Obstructive sleep apnea in Parkinson's disease patients: effect of Sinemet CR taken at bedtime

Obstructive sleep apnea (OSA) results from upper airway (UA) obstruction. In Parkinson's disease (PD), levodopa improves UA obstruction during wakefulness. We hypothesized that bedtime controlled-release levodopa (Sinemet CR) is associated with less severe OSA (lower apnea-hypopnea index [AHI]) in PD patients. Idiopathic PD subjects underwent nocturnal polysomnography (PSG) and were divided into those taking bedtime Sinemet CR (SinCR+) and those not taking Sinemet CR (SinCR-). Outcomes were compared between groups for PSG recordings analyzed in whole and split at their mid-point with each half analyzed separately, using linear regression. Fifty-seven subjects were studied, eight SinCR+, and 49 SinCR-. They were 65 % male, aged 64.4 +/- 10.3 years (mean +/- SD), with body mass index 27.26 +/- 3.98 kg/m(2). The whole night AHI was 15.6 +/- 13.3 and 29.1 +/- 20.8 in SinCR+ and SinCR-, respectively (p = 0.07 unadjusted, p = 0.11 adjusted for confounders). A similar trend was observed in the first half of the night. In the second half, the SinCR+ group had significantly lower AHI (beta = -18.8; p = 0.01 adjusted) and respiratory arousal index (beta = -14.2; p = 0.02 adjusted) than the SinCR- group. Bedtime Sinemet CR appears to reduce OSA in PD patients. There were no significant differences between groups in the first half of the night likely because of residual effects of short-acting levodopa in both groups, while Sinemet CR had residual effect in the second half. These results possibly provide an alternative to help manage OSA and improve sleep quality in PD patients.