title: Use of bone biochemical markers with dual-energy x-ray absorptiometry for early determination of bone loss in persons with spinal cord injury.
abstract: Our cross-sectional study aimed at the early determination of changes in bone metabolism in terms of bone mineral density (BMD) and bone turnover in persons with complete spinal cord injury (SCI) during the acute phase of paraplegia. Combined dual-energy x-ray absorptiometry (DXA) and specific biochemical markers of bone turnover were used to determine bone metabolism. Seven persons with SCI (age, 31.3 +/- 9.5 years) who had sustained injury an average of 3 months earlier (103 +/- 10.8 days) were compared with 10 able-bodied controls (27.5 +/- 4.3 years). Four paraplegics and 3 quadriplegics composed the SCI group. BMD was measured by DXA, while bone turnover was evaluated by serum osteocalcin (OC), bone alkaline phosphatase (B-ALP), and serum and urinary type I collagen C-telopeptide (CTXs and CTXu). Regional BMD (proximal femur, lumbar spine, radius, lower limb) was similar in the 2 groups except in the upper limb (P <.05). CTXs and CTXu were significantly higher in SCI (P <.01 and P <.001, respectively), whereas among the bone formation markers used, only serum OC was affected by immobilization (P <.05). The SCI group developed hypercalciuria (0.76 +/- 0.37 v 0.35 +/- 0.14), whereas calcemia was normal (2.42 +/- 0.09 v 2.31 +/- 0.10). Intact parathyroid hormone (iPTH) and 1.25 (OH)(2) vitamin D levels were suppressed in persons with SCI (P <.001) by 80.6% and 66%, respectively. In conclusion, it was not possible to detect any variation in BMD from the DXA technique at this early stage of demineralization, but the sensitivity and early response of the biochemical markers strongly suggested their usefulness for the early identification of persons with SCI at risk of severe osteoporosis.
authors.affiliation: Centre Propara, Montpellier, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Maïmoun
authors.forename: Isabelle
authors.initials: I
authors.lastname: Couret
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Micallef
authors.forename: Edouard
authors.initials: E
authors.lastname: Peruchon
authors.forename: Denis
authors.initials: D
authors.lastname: Mariano-Goulart
authors.forename: Michel
authors.initials: M
authors.lastname: Rossi
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Leroux
authors.forename: Freddy
authors.initials: F
authors.lastname: Ohanna
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D001823:Body Composition; D015519:Bone Density; D002118:Calcium / Q000378:metabolism; D003094:Collagen / Q000652:urine; D024042:Collagen Type I; D006706:Homeostasis; D006801:Humans; D010024:Osteoporosis / Q000175:diagnosis*; D010455:Peptides / Q000652:urine; D013119:Spinal Cord Injuries / Q000150:complications / Q000378:metabolism*
chemical_list: D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D003094:Collagen; D002118:Calcium