title: Trabecular bone scores and lumbar spine bone mineral density of US adults: comparison of relationships with demographic and body size variables.
abstract: This study examines demographic patterns and body size relationships in trabecular bone score and lumbar spine BMD of US adults from NHANES 2005-2008.
  
  
  
  Limited data exist on demographic and body size relationships for trabecular bone score (TBS), a new variable derived from bone texture analysis of lumbar spine dual-energy X-ray absorptiometry (DXA) scans. This study compares demographic patterns and correlations with body size (body mass index (BMI), weight, waist circumference, total body fat, trunk fat, trunk lean) between TBS and lumbar spine bone mineral density (LSBMD) for adults age ≥20 years from the National Health and Nutrition Examination Survey (NHANES) 2005-2008 with BMI in the optimal range for TBS (15-37 kg/m(2)).
  
  
  
  LSBMD, TBS, body fat, and lean were obtained by DXA. Weight, height, and waist circumference were measured. BMI was calculated from height and weight.
  
  
  
  Sex differences in TBS varied by age and race/ethnicity (p sex X age interaction and p sex X race/ethnicity interaction < 0.001). In most of the nine demographic subgroups examined, TBS did not differ by sex (four subgroups) or was significantly higher in women (three subgroups). TBS differences by race/ethnicity were inconsistent in men; in women, non-Hispanic whites (NHWs) had higher TBS than non-Hispanic blacks (NHBs) or Mexican Americans (MAs) in all age groups. In contrast, LSBMD was either significantly higher in men (five subgroups) or did not differ by sex (four subgroups). Race/ethnic differences in LSBMD were consistent across age and sex (NHB > NHW > MA). All body size variables were negatively related to TBS but positively related to LSBMD.
  
  
  
  Demographic patterns and body size relationships differed between TBS and LSBMD.
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, Centers for Disease Control and Prevention, 3311 Toledo Road, Hyattsville, MD, 20782, USA. ALooker@cdc.gov.
authors.forename: A C
authors.identifier: 0000-0002-6913-298X
authors.initials: AC
authors.lastname: Looker
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, Centers for Disease Control and Prevention, 3311 Toledo Road, Hyattsville, MD, 20782, USA.
authors.forename: N
authors.initials: N
authors.lastname: Sarafrazi Isfahani
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
authors.forename: B
authors.initials: B
authors.lastname: Fan
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Shepherd
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D049628:Body Size; D015519:Bone Density; D000071556:Cancellous Bone / Q000000981:diagnostic imaging / Q000502:physiology*; D003710:Demography; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D055815:Young Adult
keywords: Cross-sectional age patterns; Gender differences; Lumbar spine bone mineral density; NHANES; Race/ethnic differences; Trabecular bone score