title: Reduced growth hormone secretion improves insulin sensitivity in adolescent girls with type 1 diabetes.
abstract: The aims of the present study were to compare nocturnal growth hormone (GH) secretion, insulin requirements and insulin sensitivity on two occasions in six adolescent girls with type 1 diabetes when the GH secretion was reduced one night by an oral dose of 100 mg of pirenzepine at bedtime. The mean nocturnal intravenous insulin infusion required to maintain a normal constant blood glucose concentration between 24:00 and 07:00 was 53% higher during the night on placebo (p = 0.0212). During the night on pirenzepine, the serum GH area under the curve (AUC) was reduced in all patients to a mean concentration which was 50.1% (15-78%) of that during the night without pirenzepine (p = 0.0036). The nocturnal urinary GH excretion was also reduced in all of the investigated patients (p = 0.0229). Insulin sensitivity in the morning, measured by the euglycaemic hyperinsulinaemic glucose clamp, increased significantly from 115 +/- 51 mg m-2 min-1 after the night on placebo to 205 +/- 67 mg m-2 min-1 after the night on pirenzepine (p = 0.0161). No side-effects were observed during the pirenzepine night. Negative correlations were found between the nocturnal serum GH AUC and the insulin-stimulated glucose metabolism (r = -0.65, p = 0.0241) and between the nocturnal urinary GH excretion and the insulin-stimulated glucose metabolism (r = -0.77, p = 0.0054). In conclusion, the present study shows a relation between GH secretion and insulin resistance in adolescent girls with type 1 diabetes. The administration of pirenzepine acutely reduces GH secretion and improves insulin sensitivity.
authors.affiliation: Department of Paediatrics, Orebro Medical Centre Hospital, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Aman
authors.forename: M
authors.initials: M
authors.lastname: Kroon
authors.forename: I
authors.initials: I
authors.lastname: Karlsson
authors.forename: I
authors.initials: I
authors.lastname: Jones
authors.forename: L
authors.initials: L
authors.lastname: Hagenäs
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D007279:Injections, Subcutaneous; D007328:Insulin / Q000008:administration & dosage; D007332:Insulin Infusion Systems; D007333:Insulin Resistance / Q000502:physiology*; D018727:Muscarinic Antagonists / Q000008:administration & dosage; D010890:Pirenzepine / Q000008:administration & dosage
chemical_list: D001786:Blood Glucose; D007328:Insulin; D018727:Muscarinic Antagonists; D010890:Pirenzepine; D013006:Growth Hormone