Blood glucose monitoring in symptomatic hypoglycemia.

The relationship between blood glucose levels and the onset of hypoglycemic symptoms was studied by continuous monitoring of blood glucose levels after an oral glucose load in nine adults with normal glucose tolerance, five with chemical diabetes without symptomatic hypoglycemia, and nine with chemical diabetes with symptomatic hypoglycemia. Symptoms were associated not only with a low level of blood glucose but with a rapid fall as well. These two parameters were used to calculate a "hypoglycemic index" (defined as the fall in blood glucose during a 90-minute period prior to reaching the minimum level, divided by the value of this minimum level). The hypoglycemic index was 2.3 +/- 0.6 (mean +/- S.D.) in the group of diabetic patients with symptomatic reactive hypoglycemia and 0.7 +/- 0.3 for the other groups. This index may aid in the diagnosis of patients with symptoms of hypoglycemia and equivocally low values of blood glucose.