REM rebound and CPAP compliance.

OBJECTIVE/BACKGROUND: The objective of this study was establish if rapid-eye-movement (REM) rebound on first exposure to continuous positive airway pressure (CPAP) is associated with CPAP compliance. A rebound or drastic increase in REM sleep in response to initial CPAP exposure is associated with improvement in the subjective quality of sleep. We wished to determine if REM rebound was also associated with increased CPAP compliance.

METHODS

Split night polysomnographic studies carried out in a one-and-a-half year period were examined for REM rebound and slow wave sleep (SWS) rebound. Compliance with CPAP according to percentage of days used and percentage of days used for more than 4h was determined at 30, 60, and 120 days and compared between groups with and without REM rebound and then between groups with and without SWS rebound. Multivariate regression models were constructed to determine factors that were associated with increasing CPAP compliance.

RESULTS

CPAP compliance was greater for those with REM rebound than those without REM rebound at all time periods, but significantly so only for total percentage of days used at 30 days (86.7±46.7, 96.7 vs. 56.7 [median±1st quartile, 3rd quartile]±32.5, 90.0; p=0.04) and 60 days (78.3±37.5, 93.4 vs. 50.0±25.0, 80.9; p=0.03). There was no difference in CPAP compliance for SWS rebound and there were no SWS rebound groups. Only the presence of REM rebound was associated with increased compliance with CPAP with neither SWS rebound nor diagnostic AHI being significantly associated with CPAP compliance.

CONCLUSIONS

The presence of REM rebound, but not SWS rebound, on initial CPAP exposure is associated with early CPAP compliance. This increased compliance is not explained by severity of sleep apnea as measured by AHI.