title: Sarcopenia, obesity, and inflammation--results from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors study.
abstract: BACKGROUND
  Age-related body-composition changes are associated with health-related outcomes in elders. This relation may be explained by inflammation and hemostatic abnormalities.
  
  
  OBJECTIVE
  Our objectives were to evaluate the relation between body-composition measures [body mass index (BMI), total fat mass, and appendicular lean mass (aLM)] and C-reactive protein (CRP), interleukin 6 (IL-6), and plasminogen activator inhibitor 1 (PAI-1) and to explore the effect of obesity and sarcopenia on CRP, IL-6, and PAI-1 concentrations.
  
  
  METHODS
  The data are from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study baseline visit (n = 286; mean age = 66.0 y). Total fat mass and aLM were assessed with a dual-energy X-ray absorptiometry scan. Linear regressions were performed between body-composition measures and CRP, IL-6, or PAI-1 concentrations. The effect of sarcopenia and obesity (defined as the percentage of fat mass) on CRP, IL-6, and PAI-1 concentrations was evaluated with the use of analyses of covariance.
  
  
  RESULTS
  CRP and IL-6 were positively associated with both BMI [beta = 0.027 (P = 0.03) and beta = 0.048 (P < 0.001), respectively] and total fat mass [beta = 0.049 (P < 0.001) and beta = 0.055 (P < 0.001), respectively] and were inversely associated with fat-adjusted aLM [beta = -0.629 (P = 0.002) and beta = -0.467 (P = 0.02), respectively]. PAI-1 was positively associated with both BMI (beta = 0.038, P = 0.005) and total fat mass (beta = 0.032, P = 0.007). No significant interaction was found between either obesity or sarcopenia and CRP, IL-6, and PAI-1 concentrations. Obesity remained significantly associated with high CRP and IL-6 concentrations after adjustments for sarcopenia.
  
  
  CONCLUSIONS
  CRP and IL-6 are positively associated with total fat mass and negatively associated with aLM. Obesity-associated inflammation may play an important role in the age-related process that leads to sarcopenia. The relation of inflammation with sarcopenia was not independent of any of the considered obesity indexes.
authors.affiliation: Department of Aging and Geriatric Research, College of Medicine, Institute on Aging, University of Florida, Gainesville, FL, USA. mcesari@aging.ufl.edu
authors.forename: Matteo
authors.initials: M
authors.lastname: Cesari
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Richard N
authors.initials: RN
authors.lastname: Baumgartner
authors.forename: Hal H
authors.initials: HH
authors.lastname: Atkinson
authors.forename: Brenda W H J
authors.initials: BW
authors.lastname: Penninx
authors.forename: Leon
authors.initials: L
authors.lastname: Lenchik
authors.forename: Shana L
authors.initials: SL
authors.lastname: Palla
authors.forename: Walter T
authors.initials: WT
authors.lastname: Ambrosius
authors.forename: Russell P
authors.initials: RP
authors.lastname: Tracy
authors.forename: Marco
authors.initials: M
authors.lastname: Pahor
mesh_terms: D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001823:Body Composition; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007249:Inflammation / Q000150:complications*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009765:Obesity / Q000150:complications*; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D012307:Risk Factors
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D015850:Interleukin-6; D017395:Plasminogen Activator Inhibitor 1; D002097:C-Reactive Protein