Sleep-disordered breathing is associated with impaired attention and neurocognitive deficits. We assessed the association of snoring and intermittent hypoxia with poor academic performance in third grade school children (1,144 children). Snoring frequency and intermittent hypoxia were investigated using parental questionnaire and nocturnal home pulse oximetry. Intermittent hypoxia was specified as desaturation events of 90% or less pulse oximeter saturation. Poor academic performance was defined as grade 4-6 on a six-point scale (i.e., approximately the lowest quintile grades) in mathematics, science, reading, spelling, and/or handwriting in the most recent school report. Snoring "always" was significantly associated with poor academic performance in mathematics (odds ratio; 95% confidence interval: 3.6; 1.3-10.1), science (4.3; 1.3-14.6), and spelling (3.5; 1.2-10.3). Snoring "frequently" was also significantly associated with poor academic performance in mathematics (2.4; 1.3-4.7) and spelling (2.0; 1.04-3.8). A significant relationship between snoring and poor academic performance was also found in children without intermittent hypoxia, whereas intermittent hypoxia did not show an independent association with poor academic performance. Thus, habitual snoring (i.e., snoring frequently or always) was associated with poor academic performance in these primary school children.

We suggest that impaired behavior is a key feature of HS independent of intermittent hypoxia and improves when HS ceases.

ABSTRACT. Objective. Hypoxemia, often assessed via pulse oximetry, is associated with neurocognitive deficits in children. The best way to qualify hypoxemia, or which level of hypoxemia already affects cognition, is unknown.Methods. We assessed the association of pulse oximetry-derived variables that qualify hypoxemia with impaired academic performance in mathematics in a population-based cross-section of 995 primary school children who underwent overnight home recordings of motion-resistant new-generation pulse oximeter saturation (SpO 2 ). Impaired academic performance in mathematics was based on the last school report and defined as grade 4 to 6 on a 6-point scale (ie, approximately the lowest quintile grades).Results. Of 10 variables under study, only the nadir of the SpO 2 values was significantly associated with impaired performance. Categories of this variable representing mild (ie, 91%-93% SpO 2 ; odds ratio: 1.65; 95% confidence interval: 1.06 -2.56) and moderate hypoxemia (ie, <90% SpO 2 ; odds ratio: 2.28; 95% confidence interval: 1.30 -4.01) both were associated with impaired performance in mathematics.Conclusions. We suggest using the nadir of the SpO 2 values in an overnight study to qualify hypoxemia in future studies. This variable may predict neurocognitive deficits in school children. Mild hypoxemia, as yet widely considered benign, may already affect cognition in childhood. A dverse impacts of chronic or intermittent hypoxemia on development, behavior, cognition, and academic performance have been reported in many well-designed and controlled studies in children with sleep-disordered breathing 1-6 or congenital heart disease. [7][8][9][10][11] Data for other clinical conditions that result in chronic or intermittent hypoxemia are sparse. In some studies, adverse effects have been noted at even mild levels of oxygen desaturation. 1 Application of pulse oximetry to detect chronic or intermittent hypoxemia is a valid, reliable, and frequently used method. 12 Several variables that qualify chronic and intermittent hypoxemia can be derived from pulse oximetry and reference ranges used to identify abnormal clinical conditions. 13 However, it is yet unclear which pulse oximetry-derived variable best predicts neurocognitive impairments in children and which level of oxygen desaturation is already harmful. The mean and nadir arterial oxygen saturation measured by pulse oximetry (Spo 2 ) have been reported and shown to have some relationship to decreased intelligence, 5 impaired attention, 5 and hyperactive behavior. 1,6 We recently performed a study on the association between sleep-disordered breathing and impaired academic performance in primary school children. 14 As part of this study, children were examined for the presence of nocturnal chronic and intermittent hypoxemia using pulse oximetry. Only a weak association between intermittent hypoxemia and impaired academic performance in mathematics was found. 14 These results, however, were recently challenged: the inclusion of children with perhaps "a...

Sleep problems or disturbed sleep is common in childhood. Insomnia symptoms such as sleep onset delays and awakenings during the night affect 5-23% of school children [1,2,3,4]. Besides insomnia symptoms, 5-to 12-year-old children as well as their parents often report nightmares (2-7%) [3,4,5,6] as well as enuresis (5-18%) [4,5,7], whereas sleepwalking seems to be less frequent with prevalence rates ranging from 0.6-2% [5,8].Chronic sleep problems, in particular insomnia, are suspected to have negative effects on children's daytime performance. Nearly a fifth of children report sleepiness or decreased motivation and tiredness [9]. Furthermore, they show emotional changes and increased fluctuations in attention and performance [9,10]. Diminished sleep quantity and quality is related to compromised cognitive functioning [11].Frequent sleep disruptions have also been related to academic performance; poorer sleep is associated with lower teacher ratings [12,13]. Daytime sleepiness and inattention were found to be associated with sleep problems in school children [14,15]. Low true sleep time is highly associated with teacher-reported externalizing symptoms such as aggressive and delinquent behavior as well as inattention and social problems [16,17]. Others report that sleep problems in general in early childhood are predictors of depression/anxiety, inattention/hyperactive behavior, and aggression [18,19]. Thus, the first few years of school are a vulnerable period, and there may be long-lasting effects in children suffering from sleep disturbances.As part of an investigation into the prevalence of sleep problems in primary school children, we performed an explorative analysis to investigate associations between sleep problems and poor academic performance [20]. Of particular interest was the impact of childhood insomnia on academic achievement in this age group of school children. Methods Subjects and study proceduresSubjects participated in a cross-sectional study on the prevalence of sleep disturbances in primary school children. Children of 27 public primary schools in Germany were selected at random within strata of average socioeconomic status of parents. Following approval by the institutional review board and the regional directorate of education, all children attending the 3rd grade in these schools (n = 1,760) were identified. Pupils were contacted in their classrooms by two investigators and received a cover letter explaining the study, an informed consent form, and two questionnaires. The first questionnaire contained questions on symptoms of sleep problems and sleep-disordered breathing completed by the parents, the second one focused on sleep problems to be filled out by the children. Questionnaires were collected by the classroom teacher and picked up by a study crewmember 1-2 weeks after the initial visit. A total of 1,144 children (65.0%) with a mean age of 9.6 years (SD 0.66) participated in the study. Comparisons to all eligible 3rd graders (n = 1,760) and the underlying source population of 3rd gra...