrhosis, CKD and extra-hepatic manifestations.
“Fibrosis can be diagnosed both with special serological tests (FIB-4 score, NAFLD fibrosis score) and with liver elastography. The latter is superior to serological tests in diagnostic accuracy. It is a non-invasive method performed using ultrasound and assesses the hardness-stiffness of the liver parenchyma. The harder the liver is on elastography, the more fibrous it is, as the presence of fibrosis leads to an increase in its hardening. Therefore, elastography indirectly highlights the fibrosis and is preferred over biopsy, because it is non-invasive, easy to perform and a cheap method.
Another advantage is the possibility of repeated measurements at regular intervals, in order to assess the change in fibrosis over time, says Mr. Karagiannakis.
In our country, 3 elastographic techniques are used that are based on the use of ultrasound and are Transient Elastography (Fibroscan), point Shear Wave Elastography and 2D-Shear Wave Elastography. Magnetic elastography is not preferred due to its very high cost.
Using elastography, we will distinguish those patients with fibrosis, who are at higher risk for cirrhosis, CKD and extra-hepatic manifestations (type 2 diabetes, coronary heart disease, hypertension, malignancy (other than CKD) , in order to put them in more systematic monitoring and possibly in more targeted and intensive treatment.
Therapeutic interventions
Regarding the therapeutic interventions in the patients with MALNI, all the factors that cause the fatty deposition in the liver should be regulated. Thus, there should be weight reduction, improvement of diet quality, increase of physical activity, regulation of blood sugar and lipids, regulation of thyroid coke. Regarding the most specific for MALNI treatments, many studies are carried out on therapeutic agents that aim at either reducing inflammation or reducing fibrosis. The results of these studies are expected in the coming years, which will probably change the therapeutic approach of patients with MALNI, in relation to the drugs we have to date for the treatment of the disease.
in conclusion
“MALNI is the most common liver disease nowadays. Its impact is expected to increase even more in the future, as a result of poor quality food and sedentary lifestyle. It is imperative to diagnose the disease early, especially in patients with fibrosis, in order to prevent the development of cirrhosis and CKD, but also to avoid adverse effects from the cardiovascular system, which is usually the first complication of the disease. Liver elastography provides significant assistance in this direction. The improvement of the nutritional conditions, the exercise and in many cases the use of targeted therapeutic protocols, will not only stop the evolution of MALNI, but in many cases will even lead to its reversal “, concludes the Specialist-Hepatologist Mr. Karagiannakis.
Writes:
Dr. Dimitrios Karagiannakis MD, PhD Specialist-Hepatologist,
Academic Scholar EKPA, Deputy Director of the 3rd Pathology Clinic Metropolitan General Hospital
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