[The early breakfast--an unknown pitfall in the treatment of type-I diabetes mellitus].

In 15 type I diabetics the mean postprandial rise in blood glucose levels, 90 min after breakfast at about 8 a.m. (the customary time for this meal in hospitals), was 62.2 +/- 34.3 mg/dl, but 90 min after a breakfast which had been put forward by about 1 1/2 hours it was only 2.6 +/- 18.6 mg/dl (P less than 0.001). Seven patients developed hypoglycaemia after the early breakfast, none after the late one. This finding suggests that, to avoid hypoglycaemia after an early breakfast, an additional small meal should be given at about 8:30 a.m. or the insulin content of the morning injection should be changed. The clear connection between the time of the morning insulin injection and the insulin action during the morning explains why, in uninstructed patients who--under their usual daily conditions of starting school or work--are forced to inject insulin early or to eat early, a state of hypoglycaemia may occur.