Fat in the Liver
In diabetic patients who are resistant to the effects of insulin, the levels of glucose in the blood are elevated. Over time, according to Medline Plus, a service associated with the National Institutes of Health, elevated glucose in the blood may cause damage to, and possibly failure of, multiple organs. One of these organs is the liver. The first step in the development of liver disease in diabetes occurs when fat is deposited in the liver, according to the National Digestive Diseases Information Clearinghouse (NDDIC). Fat in the liver itself does not cause liver damage, though may lead to liver enlargement. NDDIC reports that 10 to 20 percent of Americans have fat in their liver but have no further inflammation or liver damage. According to the NDDIC, fat in the liver without further liver damage is referred to as nonalcoholic fatty liver disease (NAFLD).
Insulin Resistance
Type 2 diabetes is characterized by an inability to regulate blood glucose levels and a resistance of the cells to insulin. There is a strong association between NAFLD and insulin resistance. In fact, 50 to 75 percent of patients suffering from type 2 diabetes also suffer from NAFLD, according to a review published in 2006 in the Journal of Clinical Endocrinology by Kristina Utzschneider, M.D., and colleague at the University of Washington, Seattle. Patients with NAFLD had a 45 to 50 percent reduction in their ability to process insulin, meaning they were significantly insulin resistant. It is unclear how insulin resistance and fat tissue are specifically related, but their association is certain.
Inflammation and Scarring
Fat in the liver and insulin resistance cause liver damage only when they are associated with inflammation. When there is fat in the liver along with inflammation, the patient is diagnosed with nonalcoholic steatohepatitis (NASH). Inflammatory cells infiltrate the liver and secrete proteins that may directly cause damage or recruit more pro-inflammatory cells. NDICC reports that 2 to 5 percent of Americans are affected by NASH, in which the liver becomes damaged due to inflammation. When there is fat in the liver and inflammation in liver tissue, scarring of the may occur. Normal tissue is replaced by fibrous scar tissue, which may ultimately lead to disruption of the organ's function. Only a liver biopsy, according to NDICC, can diagnose whether an enlarged liver indicates NAFLD (fat in the liver with no inflammation) or NASH (fat in the liver with inflammation). This process of fat in the liver leading to inflammation and then progressing to tissue scarring in the liver may take years or decades to develop, notes NDICC.
