Article

Pericardial Fat, Intrathoracic Fat, and Measures of Left Ventricular Structure and Function The Framingham Heart Study

National Heart, Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA.
Circulation (Impact Factor: 14.43). 04/2009; 119(12):1586-91. DOI: 10.1161/CIRCULATIONAHA.108.828970
Source: PubMed

ABSTRACT

Background: Pericardial fat has been implicated in the pathogenesis of obesity-related cardiovascular disease. Whether the associations of pericardial fat and measures of cardiac structure and function are independent of the systemic effects of obesity and visceral adiposity has not been fully explored. Methods and Results: Participants from the Framingham Heart Study (n=997; 54.4% women) underwent chest and abdominal computed tomography and cardiovascular magnetic resonance imaging between 2002 and 2005. Pericardial fat, intrathoracic fat, and visceral adipose tissue quantified from multidetector computed tomography, along with body mass index and waist circumference, were examined in relation to cardiovascular magnetic resonance measures of left ventricular (LV) mass, LV end-diastolic volume, and left atrial dimension. In women, pericardial fat (r=0.20 to 0.35, Pr=0.25 to 0.37, Pr=0.24 to 0.45, Pr=0.36 to 0.53, Pr=0.30 to 0.48, P<0.001) were directly correlated with LV mass, LV end-diastolic volume, and left atrial dimension. In men, pericardial fat (r=0.19 to 0.37, P<0.001), intrathoracic fat (r=0.17 to 0.31, Pr=0.19 to 0.36, Pr=0.32 to 0.44, Pr=0.34 to 0.44, P<0.001) were directly correlated with LV mass and left atrial dimension, but LV end-diastolic volume was not consistently associated with adiposity measures. Associations persisted after multivariable adjustment but not after additional adjustment for body weight and visceral adipose tissue, except for pericardial fat and left atrial dimension in men. ConclusionsmdashPericardial fat is correlated with cardiovascular magnetic resonance measures, but the association is not independent of or stronger than other ectopic fat stores or proxy measures of visceral adiposity. An important exception is left atrial dimension in men. These results suggest that the systemic effects of obesity on cardiac structure and function may outweigh the local pathogenic effects of pericardial fat.

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Available from: Christopher J O'Donnell, Jun 09, 2014
    • "Besides that, mildly elevated serum liver enzymes might be also a possible marker of ectopic fat deposition in other tissues like the myocardium and pericardium. The presence of myocardial steatosis is associated with LV diastolic dysfunction[44]while the presence of increased pericardial fat is associated with a greater left atrial size[45], both conditions that might predispose to AF development[1,13]. Moreover , increased epicardial and pericardial fat might infiltrate the atrial septum leading to electro-mechanical changes, local release of pro-inflammatory mediators that might have direct arrhythmogenic consequences, and development of fibrosis in the atrial tissue[46]. "
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    ABSTRACT: Background: Hepatic steatosis (HS) affects up to 35% of adults in the general population. Atrial fibrillation (AF) is the most prevalent sustained arrhythmia and has a substantial impact on healthcare costs. We analyzed cross-sectional associations of HS and serum liver enzyme levels with prevalent AF in a general population sample. Methods: We analyzed data from 3090 women and men, aged 20-81 years, from the population-based Study of Health in Pomerania. HS was determined by ultrasonography. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltranspeptidase (GGT) were measured photometrically. AF was determined by automatic electrocardiographic analysis software. Results: The prevalences of HS and AF were 30.3% and 1.49%, respectively. ALT, AST and GGT showed a positive linear association with the risk of prevalent AF, after multivariable adjustment. The adjusted odds ratios for AF per 1-standard deviation increment in log-transformed serum liver enzyme levels were 1.65 (95% confidence interval [CI]: 1.16 to 2.35; p = 0.006) for ALT, 1.47 (95%CI: 1.07 to 2.02; p = 0.017) for AST and 2.17 (95%CI: 1.64 to 2.87; p < 0.001) for GGT. In contrast, ultrasonographic HS was not associated with AF. Conclusions: Our findings indicate that moderately elevated serum liver enzymes, but not sonographic liver hyperechogenicity, were associated with increased AF prevalence in the general adult population. The hepatic release of increased levels of serum liver enzymes might be accompanied by higher levels of pro-inflammatory, pro-coagulant and pro-fibronogenic mediators that might lead to structural and electrical remodeling of the atrium resulting in the development and persistence of AF.
    No preview · Article · Dec 2015 · Atherosclerosis
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    • "LV structure and function [26] [27]. Interestingly, it is note worthy that visceral adiposity showed a stronger association with LV diastolic parameters than BMI or subcutaneous adipose tissue. "
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    ABSTRACT: Background: Obesity and low muscle mass may coexist as age-related changes in body composition. We aimed to investigate the effect of visceral adiposity and skeletal muscle mass on left ventricular (LV) structure and function in the general population. Methods: A total of 1941 participants without known cardiovascular disease were enrolled from the Korean Genome and Epidemiology Study. Visceral fat area (VFA) was assessed by computed tomography. Appendicular skeletal muscle mass (ASM) was estimated by dual-energy X-ray absorptiometry and was used as a percentage of body weight (ASM/Wt). LV structure and function were assessed by tissue Doppler imaging (TDI) echocardiography. Results: Across VFA tertiles, ASM increased, but ASM/Wt decreased (all P<0.001). In multivariate models adjusted for conventional cardiovascular risk factors, LV mass index and LV diastolic parameters, such as left atrial dimension, TDI Ea velocity, and E/Ea ratio, were significantly impaired as VFA increased. On the other hand, an increase in ASM/Wt was associated with a decrease in LV mass index and improvement of LV diastolic parameters. With regard to LV mass index and TDI Ea velocity, VFA and ASM/Wt showed synergistic effects (all P interaction<0.05). When both VFA and ASM/Wt were simultaneously included in the same model, both remained independent predictors of LV mass index and TDI Ea velocity. Conclusions: More visceral fat and less muscle mass are independently and synergistically associated with an increase in LV mass index and impairment of LV diastolic parameters. Further research is needed to explore the complex mechanisms underlying these associations.
    Full-text · Article · Aug 2014 · International Journal of Cardiology
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    • "Both studies suggested local interactions between the regional adipose and LV function, but without ruling out the influence from systemic effects caused by overall obesity. It became particular interesting when Fox et al. performed a large population study [22] in 2009. They reported that pericardial fat correlated with LV EDV and atrial dimension, but these correlations did not hold after the multivariable adjustment for overall adiposity, and suggested that systemic influences might override local effects. "
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    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.
    Full-text · Article · May 2014 · Journal of Cardiovascular Magnetic Resonance
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