The Effect of Different Sleep Positions on the Severity of Obstructive Sleep Apnea: A Retrospective Study

Obstructive sleep apnea is a risk factor for cardiovascular diseases. Positional sleep apnea is a subtype of obstructive sleep apnea where severity is influenced by the patient's sleeping position. Previous studies have compared supine to non-supine positions; the effect of right lateral versus left lateral position remains in question. Our objective is to study and compare the severity of obstructive sleep apnea across different sleeping positions.

We conducted a retrospective, single-centered study on 338 adult patients (age ≥18 years) diagnosed with Obstructive Sleep Apnea on home sleep study test in the time period between January 2023 and January 2025 in an outpatient community clinic. Linear mixed-effects models were used for statistical analyses.

The mean age of the participants was 55.29 years, with an average AHI of 29.54. Supine position was associated with a higher AHI than prone position (Adjusted model SE= 1.06, p=0.001). However, there were no significant differences between left and right positions across different patients (p =0.327) nor within the same patient (SE 1.31, P 0.65). Comparing sleep positions that were observed more than 20% of the time showed that supine positioning was associated with a significantly higher AHI than right-lateral positioning (CI 15.08-20.61; P<0.001) and left-lateral positioning (95% CI 14.49-20.23; P<0.001). No significant difference was identified between left- and right-lateral positioning (95% CI -2.64 to 3.61; P=0.762).

There was no statistically significant difference between right lateral and left lateral positions on sleep apnea severity, whereas supine position had the highest AHI in comparison to all sleeping positions. Positional therapy remains a valid option for patients with supine‑predominant OSA. Further large scale studies are recommended to compare the true nature and severity of sleep apnea of each sleeping position.