[Results of long-term biguanide therapy as a preventive measure in protodiabetes]

55 patients with pathological glucose tolerance received a long term treatment with buformin (200 mg daily). In 43 of the protodiabetics the duration of treatment was one year, in 29 of them two years and in 11 three years. The age of the patients was 38 years and the mean relative body weight was 118 per cent. The effect of buformin on glucose tolerance and insulin secretion was tested with the glucose infusion test before and after the periods of treatment. After one year we found in 58 per cent, after two years in 69 per cent and after three years in 64 per cent of the protodiabetics an improvement of glucose tolerance. In these groups the results showed a rise of the IRI in the low responder and a decrease of the IRI in the high responder. The good effects on glucose tolerance were not demonstrable in the compared groups with long-term treatment of diet only.