Approach to the evaluation of the GH/IGF-axis in patients with pituitary disease: which test to order.
The diagnosis of adult growth hormone deficiency (AGHD) and acromegaly involves assessment of serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) concentrations. The diagnosis of AGHD typically requires a provocative test of GH reserve, but is supported by demonstration of low-serum IGF-1 levels. Therapeutic monitoring of rhGH replacement is performed utilizing measurement of serum IGF-1 concentrations. In patients with suspected acromegaly, the diagnosis is confirmed by elevated serum IGF-1 levels and further validated by the presence of elevated GH levels both before and following an oral glucose load. A goal of acromegaly therapy is to normalize IGF-1 concentrations, and, depending on the therapeutic modality, GH levels as well. Using case based clinical scenarios, we have presented a standard approach to the biochemical diagnosis and therapeutic monitoring of these disorders.
Roberts
Brian
B
Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305-5826, USA.
Katznelson
Laurence
L
D000172:Acromegaly / Q000175:diagnosis* / Q000188:drug therapy; D000328:Adult; D003940:Diagnostic Techniques, Endocrine; D005260:Female; D020249:Hormone Replacement Therapy / Q000379:methods; D019382:Human Growth Hormone / Q000032:analysis* / Q000172:deficiency / Q000627:therapeutic use; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I