Increased Epicardial Adipose Tissue Is Associated with the Airway Dominant Phenotype of Chronic Obstructive Pulmonary Disease

<div><p>Background</p><p>Epicardial adipose tissue (EAT) has been shown to be a non-invasive marker that predicts the progression of cardiovascular disease (CVD). It has been reported that the EAT volume is increased in patients with chronic obstructive pulmonary disease (COPD). However, little is known about which phenotypes of COPD are associated with increased EAT.</p><p>Methods</p><p>One hundred and eighty smokers who were referred to the clinic were consecutively enrolled. A chest CT was used for the quantification of the emphysematous lesions, airway lesions, and EAT. These lesions were assessed as the percentage of low attenuation volume (LAV%), the square root of airway wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) and the EAT area, respectively. The same measurements were made on 225 Vietnamese COPD patients to replicate the results.</p><p>Results</p><p>Twenty-six of the referred patients did not have COPD, while 105 were diagnosed as having COPD based on a FEV₁/FVC<0.70. The EAT area was significantly associated with age, BMI, FEV₁ (%predicted), FEV₁/FVC, self-reported hypertension, self-reported CVD, statin use, LAV%, and √Aaw at Pi10 in COPD patients. The multiple regression analyses showed that only BMI, self-reported CVD and √Aaw at Pi10 were independently associated with the EAT area (R² = 0.51, p<0.0001). These results were replicated in the Vietnamese population.</p><p>Conclusions</p><p>The EAT area is independently associated with airway wall thickness. Because EAT is also an independent predictor of CVD risk, these data suggest a mechanistic link between the airway predominant form of COPD and CVD.</p></div

Association of EAT area with the CT phenotypes in COPD patients.

<p>The Wilcoxon Rank-Sum test was used to compare groups. The subjects with the AD and Mixed phenotypes had greater EAT areas than those with the NCT and ED phenotypes.</p

Multiple regression analyses for predictors of EAT area.

<p>Multiple regression analyses for predictors of EAT area.</p

Spearman’s rank correlation coefficients (ρ/p value) for LAV% and √Aaw at Pi10 in COPD patients.

<p>Spearman’s rank correlation coefficients (ρ/p value) for LAV% and √Aaw at Pi10 in COPD patients.</p

Correlation between adipose tissue and quantitative CT parameters in COPD patients.

<p>Spearman’s rank correlation coefficient was used to evaluate these relationships. The EAT area was positively associated with the √Aaw at Pi10 (A) and inversely associated with the LAV% (B). The SFA was inversely associated with the LAV% (D) but not with the √Aaw at Pi10 (C).</p

Disposition of Subjects.

<p>Disposition of Subjects.</p

Comparison of the CT-measured parameters between the non-COPD and COPD groups.

<p>Comparison of the CT-measured parameters between the non-COPD and COPD groups.</p

Comparison of EAT area and CAC score between COPD patients with and without CVD.

<p>The EAT area (A) was measured using ImageJ software Ver.1.47, and the CAC score (B) was evaluated using the Agatston method. The EAT areas and CAC scores were higher in the COPD patients (p < 0.001).</p

Classification by CT phenotypes in the COPD patients.

<p>Classification by CT phenotypes in the COPD patients.</p

Spearman’s rank correlation coefficient (ρ/p value) for EAT area in COPD patients.

<p>Spearman’s rank correlation coefficient (ρ/p value) for EAT area in COPD patients.</p