Carbohydrate Intolerance in Idiopathic Haemochromatosis and Cirrhosis of the Liver

摘要

The carbohydrate tolerance of 33 patients with haemochromatosis and 21 with cirrhosis from other causes was compared by studying their oral glucose tolerance and insulin sensitivity. Sixteen subjects with normal glucose tolerance, and 27 with idiopathic diabetes mellitus were also studied.Twenty-one patients with haemochromatosis (63 per cent) and 12 with cirrhosis (57 per cent) had abnormal glucose tolerance. The derangement was more severe in haemochromatosis. The plasma insulin response to glucose was deficient and delayed in diabetes, excessive and delayed in cirrhosis, and relatively deficient but prompt in haemochromatosis.Insensitivity to intravenous insulin was more pronounced in haemochromatosis and cirrhosis than in idiopathic diabetes mellitus. There was no difference in insulin response or insulin sensitivity between patients with haemochromatosis treated by venesection and untreated patients. However, one subject studied before and after iron depletion by venesection showed improvement in carbohydrate tolerance with a greatly increased insulin response. Five patients with iron overload without hepatic fibrosis had normal glucose tolerance and normal insulin response to glucose.The familial incidence of known diabetes in haemochromatosis was 24 per cent but, of these, 21 per cent were also known to have haemochromatosis. In contrast 29 per cent of patients with cirrhosis, and 41 per cent of patients with idiopathic diabetes mellitus, gave a family history of diabetes, compared with only 6 per cent of control subjects.The vascular complications of diabetes were common in patients with idiopathic diabetes mellitus and with haemochromatosis, but uncommon in patients with cirrhosis from other causes.It is concluded that in patients with cirrhosis from any cause there is insulin insensitivity, which is largely responsible for their carbohydrate intolerance. In haemochromatosis an additional factor is operative, and data from the present study suggest that pancreatic damage from iron is more important than inheritance of the gene for diabetes.