Associations of pericardial and intrathoracic fat with coronary calcium presence and progression in a multiethnic study

Abstract

Body mass index (BMI) may not accurately or adequately reflect body composition or its role in the development of cardiovascular disease (CVD). Ectopic adipose depots may provide a more refined representation of the role of adiposity in CVD. Thus, we examined the association of pericardial and intra-thoracic fat with coronary artery calcium (CAC). Nearly 600 white men and women, as well as Filipina women and African-American women, all without known CVD, had abdominal and chest computed tomography (CT) scans at two time points about four years apart from which CAC presence, severity and progression, as well as pericardial and intra-thoracic fat volumes were obtained. Logistic and linear regression models with staged adjustment were used to assess associations of pericardial and intra-thoracic fat with CAC presence, severity and progression. After adjustment for age, BMI, sex/ethnic group, ever smoking, and lipids, each standard deviation higher increment of intra-thoracic fat, but not pericardial fat, was significantly associated with 3.84-fold higher odds of prevalent CAC (95% CI (1.54, 9.58), p=0.004) and a 38.4% higher CAC score (95% CI (3.5%, 90.0%), p=0.03). Neither pericardial nor intra-thoracic fat were associated with CAC progression. Contrary to previous reports, pericardial fat was not associated with the presence, severity or progression of CAC. We did, however, demonstrate a significant association between intra-thoracic fat and both the presence and severity of CAC. Studies measuring fat in the thoracic cavity may consider defining intra-thoracic fat as a separate entity from pericardial fat.

Rapid decline in lung function is temporally associated with greater metabolically active adiposity in a longitudinal study of healthy adults

“…While we have measurements of lung function and metabolically active adiposity at more than one time point, we studied only one time point measurement of CT-assessed fat, which limits our ability to study a longitudinal change in that variable. Fat within and around the lung includes peribronchial, pleural and mediastinal fat and is technically more difficult to measure than pericardial fat, the site of the greatest fat accumulation within the thorax 49. Our assumption that pericardial fat may reflect fat around the lung is supported by the findings of a small study that demonstrated a correlation as high as 0.68 between pericardial fat and fat at the interior margin of the chest wall anteriorly 49.…”

“…Fat within and around the lung includes peribronchial, pleural and mediastinal fat and is technically more difficult to measure than pericardial fat, the site of the greatest fat accumulation within the thorax 49. Our assumption that pericardial fat may reflect fat around the lung is supported by the findings of a small study that demonstrated a correlation as high as 0.68 between pericardial fat and fat at the interior margin of the chest wall anteriorly 49. One possible explanation for rapid decline predicting subsequent intrathoracic visceral adiposity is that individuals with rapid decline gain more weight than those without rapid decline.…”

Adipokines and severity and progression of coronary artery calcium: Findings from the Rancho Bernardo Study

“…Detailed accounts of adipokine measurement have been published previously. 13 Adipokines were measured from blood samples taken in 1997–1998. Laboratory assays were performed at the Reproductive Endocrine Research laboratory, University of Southern California (Frank Z. Stanczyk, director).…”

Immune regulators of inflammation in obesity-associated type 2 diabetes and coronary artery disease

“…Together the associations between pAT inflammation and CAD/impaired cardiovascular function, plus the known roles of obesity in AT volume and pro-inflammatory immune cell function [4–7, 10, 33, 34, 47, 72, 79, 89, 91, 104] frame the idea that obesity-associated changes in pAT physiology link obesity and CAD, and are further exacerbated in the presence of IR. However, one gap in the pAT analyses is that “pAT” is often imprecisely defined, and can denote the epicardial AT that coats the heart, the interstitial AT that coats the outside of the pericardial membrane (thus does not directly touch the heart) or both.…”