Prevalence and characteristics of positional obstructive sleep apnea in a Saudi population-based cohort.

Obstructive sleep apnea (OSA), significantly impacts public health, with varying prevalence rates across populations. Positional obstructive sleep apnea (POSA) is a subtype in which OSA predominantly occurs in the supine position. This study investigated the prevalence and characteristics of exclusive positional obstructive sleep apnea (e-POSA) in a representative Saudi population. Data from a previous cohort study on the prevalence of OSA in Saudi Arabia were utilized. A 2-phase approach was used: the first phase involved a screening questionnaire, and the second phase involved confirmatory polysomnography (PSG). E-POSA was defined as an apnea-hypopnea index (AHI) in the supine position at least twice as high as that in the lateral position, with the lateral AHI not exceeding 5. Then, an exploration method was used to estimate the prevalence of e-POSA. There were 235 OSA patients included in this study. The prevalence of e-POSA among the OSA patients was 21.28%, with a higher prevalence in females (26.76%) than in males (18.90%). However, the estimated prevalence of e-POSA in the Saudi population was 1.86%. Patients with e-POSA tended to be younger and to have lower AHI, Epworth Sleepiness Scale (ESS) and arousal index scores (P < .001). Multivariate analysis revealed that the rapid eye movement (REM) related AHI and nonsupine AHI were predictors of e-POSA (P < .01). E-POSA is common in patients with OSA. However, the estimated prevalence of e-POSA across the general population was 1.86%. Patients with e-POSA have milder disease, and the AHI-REM and AHI-nonsupine were identified as predictors.