Community prevalence of positional obstructive sleep apnea.

Abstract

Study objectives: The prevalence of positional obstructive sleep apnea (POSA) in community populations warrants further investigation. Further, more research is needed into the clinical characteristics of its subtypes such as supine predominant OSA (spOSA) and supine isolated OSA (siOSA).

Methods: A cross-sectional analysis was performed on 1870 Sleep Heart Health Study participants. OSA was defined by an apnea-hypopnea index (AHI) of five events or more per hour of sleep. Participants with OSA were classified as POSA if the supine AHI was ≥2 times the non-supine AHI. Participants with OSA who did not meet this threshold were classified as non-positional OSA participants (non-POSA). Demographics, polysomnographic data, comorbidities, and medications were all considered. The POSA subtypes spOSA and siOSA were also investigated.

Results: POSA participants were slightly older, less obese, and had higher systolic blood pressure than non-POSA subjects, in addition to being more prevalent (62% and 38%, respectively). POSA exhibited higher supine and total AHI. The prevalence of comorbidities or prescription drugs did not differ. In the POSA cohort, spOSA was more prevalent than siOSA (56% vs. 44%). When compared to siOSA, spOSA was associated with more fragmented sleep and higher AHI. Furthermore, when compared to the siOSA group, the spOSA group had a higher prevalence of hypertension and diabetes, as well as more frequently prescribed medications for these comorbidities.

Conclusions: In the SHHS population the prevalence of POSA is greater than non-POSA. The spOSA subtype is more prevalent and appears to have worse health consequences than siOSA.