Acute stress modulates symptom awareness and hormonal counterregulation during insulin-induced hypoglycemia in healthy individuals.

The purpose of this study was to determine whether the perception of hypoglycemia is reduced during acute stress. In Session I each of our 40 healthy male volunteers received a bolus injection of human insulin (0.05 IU/kg) resulting in plasma glucose nadirs of below 2.8 mmo/L. In Session 2 participants received insulin or saline, with half of each group being stressed by having to prepare and give a speech. Data collection at 5- to 25-min intervals included a symptom checklist, blood pressure, heart rate, and blood sampling for measurement of plasma glucose and counterregulatory hormones. Individuals in the stress + insulin group were less sure of having received insulin and ate fewer cookies compared with controls. They reported lower intensity of the hypoglycemic symptoms of palpitations, tremor, dizziness, and blurred vision, in contrast to the reduced subjective and behavioral reactions, they showed the strongest hormonal counterregulation. We conclude that acute stress during hypoglycemia reduces symptom awareness and the ability to detect hypoglycemia.