Normal Polysomnographic Characteristics in Korean Children and Adolescents

Purpose: The objective of this study was to describe polysomnographic charateristics in normal children and adolescents in Korea. Little is known regarding sleep architecture in Korean children. Methods: We conducted a prospective study and examined sleep architecture, respiratory parameters, arousals, and periodic limb movement index during sleep (PLMS) in healthy children and adolescents for 2 consecutive days. Results: The study population consisted of 29 subjects and 15 subjects (52%) were male. Ages ranged from 5-16 years, with a mean of 11.6±.7 years. The average total sleep time (TST) was 438±35.6 min, and the mean sleep efficiency was 90.9±17.7%. The distribution of sleep stages as percentage of TST was as follows: stage N1, 6.6±2.9%; stage N2, 54.2±5.8%; stage N3, 21.1±6.7%; and stage R, 18.1±5.4%. The wake after sleep onset (WASO) was 2.0±2.9% of TST. The total arousal index (TAI) was 7.6±2.2. The current study findings are similar to those of previous studies in Western countries except longer stage N2 sleep and higher WASO. Conclusion: This is the first report of normal polysomnography values in Korean children. In order to accurately diagnose sleep disorders, normative sleep reference values are essential and our findings will provide fundamental data for pediatric sleep research.