Sclerostin: a candidate biomarker of SCI-induced osteoporosis.
We assessed several circulating proteins as candidate biomarkers of bone status in men with chronic spinal cord injury. We report that sclerostin is significantly associated with bone mineral content and bone density at all skeletal sites tested. We found no association between bone and any other tested biomarker.


BACKGROUND
Spinal cord injury results in severe osteoporosis. To date, no circulating biomarker of spinal cord injury (SCI)-induced osteoporosis has been identified. We recently reported that circulating sclerostin is associated with bone density in chronic SCI. In this study, we assessed several circulating proteins as candidate biomarkers of bone in men with chronic SCI.


METHODS
We assessed the relationship between bone mineral content or bone density and the following circulating bone-related proteins: sclerostin, DKK-1, soluble receptor activator of nuclear factor kappa B ligand, osteoprotegerin, osteocalcin, and c-telopeptide in 39 men with chronic SCI and 10 men with no SCI.


RESULTS
After adjusting for age, lower sclerostin levels were significantly associated with lower bone mineral content and bone density at all skeletal sites tested (p = 0.0002-0.03). No other circulating protein was associated with bone mineral content or bone mineral density (p = 0.18-0.99).


CONCLUSIONS
These findings suggest that circulating sclerostin reflects the severity of bone loss and is a candidate biomarker of osteoporosis severity in chronic SCI.
Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA.
L R
LR
Morse
S
S
Sudhakar
A A
AA
Lazzari
C
C
Tun
E
E
Garshick
R
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Zafonte
R A
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Battaglino
D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001798:Blood Proteins / Q000378:metabolism; D015519:Bone Density / Q000502:physiology; D019485:Bone Morphogenetic Proteins / Q000097:blood*; D002908:Chronic Disease; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012720:Severity of Illness Index; D013119:Spinal Cord Injuries / Q000150:complications*
D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; D001798:Blood Proteins; D019485:Bone Morphogenetic Proteins; D005819:Genetic Markers; C422903:SOST protein, human