title: Racial Differences in Bone Microarchitecture and Estimated Strength at the Distal Radius and Distal Tibia in Older Adolescent Girls: a Cross-Sectional Study.
abstract: Previous studies have demonstrated that an individual's race and ethnicity are important determinants of their areal bone mineral density (aBMD), assessed by dual-energy X-ray absorptiometry. However, there are few data assessing the impact of race on bone microarchitecture and strength estimates, particularly in older adolescent girls and young adults. We hypothesized that bone microarchitecture and strength estimates would be superior in Blacks compared to White and Asian American adolescent girls and young adults of similar age based on reports of higher aBMD in Blacks.
  
  
  
  We assessed BMD using dual-energy X-ray absoptiometry (DXA), bone microarchitecture at the distal radius and distal tibia using high-resolution peripheral quantitative computed tomography (HRpQCT) and estimated measures of bone strength using micro-finite element analysis (FEA) in 35 White, 15 Asian American, and 10 Black girls 14-21 years.
  
  
  
  After controlling for height, most DXA measures of aBMD and aBMD Z scores were higher in Black girls compared with Whites and Asian Americans. HRpQCT and FEA showed that at the distal radius, Blacks had greater cortical perimeter, cortical area, trabecular thickness, trabecular BMD, estimated failure load, and stiffness than the other two groups. For the distal tibia, trabecular number and BMD were higher in Blacks than Asian Americans.
  
  
  
  Particularly at the distal radius, adolescent and young adult White and Asian American girls have less favorable bone microarchitecture and lower bone strength than Blacks, possibly explaining the lower risk of fracture seen in Blacks.
  
  
  
  Level II.
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital, Harvard Medical School, BUL 457, Boston, MA, 02114, USA. mmisra@mgh.harvard.edu.|Pediatric Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA. mmisra@mgh.harvard.edu.
authors.forename: Madhusmita
authors.initials: M
authors.lastname: Misra
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital, Harvard Medical School, BUL 457, Boston, MA, 02114, USA.|Division of Sports Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Ackerman
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
authors.forename: Miriam A
authors.initials: MA
authors.lastname: Bredella
authors.affiliation: MGH Weight Center, Medicine-Gastrointestinal Unit, Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.
authors.forename: Fatima Cody
authors.initials: FC
authors.lastname: Stanford
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital, Harvard Medical School, BUL 457, Boston, MA, 02114, USA.
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Faje
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital, Harvard Medical School, BUL 457, Boston, MA, 02114, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Nordberg
authors.affiliation: Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Derrico
authors.affiliation: Endocrine Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.|Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, 02115, USA.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Bouxsein
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D001741:Black or African American / Q000706:statistics & numerical data*; D001213:Asian / Q000706:statistics & numerical data*; D015519:Bone Density; D003430:Cross-Sectional Studies; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D011884:Radius / Q000502:physiology*; D013977:Tibia / Q000502:physiology*; D044465:White People / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Failure load; Finite element analysis; Microarchitecture; Race