title: Serum IGF-1 in treated acromegaly - how normal is "normal"?
abstract: We describe four acromegalic patients with persisting typical symptoms - excessive sweating, lack of suppleness of hands, joint pains - despite the achievement of normal serum IGF-1 levels after pituitary surgery. In three patients there was a clear improvement in symptoms when lower IGF-1 levels within the normal range were achieved with pegvisomant treatment. In the fourth patient IGF-1 levels have fluctuated within the normal range with persistence of abnormal sweating, particularly at night. Two of three patients who had an oral glucose tolerance test when serum IGF-1 was in the normal range failed to suppress GH levels to less than 1 ng/ml. We conclude that, in the treated acromegalic patient, IGF-1 levels within the normal range need to be looked at critically to determine what is truly normal for that individual. Relief of symptoms seems a reasonable yardstick, in addition to population norms, by which to judge whether the prevailing IGF-1 level is appropriate; in some cases the aim should be an IGF-1 level in the lower half of the normal range, or perhaps even the lowest quartile.
authors.affiliation: Division of Endocrinology, Department of Medicine, University of Florida, Gainesville, FL 32610-0226, USA.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lansang
authors.forename: Nikoloz
authors.initials: N
authors.lastname: Chitaia
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Simpson
authors.forename: Laurence
authors.initials: L
authors.lastname: Kennedy
mesh_terms: D000172:Acromegaly / Q000097:blood* / Q000628:therapy; D000328:Adult; D005260:Female; D019382:Human Growth Hormone / Q000031:analogs & derivatives / Q000627:therapeutic use; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012016:Reference Values
chemical_list: D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; C406545:pegvisomant