Ambulatory positional obstructive sleep apnea syndrome.

Objective: To establish the prevalence of positional (PP) OSA patients using self-administered home-based respiratory polygraphy (RP).

Materials and Methods: 52 month retrospective study based on RP records.

Results: 200 PR records: 70.5% men 29.5% women. 76% were diagnosed with OSA and 54.6% with PP OSA. There were no significant differences in Epworth Sleepiness Scale, apnea hypopnea index and oxygen desaturation index. PP OSA patients were younger, had a lower BMI (30.3±0.9 vs. 35.3±1.2) ( p <0.0001), and the time they spent with oxygen saturation <90% (T<90) was lower (8.8 vs. 28.7±6.7, p =0.0038). The PP OSA group spent 43% of total recording time in the supine position.

Conclusions: The prevalence of PP OSA patients studied with RP is similar to the one described by sleep laboratories. They have lower BMI, present mostly mild OSA with less desaturation, and are less likely to receive CPAP therapy.