Insulin-like growth factor binding protein-3 levels during early and late follow-up after surgery in acromegalic patients.
Disease activity in acromegaly is accurately reflected by growth hormone (GH) concentration during oral glucose tolerance test (OGTT) and insulin-like growth factor-I (IGF-I) levels, representing an integrated index of GH activity. This prospective study was performed to evaluate whether plasma IGF binding protein 3 (IGFBP-3) might also reflect the hormonal disease activity in pituitary acromegaly after operative treatment during early and late follow-up. Twenty-two acromegalic patients were studied. Data were obtained pre-, intra- and post-operatively in 13 cases. In 9 patients the acromegalic activity was studied only after treatment. The hormonal assessment included repeated blood samples for estimation of IGF-I, IGFBP-3 and repeated OGTTs. In each case 100 sigma g octreotide (Sandostatin lambda, Sandoz, Basel) was injected to test the acute response of GH, IGF-I and IGFBP-3. Intraoperatively, GH levels were estimated to examine acutely the influence of tumour reduction on GH levels. Patients were considered cured when GH levels (GH60min) were less than 2 ng/ml during OGTT 4 weeks after surgery. The data outlined that in patients with normalized GH60min levels, normalized IGFBP-3 levels were noticed 4 weeks and 12 months post-operatively. In non-cured patients normalized IGFBP-3 concentrations were found in 11 out of 15 cases in the late post-treatment phase. In contrast only 1 of 7 cured patients had persistently elevated IGF-I levels within the first month post-operatively, whereas no case of the non-cured patients had IGF-I values in the normal range. Despite these observations a strong correlation of IGF-I and IGFBP-3 did not exist before one year post-operatively -- either in the cured or in the non-cured patients. Serum IGFBP-3 in patients with pituitary acromegaly does not provide a predictive value of appreciable magnitude concerning cure or non-cure from the disease- whether examined early or late in the post-operative period. Absolute levels of IGFBP-3 may thus cause misinterpretation concerning cure of acromegalics after surgery.
Charalampaki
P
P
Department of Neurosurgery, University of Cologne.
Hildebrandt
G
G
Schaeffer
H J
HJ
Schönau
E
E
Klug
N
N
D000172:Acromegaly / Q000097:blood* / Q000188:drug therapy / Q000601:surgery*; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D013006:Growth Hormone / Q000097:blood / Q000187:drug effects; D006728:Hormones / Q000627:therapeutic use; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood* / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use; D011184:Postoperative Period; D011446:Prospective Studies; D013997:Time Factors
D006728:Hormones; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D015282:Octreotide