Effects of Salmeterol on Autonomic Nervous System

This is a 4-week non-randomized, partially blinded, single-arm monocentre study in subjects with COPD 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. During a complex data registration period comprising the continuous recording of muscle sympathetic nerve activity (MSNA) and respiration and of various other measurements at Visit 1, placebo and 50 μg of salmeterol via Diskus™ inhaler will be administered in a sequential design. Following Visit 1, the subjects will be treated with salmeterol 50 μg twice daily via Diskus inhaler for 4 weeks. At the Final Visit (Visit 2) the data registration period of Visit 1 will be repeated with the only difference that no placebo will be administered. Further endpoints, besides the evaluation of MSNA, include heart rate variability (HRV), spontaneous baroreflex sensitivity and lung function parameters. Study enrolment will be stopped when valid MSNA data on the immediate effect of inhalation (manoeuvres at Visit 1) are available for 24 subjects.