We have studied the physiological and clinical relevance of measurements
of serum total and free IGF-I and IGF-binding protein-3 (IGFBP-3) in 57
previously untreated patients with active acromegaly (32 males, 25
females; mean age 47 years) as compared with sex- and age-matched normal
healthy controls. Serum total and free IGF-I, but not IGFBP-3, are
suitable biochemical parameters for screening for acromegaly. In
acromegalics, the mean 24 h serum GH, total IGF-I and IGFBP-3 levels tend
to decrease with age. However, in our series of patients, mean 24 h serum
GH levels, IGFBP-3, total and free IGF-I do not correlate with disease
activity in acromegaly