Increased brachial intima-media thickness is associated with circulating levels of asymmetric dimethylarginine in patients with COPD

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with an increased cardiovascular risk. However, the mechanisms for this association are yet unclear. The aim of this study was to investigate the relationship between brachial intima-media thickness (B-IMT), an independent predictor of cardiovascular risk, systemic inflammation, and asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, in patients with COPD and respective controls. METHODS: The study sample consisted of 60 patients with stable COPD, free from overt cardiovascular disorders, as well as 20 smoking and 20 nonsmoking controls. Ultrasound assessment of B-IMT, spirometry, venous blood sampling for quantification of inflammatory markers and ADMA levels were carried out, and individual cardiovascular risk was calculated via the Framingham risk score. RESULTS: Patients with COPD showed significantly higher B-IMT compared to smoking (P=0.007) and nonsmoking controls (P=0.033). COPD patients with elevated B-IMT had a twofold increased calculated 10-year risk for cardiovascular events compared to those below the recommended cutoff (P=0.002). B-IMT was significantly associated with systemic inflammation (interleukin-6 [IL-6]; r=0.365, P=0.006) and ADMA (r=0.331, P=0.013) in COPD. Multivariate linear regression revealed male sex and ADMA as independent predictors of B-IMT in this study sample. CONCLUSION: B-IMT is significantly increased in patients with COPD and is associated with systemic inflammation and ADMA levels.