Whereas the association of type 2 diabetes with microvascular complications and macrovascular disease is well established, the association of type 2 diabetes with NAFLD is more recently recognised and probably less well-known to physicians. Furthermore, because patients are usually asymptomatic and routine blood tests are often normal, it may be a diagnosis that is overlooked in patients with type 2 diabetes.7,8
There is evidence that patients with NAFLD who have type 2 diabetes are particularly at risk of progressive forms of the disease and that they are at higher risk of developing cirrhosis compared with those who do not have diabetes.9,10 Although cardiovascular disease is the major cause of excess morbidity and mortality in type 2 diabetes, liver failure may also be a threat to patients with type 2 diabetes NAFLD.3,10
Therefore, it is important for physicians to be aware of the high likelihood that their patients with type 2 diabetes have NAFLD, as this is another potential complication that requires attention.
NAFLD is characterised by fatty infiltration of the liver, mostly in the form of triglycerides, which exceeds 5% of the liver weight.11 NAFLD is histologically similar to alcoholic liver disease, but by definition it occurs in the absence of excessive alcohol consumption and is not due to other identifiable causes of fatty liver such as hepatitis C and certain medications.11 NAFLD represents a spectrum of clinical–pathological features ranging from simple steatosis, which is characterised by fatty infiltration only, to non-alcoholic steatohepatitis (NASH), which is characterised by inflammation and hepatocellular injury with or without fibrosis and cirrhosis.11,12 Most with NAFLD have an increase in liver fat content alone, which is apparently benign; others develop NASH that can progress to cirrhosis.10–12