COMPARATIVE-STUDY OF INSULIN-LIKE GROWTH-FACTOR-I (IGF-I) AND IGF-BINDING PROTEIN-3 (IGFBP-3) LEVEL AND IGF-I IGFBP-3 RATIO MEASUREMENTS AND THEIR RELATIONSHIP WITH AN INDEX OF CLINICAL ACTIVITY IN THE MANAGEMENT OF PATIENTS WITH ACROMEGALY/

To evaluate the utility of measuring the serum insulin-like growth fac tor (IGF)-binding protein-3 [IGFBP-3) level and the IGF-I/IGFBP-3 rati o in the management of acromegalic patients, we comparatively studied the basal concentration of the aforementioned parameters with determin ation of plasma IGF-I levels and an index of clinical activity of acro megaly in 16 newly diagnosed acromegalic patients (aged 34 to 64 years ) before and after hypophysectomy; After adenomectomy, 10 patients rem ained with ''active'' disease and six were ''cured.'' Twenty-nine heal thy sex- and age-matched volunteers were also studied. Comparison of i ndividual values between untreated acromegalic patient's and control s ubjects showed that none of the patients had overlapping Values for IG F-I, whereas five of 16 and three of 16 patients had overlapping value s for serum IGFBP-3 and IGF-I/IGFBP-3 ratio, respectively. When we com pared the study parameters between the patients who remained with acti ve disease after adenomectomy and the controls, two of 10 had overlapp ing values for IGF-I, but six of 10 and five of 10 had overlapping val ues for serum IGFBP-3 and IGF-I/IGFBP-3 ratio, respectively Moreover, comparison of these parameters between cured and active patients after hypophysectomy showed that none had overlapping values for IGF-I, whe reas three of six and one of six had overlapping values for serum IGFB P-3 and IGF-I/IGFBP-3 ratio, respectively. All biochemical variables s tudied showed significant relationships with an index of clinical acti vity of disease, In conclusion, our results seem to indicate that amon g determinations of plasma IGF-I, serum IGFBP-3, and the ratio IGF-I/I GFBP-3 in the evaluation of acromegalic patients, measurement of the p lasma IGF-I level has the most discriminative value in the management of these patients. Copyright (C) 1997 by W.B. Saunders Company .