[Light and electron microscopic study of hepatic lesions in the course of hyperlactatemia in diabetic patients (author's transl)].

Histopathological study of the liver has been undertaken on twenty-one diabetics with hyperlactatemia exceeding 5 mEq/1 of whom seven were treated with phenformin, six with metformin and eight not biguanide-treated. Hyperlactatemia occurred during the course or during resolution of severe ketoacidosis or of hyperosmolar coma. Hepatic lesions were invariably present. By light microscopy, massive steatosis, steatonecrosis or necrosis of variable extent were observed. Ultrastructural study showed constant mitochondrial abnormalities. These results support the hypothesis of a major role for mitochondrial changes in hepatic cells in provoking pathological hyperlactatemia. In diabetic patients, these mitochondrial lesions could be induced either by an anoxic process resulting from a variety of metabolic insults or by some as yet undefined toxic action of biguanides or by the combination of both of these factors.