title: The impact of obesity on the relationship between epicardial adipose tissue, left ventricular mass and coronary microvascular function.
abstract: OBJECTIVE
  Epicardial adipose tissue (EAT) has been linked to coronary artery disease (CAD) and coronary microvascular dysfunction. However, its injurious effect may also impact the underlying myocardium. This study aimed to determine the impact of obesity on the quantitative relationship between left ventricular mass (LVM), EAT and coronary microvascular function.
  
  
  METHODS
  A total of 208 (94 men, 45 %) patients evaluated for CAD but free of coronary obstructions underwent quantitative [(15)O]H2O hybrid positron emission tomography (PET)/CT imaging. Coronary microvascular resistance (CMVR) was calculated as the ratio of mean arterial pressure to hyperaemic myocardial blood flow.
  
  
  RESULTS
  Obese patients [body mass index (BMI) > 25, n = 133, 64 % of total] had more EAT (125.3 ± 47.6 vs 93.5 ± 42.1 cc, p < 0.001), a higher LVM (130.1 ± 30.4 vs 114.2 ± 29.3 g, p < 0.001) and an increased CMVR (26.6 ± 9.1 vs 22.3 ± 8.6 mmHg×ml(-1)×min(-1)×g(-1), p < 0.01) as compared to nonobese patients. Male gender (β = 40.7, p < 0.001), BMI (β = 1.61, p < 0.001), smoking (β = 6.29, p = 0.03) and EAT volume (β = 0.10, p < 0.01) were identified as independent predictors of LVM. When grouped according to BMI status, EAT was only independently associated with LVM in nonobese patients. LVM, hypercholesterolaemia and coronary artery calcium score were independent predictors of CMVR.
  
  
  CONCLUSIONS
  EAT volume is associated with LVM independently of BMI and might therefore be a better predictor of cardiovascular risk than BMI. However, EAT volume was not related to coronary microvascular function after adjustments for LVM and traditional risk factors.
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: M J
authors.initials: MJ
authors.lastname: Bakkum
authors.forename: I
authors.initials: I
authors.lastname: Danad
authors.forename: M A J
authors.initials: MA
authors.lastname: Romijn
authors.forename: W J A
authors.initials: WJ
authors.lastname: Stuijfzand
authors.forename: R M
authors.initials: RM
authors.lastname: Leonora
authors.forename: I I
authors.initials: II
authors.lastname: Tulevski
authors.forename: G A
authors.initials: GA
authors.lastname: Somsen
authors.forename: A A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: C
authors.initials: C
authors.lastname: van Kuijk
authors.forename: A C
authors.initials: AC
authors.lastname: van Rossum
authors.forename: P G
authors.initials: PG
authors.lastname: Raijmakers
authors.forename: P
authors.initials: P
authors.lastname: Knaapen
mesh_terms: D000273:Adipose Tissue / Q000503:physiopathology*; D050154:Adiposity; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008833:Microcirculation; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D009929:Organ Size; D010496:Pericardium / Q000503:physiopathology*; D011859:Radiography; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity