Exploring the Impact of Positional Sleep Apnea in a Turkish Population: Unveiling the Untold Story

BACKGROUND: This retrospective study aimed to evaluate the demographic, clinical, and polysomnographic findings in patients with obstructive sleep apnea (OSA) and to identify factors associated with positional OSA (POSA), exclusive POSA (e-POSA), and non-positional OSA (non-POSA). MATERIAL/METHODS: A total of 782 OSA patients who were further diagnosed with POSA (total: n=470, e-POSA: n=204) or non-POSA (n=312) based on apnea-hypopnea index (AHI) events by overnight polysomnography were included. Demographical, clinical, and polysomnographic characteristics were recorded, while independent predictors of POSA and e-POSA were determined via linear regression analysis. RESULTS: Severe OSA (AHI ≥30/h) was less common in the POSA (33.4% vs 71.5%, P<0.001) and e-POSA (9.8% vs 62.3%, P<0.001) groups than in the non-POSA and non-e-POSA groups, respectively. For POSA and e-POSA, male sex (OR 2.195, P<0.001 and OR 2.021, P=0.004, respectively), low body mass index (BMI; OR 0.932, P<0.001 and OR 0.948, P=0.006), low AHI (OR 0.954 and OR 0.902, P<0.001 for each), and less desaturation (T90%, OR 0.972 and OR 0.968, P<0.001 for each) were the common statistically significant predictors. Younger age was an independent predictor of POSA (OR 0.97, P=0.003). POSA (median 20.4 s) and e-POSA (20.5 s) groups demonstrated similar apnea-hypopnea durations (min) as the non-POSA (median 21.1 s) group. CONCLUSIONS: Our findings revealed that male sex and lower values of BMI, AHI, and desaturation were common determinants of POSA and e-POSA, while younger age independently predicted POSA. POSA and e-POSA had similar clinical and polysomnographic characteristics and shared the unvaried hypoxic burden.