title: Elevated plasma levels of interleukin-6 in postmenopausal women do not correlate with bone density.
abstract: OBJECTIVE
  To determine if plasma levels of Interleukin-6 (IL-6) across the lifespan correlate with bone density or plasma osteocalcin.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Forty-five healthy community-dwelling volunteers aged 25-74 years. Exclusion criteria were smoking use of medications known to affect bone metabolism (corticosteroids, heparin, thyroxine, thiazides, and anticonvulsants), and presence of chronic inflammatory disease.
  
  
  METHODS
  Bone density was measured by dual-energy X-ray absorptiometry at the femoral neck and lumbar spine. Plasma levels of IL-6 and osteocalcin were determined by ELISA and RIA, respectively.
  
  
  RESULTS
  Plasma levels of IL-6 increased with advancing age (P < .0001) and correlated with postmenopausal status (P < .0001). No correlation was observed between plasma IL-6 level and bone mineral density at either the lumbar spine or femoral neck, and none was observed with plasma osteocalcin.
  
  
  CONCLUSIONS
  The elevation of plasma IL-6 observed following menopause is consistent with the proposed importance of estrogen in the regulation of IL-6. These findings do not provide support for a role of IL-6 in determination of peak bone density or subsequent development of osteoporosis. However, it is possible that plasma levels of IL-6 differ from those in the bone microenvironment.
authors.affiliation: Department of Medicine, University of Wisconsin-Madison.
authors.forename: D M
authors.initials: DM
authors.lastname: Kania
authors.forename: N
authors.initials: N
authors.lastname: Binkley
authors.forename: M
authors.initials: M
authors.lastname: Checovich
authors.forename: T
authors.initials: T
authors.lastname: Havighurst
authors.forename: M
authors.initials: M
authors.lastname: Schilling
authors.forename: W B
authors.initials: WB
authors.lastname: Ershler
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000367:Age Factors; D000368:Aged; D015519:Bone Density; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D015663:Osteoporosis, Postmenopausal / Q000097:blood* / Q000000981:diagnostic imaging; D017698:Postmenopause / Q000097:blood*
chemical_list: D015850:Interleukin-6; D015675:Osteocalcin