[Arousals in children with obstructive sleep apnea-hypopnea syndrome]

To explore the difference of arousal index between the children with obstructive sleep apnea-hypopnea syndrome (OSAHS) and children with primary snoring. Furthermore, to explore the correlation between the above mentioned arousals and the apnea-hypopnea index (AHI) and lowest oxygen saturation (LSaO(2)).

Between March 2007 and February 2008, 102 children suspected of OSAHS underwent overnight polysomnogram monitoring in our medicine sleep center. OSAHS was diagnosed according to the general criterion [Draft of guidelines for the diagnosis and treatment of pediatric sleep apnea hypopnea syndrome (Urumqi) which was published in Chin J Otorhinolaryngol Head Neck Surg in February, 2007]. One-hundred and two children were divided into two groups according to the guidelines. Sixty six children [56 boys, 10 girls; aged 4 - 17 years, (7.01 +/- 2.24) years (x(-) +/- s)] who were diagnosed as OSAHS were enrolled in study group and 36 children [29 boys, 7 girls; aged 4 - 13 years, (7.44 +/- 2.68) years] who were diagnosed as primary snoring made up control group. The difference of spontaneous arousal index, total arousal index and arousal index related to respiratory stimuli and limb movement were compared between the two groups. Besides this, the correlation between spontaneous arousal index, total arousal index and arousal index related to respiratory stimuli and limb movement and AHI and LSaO(2) were also analyzed. Furthermore, the study group were divided into three subgroups according to AHI (< or = 10 times/h, 10 times/h < AHI < or = 20 times/h, > 20 times/h). Spontaneous arousal index, total arousal index and arousal index related to respiratory stimuli and limb movement were compared among the three groups.

The increased total arousal index and arousal index related to respiratory stimuli and the decreased spontaneous arousal index of study group were significant as compared to those of control group (Mann-Whitney U, z value, -3.148, -3.866, -2.791; P value, 0.002, 0.000, 0.005, respectively). The increased arousal index related to respiratory stimuli were significant as being compared among the three groups. Arousal index related to respiratory stimuli was correlated with AHI (coefficient correlation: 0.734, P = 0.000). Other kinds of arousals and arousal index related to respiratory stimuli were not correlated with LSaO(2) (Spearman rank correlation analysis). When compared to control group, stage I increased and stage REM decreased and the difference was significant (z were -2.423, -3.519; P were 0.015, 0.000).

The arousal index related to respiratory stimuli were increased and spontaneous arousal index were decreased in children with OSAHS. Arousal index related to respiratory stimuli is more suitable to show the degree of sleep fragment than other arousal index.