Abstract
The diurnal change in plasma immunoreactive insulin level of seventeen diabetic patients was studied before and after the treatment with sulfonylurea. The insulin area was calculated as an index to represent the diurnal summation of plasma insulin. The insulin area of the mild diabetic group and that of the moderately severe group were within a normal range before and after the treatment. The area decreased significantly in the mild diabetic group by the treatment, with a concomitant decrease in the blood glucose. However, the insulin area was unchanged in the moderately severe group. This result may be attributed to an increase of the sensitivity to insulin of the tissues by the treatment in mild diabetic group. In moderately severe group, the plasma free fatty acids (FFA) remained high still after the treatment and this high FFA is thought to be one of the reasons for unchanged plasma insulin level in this group.
