title: Lumbar spine bone mineral density in US adults: demographic patterns and relationship with femur neck skeletal status.
abstract: This analysis examines lumbar spine bone mineral density (BMD) of US adults from NHANES 2005-2008 by age, sex, and race/ethnicity. Prevalence of low spine BMD and agreement between the prevalence of low BMD at the spine and femur neck in older adults are also assessed.
  
  
  BACKGROUND
  Lumbar spine BMD data from a representative sample of the US population have not been previously available.
  
  
  METHODS
  We used data from the National Health and Nutrition Examination Survey 2005-2008 to examine demographic patterns in lumbar spine BMD among US adults age ≥20 years and the prevalence of low lumbar spine BMD in adults age ≥50 years. Agreement between the prevalence of low BMD at the femur neck and spine in older adults was also assessed. Dual-energy X-ray absorptiometry was used to measure lumbar spine and femur neck BMD. World Health Organization definitions were used to categorize skeletal status as normal, osteopenia, or osteoporosis.
  
  
  RESULTS
  Compared to non-Hispanic whites, non-Hispanic blacks had higher and Mexican Americans had lower lumbar spine BMD. Lumbar spine BMD declined with age in women, but not in men. Approximately 4.7 million (10%) older US women and 1 million (3%) older men had lumbar spine osteoporosis in 2005-2008. Roughly one third of them differed in skeletal status at the spine and hip but most were normal at one site and osteopenic at the other. Only 3-10%, depending on sex, had osteoporosis at one skeletal site but not at the other skeletal site. Between 76% and 87% with discordant skeletal status had lumbar spine T-scores within 1 unit of the category threshold.
  
  
  CONCLUSIONS
  These findings suggest that measuring either the femur neck or the lumbar spine will correctly classify the majority of individuals who present for care as osteoporotic or not.
authors: National Center for Health Statistics, Centers for Disease Control and Prevention, Room 4310, 3311 Toledo Road, Hyattsville, MD 20782, USA. Alooker@cdc.gov
authors: A C
authors: AC
authors: Looker
authors: L J
authors: LJ
authors: Melton
authors: L G
authors: LG
authors: Borrud
authors: J A
authors: JA
authors: Shepherd
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000375:Aging / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology; D005260:Female; D005272:Femur Neck / Q000502:physiology* / Q000503:physiopathology; D006306:Health Surveys; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D017058:Mexican Americans / Q000706:statistics & numerical data; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis / Q000208:ethnology* / Q000503:physiopathology; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology; D015995:Prevalence; D012727:Sex Characteristics; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult