title: Bone mass and hormone analysis in patients with spinal cord injury: evidence for a gonadal axis disruption.
abstract: BACKGROUND
  Bone loss is a constant finding in patients with spinal cord injury (SCI).
  
  
  OBJECTIVE
  We sought to evaluate potential modifiable factors that could lead to bone loss in complete motor paraplegia by examining gonadal axis hormones, vitamin D status, and bone markers.
  
  
  METHODS
  This is a cross sectional.
  
  
  METHODS
  It includes SCI Outpatient.
  
  
  METHODS
  Twenty-nine chronic male patients with SCI were compared with 17 age-matched, able-bodied men.
  
  
  METHODS
  The bone mineral density (BMD) of lower limbs and lumbar spine were measured using dual x-ray absorptiometry. Parathormone, 25-hydroxyvitamin D [25(OH)D], collagen type I C-terminal telopeptide (CTX), and sexual hormone were measured.
  
  
  RESULTS
  Patients with SCI had lower BMD at the inferior limbs sites. CTX showed an inverse relationship with the time since injury. Patients had lower free T levels (SCI, 12.00 ± 2.91 vs controls, 19.51 ± 5.72; P ≤ .001), and the majority (72%) had normal/low levels of gonadotropins. Low T, however, was not related to low bone mass in patients with SCI. In the controls, the 25(OH)D level was positively correlated with the T and with the lumbar spine BMD, but these correlations were not observed in the SCI.
  
  
  CONCLUSIONS
  Impairment of testicular function after SCI was indicated by the low levels of T and the loss of correlation between T and 25(OH)D levels; this correlation was present in the able-bodied controls. Inappropriate levels of gonadotropins were identified in most patients, featuring a hypogonadotropic hypogonadism and suggesting a disruption of the pituitary-gonadal axis. T concentrations might not be an effective target for bone loss therapy.
authors.affiliation: Division of Endocrinology (A.P.G., C.M.A.B., M.L.-C.), Universidade Federal de São Paulo, São Paulo 04021-001, Brazil; and Associação de Assistência à Criança Deficiente (A.P.G.), São Paulo 04027-000, Brazil.
authors.forename: Alexandra Passos
authors.initials: AP
authors.lastname: Gaspar
authors.forename: Cynthia M A
authors.initials: CM
authors.lastname: Brandão
authors.forename: Marise
authors.initials: M
authors.lastname: Lazaretti-Castro
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D001842:Bone and Bones / Q000473:pathology*; D024042:Collagen Type I / Q000097:blood; D003430:Cross-Sectional Studies; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006066:Gonads / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010264:Paraplegia / Q000097:blood / Q000503:physiopathology; D010281:Parathyroid Hormone / Q000097:blood; D010455:Peptides / Q000097:blood; D013119:Spinal Cord Injuries / Q000097:blood* / Q000473:pathology / Q000503:physiopathology*; D014807:Vitamin D / Q000097:blood; D055815:Young Adult
chemical_list: D024042:Collagen Type I; D012739:Gonadal Steroid Hormones; D010281:Parathyroid Hormone; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D014807:Vitamin D