Depressed baroreceptor reflex in patients with obstructive sleep apnea (OSA).

In this study we evaluated the cardiovascular autonomic function in twenty-five OSA patients and in twenty-five control healthy subjects, by computerized spectral analysis of R-R interval variation at rest and during orthostatism by head-up tilt maneuver to up-right position (80 degrees) as a sympathetic provocation. The results of our study show that most patients affected by OSA have a sympathetic overactivity and a decreased baroreflex response in comparison with normal subjects. The method here described is simple, objective and very sensitive and may be utilized to discover early signs of an autonomic dysfunction consequent to OSA leading to cardiovascular complications of the late stage of the disease.