Change in C-terminal cross-linking domain of type I collagen in urine, a new marker of bone resorption, during and after gonadotropin-releasing hormone agonist administration.
OBJECTIVE
The major side effect of GnRH agonist (GnRHa) therapy is the reduction of bone mass. To analyze bone resorption by GnRHa, we measured the urinary excretion of C-terminal telopeptides of type I collagen (CTX), a new marker of bone resorption.


METHODS
We used a new ELISA for CTX (CrossLaps) in a sample of 18 premenopausal women with leiomyoma who were treated with daily administration of 400 micrograms nafarelin or 900 micrograms buserelin for 16 weeks.


RESULTS
Urinary CTX excretion increased significantly during GnRHa treatment and then decreased at 12 and 24 weeks after the cessation of GnRHa therapy. Whereas the excretory profile of CTX during GnRHa therapy was almost similar to that of pyridinoline (Pyr) or deoxypyridinoline (D-Pyr), both biochemical markers of bone resorption, the magnitude of the change in CTX was significantly greater than that in Pyr or D-Pyr.


CONCLUSIONS
These results indicate that CTX could be a more sensitive marker for bone resorption than the currently used biochemical markers, and that CrossLaps ELISA is useful for therapeutic monitoring during and after GnRHa treatment.
Taga
M
M
Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, Japan.
Minaguchi
H
H
D000328:Adult; D000596:Amino Acids / Q000652:urine; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use; D015415:Biomarkers; D015519:Bone Density / Q000187:drug effects; D001862:Bone Resorption / Q000139:chemically induced* / Q000652:urine*; D002064:Buserelin / Q000009:adverse effects / Q000627:therapeutic use; D003094:Collagen / Q000737:chemistry* / Q000652:urine*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000009:adverse effects / Q000819:agonists*; D006728:Hormones / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D007889:Leiomyoma / Q000188:drug therapy; D008875:Middle Aged; D017274:Nafarelin / Q000009:adverse effects / Q000627:therapeutic use; D014594:Uterine Neoplasms / Q000188:drug therapy
D000596:Amino Acids; D018931:Antineoplastic Agents, Hormonal; D015415:Biomarkers; D006728:Hormones; D017274:Nafarelin; D007987:Gonadotropin-Releasing Hormone; C015484:pyridinoline; C036020:deoxypyridinoline; D003094:Collagen; D002064:Buserelin