Serum levels of bone Gla protein (osteocalcin, BGP) and carboxyterminal propeptide of type I procollagen (PICP) in acromegaly: effects of long-term octreotide treatment.
We measured serum concentrations of bone Gla-protein (osteocalcin, BGP) and carboxyterminal propeptide of type I procollagen (PICP) in 14 patients with active acromegaly. Blood was collected at 0800 for measurement of bone Gla-protein (BGP), carboxyterminal propeptide of type I procollagen (PICP), and insulin-like growth factor I (IGF-I); growth hormone (GH) was then determined at 15-minute intervals for 3 hours and the integrated mean was calculated. The same protocol was repeated at regular intervals during treatment with the long-acting somatostatin analog, octreotide, 150-450 micrograms/day for 6-33 months (median 15). In a case-control analysis, serum BGP concentrations recorded in the acromegalic patients were significantly elevated (14.2 +/- 4.2 micrograms/liter versus 8.0 +/- 3.3 micrograms/liter, P < 0.001). Octreotide treatment induced a roughly parallel reduction in serum GH, IGF-I, and BGP. We found a significant positive correlation between BGP levels recorded before and during therapy and the logarithm of corresponding mean GH levels (r = 0.67, P < 0.001). Also IGF-I concentrations were positively correlated with BGP (r = 0.66, P < 0.001). On the other hand, PICP levels recorded in the acromegalics did not differ from control subjects (146 +/- 46 micrograms/liter versus 127 +/- 44 micrograms/liter, NS) and no correlation was found between either GH and PICP or IGF-I and PICP. To conclude, the present data are compatible with the view that GH and IGF-I play an important role in the control of BGP but not PICP production. It could be that BGP and PICP are submitted to different hormonal modulation.
Terzolo
M
M
Department of Clinical and Biological Sciences, S. Luigi Hospital, University of Turin, Italy.
Piovesan
A
A
Osella
G
G
Pia
A
A
Reimondo
G
G
Pozzi
C
C
Raucci
C
C
Torta
M
M
Paccotti
P
P
Angeli
A
A
D000172:Acromegaly / Q000097:blood* / Q000188:drug therapy; D000328:Adult; D000368:Aged; D015519:Bone Density / Q000187:drug effects; D016022:Case-Control Studies; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use*; D015675:Osteocalcin / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011347:Procollagen / Q000097:blood*
D010446:Peptide Fragments; D011347:Procollagen; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D015282:Octreotide