Relationship between metabolic syndrome and epicardial fat tissue thickness in patients with chronic obstructive pulmonary disease

Objective: An increase in epicardial fat tissue (EFT) thickness was found to be associated with metabolic syndrome (MS) and ischemic heart disease. MS is a comorbidity of chronic obstructive pulmonary disease (COPD) resulting from the accompanying systemic inflammation. The aim of our study was to investigate the usefulness of EFT thickness to predict MS in COPD patients. Methods: COPD patients admitted to our clinic during January-December 2014 and healthy controls were included in this prospective case-control study. Patients with comorbidities, COPD exacerbation, and malignancies were excluded. Patients and controls were compared in terms of anthropometric measurements, MS-related examination and laboratory findings, pulmonary function tests, and EFT thickness. The correlations between EFT thickness and markers of MS in COPD were evaluated using the Student's t-test and logistic regression analysis. Results: COPD patients and controls were composed of 82 and 84 individuals, respectively. MS was diagnosed in 31 (37.8%) COPD patients. The EFT thickness was significantly higher in COPD patients than in the controls and was also higher in COPD patients with MS than in those without MS (all p<0.001). Each 1-mm increment of EFT raised the risk of MS two-fold (p=0.011, OR=2.08, 95% CI: 1.18-3.68). Increase in triglyceride level (p=0.004, OR=1.02, 95% CI: 1.01-1.03) and reduction in forced vital capacity (p=0.025, OR=0.26, 95% CI: 0.08-0.84) were found to be associated with increased MS risk. The cut-off value for EFT thickness in the prediction of MS in COPD patients was 6.75 mm (sensitivity: 83%, specificity: 65%). Conclusion: EFT thickness is a non-invasive and easily available parameter, which is valuable in the prediction of increased MS risk in COPD patients. Early diagnosis of patients at risk of MS may help to prevent ischemic heart disease in these patients.