From the Guidelines
Fatty liver disease is primarily caused by excessive fat accumulation in liver cells, with non-alcoholic fatty liver disease (NAFLD) being the most common type, often associated with obesity, insulin resistance, type 2 diabetes, and metabolic syndrome. The two main types of fatty liver disease are alcoholic fatty liver disease, caused by heavy alcohol consumption, and NAFLD, which occurs in people who drink little to no alcohol 1. NAFLD is estimated to affect over 70% of people with type 2 diabetes, and its prevalence is increasing rapidly worldwide due to the rising rates of obesity and diabetes 1.
Risk Factors
Some of the key risk factors for NAFLD include:
- Obesity
- Insulin resistance
- Type 2 diabetes
- High blood pressure
- High cholesterol
- Metabolic syndrome
- Poor diet, particularly one high in processed foods, sugars, and saturated fats
- Certain medications
- Rapid weight loss
- Genetic factors
Pathophysiology
The liver normally processes fats efficiently, but when overwhelmed by excess fat intake, sedentary lifestyle, or metabolic issues, it begins storing fat within its cells, leading to inflammation and potential scarring over time 1. The increasing quantity of fructose in the diet, particularly from sugar additives and high fructose corn syrup in beverages and processed foods, has been linked to the development and severity of NAFLD 1.
Diagnosis and Management
The diagnosis and management of NAFLD involve a comprehensive medical evaluation, including assessment of comorbidities and cardiometabolic risk factors 1. Weight loss through diet and exercise is the primary treatment for non-alcoholic fatty liver disease, while abstaining from alcohol is essential for alcoholic fatty liver disease 1.
Prognosis
NAFLD is associated with increased cardiovascular, liver, and all-cause mortality, and its progression can lead to end-stage liver diseases such as cirrhosis and hepatocellular carcinoma (HCC) 1. Therefore, early diagnosis and management of NAFLD are crucial to prevent its progression and reduce the risk of complications. The most recent and highest quality study recommends a systematic approach to the diagnosis and management of NAFLD, reflecting evidence-based medicine and expert opinions 1.
From the Research
Causes of Fatty Liver Disease
Fatty liver disease can be caused by various factors, including:
- Alcohol consumption: Chronic alcohol consumption can lead to the development of fatty liver, which may progress to more severe liver damage, such as hepatitis and fibrosis 2
- Obesity: Excess body fat, particularly around the abdominal area, can contribute to the development of fatty liver disease by generating free radicals, increasing tumor necrosis factor-alpha production, and inducing insulin resistance 2, 3
- Dietary factors: A diet high in saturated fats, cholesterol, and sugar can contribute to the development of fatty liver disease 4, 5
- Insulin resistance: Insulin resistance, often associated with type 2 diabetes, can lead to the accumulation of fat in the liver, increasing the risk of fatty liver disease 3, 4
- Genetic factors: Genetic predisposition can influence the susceptibility to and severity of fatty liver disease 6
Mechanisms of Fatty Liver Disease
The development of fatty liver disease involves several mechanisms, including:
- Fat accumulation in hepatocytes: The accumulation of triglycerides in liver cells can lead to steatosis, a reversible condition that can progress to more severe liver damage 2, 6
- Oxidative stress: The production of reactive oxygen species can damage liver cells, contributing to the progression of fatty liver disease 2, 6
- Inflammation: The activation of inflammatory pathways can contribute to the development of fatty liver disease, particularly in the context of obesity and insulin resistance 2, 3
- Mitochondrial dysfunction: Impaired mitochondrial function can contribute to the development of fatty liver disease by disrupting energy metabolism and increasing oxidative stress 6
Risk Factors
Several risk factors can increase the likelihood of developing fatty liver disease, including: