[Diabetes mellitus in hemochromatosis]

The degree of glucose intolerance and diabetes mellitus in hemochromatosis is closely associated with the stage of iron overload and thus also the stage of the accompanying liver disease. Similar to other liver diseases glucose intolerance due to insulin resistance precedes diabetes mellitus also in hemochromatosis. Insulin resistance is probably caused by alterations of insulin or glucose metabolism in the liver and potentially also in extrahepatic peripheral tissue. Diabetes mellitus is found more frequently in iron overload when compared with other forms of chronic liver disease and cirrhosis, respectively. In advanced iron overload, iron accumulation in pancreatic B-cells deteriorates pancreatic insulin secretion and leads to insulin-dependent diabetes mellitus which cannot be reversed by iron removal. In contrast, early alteration of glucose intolerance and insulin resistance may partially be improved by phlebotomies. Thus, in the future we should aim to diagnose hemochromatosis in early stages which are not associated with diabetes mellitus or liver cirrhosis.