Positional obstructive sleep apnea in children: prevalence and risk factors

Purpose Positional (supine dependent) obstructive sleep apnea (POSA) affects about 55% of adults with obstructive sleep apnea (OSA). We aimed to study the prevalence and risk factors for POSA in children. Methods Cross-sectional analysis of data obtained in 171 children with moderate to severe OSA confirmed by polysomnography (PSG) performed over a 2-year period. POSA is defined by an obstructive apnea-hypopnea index (oAHI) in the supine position >= 2x oAHI in the non-supine position. Results The overall prevalence of POSA was 18.7%. Children with POSA were significantly older (p < 0.001), had a higher prevalence of obesity (p = 0.04), a lower tonsil score (p = 0.049), and less severe OSA (lower oAHI) (p = 0.02) compared to children without POSA, while age was the only significant independent predictor of POSA. The ratio AHI supine to AHI non-supine was not significantly higher during REM than during NREM sleep in children with POSA. Conclusions POSA is less common in children compared to adults and the prevalence of POSA increases with age. Although OSA worsens during REM sleep, this was not observed for POSA. Future studies should investigate the prevalence of POSA in specific subgroups and upper airway characteristics of POSA in children.