Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver condition affecting individuals with minimal to no alcohol consumption. Characterized by excessive fat accumulation in the liver, NAFLD is frequently observed in those who are overweight or obese. As obesity rates surge globally, particularly in Western and Middle Eastern countries, NAFLD has become increasingly common and is now the most widespread form of liver disease worldwide. The severity of NAFLD spans from simple hepatic steatosis, often referred to as fatty liver, to a more aggressive form known as nonalcoholic steatohepatitis (NASH).
NASH is marked by inflammation and damage to the liver resulting from fat deposits. If left unmanaged, NASH can progress to cirrhosis, a severe form of liver scarring, and even liver cancer. The damage caused by NASH is comparable to that resulting from excessive alcohol consumption.
Currently, there is a movement to rename nonalcoholic fatty liver disease to metabolic dysfunction-associated steatotic liver disease (MASLD). Experts have also recommended renaming nonalcoholic steatohepatitis to metabolic dysfunction-associated steatohepatitis (MASH).
Symptoms of Hepatic Steatosis
In many cases, NAFLD is asymptomatic. However, when symptoms do manifest, they may include:
- Fatigue
- Malaise or a general feeling of unwellness
- Pain or discomfort in the upper right abdominal region
Symptoms indicative of NASH and cirrhosis, or advanced scarring, can include:
- Itchy skin
- Abdominal swelling, also known as ascites
- Shortness of breath
- Swelling in the legs
- Spider angiomas, which are spider-like blood vessels visible just beneath the skin’s surface
- Enlarged spleen
- Palmar erythema (redness of the palms)
- Jaundice (yellowing of the skin and eyes)
It’s crucial to consult with a healthcare professional if you experience persistent and concerning symptoms.
Causes of Fatty Liver
The exact mechanisms behind fat accumulation in the liver for some individuals remain unclear. Similarly, the progression from fatty liver to NASH isn’t fully understood.
However, both NAFLD and NASH have been linked to several factors, including:
- Genetics: A family history can increase your risk.
- Obesity and Overweight: Excess body weight is a major contributor.
- Insulin Resistance: When cells don’t respond effectively to insulin, it can lead to fat buildup in the liver.
- Type 2 Diabetes: High blood sugar levels are strongly associated with NAFLD.
- Hyperlipidemia: Elevated levels of fats, particularly triglycerides, in the blood.
While these factors can contribute to hepatic steatosis, some individuals develop NAFLD without exhibiting any apparent risk factors.
Risk Factors for Developing NAFLD
Several health conditions and lifestyle factors can elevate the risk of developing NAFLD, including:
- Family history of obesity or fatty liver disease
- Growth hormone deficiency
- High cholesterol
- High triglyceride levels
- Insulin resistance
- Metabolic syndrome
- Obesity, especially abdominal obesity (excess fat around the waist)
- Polycystic ovary syndrome (PCOS)
- Obstructive sleep apnea
- Type 2 diabetes
- Hypothyroidism (underactive thyroid)
- Hypopituitarism (underactive pituitary gland)
NASH is more prevalent among:
- Individuals over 50 years of age
- Those with specific genetic predispositions
- People with obesity
- Individuals with diabetes or elevated blood sugar levels
- Those displaying metabolic syndrome characteristics, such as high blood pressure, elevated triglycerides, and a large waist circumference.
Distinguishing between NAFLD and NASH necessitates clinical evaluation and testing.
Complications of Untreated Fatty Liver
Cirrhosis, or severe liver scarring, is the primary complication associated with both NAFLD and NASH. Liver injury, such as inflammation in NASH, triggers cirrhosis. The liver attempts to repair itself after injury and inflammation by producing scar tissue (fibrosis). Continued inflammation results in the spread of fibrosis and the replacement of healthy liver tissue.
If cirrhosis is left unchecked, it can progress to:
- Ascites (fluid accumulation in the abdominal cavity)
- Esophageal varices (enlarged veins in the esophagus that can rupture and bleed)
- Hepatic encephalopathy (confusion, drowsiness, and slurred speech)
- Hypersplenism (overactive spleen, leading to reduced blood platelet count)
- Liver cancer
- End-stage liver failure
It is estimated that approximately 24% of adults in the United States have NAFLD, and about 1.5% to 6.5% have NASH.
Preventing Hepatic Steatosis
To minimize the risk of developing NAFLD:
- Adopt a healthy diet: Prioritize fruits, vegetables, whole grains, and healthy fats.
- Limit Alcohol, Simple Sugars and Portion Sizes: Avoid sugary drinks and minimize or eliminate alcohol consumption, as it can harm the liver.
- Maintain a healthy weight: If overweight or obese, consult with a healthcare professional to develop a gradual weight loss plan. If at a healthy weight, maintain it through a balanced diet and regular exercise.
- Exercise regularly: Engage in physical activity most days of the week. Consult with your healthcare provider before starting a new exercise program, particularly if you haven’t been active regularly.
By implementing these preventative measures, you can significantly reduce your risk of developing hepatic steatosis and improve your overall liver health.
