About Fatty Liver

Fatty liver occurs when excess fat, mainly triglycerides, accumulates in the liver. In general, when fat makes up more than 5% of the liver’s weight, it is diagnosed as fatty liver. However, because the liver cannot be removed and weighed for diagnosis, the amount of fat accumulation is assessed indirectly through imaging tests (such as ultrasound, abdominal CT, and MRI) and tissue examination (obtained by using a thin needle to take a small part of the liver).

Fatty liver can be divided into alcoholic fatty liver, which is caused by heavy drinking, and nonalcoholic fatty liver, which occurs regardless of alcohol consumption and is associated with obesity, diabetes, hyperlipidemia, and similar conditions. Alcohol is one of the most important causes of fatty liver. Long-term drinking leads to nutritional deficiency, causes fat to accumulate in liver cells, and the metabolites of alcohol damage liver cells.

Most people who drink heavily for a long time (about 90%) develop alcoholic fatty liver. If drinking continues in such cases, about 20% are known to progress through hepatitis to cirrhosis. Although alcohol comes in many types depending on the ingredients and manufacturing method, the degree of liver damage does not differ according to the type or how it is consumed. The most important factors are the amount of alcohol consumed and the frequency of drinking.

In general, fatty liver develops when men aged 65 or younger drink 30 g or more per day, and women 20 g or more per day (10 g of alcohol is equivalent to 250 cc of beer, 40 cc of soju, or 25 cc of whiskey). Converted into the soju that we commonly drink, this is 3 or more bottles per week for men and 2 or more bottles per week for women.

In the past, it was thought that only people who drank alcohol could develop fatty liver, but recently fatty liver has also been found frequently in people who do not drink alcohol at all. Fatty liver that occurs in people who drink little or no alcohol is called "nonalcoholic fatty liver disease." Nonalcoholic fatty liver disease is not a single condition, but rather includes a range of diseases from mild fatty liver

to chronic hepatitis and cirrhosis. Most cases of fatty liver are mild, but one in four patients with fatty liver progresses over time to cirrhosis, a serious liver disease, if not treated.

In addition, medications such as steroids, anti-inflammatory pain relievers, and heart medications, as well as some herbal medicines or various folk remedies, can also cause fatty liver.

Although there are no statistics yet in Korea, in other countries most patients who visit hospitals for abnormal liver function results (60–80%) are found to have fatty liver. There are even studies suggesting that 20–30% of the entire population has fatty liver, showing how common it is. While there are no exact statistics on the proportion of alcoholic fatty liver versus nonalcoholic fatty liver, in a society like ours where people often encourage one another to drink, alcoholic fatty liver is still presumed to be more common. However, according to the National Health and Nutrition Survey conducted by the government in recent years, the obese population has increased rapidly over a short period, and the prevalence of diabetes has also increased. Therefore, it is expected that nonalcoholic fatty liver associated with metabolic syndrome will continue to increase in Korea as well.

So far, I have explained fatty liver.

In the next part, we will look at the symptoms and complications of fatty liver.

Source: Korea Disease Control and Prevention Agency National Health Information Portal