This is a 4-week non-randomized, partially blinded, single-arm monocentre study in subjects with Chronic Obstructive Pulmonary Disease (COPD) Global Initiative for Chronic Obstructive Lung Disease (GOLD) class II or III with the aim to demonstrate that inhaled therapy with salmeterol reduces sympathetic activity as evaluated by microneurography. A maximum of 32 subjects is planned to be enrolled.