It has been found that in some cases, when a person with Diabetes Mellitus has an episode of low blood sugar,or hypoglycemia, and then later exercises, he or she is vulnerable to another bout of hypoglycemia during that exercise. The purpose of this study is to determine what factors during the previous bout of hypoglycemia might cause another bout of hypoglycemia while exercising later.

The SPECIFIC AIM of the study outlined in this proposal is to determine if hypoglycemia blunts counterregulatory responses during subsequent exercise in Type 1 Diabetes Mellitus due to physiologic increases in plasma cortisol.

Inclusion Criteria:

• Males and females with Type 1 Diabetes Mellitus will be studied. Subjects recruited will be 18-50 years, with an HBA1c less than 9.5%, who have been diagnosed with diabetes for >5 years, with no clinical evidence of diabetic tissue complications.

Exclusion Criteria:

• Subjects with known prior cardiac events will be excluded from the study. Additional exclusion criteria:

  1. all medical students (Vanderbilt policy)
  2. prior or current history of poor health
  3. abnormal results following blood and physical examination
  4. pregnancy