Figure 1.

GABA treatment improves the counter-regulatory hormone response to hypoglycemia in type 1 diabetes. (A) Flash glucose monitoring for all subjects (n=6) at baseline and during short-term oral treatment with GABA in increasing doses. (B–F) Hormonal counter-regulatory response during hyperinsulinemic hypoglycemic clamps. Glucose levels were regulated by an intravenous continuous rate of insulin and a variable rate of glucose in order to reach first a 30 min plateau with glucose levels of 5.5 mmol/L, followed by a 30 min plateau at 2.5 mmol/L. Blood samples were collected at the end of each plateau. The analysis contains data from the five subjects without detectable C peptide (<0.01 nmol/L) in which the counter-regulatory response was blunted at baseline. Black bars represent normoglycemia (5.5 mmol/L) and gray bars hypoglycemic conditions (2.5 mmol/L). Data are presented as mean±SEM. *P<0.05 and **P<0.01 compared with the normoglycemic levels at the respective occasion. GABA, gamma-aminobutyric acid.