Transcutaneous Vagus Nerve Stimulation (tVNS) Decreases Sympathetic Nerve Activity in Older Healthy Human Subjects

Increasing age can alter the autonomic balance towards elevated sympathetic nerve activity and reduced parasympathetic activity. This age-associated autonomic dysfunction is linked with chronic conditions such as cardiovascular disease and impaired mental health. Vagus nerve stimulation (VNS), using a surgically-implanted bipolar electrode in the neck, is under investigation in a number of chronic conditions but the invasiveness of the procedure and risk of post-operative complications limits its therapeutic use for age-associated diseases. The aim of the present study is to investigate the effects of a non-invasive stimulation technique, transcutaneous vagus nerve stimulation (tVNS) on autonomic activity in older healthy human subjects aged 60 and above. The study was conducted in accordance with the Declaration of Helsinki and approved by the University of Leeds Ethics Committee. tVNS was applied to the tragus of the ear using transcutaneous electrical nerve stimulation (TENS; 20–50mA, 30Hz, 200μs) in 1...