title: Association of fat density with subclinical atherosclerosis.
abstract: BACKGROUND
  Ectopic fat density is associated with cardiovascular disease (CVD) risk factors above and beyond fat volume. Volumetric measures of ectopic fat have been associated with CVD risk factors and subclinical atherosclerosis. The aim of this study was to investigate the association between fat density and subclinical atherosclerosis.
  
  
  RESULTS
  Participants were drawn from the Multi-Detector Computed Tomography (MDCT) substudy of the Framingham Heart Study (n=3079; mean age, 50.1 years; 49.2% women). Fat density was indirectly estimated by computed tomography attenuation (Hounsfield Units [HU]) on abdominal scan slices. Visceral fat (VAT), subcutaneous fat (SAT), and pericardial fat HU and volumes were quantified using standard protocols; coronary and abdominal aortic calcium (CAC and AAC, respectively) were measured radiographically. Multivariable-adjusted logistic regression models were used to evaluate the association between adipose tissue HU and the presence of CAC and AAC. Overall, 17.1% of the participants had elevated CAC (Agatston score [AS]>100), and 23.3% had elevated AAC (AS>age-/sex-specific cutoffs). Per 5-unit decrement in VAT HU, the odds ratio (OR) for elevated CAC was 0.76 (95% confidence interval [CI], 0.65 to 0.89; P=0.0005), even after adjustment for body mass index or VAT volume. Results were similar for SAT HU. With decreasing VAT HU, we also observed an OR of 0.79 (95% CI, 0.67 to 0.92; P=0.004) for elevated AAC after multivariable adjustment. We found no significant associations between SAT HU and AAC. There was no significant association between pericardial fat HU and either CAC or AAC.
  
  
  CONCLUSIONS
  Lower VAT and SAT HU, indirect estimates of fat quality, are associated with a lower risk of subclinical atherosclerosis.
authors.affiliation: Harvard Medical School, Boston, MA (N.J.A.) National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA (N.J.A., A.P., K.J.R., C.J.D., C.S.F.).
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Alvey
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA (N.J.A., A.P., K.J.R., C.J.D., C.S.F.).
authors.forename: Alison
authors.initials: A
authors.lastname: Pedley
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA (N.J.A., A.P., K.J.R., C.J.D., C.S.F.) Division of Endocrinology and Metabolism, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (K.J.R., C.S.F.) NHLBI Division of Intramural Research and the Center for Population Studies, Framingham, MA (K.J.R., C.S.F.).
authors.forename: Klara J
authors.initials: KJ
authors.lastname: Rosenquist
authors.affiliation: Department of Biostatistics, Boston University School of Public Health, Boston, MA (J.M.M.).
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Massaro
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA (N.J.A., A.P., K.J.R., C.J.D., C.S.F.) Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA (C.J.D.) NHLBI Division of Intramural Research, Cardiovascular Epidemiology and Human Genomics Research, Bethesda, MD (C.J.D.).
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: O'Donnell
authors.affiliation: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (U.H.).
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA (N.J.A., A.P., K.J.R., C.J.D., C.S.F.) Division of Endocrinology and Metabolism, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (K.J.R., C.S.F.) NHLBI Division of Intramural Research and the Center for Population Studies, Framingham, MA (K.J.R., C.S.F.).
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Fox
mesh_terms: D000328:Adult; D001018:Aortic Diseases / Q000000981:diagnostic imaging*; D058070:Asymptomatic Diseases; D050197:Atherosclerosis / Q000000981:diagnostic imaging; D050218:Body Fat Distribution; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D050507:Subcutaneous Fat, Abdominal / Q000000981:diagnostic imaging*; D061205:Vascular Calcification / Q000000981:diagnostic imaging*
keywords: atherosclerosis; epidemiology; fat density; obesity