Evaluating Glial Acetate Metabolism as a Biomarker of Hypoglycemic Counterregulation

Evaluating Glial Acetate Metabolism as a Biomarker of Hypoglycemic Counterregulation Using 13C Magnetic Resonance Spectroscopy.

Hypoglycemic complications are a major impediment to the maintenance of healthy glucose levels in persons with diabetes. The investigators recently completed a clinical pilot and feasibility study (GLIMPSE, NCT02690168), which identified a novel biomarker, glial acetate metabolism, that appears to predict the susceptibility to hypoglycemia. By providing an assay to predict hypoglycemic events and therefore diabetic complications, the development of this biomarker could significantly improve the treatment of persons with diabetes.

The goal of this study is to determine the efficacy of our biomarker for predicting susceptibility to insulin-induced hypoglycemia. In order to accomplish this goal the investigatiors will pair our 13C magnetic resonance spectroscopy procedure to assess glial acetate metabolism, developed in the GLIMPSE study, with a hyperinsulinemic-hypoglycemic clamp procedure, developed in the HYPOCLAMP study (NCT03839511). The two procedures will be separated by a three day interval. The investigators will then correlate the participants' rates of glial acetate metabolism with their neuroendocrine responses to the hypoglycemic clamp. This proof of concept study will test the hypothesis that glial acetate metabolism is inversely proportional to the neuroendocrine response to hypoglycemia, that is, as glial acetate metabolism increases the neuroendocrine response will decrease.

Inclusion Criteria:

• Healthy male or female
• Ages 18-40 years
• BMI between 20 kg/m2 and 30 kg/m2 (±0.5 kg/m2 will be accepted)
• Medically cleared for participation in the study

Exclusion Criteria:

• Contraindication to MRI
• Consume >10 alcoholic drinks/week
• History of chronic smoking or have quit less than 10 years ago
• History of clinically diagnosed diabetes or a fasting blood glucose >126 mg/dL
• Average screening blood pressure >140/90 mmHg
• History of cardiovascular disease
• Pregnant, planning to become pregnant, or breastfeeding
• Use of medications affecting glucose metabolism, e.g., benzodiazepines, thiazide diuretics, cortisone, and prednisone.
• Use of beta-adrenergic antagonists.
• Based on the investigative team's clinical judgement, a subject may not be appropriate for participation in the study.