Kathleen Corey, MD, MPH, director of the Fatty Liver Clinic at Massachusetts General Hospital, offers advice for physicians diagnosing and treating patients with suspected fatty liver disease.
Diagnosing Fatty Liver Disease
If I think a patient has nonalcoholic fatty liver disease (NAFLD), who should I biopsy and why?
Patients who are at high risk of nonalcoholic steatohepatitis (NASH) should undergo an evaluation and liver biopsy. Patients at high risk include those who are 50 years or older with diabetes or obesity. In addition, those with an elevated NAFLD fibrosis score should be biopsied (see Question Two).
For patients with NASH and any stage of fibrosis, the risk of progression to cirrhosis is as high as 30% over 10 years. These patients need to be identified for aggressive treatment including weight loss, exercise, vitamin E and treatment of risk factors including insulin resistance and hyperlipidemia. In addition, patients with advanced fibrosis are at risk of hepatocellular carcinoma (HCC) and need to be in HCC screening programs for early detection.
What is the NAFLD Fibrosis Score?
The NAFLD Fibrosis Score is a validated method of noninvasively estimating the fibrosis stage in a patient with NAFLD and is recommended by the American Association for the Study of Liver Diseases (AASLD). (See Angulo et al., The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD. Hepatology 2007;45:846-54). This score calculates a patient’s risk of fibrosis based on age, body mass index (BMI), presence of impaired fasting glucose/diabetes, platelets, albumin, ALT and AST.
How do I differentiate alcoholic fatty liver disease from NAFLD?
The AASLD defines significant alcohol consumption as more than 21 drinks per week for men and 14 drinks or more per week for women. Patients consuming these amounts of alcohol should be considered to have alcoholic, rather than nonalcoholic, fatty liver disease.
What are secondary causes of fatty liver?
Secondary causes of fatty liver include:
- Hepatitis C
- Alcohol use
- Celiac disease
- Thyroid disease
Since diabetic patients have a high prevalence of NAFLD, should I be screening my patients with diabetes for NAFLD?
While patients with diabetes do have a high prevalence of NAFLD and NASH, there is currently a lack of data about the benefit and cost effectiveness of screening. At this time, the AASLD does not recommend routine screening for these patients.
Treating Fatty Liver Disease
How much weight should I advise my patients to lose to help their fatty liver disease?
Patients should be advised that a 5-7% total body weight loss is needed for an improvement in steatosis. To significantly improve inflammation, at least 10% total body weight loss is needed.
Is exercise helpful in the treatment of fatty liver?
Exercise has been shown to decrease steatosis in NAFLD, but its impact on inflammation and fibrosis is not known.
Can patients with fatty liver disease safely be treated for hyperlipidemia?
Yes, patients with NAFLD liver are at especially high risk for cardiovascular disease and should receive appropriate risk management, including treatment for hyperlipidemia. Patients with fatty liver are not at increased risk of hepatotoxicity from HMG-CoA reductase inhibitors (statins) and can safely receive standard doses of these medications. Patients with NAFLD often have hypertriglyceridemia and can be treated with omega-3 fatty acids (fish oils), nicotinic acids or fibrates. (See Corey et al. Assessment and management of co-morbidities including cardiovascular disease in patients with NAFLD.Clinical Liver Disease 2012).
Is weight loss surgery effective treatment for fatty liver disease?
Yes, the majority of patients who undergo weight loss surgery have resolution of steatosis and resolution or improvement of fibrosis. For patients with obesity and fatty liver disease, weight loss surgery is an important treatment to consider. The Mass General Weight Center specializes in the treatment of patients with obesity and liver disease and can offer evaluation and management.