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.