Background: Sleep-disordered breathing (SDB) occurring during rapid eye movement (REM) sleep occurs more frequently in women than men. We sought to characterize REM SDB prevalence by gender and age to identify factors that could account for this discrepancy.
Methods: Subjects with REM SDB were identified among 2,486 patients referred to a university sleep laboratory with an apnea-hypopnea index (AHI) >or= 5 events per hour. REM SDB was defined as non-REM (NREM) AHI <or= 15/h and REM AHI/NREM AHI ratio >or= 2. Regression analyses were utilized to determine factors associated with REM SDB.
Results: REM SDB prevalence was 40.8% in women and 21.0% in men. After adjusting for age and obesity, female sex remained a risk factor for REM SDB (odds ratio, 3.0; 95% confidence interval [CI], 1.8 to 4.2). REM SDB prevalence waned with increasing age in both sexes, such that the odds of having REM SDB fell by 26.7% (95% CI, 15.2 to 38.2%) per decade. REM AHI/NREM AHI decreased with age only in women, falling 10.9% (95% CI, 5.5 to 16.3%) per decade. NREM AHI in women increased the most with age (16.0%; 95% CI, 11.1 to 20.9%) per decade, and least with body mass index (BMI) [13.0%; 9.1 to 16.9%] for every 5-unit BMI increase when compared to REM AHI for women and either index for men.
Conclusions: REM SDB prevalence decreases with age in women as does REM AHI/NREM AHI, perhaps secondary to a disproportionate age-dependent rise in NREM vs REM AHI in women. Younger women may be protected from SDB during NREM sleep, even in the face of obesity. These patterns may reflect age-related decreases in female hormones.