title: Ethnic and sex differences in bone marrow adipose tissue and bone mineral density relationship.
abstract: The relationship between bone marrow adipose tissue and bone mineral density is different between African Americans and Caucasians as well as between men and women. This suggests that the mechanisms that regulate the differentiation and proliferation of bone marrow stromal cells may differ in these populations.
  
  
  BACKGROUND
  It has long been established that there are ethnic and sex differences in bone mineral density (BMD) and fracture risk. Recent studies suggest that bone marrow adipose tissue (BMAT) may play a role in the pathogenesis of osteoporosis. It is unknown whether ethnic and sex differences exist in the relationship between BMAT and BMD.
  
  
  METHODS
  Pelvic BMAT was evaluated in 455 healthy African American and Caucasian men and women (age 18-88 years) using whole-body T1-weighted magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry.
  
  
  RESULTS
  A negative correlation was observed between pelvic BMAT and total body BMD or pelvic BMD (r = -0.533, -0.576, respectively; P < 0.001). In multiple regression analyses with BMD as the dependent variable, ethnicity significantly entered the regression models as either an individual term or an interaction with BMAT. Menopausal status significantly entered the regression model with total body BMD as the dependent variable. African Americans had higher total body BMD than Caucasians for the same amount of BMAT, and the ethnic difference for pelvic BMD was greater in those participants with a higher BMAT. Men and premenopausal women had higher total body BMD levels than postmenopausal women for the same amount of BMAT.
  
  
  CONCLUSIONS
  An inverse relationship exists between BMAT and BMD in African American and Caucasian men and women. The observed ethnic and sex differences between BMAT and BMD in the present study suggest the possibility that the mechanisms regulating the differentiation and proliferation of bone marrow stromal cells may differ in these populations.
authors.affiliation: New York Obesity Nutrition Research Center, St. Luke's-Roosevelt Hospital, New York, NY, USA. WS2003@Columbia.edu
authors.forename: W
authors.initials: W
authors.lastname: Shen
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Gantz
authors.forename: M
authors.initials: M
authors.lastname: Punyanitya
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: D
authors.initials: D
authors.lastname: Gallagher
authors.forename: J
authors.initials: J
authors.lastname: Albu
authors.forename: E
authors.initials: E
authors.lastname: Engelson
authors.forename: D
authors.initials: D
authors.lastname: Kotler
authors.forename: X
authors.initials: X
authors.lastname: Pi-Sunyer
authors.forename: S
authors.initials: S
authors.lastname: Shapses
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology*; D001853:Bone Marrow / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010384:Pelvic Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012737:Sex Factors; D055815:Young Adult