Background. Chronic obstructive pulmonary disease (COPD) is characterized by inhaled particles and gases inducing chronic inflammation of the airways accompanied by a not fully reversible airflow limitation. Systemic inflammation has an important role in the pathogenesis of COPD. In parallel, several comorbidites can be observed. Microalbuminuria is related to endothelial dysfunction. Microalbuminuria was increased in exacerbation periods of COPD.