Epicardial Adipose Tissue in Patients with Chronic Obstructive Pulmonary Disease

<div><p>Rationale</p><p>Epicardial Adipose Tissue (EAT) volume as determined by chest computed tomography (CT) is an independent marker of cardiovascular events in the general population. COPD patients have an increased risk of cardiovascular disease, however nothing is known about the EAT volume in this population.</p><p>Objectives</p><p>To assess EAT volume in COPD and explore its association with clinical and physiological variables of disease severity.</p><p>Methods</p><p>We measured EAT using low-dose CT in 171 stable COPD patients and 70 controls matched by age, smoking history and BMI. We determined blood pressure, cholesterol, glucose and HbA1c levels, microalbuminuria, lung function, BODE index, co-morbidity index and coronary artery calcium score (CAC). EAT volume were compared between groups. Uni and multivariate analyses explored the relationship between EAT volume and the COPD related variables.</p><p>Results</p><p>COPD patients had a higher EAT volume [143.7 (P_25–75, 108.3–196.6) vs 129.1 (P_25–75, 91.3–170.8) cm³, p = 0.02)] and the EAT volume was significantly associated with CAC (r = 0.38, p<0.001) and CRP (r = 0.32, p<0.001) but not with microalbuminuria (r = 0.12, p = 0.13). In COPD patients, EAT volume was associated with: age, pack-years, BMI, gender, FEV₁%, 6 MWD, MMRC and HTN. Multivariate analysis showed that only pack-years (B = 0.6, 95% CI: 0.5–1.3), BMI (B = 7.8, 95% CI: 5.7–9.9) and 6 MWD (B = −0.2, 95% CI: −0.3–−0.1), predicted EAT volume.</p><p>Conclusions</p><p>EAT volume is increased in COPD patients and is independently associated with smoking history, BMI and exercise capacity, all modifiable risk factors of future cardiovascular events. EAT volume could be a non-invasive marker of COPD patients at high risk for future cardiovascular events.</p></div

Flow diagram of the study population.

<p>Flow diagram of the study population.</p

Univariate analysis exploring the independent association of the studied variables with EAT volume in patients with COPD and in smokers.

<p>BMI = Body Mass Index; FEV1% = Forced Expiratory Volume in the first second percent; 6 MWD = Six Minutes Walk distance; MMRC = Modified Medical Research Council Dyspnea Scale; BODE = Body Mass Index, Obstruction, Dyspnea, Exercise; HTN = Hypertension; LDL-C = Low Density Protein Cholesterol; HDL-C = High Density Protein Cholesterol; DM = Diabetes Mellitus; HbA1c = glycosylated haemoglobin.</p

Multivariate analysis exploring the independent association of the studied variables with EAT volume in patients with COPD and in smokers.

<p>(*) Variables included in the model: Pack-years, Gender, BMI, 6 MWD, HDL-C, Glucose.</p

Patients characteristics.

<p>n = Number of participants for each group; BMI = Body Mass Index; FEV₁ =  Forced Expiratory Volume in the fisrt second; FVC = Forced Vital Capacity; TLC = Total Lung Capacity; MMRC = Modified Medical rtesearch Council; 6 MWD  = 6 Minutes Walk Distance; BODE index: BMI, Obstruction, Dyspnea, Exercise; SBP = Systolic Blood Presure; DBP = Dyastolic Blood Presure; DM = Diabetes Mellitus; LDL-C = Low Density Protein; HDL-C = High Density Protein; EAT = Epicardial Adipose Tissue CRP =  C reactive Protein.</p><p>X ± SD = means ± Standart Desviation; y/n = Yes/No; p25–p75 =  interquartile range.</p

Panel A. Univariable analysis showing the independent association of each parameter with survival.

<p>Panel B. Multivariable analysis showing those that remained in the model.</p

Flowchart showing the inclusion of patients for the final statistical analysis.

<p>Flowchart showing the inclusion of patients for the final statistical analysis.</p

Clinical, radiological and physiological characteristics of the patients diagnosed with and without PAE.

<p>Clinical, radiological and physiological characteristics of the patients diagnosed with and without PAE.</p

Association between pulmonary artery diameter and other studied variables.

<p>Association between pulmonary artery diameter and other studied variables.</p

Kaplan Meier curves showing the cumulative survival for those with and without PAE and for pulmonary artery diameter quartiles.

<p>Kaplan Meier curves showing the cumulative survival for those with and without PAE and for pulmonary artery diameter quartiles.</p