Metabolic Syndrome as a Factor Affecting Systemic Inflammation in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a systemic disease which may be associated with other comorbidities. The aim of the study was to estimate the incidence of metabolic syndrome (MS) in COPD patients and to assess its impact on systemic inflammation and lung function. MS was diagnosed in accordance with the recommendations of the Polish Forum for the Prevention of Cardiovascular Diseases. The study group consisted of 267 patients with stable COPD in all stages of severity. All patients underwent spirometry with bronchial reversibility testing and 6 min walk test (6MWT). The following blood tests were evaluated: lipid profile, glucose and C-reactive protein as well as serum concentration of IL-6, leptin, adiponectin, and endothelin. MS was diagnosed in 93 patients (35.8%). No differences were observed in the incidence of MS in relation to airflow limitation severity (mild; moderate; severe and very severe: 38.9; 36.3; 35.2 and 25.0%, respectively). FEV₁ (% predicted), FVC (% predicted), 6MWT distance (6MWD), age, and the number of pack-years were similar in patients with and without MS. MS was more frequent in males than females (38.7 vs. 28.4%, p > 0.05). Serum concentrations of IL-6, endothelin, leptin, and CRP were higher in the MS group, contrary to adiponectin concentration which was lower (p < 0.01). MS was more frequent in male COPD patients, but there were no differences in its frequency between patients with different severity of airflow limitation. We conclude that MS, as a comorbidity, occurs in all COPD stages and affects systemic inflammation. MS incidence does not depend on COPD severity.