From the Guidelines
Fatty liver disease is primarily caused by excessive fat accumulation in liver cells, with two main types: alcoholic fatty liver disease (AFLD) and non-alcoholic fatty liver disease (NAFLD), with the latter being associated with metabolic risk factors including obesity, type 2 diabetes, high blood pressure, and elevated cholesterol or triglyceride levels, as supported by recent studies 1. The causes of fatty liver disease can be broken down into several key factors, including:
- Heavy alcohol consumption, which is the direct cause of AFLD
- Metabolic risk factors, such as obesity, type 2 diabetes, high blood pressure, and elevated cholesterol or triglyceride levels, which are associated with NAFLD
- Insulin resistance, which plays a central role in NAFLD development by disrupting normal fat metabolism
- Other contributing factors, including rapid weight loss, certain medications, viral hepatitis, autoimmune conditions, and genetic disorders like Wilson's disease
- Poor diet, particularly one high in processed foods, sugars, and saturated fats, which significantly increases risk The disease develops when the liver can no longer efficiently process fats, leading to inflammation and potential progression to more serious conditions like cirrhosis if left untreated, as noted in studies 1. Lifestyle modifications, including weight loss, reduced alcohol consumption, and a balanced diet, are the primary interventions for managing fatty liver disease, with recent guidelines emphasizing the importance of a comprehensive approach to management, including the assessment and management of underlying metabolic risk factors 1. It is also important to avoid excess alcohol consumption, as it can increase the risk of more advanced and severe liver outcomes in individuals with NAFLD, as highlighted in a systematic review 1.
From the Research
Fatty Liver Disease Causes
The causes of fatty liver disease can be attributed to various factors, including:
- Alcoholic and non-alcoholic factors, with both types of liver diseases having an identical pathology, starting from simple steatosis to cirrhosis and, ultimately to hepatocellular carcinoma 2
- Metabolic syndrome, which is closely tied with hyperinsulinemia, and is thought to be the hepatic manifestation of metabolic syndrome 3
- Obesity, diabetes, and metabolic syndrome, which are more prevalent in patients with nonalcoholic steatohepatitis (NASH) 3
- Excessive caloric intake and high fructose consumption, which are certain dietary factors that play a role in the development of NAFLD 3
- Alcohol consumption, which can interact with metabolic factors to exacerbate the progression of liver disease, and significant alcohol consumption is often under-reported in patients classified as having NAFLD 4, 5
Risk Factors
Risk factors for fatty liver disease include:
- Obesity, which is a main risk factor for nonalcoholic fatty liver disease (NAFLD) 5
- Hazardous alcohol use, which is a main risk factor for alcoholic liver disease, and can coexist with obesity-associated metabolic abnormalities in the development and progression of fatty liver disease 5
- Metabolic abnormalities, such as insulin resistance and hyperlipidemia, which can contribute to the development and progression of NAFLD 6
- Family history, which may play a role in the development of NAFLD, although the exact mechanisms are not fully understood 3
Interaction between Alcoholic and Nonalcoholic Fatty Liver Disease
There is a significant interaction between alcoholic and nonalcoholic fatty liver disease, with both types of liver diseases sharing pathophysiological, histological, and genetic features 4
- Alcohol consumption can exacerbate the progression of liver disease in patients with NAFLD, and significant alcohol consumption is often under-reported in patients classified as having NAFLD 4, 5
- The coexistence of alcohol consumption and metabolic syndrome can lead to a worse prognosis and increased risk of liver disease progression 4, 5