Serum IGF-1 in treated acromegaly - how normal is "normal"?
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.
Lansang
Cecilia
C
Division of Endocrinology, Department of Medicine, University of Florida, Gainesville, FL 32610-0226, USA.
Chitaia
Nikoloz
N
Simpson
Nicholas E
NE
Kennedy
Laurence
L
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
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; C406545:pegvisomant