title: Association between inflammatory biomarkers and bone mineral density in a community-based cohort of men and women.
abstract: OBJECTIVE
  Based upon evidence in animal and in vitro studies, we tested the hypothesis that higher serum concentrations of the cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) and the inflammatory marker C-reactive protein (CRP) would be inversely associated with bone mineral density (BMD) in a community-based cohort of men and women, with the strongest associations among postmenopausal women not receiving menopause hormonal therapy (MHT).
  
  
  METHODS
  We ascertained fasting serum concentrations of IL-6, TNFα, and CRP and measured BMD at the femoral neck, trochanter, total femur, and spine (L2-L4) using dual x-ray absorptiometry in 2,915 members of the Framingham Offspring Study (1996-2001). We used multivariable linear regression to estimate the difference (β) in BMD at each bone site associated with a 1-unit increase in log-transformed serum concentrations of IL-6, TNFα, and CRP separately for men (n = 1,293), premenopausal women (n = 231), postmenopausal women receiving MHT (n = 498), and postmenopausal women not receiving MHT (n = 893).
  
  
  RESULTS
  Inflammatory biomarkers were not associated with BMD in men. Among premenopausal women, there were statistically significant, modest inverse associations between IL-6 and trochanter BMD (β = -0.030, P < 0.01) and between CRP and femoral neck (β = -0.015, P = 0.05) and trochanter BMD (β = -0.014, P = 0.04). TNFα was positively associated with spine BMD (β = 0.043, P = 0.01). In postmenopausal women receiving MHT, CRP was positively associated with femoral neck BMD (β = 0.011, P = 0.04). There were no associations among postmenopausal women not receiving MHT.
  
  
  CONCLUSIONS
  The lack of consistency in our results suggests that elevated circulating concentrations of inflammatory biomarkers may not be a risk factor for low BMD.
authors.affiliation: Boston University School of Public Health, Boston, Massachusetts.
authors.forename: Todd R
authors.initials: TR
authors.lastname: Sponholtz
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Zhang
authors.forename: Joao D T
authors.initials: JD
authors.lastname: Fontes
authors.forename: James B
authors.initials: JB
authors.lastname: Meigs
authors.forename: L Adrienne
authors.initials: LA
authors.lastname: Cupples
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Kiel
authors.forename: Marian T
authors.initials: MT
authors.lastname: Hannan
authors.forename: Robert R
authors.initials: RR
authors.lastname: McLean
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood* / Q000000981:diagnostic imaging; D011859:Radiography; D012307:Risk Factors; D013131:Spine / Q000000981:diagnostic imaging; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein