PURPOSE: Rapid eye movement (REM)-related obstructive sleep apnea (OSA) is characterized by clustered apneas occurring during REM sleep. The clinical significance of REM OSA has been disputed. The aim of this study was to determine the prevalence of REM OSA and evaluate the influence of sleep position on REM OSA.
METHODS: Polysomnographic records from January 2004 to June 2005 were reviewed. The severity of OSA was determined from apnea-hyponea index (AHI) for total sleep time, and was classified as a mild (5 to 15/h), moderate (15 to 30/h) and severe (> 30/h) group. REM OSA was defined as REM AHI/Non REM AHI ≥ 2, and control OSA other than REM OSA was defined as REM AHI/Non REM AHI ≤; 1.5, and patients were excluded if they had less than 30 minutes of REM sleep. Positional influence was regarded as present if supine-AHI/nonsupine-AHI ≥ 2.
RESULTS: Of 538 patients, 111 (20.6%) met the criteria of REM OSA. Mean age of REM OSA was 45.6 (± 9.8) years, mean BMI was 25.7 (± 3.1) kg/m2 and female: male ratio was 0.35:1. REM OSA represents 67 (38.3%), 35 (21.3%) and 9 (4.5%) in mild, moderate and severe OSA, respectively. Positional influence was present in 55/67 (82.1%) with mild REM OSA and 87/96 (90.6%) with mild control OSA (p=0.15), 24/35 (68.6%) with moderate REM OSA and 108/118 (91.5%) in moderate control OSA (p=0.001).
CONCLUSION: REM OSA represents a significant proportion in patients with mild to moderate OSA and there are fewer patients with positional influence than the other OSA. Positional therapy might not be effective in patients with REM OSA, especially of moderate AHI severity.
CLINICAL IMPLICATIONS: Positional therapy might not be effective in patients with REM OSA, especially of moderate AHI severity.
DISCLOSURE: Kyung-Wook Jo, No Financial Disclosure Information; No Product/Research Disclosure Information