Decreased half-life of insulin-like growth factor I in Rabson-Mendenhall syndrome.
Rabson-Mendenhall syndrome is an autosomal recessive disorder of insulin signalling caused by mutations in the insulin receptor gene. Affected patients are insensitive to exogenous insulin. Insulin-like growth factor I (IGF-I), whose receptor is similar to the one for insulin and is not impaired in this condition, is not always effective in these patients. To understand the reason for this failure, IGF-I concentrations were measured in a patient after subcutaneous injection of 0.1 and 0.2 mg/kg of rhIGF-I. IGF-I concentrations increased only transiently because of the short half-life (1.3-3 h, compared to a normal range of 17-22 h). No correlation was found between IGF-I concentrations and glucose or insulin concentrations. The short half-life of IGF-I may contribute to treatment failure in patients with inherited insulin-resistant syndromes.
Longo
N
N
Division of Medical Genetics, Department of Pediatrics, Emory University, Atlanta, Georgia 30322, USA. nl@rw.ped.emory.edu
Singh
R
R
Elsas
L J
LJ
D000052:Acanthosis Nigricans / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D006207:Half-Life; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000235:genetics*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000493:pharmacokinetics*; D008297:Male; D009154:Mutation / Q000235:genetics; D011972:Receptor, Insulin / Q000235:genetics*; D011994:Recombinant Proteins / Q000493:pharmacokinetics; D013577:Syndrome
D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin