Obesity and Fatty Liver Disease: Chronic Diseases That Are Related

Dr. Landzberg Responds:

Dear Maria,

Thanks for your timely question. Nonalcoholic fatty liver disease, or NAFLD, has become an extraordinarily prevalent problem in our country, paralleling the rise of overweight and non-insulin-dependent diabetes mellitus over the last few decades. The unifying theme is insulin resistance, which causes increased weight, which worsens insulin resistance in a vicious cycle.

NAFLD is essentially a spin-off of the metabolic syndrome of abdominal obesity, elevation in triglycerides, hypertension, hyperglycemia (high blood sugar), and low-HDL cholesterol. Insulin resistance makes weight loss harder, not impossible, but I am going to focus on your questions regarding NAFLD.

NAFLD has become an increasingly frequent cause of liver failure requiring liver transplantation. It lags behind hepatitis C and alcoholic liver disease (for now), but probably has a higher prevalence than we appreciate, as it likely reflects a large portion of “idiopathic,”  cirrhosis (cirrhosis with no clear cause). The good news is that only a small percentage of NAFLD cases ever go on to cirrhosis, and these cases generally demonstrate a subset of NAFLD called nonalcoholic steatohepatitis, or NASH.

As opposed to patients who have only steatosis (fat deposition in the liver, often detected by sonography but with normal liver blood work), NASH patients usually have elevated transaminases (liver blood tests) in the blood and are the ones at risk for advanced liver disease. Ten percent to 20 percent of Americans may have steatosis, while only 2 percent to 5 percent have NASH. Twenty percent to 25 percent of NASH patients may go on to cirrhosis. In addition to steatosis, cytokines (pro-inflammatory proteins) released by adipose (fat) cells and oxidative stress play key roles in NASH.

Diagnosing NASH is usually accomplished with sonography and blood work that includes a liver panel and serologies and chemistries to rule out other causes of liver function test elevation, like hepatitis B and C, autoimmune hepatitis, celiac disease, hemochromatosis, Wilson’s disease, et al.  Some physicians are beginning to use special sonograms that measure elasticity, and therefore scarring, such as Fibroscan, to get a non-invasive sense of whether advanced liver disease is present.

The gold standard for diagnosing and staging NASH remains a core needle biopsy of the liver.  What has diminished many hepatologists’ enthusiasm for the procedure is the 0.5% risk of bleeding complications, offset by a lack of clearly helpful medical intervention for NASH. I have to admit that at times I have found the liver biopsy most useful as an incentive for the patient to lose weight.

The most effective (and toughest) way to treat NASH is gradual weight loss. When told that at a three-month follow-up, a liver biopsy will be performed if the weight and transaminases (liver blood tests) remain elevated, I have found that a percentage of patients will push themselves harder and actually begin to lose the weight. I do not mean to imply that losing weight is simply a matter of will — it is not, at least not for everyone. Diet, weight loss, alcohol abstinence, exercise, all clearly work and are indicated. Drug therapy to increase body sensitivity to insulin over the years has tended to show promising results in improving liver blood tests, but little change in long-term health of the liver as shown by serial liver biopsies. Obeticholic acid is a possible future approach to keep an eye on. Vitamin E may have some benefit with little downside, and has been recommended by some hepatologists.

A word of clarification regarding physician terminology: All board-certified gastroenterologists are also board-certified in hepatology, the study of liver disease. Many gastroenterologists choose to focus solely on liver disease and refer to themselves as hepatologists. Others choose not to include liver disease in their practice, especially those who act primarily as endoscopists rather than consultants. I am a consultant in both gastroenterology and hepatology.

Hope this information is  helpful. A good lay review on NASH can be found at the NIH website.

Dr. Landzberg


Brian Landzberg, M.D. is a gastroenterologist and liver specialist affiliated with the Weill Medical College of Cornell University, New York-Presbyterian Hospital and Hospital for Special Surgery where he serves as Clinical Assistant Professor of Medicine in the Division of Gastroenterology and Hepatology. His particular areas of clinical interest are celiac disease, functional gastrointestinal disorders including constipation, diarrhea and irritable bowel syndrome, inflammatory bowel disease, gastritis, GERD and liver disease. He has published and lectured on these topics and maintains a very active clinical practice on the Upper East Side of Manhattan.

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