Bone biomarkers in patients with chronic traumatic spinal cord injury

Abstract Background context Bone loss after spinal cord injury (SCI) occurs because of pathologic changes in osteoblastic and osteoclastic activities due to mechanical unloading. Some biochemical changes in bone metabolism after SCI are described before that were related to bone mineral loss. Purpose Our purpose was to determine bone markers' changes and related effective factors in patients with chronic traumatic SCI. Study design This investigation was designed as an observational cross-sectional study. Patient sample All patients with chronic SCI who were referred to Brain and Spinal Injury Research Center and did not meet our exclusion criteria entered the study. Outcome measures Self-reporting measures including patient's demographic features and date of accident were obtained using a questionnaire and physiologic measures including spinal magnetic resonance imaging to determine the level of injury accompanied with physical examination along with dual-energy X-ray absorptiometry were performed. Blood samples were analyzed in the laboratory. Methods Dual-energy X-ray was used to determine bone mineral density in femoral and spinal vertebrae bone sites. Serum level of C-telopeptide cross-linked Type 1 collagen (CTX), parathyroid hormone, calcitonin, osteocalcin, and bone alkaline phosphatase (BALP) were measured. Results We detected a negative association between CTX level and bone mineral density in femoral and spinal bone sites that confirms that CTX is a bone resorption marker. C-telopeptide cross-linked Type 1 collagen and BALP levels did not show any significant correlation with postduration injury. Patients with spinal injury at lumbar level had the highest calcitonin level (p