[Clinical value of urinary pyridinium crosslinks as osteoporosis markers: evaluation of a population survey of vertebral osteoporosis].
BACKGROUND
The diagnostic value of biochemical parameters of bone turnover for the diagnosis of osteoporosis is open to discussion. We investigated whether the determination of crosslinks, bone type I collagen degradation products, correctly identifies osteoporotic subjects.


METHODS
In a sample of 370 individuals recruited at random within a population survey of vertebral osteoporosis, urinary concentration of total pyridinoline and desoxypyridinoline were determined by HPLC. Standardized lateral X-rays of the thoracic and lumbar spine were taken and evaluated morphometrically using the method described by Eastell-Melton.


RESULTS
Crosslink excretion was significantly higher in female but not in male individuals with vertebral deformities as defined by Eastell. The specificity of these biochemical parameters with regard to radiological osteoporotic alterations was 76-81%, but the sensitivity was 32.4-42.9% only.


CONCLUSIONS
Pyridinoline and desoxypyridinoline reflect the process of bone degradation which leads to vertebral deformity. Crosslinks are specific markers of bone resorption and provide a valid parameter in the diagnosis of osteoporosis. The low sensitivity indicates that the measurement of pyridinoline and desoxypyridinoline is less suitable for screening purposes, but may be useful in confirming presence or extent of osteoporosis.
Behre
A
A
Abteilung für Endokrinologie und Stoffwechselerkrankungen, Medizinische Universitätsklinik Bergmannsheil Bochum. Ariane.Behre@t-online.de
Janott
J
J
Pfohl
M
M
Schatz
H
H
Pfeiffer
A
A
D000368:Aged; D000596:Amino Acids / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D001862:Bone Resorption / Q000652:urine*; D003404:Creatinine / Q000652:urine*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000652:urine; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis; D011237:Predictive Value of Tests; D011859:Radiography; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013131:Spine / Q000000981:diagnostic imaging* / Q000378:metabolism
D000596:Amino Acids; D015415:Biomarkers; C015484:pyridinoline; C036020:deoxypyridinoline; D003404:Creatinine