title: MRI-measured pelvic bone marrow adipose tissue is inversely related to DXA-measured bone mineral in younger and older adults.
abstract: OBJECTIVE
  Recent research has shown an inverse relationship between bone marrow adipose tissue (BMAT) and bone mineral density (BMD). There is a lack of evidence at the macro-imaging level to establish whether increased BMAT is a cause or effect of bone loss. This cross-sectional study compared the BMAT and BMD relationship between a younger adult group at or approaching peak bone mass (PBM; age 18.0-39.9 years) and an older group with potential bone loss (PoBL; age 40.0-88.0 years).
  
  
  METHODS
  Pelvic BMAT was evaluated in 560 healthy men and women with T1-weighted whole-body magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry.
  
  
  RESULTS
  An inverse correlation was observed between pelvic BMAT and pelvic, total and spine BMD in the younger PBM group (r=-0.419 to -0.461, P<0.001) and in the older PoBL group (r=-0.405 to -0.500, P<0.001). After adjusting for age, sex, ethnicity, menopausal status, total body fat, skeletal muscle, subcutaneous and visceral adipose tissue, neither subject group (younger PBM vs older PoBL) nor its interaction with pelvic BMAT significantly contributed to the regression models with BMD as dependent variable and pelvic BMAT as independent variable (P=0.434-0.928).
  
  
  CONCLUSIONS
  Our findings indicate that an inverse relationship between pelvic BMAT and BMD is present both in younger subjects who have not yet experienced bone loss and also in older subjects. These results provide support at the macro-imaging level for the hypothesis that low BMD may be a result of preferential differentiation of mesenchymal stem cells from osteoblasts to adipocytes.
authors.affiliation: New York Obesity Nutrition Research Center, St Luke's-Roosevelt Hospital and Institute of Human Nutrition, Columbia University, New York, NY 10025, 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: V
authors.initials: V
authors.lastname: Gilsanz
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology*; D001853:Bone Marrow / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D008159:Lumbar Vertebrae / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D010384:Pelvic Bones / Q000378:metabolism*; D012044:Regression Analysis; D050151:Subcutaneous Fat / Q000378:metabolism*; D055815:Young Adult
chemical_list: D008903:Minerals