Monitoring Sleep-Wake Rhythm with Actigraphy in Patients on Continuous Positive Airway Pressure Therapy

Background Continuous positive airway pressure (CPAP) therapy has been shown to be effective in alleviating the underlying obstruction as well as reducing patients’ excessive sleepiness and improving their functioning and health-related quality of life. However, residual excessive sleepiness is observed in some patients even though CPAP therapy eliminates sleep apnea and desaturation.

Objectives The aim of this study was to determine the prognostic effect of actigraphic sleep-wake rhythm evaluation in the management of patients with obstructive sleep apnea syndrome (OSAS) treated with CPAP.

Methods Eighteen patients with OSAS diagnosed by standard polysomnography (PSG; 48.1 ± 12.5 years) were enrolled in this study. The sleep-wake parameters were determined by actigraphy before and after 1 month of CPAP treatment, and results were compared with PSG data. In addition, data obtained before CPAP were compared with those measured after 1 month of CPAP treatment.

Results The total sleep time (TST) and sleep efficiency using PSG were significantly correlated with those using actigraphy. Bland-Altman plots of TST and sleep efficiency confirmed good agreement between PSG and actigraphy data. Sleep efficiency significantly improved following CPAP compared to baseline, and sleep fragmentation and sleep fragmentation >5 min determined by actigraphy were significantly lower during CPAP therapy than at baseline. Movement was significantly lower on CPAP therapy than at baseline.

Conclusions Actigraphy provides a valuable sleep-wake rhythm assessment in outpatients with OSAS where PSG is difficult to perform.