title: Nutrition therapy for hepatic glycogen storage diseases.
abstract: Hepatic glycogen storage diseases (GSD) are a group of rare genetic disorders in which glycogen cannot be metabolized to glucose in the liver because of one of a number of possible enzyme deficiencies along the glycogenolytic pathway. Patients with GSD are usually diagnosed in infancy or early childhood with hypoglycemia, hepatomegaly, poor physical growth, and a deranged biochemical profile. Dietary therapies have been devised to use the available alternative metabolic pathways to compensate for disturbed glycogenolysis in GSD I (glucose-6-phosphatase deficiency), GSD III (debrancher enzyme deficiency), GSD VI (phosphorylase deficiency, which is less common), GSD IX (phosphorylase kinase deficiency), and GSD IV (brancher enzyme deficiency). In GSD I, glucose-6-phosphate cannot be dephosphorylated to free glucose. Managing this condition entails overnight continuous gastric high-carbohydrate feedings; frequent daytime feedings with energy distributed as 65% carbohydrate, 10% to 15% protein, and 25% fat; and supplements of uncooked cornstarch. In GSD III, though glycogenolysis is impeded, gluconeogenesis is enhanced to help maintain endogenous glucose production. In contrast to treatment for GSD I, advocated treatment for GSD III comprises frequent high-protein feedings during the day and a high-protein snack at night; energy is distributed as 45% carbohydrate, 25% protein, and 30% fat. Patients with GSD IV, VI, and IX have benefited from high-protein diets similar to that recommended for patients with GSD III.
authors.affiliation: Division of Pediatric Endocrinology and Metabolism, North Shore University Hospital-Cornell University Medical College, Manhasset, NY 11030.
authors.forename: T
authors.initials: T
authors.lastname: Goldberg
authors.forename: A E
authors.initials: AE
authors.lastname: Slonim
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D004044:Dietary Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D004750:Enteral Nutrition; D006008:Glycogen Storage Disease / Q000178:diet therapy* / Q000628:therapy; D005953:Glycogen Storage Disease Type I / Q000178:diet therapy* / Q000628:therapy; D006010:Glycogen Storage Disease Type III / Q000178:diet therapy*; D006011:Glycogen Storage Disease Type IV / Q000178:diet therapy; D006013:Glycogen Storage Disease Type VI / Q000178:diet therapy; D006801:Humans; D007003:Hypoglycemia / Q000517:prevention & control; D007223:Infant; D007231:Infant, Newborn; D010764:Phosphorylase Kinase / Q000172:deficiency; D013213:Starch / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D004044:Dietary Proteins; D013213:Starch; D010764:Phosphorylase Kinase