Insulin and cortisol secretion during OGTT in patients with reactive hypoglycaemia with or without clinical symptoms

A five hour OGTT was performed on 24 women with 75 g glucose load. Seven of these were normal controls (group I). Eleven women had symptomatic reactive hypoglycaemia (group II). Six women were without clinical symptoms of reactive hypoglycaemia but had biological hypoglycaemia (group III). Biological hypoglycaemia was defined by a plasma glucose level below 2.8 mmol/l, occurring between 150 and 270 minutes during OGTT. Plasma glucose, insulin and cortisol levels were assayed every 30 minutes before and after glucose ingestion. In normal subjects and in the 6 women with asymptomatic reactive hypoglycaemia, plasma insulin and cortisol levels did not differ between both groups during the five hour OGTT. In these patients the cortisol level decreased during the OGTT. In patients with reactive hypoglycaemia with clinical symptoms, the cortisol decreased between 0 and 150 minutes, and then increased between 150 and 240 minutes from 5.9 to 19.8 +/- 1.4 micrograms/100 ml during the phase of clinical hypoglycaemia. This suggests increased plasma cortisol after reactive hypoglycaemia is a specific biological finding with clinical symptoms due to reactive hypoglycaemia; this differentiates the pathological hypoglycaemia from a transitory physiological state, both associated with biological hypoglycaemia.