Cardiovascular regulation in different sleep stages in the obstructive sleep apnea syndrome

In order to show the value of the analysis of heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS) for the study of sleep disorders we consider 38 subjects, 18 of which are normotensive (NT) and 10 hypertensive (HT) patients suffering from obstructive sleep apnea syndrome (OSAS), the rest being controls. To detect differences in cardiovascular regulation between the different sleep stages and these age and sex matched groups, linear and nonlinear parameters are used. The therapeutic effect of continuous positive airway pressure (CPAP) therapy is investigated by comparing an initial diagnostic measurement with a follow-up after three month of therapy.