Causes & Risk Factors
Causes
Experts don’t know exactly why some people accumulate fat in the liver while others do not. Similarly, there is limited understanding of why some fatty livers develop inflammation that progresses to cirrhosis. Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis are both linked to the following:
- Overweight or obesity
- Insulin resistance, in which your cells don’t take up sugar in response to the hormone insulin
- High blood sugar (hyperglycemia), indicating prediabetes or actual type 2 diabetes
- High levels of fats, particularly triglycerides, in the blood
These combined health problems appear to promote the deposit of fat in the liver. For some people, this excess fat acts as a toxin to liver cells, causing liver inflammation and nonalcoholic steatohepatitis, which may lead to a buildup of scar tissue (fibrosis) in the liver.
Risk Factors
A wide range of diseases and conditions can increase your risk of nonalcoholic fatty liver disease, including:
- High cholesterol
- High levels of triglycerides in the blood
- Metabolic syndrome
- Obesity, particularly when fat is concentrated in the abdomen
- Polycystic ovary syndrome
- Sleep apnea
- Type 2 diabetes
- Underactive thyroid (hypothyroidism)
- Underactive pituitary gland (hypopituitarism)
Nonalcoholic steatohepatitis is more likely in these groups:
- Older people
- People with diabetes
- People with body fat concentrated in the abdomen
It is difficult to distinguish nonalcoholic fatty liver disease from nonalcoholic steatohepatitis without further testing.