Those of you old enough to remember the last Nash automobile that rolled off the production line in 1957 know that it is extinct and only available as a collector car. But the liver disease NASH (nonalcoholic steatohepatitis) is far from extinct, and unfortunately it has been rising in prevalence in the United States. NASH affects between 2 and 5 percent of Americans and is not always a benign disease or an incidental finding. Along with hepatitis B and hepatitis C, it is attracting large amounts of research dollars in the study of its prevention and treatment.
As people develop more sedentary lifestyles, obesity, diabetes, cholesterol abnormalities and a lack of exercise have caused a higher incidence of fatty liver. It becomes more serious as the entity of NASH, where additional findings of liver cell injury and inflammation develop. It’s a disease that can only be proven from a biopsy, where tissue is obtained and looked at under a microscope, and indeed early on there are few if any symptoms. Most cases are discovered accidentally through normal screening laboratory results as part of a history and physical exam. Alcohol may cause these changes (and often does), but when alcohol is determined not to be a causative factor, the suspicion swings to NASH.
There are really no symptoms until later in the disease, when weakness, fatigue and weight loss may develop. The progression can take years, and in some cases even decades. Sometimes the progression actually stops. Other times it worsens into fibrosis (where the liver becomes inelastic and nonfunctioning) and cirrhosis (an end-stage liver disease usually associated more with alcohol overuse). Once cirrhosis is in the picture, no real treatment short of eventual liver transplantation exists at this point in time. NASH ranks only behind hepatitis C and alcoholic liver disease as a cause of cirrhosis.
Tests early on in the disease involve monitoring liver function tests and ruling out other causes of fatty liver disease, such as viral, hemochromatosis, diabetes, metabolic syndrome, and medication taken for other causes, just to name a few. Liver imaging (ultrasound) and CT scanning help to determine the extent. Lifestyle changes such as improvement of diet, weight loss and exercise are incorporated, and blood testing is followed. If the results fail to correct, a liver biopsy confirms the diagnosis.
The goals of therapy once a diagnosis is made are to try and reverse hepatic injury and prevent further fibrosis. No specific therapies at present exist for NASH. Weight reduction, balanced and healthy diet, increased physical activity and avoidance of alcohol and other offending medications help. More vigorous treatment of adjuvant disease such as diabetes, heart disease and high cholesterol also are a net benefit. Medications such as bile acids, antioxidants, metformin for insulin resistance states, and vitamin E haven’t shown a sufficient proactive benefit to be recommended.
The National Institute of Diabetes and Digestive and Kidney Diseases funds the NASH Clinical Research Network, which is doing active research into therapies and progression of the disease.
Fatty liver disease in itself usually isn’t rateable separately from any assessment of the primary cause, such as cholesterol, diabetes, etc. When the diagnosis is biopsy-proven NASH, the mortality is increased due to the eventual appearance of significant fibrosis and cirrhosis and a mild to moderate rating may be added. Advanced liver disease and those cases in which liver transplantation is being considered are generally not insurable. Cases in which there is no documented progression of disease over time are looked at more favorably, as are the institution and persistence of positive lifestyle changes.
