Glucagon-like peptide-1 and impaired counterregulatory responses to hypoglycemia in type 1 diabetes.

This letter comments on a study by Jin et al, published recently in the World Journal of Diabetes. Hypoglycemia is a significant complication of diabetes, with primary defense mechanisms involving the stimulation of glucagon secretion in α-cells and the inhibition of insulin secretion in pancreatic β-cells, which are often compromised in type 1 diabetes mellitus (T1DM) and advanced type 2 diabetes mellitus. Recurrent hypoglycemia predisposes the development of impaired hypoglycemia awareness, a condition underpinned by complex pathophysiological processes, encompassing central nervous system adaptations and several hormonal interactions, including a potential role for glucagon-like peptide-1 (GLP-1) in paracrine and endocrine vias. Experimental evidence indicates that GLP-1 may impair hypoglycemic counterregulation by disrupting the sympathoadrenal system and promoting somatostatin release in pancreatic δ-cells, which inhibits glucagon secretion from neighboring α-cells. However, current trials evaluating GLP-1 receptor agonists (GLP-1 RAs) in T1DM patients have shown promising benefits in reducing insulin requirements and body weight, without increasing the risk of hypoglycemia. Further research is essential to elucidate the specific roles of GLP-1 and GLP-1 RAs in modulating glucagon secretion and the sympathetic-adrenal reflex, and their impact on hypoglycemia unawareness in T1DM patients.