Non Alcoholic Fatty Liver Disease

 

Non-Alcoholic Fatty Liver

PKGhatak, MD

An ultrasound scan of the abdomen is an unusually simple procedure for investigating abdominal and pelvic conditions. Many patients were found to have fatty liver unexpectedly and unrelated to their symptoms for which ultrasound scans were performed.

Incidence is quite high and is rising not only in the USA but also worldwide. In the USA about 25 % of people have fatty liver on ultrasound scan, in India it is about 35 %.

Chronic alcoholism is a common cause of fatty liver. But it is also detected in high numbers in non-alcoholics. This is now designated as Non-Alcoholic Fatty Liver Disease (NAFLD).

The cause of NAFLD is unknown. People with NAFLD have a high association with Diabetes II, hepatitis C and HIV infections. More causal associations are seen in hepatitis B and A, obesity, physical inactivity, metabolic syndrome - the combination of high BP, obesity around the waist, high triglyceride & LDL cholesterol. Psoriasis, Hypothyroidism, hypopituitarism, Hemochromatosis, sleep apnea, polycystic disease of the ovary, and high fructose soft drinks and prepacked food and frozen TV dinners.

The adverse effect of the medication is known to produce NAFLD -   Acetaminophen. A heavy dose of tetracycline, oral hormone therapy, amiodarone, valproic acid, certain cancer drugs, some HIV drugs.

NAFLD is the initial stage of fatty liver, a more advanced stage of inflammation of the liver leads to a state called Non-Alcoholic Steatohepatitis (NASH). The incidence of NASH in the USA is about 6% of the population and in India, it is about 12 %.

Symptoms.

The majority of patients are symptoms free. Some complaints of vague upper abdominal discomfort, right upper abdominal pain, bloating, and anorexia. Some other patients with more advanced diseases have a loss of weight, enlargement of the liver, anemia, frequent infections, gastrointestinal bleeding.

Investigation and diagnosis.

Liver enzymes - ALT and AST are elevated, due to liver damage. Platelet count falls due to decreased production of Thrombopoietin, a hormone produced in the liver and needed for platelet generation in the bone marrow.

Later, vitamin K-dependent clotting factor deficiency leads to the prolongation of Prothrombin time. Serum albumin level falls.

MRI of the liver clearly delineates pathological changes in liver cells. A new generation of Ultrasound scans – Fibroscan of the liver is also very sensitive like MRI and detects the degree of fibrosis. Fibrosis is the result of deaths of hepatocytes and inflammatory cell infiltration of the liver. Hepatic cirrhosis is the end stage.

Fibrosis Calculation.

Several institutions have developed a Fibrosis score, corroborated by liver biopsy, based on Age, ASL and ALT, and Platelet count. It is very useful for patients and the treating physician for monitoring progress. This practice has decreased the need for liver biopsy.

Formula : 

 Age ([yr] x AST [U/L])   /   ((PLT [10(9)/L]) x (ALT [U/L])(1/2)). 

Using this formula, patients with a score > 3.25 are likely to have advanced fibrosis whereas, those with a score < 1.45 are unlikely to have advanced fibrosis.

A biopsy of the liver is the final confirmatory test, but biopsy is not necessary in the majority of cases.

Complications.

As the NAFLD progress, the inflammation leads to the development of Steatohepatitis, the next step and ultimately to hepatic cirrhosis. Complications of cirrhosis are bleeding esophageal varices, hypoalbuminemia, ascites, hypersplenism, thrombocytopenia, and hepatic failure.

About 5 % of NAFLD patients with hepatic cirrhosis develop Hepatocellular carcinoma.

Treatment.

No effective drug treatment is available.

A weight reduction of 5 to 7 % of body weight is associated with improvement.

Daily physical exercise or 45 minutes walk is advocated.

Elimination of Fructose from food and drinks should be done.

Vitamin E as high as 700 IU was advised but worsening Diabetes and increased prostate cancer risk should be taken into consideration before undertaking such therapy.

Liraglutide with vitamin E is also tried.

Aramchol a combined fatty acid and bile acid conjugate is approved in Israel and in India for use in NASH.

Several anti fibrosis agents are undergoing trial in the final stages.

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