title: [Comparison of polysomnographic characteristics in preschool and school aged children with obstructive sleep apnea hypopnea syndrome].
abstract: OBJECTIVE
  To compare the characteristics of polysomnography in preschool and school aged children with obstructive sleep apnea hypopnea syndrome (OSAHS).
  
  
  METHODS
  The clinical data were collected from October 2009 to October 2013 among children monitored in Sleep Medical Center of West China Hospital. Among them, 189 preschool aged (aged 3-5 years) and 211 school aged (aged 6-13 years) children with sleep breathing disorder, and 33 children complained with sleep talking as controls were enrolled and underwent polysomnography. According to apnea hyponea index (AHI), they were classified as primary snoring (AHI<1/h), mild OSAHS (1/h≤AHI<5/h), and moderate/severe OSAHS (AHI≥5/h) and then their sleep architecture was compared among groups.
  
  
  RESULTS
  No significant difference was found in sleep latency, total sleep time, sleep efficiency, the percentage of rapid eye movement stage and N2 stage among groups (P>0.05). In preschool aged children, the percentage of N1 stage in the moderate/severe group was more than other three groups (moderate/severe group vs control group, primary snoring group, mild group: 24.7%±13.7% vs 17.0%±8.7%, 21.7%±12.4%, 20.9%±11.6%, all P<0.05). In school aged children, the percentage of N1 stage in the moderate/severe group was more than the control group (moderate/severe group vs control group: 18.0%±10.4% vs 12.0%±4.8%, P<0.05), the percentage of N3 stage in the moderate/severe group and the mild group were less than the control group (moderate/severe group, mild group vs control group: 28.3%±9.6%, 28.8%±8.8% vs 33.9%±13.0%, both P<0.05). In addition, in preschool and school aged children group, the arouse index in the moderate/severe group was higher than other three groups, the mean oxygen saturation and the lowest oxygen saturation in the moderate/severe group were lower than those of the other three groups, the differences were statistically significant (all P<0.05). Correlation analysis suggested that no significant correlation was found between AHI and body mass index (BMI) in preschool children (r=-0.02, P>0.05). However, there was significance in school aged children (r=0.26, P<0.01). In addition, the correlations were significant between AHI and arousal index in preschool and school aged (r=0.42, 0.55, both P<0.01).
  
  
  CONCLUSIONS
  The sleep architecture is milder affected by OSAHS in preschool children than in school aged children. The severity is mainly related to enlarged tonsils and adenoids. School aged children with OSAHS may be more susceptible to sleep structure disorder and the severity is mainly related to BMI.
authors.affiliation: Sleep Medicine Center, West China Hospital of Sichuan University, Chengdu 610041, China.
authors.forename: Yuanfeng
authors.initials: Y
authors.lastname: Sun
authors.forename: Fei
authors.initials: F
authors.lastname: Lei
authors.forename: Lina
authors.initials: L
authors.lastname: Du
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Tang
authors.forename: Linghui
authors.initials: L
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D001143:Arousal; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D006801:Humans; D006984:Hypertrophy; D017286:Polysomnography; D012890:Sleep; D020181:Sleep Apnea, Obstructive; D012913:Snoring