title: Adipose tissue density, a novel biomarker predicting mortality risk in older adults.
abstract: BACKGROUND
  Knowledge of adipose composition in relation to mortality may help delineate inconsistent relationships between obesity and mortality in old age. We evaluated relationships between abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) density, mortality, biomarkers, and characteristics.
  
  
  METHODS
  VAT and SAT density were determined from computed tomography scans in persons aged 65 and older, Health ABC (n = 2,735) and AGES-Reykjavik (n = 5,131), and 24 nonhuman primates (NHPs). Associations between adipose density and mortality (4-13 years follow-up) were assessed with Cox proportional hazards models. In NHPs, adipose density was related to serum markers and tissue characteristics.
  
  
  RESULTS
  Higher density adipose tissue was associated with mortality in both studies with adjustment for risk factors including adipose area, total fat, and body mass index. In women, hazard ratio and 95% CI for the densest quintile (Q5) versus least dense (Q1) for VAT density were 1.95 (1.36-2.80; Health ABC) and 1.88 (1.31-2.69; AGES-Reykjavik) and for SAT density, 1.76 (1.35-2.28; Health ABC) and 1.56 (1.15-2.11; AGES-Reykjavik). In men, VAT density was associated with mortality in Health ABC, 1.52 (1.12-2.08), whereas SAT density was associated with mortality in both Health ABC, 1.58 (1.21-2.07), and AGES-Reykjavik, 1.43 (1.07-1.91). Higher density adipose tissue was associated with smaller adipocytes in NHPs. There were no consistent associations with inflammation in any group. Higher density adipose tissue was associated with lower serum leptin in Health ABC and NHPs, lower leptin mRNA expression in NHPs, and higher serum adiponectin in Health ABC and NHPs.
  
  
  CONCLUSIONS
  VAT and SAT density provide a unique marker of mortality risk that does not appear to be inflammation related.
authors.affiliation: Laboratory of Population Science, National Institute on Aging, 7201 Wisconsin Ave, 3C-309 Bethesda, MD 20814. rachel.murphy@nih.gov.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Murphy
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Register
authors.forename: Carol A
authors.initials: CA
authors.lastname: Shively
authors.forename: J Jeffrey
authors.initials: JJ
authors.lastname: Carr
authors.forename: Yaorong
authors.initials: Y
authors.lastname: Ge
authors.forename: Marta E
authors.initials: ME
authors.lastname: Heilbrun
authors.forename: Steven R
authors.initials: SR
authors.lastname: Cummings
authors.forename: Annemarie
authors.initials: A
authors.lastname: Koster
authors.forename: Michael C
authors.initials: MC
authors.lastname: Nevitt
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.forename: Frances A
authors.initials: FA
authors.lastname: Tylvasky
authors.forename: Elsa S
authors.initials: ES
authors.lastname: Strotmeyer
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: Ann
authors.initials: A
authors.lastname: Scherzinger
authors.forename: Bret H
authors.initials: BH
authors.lastname: Goodpaster
authors.forename: Lenore J
authors.initials: LJ
authors.lastname: Launer
authors.forename: Gudny
authors.initials: G
authors.lastname: Eiriksdottir
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Sigurdsson
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sigurdsson
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Lang
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
mesh_terms: D015502:Absorptiometry, Photon; D052242:Adiponectin / Q000378:metabolism; D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020738:Leptin / Q000378:metabolism; D008252:Macaca fascicularis; D008297:Male; D009765:Obesity / Q000000981:diagnostic imaging / Q000378:metabolism / Q000401:mortality*; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends
chemical_list: D052242:Adiponectin; D015415:Biomarkers; D020738:Leptin
keywords: Adiponectin.; Aging; Leptin; Obesity