title: Relationship of femoral neck areal bone mineral density to volumetric bone mineral density, bone size, and femoral strength in men and women.
abstract: Using combined dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography, we demonstrate that men matched with women for femoral neck (FN) areal bone mineral density (aBMD) have lower volumetric BMD (vBMD), higher bone cross-sectional area, and relatively similar values for finite element (FE)-derived bone strength.
  
  
  BACKGROUND
  aBMD by DXA is widely used to identify patients at risk for osteoporotic fractures. aBMD is influenced by bone size (i.e., matched for vBMD, larger bones have higher aBMD), and increasing evidence indicates that absolute aBMD predicts a similar risk of fracture in men and women. Thus, we sought to define the relationships between FN aBMD (assessed by DXA) and vBMD, bone size, and FE-derived femoral strength obtained from quantitative computed tomography scans in men versus women.
  
  
  METHODS
  We studied men and women aged 40 to 90 years and not on osteoporosis medications.
  
  
  RESULTS
  In 114 men and 114 women matched for FN aBMD, FN total cross-sectional area was 38% higher (P < 0.0001) and vBMD was 16% lower (P < 0.0001) in the men. FE models constructed in a subset of 28 women and 28 men matched for FN aBMD showed relatively similar values for bone strength and the load-to-strength ratio in the two groups.
  
  
  CONCLUSIONS
  In this cohort of young and old men and women from Rochester, MN, USA who are matched by FN aBMD, because of the offsetting effects of bone size and vBMD, femoral strength and the load-to-strength ratio tended to be relatively similar across the sexes.
authors: Endocrine Research Unit, Mayo Clinic, Guggenheim 7, 200 First Street SW, Rochester, MN 55905, USA.
authors: B
authors: B
authors: Srinivasan
authors: D L
authors: DL
authors: Kopperdahl
authors: S
authors: S
authors: Amin
authors: E J
authors: EJ
authors: Atkinson
authors: J
authors: J
authors: Camp
authors: R A
authors: RA
authors: Robb
authors: B L
authors: BL
authors: Riggs
authors: E S
authors: ES
authors: Orwoll
authors: L J
authors: LJ
authors: Melton
authors: T M
authors: TM
authors: Keaveny
authors: S
authors: S
authors: Khosla
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology; D000886:Anthropometry / Q000379:methods; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005272:Femur Neck / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000473:pathology / Q000503:physiopathology; D012727:Sex Characteristics; D014057:Tomography, X-Ray Computed / Q000379:methods; D016474:Weight-Bearing