Nonalcoholic Fatty Liver Disease
Causes and Risk Factors of Nonalcoholic Fatty Liver Disease.
Although the cause of NAFLD is unclear, the condition is associated with many risk factors.
Overweight and obesity : The risk increases with every pound of excess weight. More than 70 per cent of people with NASH are obese.
Diabetes : High blood sugar level can damage many organs in the body, including the liver. Up to 75 per cent of people with NASH also have diabetes. Insulin resistance may be the most important trigger of simple fatty liver ( steatosis) and NASH.
Hyperlipidaemia : As many as 80 per cent of people with NASH have elevated cholesterol and triglyceride levels.
Abdominal surgery : Operations to remove large sections of the small intestine ( small bowel resection), treat obesity ( gastric by pass) or bypass parts of the small intestine ( jejunal bypass) often lead to rapid weight loss. Losing more than 1-2 pounds a week, even from dieting, may increase the risk of NAFLD.
Medications : These include oral corticosteroids ( prednisone hydrocortisone and others), synthetic estrogens for menopause, amiodarone for heart arrhythmias and diltiazem for high blood pressure.
It is unclear exactly how a liver becomes fatty. The fat may come from other parts of the body, or the liver may absorb an increased amount of fat from the intestine. Another possible explanation is that the liver loses its ability to change fat into a form that can be eliminated.
Signs and Symptoms of Nonalcoholic Fatty Liver Disease
Usually there are no signs and symptoms of simple fatty liver ( steatosis ) or nonalcoholic steatoHepatitis (NASH). When symptoms do occur, they are usually vague and nonspecific and may include fatigue and nausea. Sometimes dull right upper quadrant pain is felt, occasionally radiating to the right shoulder. Mild icterus ( jaundice) can sometimes be noticed. At a more advanced stage, symptoms and signs of cirrhosis may appear.
Diagnosis
Because early-stage NAFLD seldom causes signs and symptoms, it is during a routine medical examination or ultrasound being done for some other cause that the disease gets detected.
Following diagnostic tools are recommended.
- A liver-function blood test (LFT)
- Ultrasound ( ultrasonography)
- CT scan
- MRI
- Liver biopsy.
Although other tests can provide a great deal of information about the extent and type of liver damage, a biopsy is the only way to definitively diagnose NAFLD. In this procedure, a small sample of tissue is removed from the liver and examined under a microscope .
- To distinguish NASH from viral Hepatitis, blood tests are generally done to exclude Hepatitis A, B, C, EBV, CMV, herpes viruses and rubella to ensure these are not playing a role.
- TSH is estimated, as hypothyroidism is more prevalent in NASH patients.
Clinical indicators in NAFLD patients that predict the likelihood of diagnosis of the NASH subset by a liver biopsy are : BMI > 30, type II DM, age > 45 years and an AST:ALT ratio >1.
Nonalcoholic Fatty Liver Disease
Causes and Risk Factors of Nonalcoholic Fatty Liver Disease
Complications and Treatment for Nonalcoholic Fatty Liver Disease |