Patients with chronic obstructive pulmonary disease (COPD) have abnormally high epicardial adipose tissue (EAT), which may be associated with systemic inflammatory responses in COPD, according to systematic review and meta-analysis published in BMC Pulmonary Medicine.
Previous research suggests a possible link between the volume and thickness of EAT and C-reactive protein, suggesting that EAT may have an important role in the inflammatory response observed in COPD patients as well as in the occurrence of cardiovascular diseases in these patients. Investigators therefore aimed to evaluate whether an association exists between EAT and COPD.
The reviewers searched the Cochrane Library, Web of Science, EMBASE, and PubMed electronic databases until October 2022 for controlled human studies in English comparing differences in EAT among patients with and without COPD. Differences for EAT thickness levels were compared, with measurements based on echocardiography (2 studies), volume or area measured by cardiac magnetic resonance (2 studies), and volume measured by computed tomography (1 study). Meta-analysis and trial sequential analysis were used to evaluate the differences measured in 5 studies (n=596 patients with COPD; n=306 patients without COPD).
Meta-analysis showed patients with COPD vs without COPD had significantly more EAT (standard mean difference [SMD], 0.802; 95% CI, 0.231-1.372; P =.006; with significant heterogeneity, I2=93%). Investigators noted C-reactive protein (CRP) levels were significantly higher in patients with COPD vs without (SMD, 0.526; 95% CI, 0.084-0.968; P =.02; with great heterogeneity between studies, I2=84%). Trial sequential analysis results suggest these current analysis results are reliable.
“
EAT is abnormally elevated in COPD patients, which may be related to systemic inflammatory responses in COPD.
Low-density lipoprotein and triglycerides were not significantly different between patients with and without COPD. Patients with COPD had significantly lower serum levels of high-density lipoprotein than patients without COPD (weighted mean difference, -5.458mg/dL; 95% CI, -8.703 to -2.214; P =.001; I2=66%).
All 5 studies were rated very low quality of evidence for detecting EAT and very low quality of evidence for triglycerides and CRP using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. For LDL, HDL, and total cholesterol, the quality of evidence was rated low using GRADE. Investigators noted low publication bias in all included studies.
Systematic review and meta-analysis limitations include the small number of studies included in final analysis, the low quality of evidence, and very high heterogeneity between studies.
“EAT is abnormally elevated in COPD patients, which may be related to systemic inflammatory responses in COPD,” the study authors concluded. They further added that EAT has potential for use in risk assessment and prediction of cardiovascular diseases patients with COPD.
