title: Racial and ethnic differences in physical activity and bone density: National Health and Nutrition Examination Survey, 2007-2008.
abstract: BACKGROUND
  Participation in regular physical activity (PA) may help maintain bone health as people age. However, most American adults do not engage in the recommended minimum levels of PA, and there are racial/ethnic differences in PA participation. This study aimed to determine whether current physical activity is related to bone density in a racially/ethnically diverse sample after controlling for age, sex, body mass index, poverty-income ratio, tobacco use, vitamin D and calcium intake, and use of osteoporosis medications.
  
  
  METHODS
  We obtained data on femoral bone mineral density for 2,819 adults aged 40 to 80 years who self-reported their race/ethnicity on the 2007-2008 National Health and Nutrition Examination Survey. Data on PA levels were obtained by self-report. We used linear regression models to examine the association between PA and bone density for each racial/ethnic group.
  
  
  RESULTS
  A greater percentage of non-Hispanic blacks (60.9%) and Hispanics (53.3%) reported low levels of PA than non-Hispanic whites (45.3%, P < .001). Non-Hispanic blacks (16.3%) and Hispanics (18.5%) had a lower prevalence of osteopenia than non-Hispanic whites (25.5%; P = .01) but were similar in the prevalence of normal and osteoporosis categories when compared with whites. There was a 0.031 g/cm(2) difference in bone density between those in the high PA versus the low PA category (P = .003). This association remained (β = 0.027, P < .001) after adjusting for race/ethnicity, sex, body mass index, poverty-income ratio, tobacco use, and use of osteoporosis medications.
  
  
  CONCLUSIONS
  Despite lower levels of activity, blacks and Hispanics were not more likely to have osteoporosis, and high levels of activity were significantly associated with higher bone density even when controlling for race/ethnicity and confounders. The lack of consistency in bone density differences suggests that the cause of the differences maybe multifactorial.
authors.affiliation: University at Albany, State University of New York (SUNY), School of Public Health, One University Place, GEC 125 Rensselaer, NY 12144. E-mail: egrubert@albany.edu.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Vásquez
authors.affiliation: University at Albany, SUNY, Rensselaer, New York.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Shaw
authors.affiliation: University at Albany, SUNY, Rensselaer, New York.
authors.forename: Lenore
authors.initials: L
authors.lastname: Gensburg
authors.affiliation: Duke University Medical Center, Durham, North Carolina.
authors.forename: Daniel
authors.initials: D
authors.lastname: Okorodudu
authors.affiliation: Duke University Medical Center, Durham, North Carolina.
authors.forename: Leonor
authors.initials: L
authors.lastname: Corsino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People / Q000523:psychology; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000453:epidemiology / Q000208:ethnology*; D005006:Ethnicity / Q000523:psychology / Q000706:statistics & numerical data*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D010024:Osteoporosis / Q000453:epidemiology / Q000208:ethnology*; D015995:Prevalence; D057566:Self Report; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D044465:White People / Q000523:psychology; D001741:Black or African American