TNF and diabetes mellitus: The high prevalence of HBV infection in diabetic cases might be due to the possible role of HBV in the development of diabetes mellitus through induction of insulin resistance associated with persistent inflammatory reactions in response to HBV infection and overproduction of tumor necrosis factor-α and nitric oxide in the liver which are involved in the destruction of the insulin metabolic action, destruction of β-cell of the islet due to the replication of HBV in the pancreas, or induction of glycometabolism disorders due to hepatic damage caused by HBV infection [14, 15].