[Insulin secretion after a protein and lipid meal in healthy subjects]

Previous studies suggested that insulin requirement in type I diabetics could be split in a "basal" insulin requirement, mainly related to body weight and in a "post-prandial" insulin requirement, mainly related to carbohydrates intake. In the present study we wanted to investigate the occurrence and the magnitude of insulin response to protein only or fat only meals in normal subjects, trying to obtain some evidences for an insulin requirement possibly related to these substrates in diabetic subjects. Fat only meals did not evoke any insulin response while a small but significant increase in plasma insulin was observed after a protein only meal (from 16.6 +/- 2.85 to 25.83 +/- 2.52 microU at 90', p less than 0.05). Blood glucose remained unchanged after fat or protein meals. It is concluded that a small sovrabasal insulin dose would be probably required by diabetic patients after a protein meal: this is however so small that a carbohydrates related insulin dose given before a normal mixed meal would be able to normalize aminoacids as well as glucose metabolism.