Identifying the Brain Substrates of Hypoglycemia Unawareness in Type 1 Diabetes
Condition: Hypoglycemia
MeSH terms: Hypoglycemia
Study type: Interventional
Phase: Early Phase 1

Summary: 
      The purpose of this study is to investigate how the brain responds to low blood glucose in
      non-diabetic individuals. The ultimate goal is to understand the brain substrates of
      hypoglycemia unawareness, a condition that can occur in patients with type1 diabetes
      undergoing insulin treatment.In the present study, the investigators focus on differences
      between two groups of non-diabetic subjects: one group who experienced two episodes of
      hypoglycemia the day prior to the study (and supposedly developed some level of unawareness
      to hypoglycemia), and one group who did not. In this study, a 3 tesla MRI scanner is used to
      acquire brain images. The imaging system is identical to the ones used in hospitals.
    

Detailed description: 
      Hypoglycemia, also called low blood glucose or low blood sugar, occurs when blood glucose
      drops below normal levels. When blood glucose starts to drop, the body reacts to this drop,
      trying to restore the blood glucose level. Symptoms of hypoglycemia are usually easily
      recognized. Hypoglycemia can be treated quickly and easily by eating or drinking a small
      amount of glucose-rich food. However some people with long history of diabetes can have an
      impaired response to hypoglycemia and therefore don't recognize the symptoms of hypoglycemia,
      condition called hypoglycemia unawareness. If not treated hypoglycemia can get worse and
      cause confusion, clumsiness, fainting etc. Currently, it is not fully understood which brain
      areas are involved in sensing the drop of glucose levels. Absence of such knowledge is a
      critical barrier to the design and monitoring of effective intervention strategies to avoid
      and/or reverse hypoglycemia unawareness. The purpose of this study is to investigate how the
      brain responds to low blood glucose in non-diabetic individuals. Specific focus is given to
      differences between two groups of non-diabetic subjects: one group who experienced two
      episodes of hypoglycemia the day prior to the study (and therefore supposedly developed some
      level of unawareness to hypoglycemia), and one group who did not.
    

Intervention name(s): Insulin; Glucose; Potassium phosphate
Intervention type(s): Drug; Drug; Drug
Intervention description(s): In each clamp, a small intravenous catheter is placed in participant's arm for infusion of insulin together with potassium phosphate and glucose. Insulin is a hormone that body makes naturally and it causes blood sugar to decrease. Insulin (and glucose) will be infused in calculated doses to maintain blood sugar level in the target range of 95 mg/dl or 50 mg/dl depending on the clamp.; Glucose is administered together with insulin and potassium phosphate during each clamp via the intravenous catheter. Glucose is a sugar and it is used to carefully regulate blood sugar level.; Potassium phosphate is administered together with glucose and insulin during each clamp via the intravenous catheter. Potassium is a salt-like substance that is present in the blood.
Other intervention name(s): Humulin; Dextrose; K Phos
Intervention MeSH terms: Potassium phosphate
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: MRI