title: Greater skeletal muscle fat infiltration is associated with higher all-cause mortality among men of African ancestry.
abstract: fat infiltration within and around skeletal muscle (i.e. myosteatosis) increases with ageing, is greater in African versus European ancestry men and is associated with poor health. Myosteatosis studies of mortality are lacking, particularly among African ancestry populations.
  
  
  
  in the Tobago Health study, a prospective longitudinal study, we evaluated the association of all-cause mortality with quantitative computed tomography (QCT) measured lower leg myosteatosis (intermuscular fat (IM fat) and muscle density) in 1,652 African ancestry men using Cox proportional hazards models. Date of death was abstracted from death certificates and/or proxy.
  
  
  
  one hundred and twelve deaths occurred during follow-up (mean 5.9 years). In all men (age range 40-91 years), higher all-cause mortality was associated with greater IM fat (HR (95% CI) per SD: 1.29 (1.06-1.57)) and lower muscle density (HR (95% CI) per SD lower: 1.37 (1.08-1.75)) in fully adjusted models. Similar mortality hazard rates were seen in the subset of elderly men (aged ≥65 years) with greater IM fat (1.40 (1.11-1.78) or lower muscle density (1.66 (1.24-2.21)) in fully adjusted models.
  
  
  
  our study identified a novel, independent association between myosteatosis and all-cause mortality in African ancestry men. Further studies are needed to establish whether this association is independent of other ectopic fat depots and to identify possible biological mechanisms underlying this relationship.
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Zmuda
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Kuipers
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Jonnalagadda
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Clareann H
authors.initials: CH
authors.lastname: Bunker
authors.affiliation: Tobago Health Studies Office, Scarborough, Trinidad and Tobago.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Patrick
authors.affiliation: Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Ada O
authors.initials: AO
authors.lastname: Youk
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Iva
authors.initials: I
authors.lastname: Miljkovic
mesh_terms: D050154:Adiposity / Q000208:ethnology*; D000368:Aged; D044383:Black People; D002423:Cause of Death; D016009:Chi-Square Distribution; D015897:Comorbidity; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009135:Muscular Diseases / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000401:mortality / Q000503:physiopathology; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014300:Trinidad and Tobago; D001741:Black or African American
keywords: African American; all-cause mortality; myosteatosis; obesity; older people