The hepatitis C virus (HCV)
infection is characterized by a variety of extra-hepatic manifestations in many individuals. Among these,
diabetes mellitus (DM) can be included, as such a metabolic disorder has been demonstrated to be more frequent in
chronic hepatitis C than in
liver disease due to other causes. Recently, we have observed that most patients affected with HCV-associated mixed
cryoglobulinemia (13 out of 15, 86.7%), that were at baseline normoglycemic, developed DM following
corticosteroid treatment (
prednisone > 25 mg/daily) for at least three months. Conversely, when we consider a control group including 36 HCV negative patients affected with various immunomediated disorders, i.e.,
systemic lupus erythematosus,
myasthenia gravis, poly/
dermatomyositis and chronic inflammatory demyelinating
polyneuropathy, that were initially normoglycemic,
corticosteroid induced DM (
prednisone > 25 mg/daily for at least three months) occurred only in 16.7% of subjects. Moreover, in other two HCV positive patients suffering from
myasthenia gravis, prolonged
corticosteroid treatment was complicated by DM. These data, that are still unclear from a pathophysiologic viewpoint, seem to indicate
corticosteroid induced DM as a further, unusual extra-hepatic manifestation of the HCV
infection.