Michael G. Ziegler Research

Sympathetic nervous control of the cardiovascular system

Dr. Ziegler's research on sympathetic nervous control of the cardiovascular system bridges basic and clinical research in over 400 publications. His recent studies found increased adrenaline day and night in hypertensive subjects with obstructive sleep apnea. Two clinical trials demonstrated that drugs that block this excess sympathetic nerve activity lowered blood pressure twice as well as standard antihypertensive therapy. His NASA research has examined why astronauts lose postural control of blood pressure on their return from space flight.

Watch Dr. Michael G. Ziegler's presentation, "How a Year in Space Affects the Human Body":

Dr. Ziegler has studied astronaut health since 1978. He chaired NASA's yearly cardiovascular reviews, helped devise current astronaut protocols, and studied physiologic and genomic changes during the Year in Space study. He has received a NASA research award and has chaired several NIH Review Committees. He is particularly interested in mechanisms that allow the brain to use the sympathetic nervous system to alter physiology and the consequences of stress and sleep apnea on blood pressure control. He specializes in clinical care of patients with high blood pressure and postural hypotension.

The Ziegler lab studies the regulation of blood pressure, particularly by the autonomic nervous system. There is a focus on hypotensive disorders including autonomic neuropathies, POTS and the postural hypotension astronauts experience on return to earth's gravity. Hypertensive disorders under study include PTSD, sleep apnea and chronic stress responses. The lab develops non-invasive tools to study the baroreflex, chemoreflex pulse transit time, flow mediated dilation and heart rate variability. These tools measure cardiovascular responses to interventions such as Tai Chi or behavioral activation counseling to evaluate if they decrease pressor responses and promote vascular health.