title: Age, gender, and race/ethnic differences in total body and subregional bone density.
abstract: CONCLUSIONS
  Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing.
  
  
  BACKGROUND
  Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton.
  
  
  METHODS
  The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing.
  
  
  RESULTS
  Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm.
  
  
  CONCLUSIONS
  This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.
authors.affiliation: National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD 20782, USA. Alooker@cdc.gov
authors.forename: A C
authors.initials: AC
authors.lastname: Looker
authors.forename: L J
authors.initials: LJ
authors.lastname: Melton
authors.forename: T
authors.initials: T
authors.lastname: Harris
authors.forename: L
authors.initials: L
authors.lastname: Borrud
authors.forename: J
authors.initials: J
authors.lastname: Shepherd
authors.forename: J
authors.initials: J
authors.lastname: McGowan
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001132:Arm / Q000000981:diagnostic imaging / Q000502:physiology*; D050280:Arm Bones / Q000000981:diagnostic imaging / Q000502:physiology*; D044383:Black People / Q000706:statistics & numerical data; D015519:Bone Density / Q000502:physiology*; D005260:Female; D006801:Humans; D007867:Leg Bones / Q000000981:diagnostic imaging / Q000502:physiology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D017058:Mexican Americans / Q000706:statistics & numerical data; D008875:Middle Aged; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000502:physiology*; D012737:Sex Factors; D014481:United States / Q000208:ethnology; D016474:Weight-Bearing; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult; D001741:Black or African American