Chronic obstructive pulmonary disease is associated with a low grade systemic inflammatory process. Systemic inflammation is hypothesized to maintain cardiovascular morbidity and mortality in COPD. Early changes of vascular integrity can be detected via markers of subclinical atherosclerosis. Selective Inhibition of phosphodiesterase subtype 4 describes a promising therapeutic option in COPD with beneficial impact on lung function and exacerbation rate. Moreover, an anti-inflammatory effect of phosphodiesterase-4 inhibition was confirmed by recent data. The aim of this study is to assess the effects of the phosphodiesterase-4 inhibitor Roflumilast on firstly surrogates of subclinical atherosclerosis and secondly markers of systemic inflammation in the peripheral circulation of patients with stable chronic obstructive pulmonary disease.