Protein-sensitive hypoglycemia without leucine sensitivity in hyperinsulinism caused by K(ATP) channel mutations

J Pediatr. 2006 Jul;149(1):47-52. doi: 10.1016/j.jpeds.2006.02.033.

Abstract

Objective: Because children with congenital hyperinsulinism (HI) caused by recessive loss of function mutations in the adenosine triphosphate (ATP)-dependent potassium channel (K(ATP)-HI) are not leucine sensitive, we evaluated for protein-induced hypoglycemia with oral protein tolerance tests.

Study design: Blood glucose and insulin concentrations were measured every 15 minutes for 3 hours after an oral protein load in children with K(ATP)-HI (n = 11) and compared with those of children with glutamate dehydrogenase HI (n = 12) and control subjects (n = 12).

Results: Similar to children with glutamate dehydrogenase HI, patients with K(ATP)-HI displayed protein-induced hypoglycemia (10/11) with blood glucose concentrations declining by 17 to 69 mg/dL. In contrast, oral protein had little effect on blood glucose concentrations in control subjects.

Conclusions: Protein-induced hypoglycemia is a feature of K(ATP)-HI, despite the absence of leucine sensitivity. The results indicate that amino acids can stimulate insulin secretion via a glutamate dehydrogenase- and K(ATP) channel-independent pathway.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics*
  • ATP-Binding Cassette Transporters / metabolism
  • Adenosine Triphosphate / metabolism
  • Administration, Oral
  • Adolescent
  • Adult
  • Blood Glucose / analysis
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Congenital Hyperinsulinism / genetics*
  • Female
  • Glutamate Dehydrogenase / genetics
  • Glutamate Dehydrogenase / metabolism
  • Humans
  • Hypoglycemia / etiology*
  • Hypoglycemia / metabolism
  • Infant
  • Infant, Newborn
  • Insulin / blood
  • Leucine
  • Male
  • Mutation
  • Potassium Channels / genetics*
  • Potassium Channels / metabolism
  • Potassium Channels, Inwardly Rectifying / genetics*
  • Potassium Channels, Inwardly Rectifying / metabolism
  • Proteins / adverse effects*
  • Receptors, Drug / genetics*
  • Receptors, Drug / metabolism
  • Sulfonylurea Receptors

Substances

  • ATP-Binding Cassette Transporters
  • Blood Glucose
  • Insulin
  • Potassium Channels
  • Potassium Channels, Inwardly Rectifying
  • Proteins
  • Receptors, Drug
  • Sulfonylurea Receptors
  • Adenosine Triphosphate
  • Glutamate Dehydrogenase
  • Leucine