The effect of childhood obstructive sleep apnea on ambulatory blood pressure is modulated by the distribution of respiratory events during rapid eye movement and nonrapid eye movement sleep

Abstract

ObjectiveWe aimed to investigate if different childhood obstructive sleep apnea (OSA) subtypes, namely rapid eye movement (REM)-related, nonrapid eye movement (NREM)-related and stage-independent OSA would exert different effects on ambulatory blood pressure (ABP). MethodsData from our previous school-based cross-sectional study were reanalyzed. Subjects who had an obstructive apnea–hypopnea index (OAHI) between 1 and 10 events per hour and a total REM sleep duration of >30min were included in our analysis. REM-related and NREM-related OSA were defined as a ratio of OAHI in REM sleep (OAHIREM) to OAHI in NREM sleep (OAHINREM) of >2 and <0.5, respectively. The others were classified as stage-independent OSA. ResultsA total of 162 subjects were included in the analysis. In the mild OSA (OAHI, 1–5events/h) subgroup, no significant differences in any ABP parameters were found between OSA subtypes. On the other hand, in subjects with moderate OSA (OAHI, 5–10events/h), the REM-related OSA subtype had a significantly lower daytime systolic blood pressure (SBP) z score (−0.13±0.90 cf 1.15±0.67; P=.012) and nighttime SBP z score (0.29±1.06 cf 1.48±0.88, P=.039) than the stage-independent OSA subtype. Linear regression analyses revealed that OAHINREM but not OAHIREM was significantly associated with both daytime (P=.008) and nighttime SBP (P=.042) after controlling for age, gender, and body size. ConclusionChildren with obstructive events mainly in REM sleep may have less cardiovascular complications than those with stage-independent OSA.