title: The influence of pericardial fat upon left ventricular function in obese females: evidence of a site-specific effect.
abstract: BACKGROUND
  Although increased volume of pericardial fat has been associated with decreased cardiac function, it is unclear whether this association is mediated by systemic overall obesity or direct regional fat interactions. We hypothesized that if local effects dominate, left ventricular (LV) function would be most strongly associated with pericardial fat that surrounds the left rather than the right ventricle (RV).
  
  
  METHODS
  Female obese subjects (n = 60) had cardiovascular magnetic resonance (CMR) scans to obtain measures of LV function and pericardial fat volumes. LV function was obtained using the cine steady state free precession imaging in short axis orientation. The amount of pericardial fat was determined volumetrically by the cardiac gated T1 black blood imaging and normalized to body surface area.
  
  
  RESULTS
  In this study cohort, LV fat correlated with several LV hemodynamic measurements including cardiac output (r = -0.41, p = 0.001) and stroke volume (r = -0.26, p = 0.05), as well as diastolic functional parameters including peak-early-filling rate (r = -0.38, p = 0.01), early late filling ratio (r = -0.34, p = 0.03), and time to peak-early-filling (r = 0.34, p = 0.03). These correlations remained significant even after adjusting for the body mass index and the blood pressure. However, similar correlations became weakened or even disappeared between RV fat and LV function. LV function was not correlated with systemic plasma factors, such as C-reactive protein (CRP), B-type natriuretic peptide (BNP), Interleukin-6 (IL-6), resistin and adiponectin (all p > 0.05).
  
  
  CONCLUSIONS
  LV hemodynamic and diastolic function was associated more with LV fat as compared to RV or total pericardial fat, but not with systemic inflammatory markers or adipokines. The correlations between LV function and pericardial fat remained significant even after adjusting for systemic factors. These findings suggest a site-specific influence of pericardial fat on LV function, which could imply local secretion of molecules into the underlying tissue or an anatomic effect, both mechanisms meriting future evaluation.
authors.forename: Ning
authors.initials: N
authors.lastname: Hua
authors.forename: Zhongjing
authors.initials: Z
authors.lastname: Chen
authors.forename: Alkystis
authors.initials: A
authors.lastname: Phinikaridou
authors.forename: Tuan
authors.initials: T
authors.lastname: Pham
authors.forename: Ye
authors.initials: Y
authors.lastname: Qiao
authors.forename: Michael P
authors.initials: MP
authors.lastname: LaValley
authors.forename: Sherman J
authors.initials: SJ
authors.lastname: Bigornia
authors.forename: Megan R
authors.initials: MR
authors.lastname: Ruth
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Apovian
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Ruberg
authors.affiliation: The Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, USA. jhamilt@gmail.com.
authors.forename: James A
authors.initials: JA
authors.lastname: Hamilton
mesh_terms: D054392:Adipokines / Q000097:blood; D000273:Adipose Tissue / Q000473:pathology / Q000503:physiopathology*; D050154:Adiposity; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D005260:Female; D006439:Hemodynamics; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D019028:Magnetic Resonance Imaging, Cine; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D010496:Pericardium / Q000473:pathology / Q000503:physiopathology*; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult
chemical_list: D054392:Adipokines; D015415:Biomarkers; D018836:Inflammation Mediators