Nocturnal arterial oxygen saturation and academic performance in a community sample of children

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 (SpO2). 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 SpO2 values was significantly associated with impaired performance. Categories of this variable representing mild (ie, 91%-93% SpO2; odds ratio: 1.65; 95% confidence interval: 1.06-2.56) and moderate hypoxemia (ie, < or =90% SpO2 ; 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 SpO2 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. SpO2

Habitual snoring, intermittent hypoxia, and impaired behavior in primary school children

OBJECTIVES

Sleep-disordered breathing is associated with impaired behavior and poor academic performance in children. We aimed to determine the extent of behavioral problems in snoring children, clarify the role of intermittent hypoxia, and test the reversibility of impaired behavior and poor academic performance.

METHODS

In 1144 children, habitual snoring (HS; snoring frequently or always) and impaired behavior were assessed using parental questionnaires. Intermittent hypoxia (ie, presence of > or =5 arterial oxygen desaturations by > or =4% or > or =1 desaturation to < or =90%) was investigated with pulse oximetry. Poor academic performance (grade 4-6 on a 6-point scale in mathematics, science, or spelling) was based on the last school report. HS, impaired behavior, and academic performance were reevaluated after 1 year. Adjusted odds ratios (ORs) were calculated using unconditional logistic regression.

RESULTS

HS was significantly associated with hyperactive (OR: 2.4) and inattentive behavior (OR: 4.0), daytime tiredness (OR: 7.1), and sleepiness (OR: 2.6-4.8). These associations were independent of intermittent hypoxia. HS was also significantly associated with bad conduct (OR: 2.8), emotional symptoms (OR: 5.5), and peer problems (OR: 9.7). At follow-up, hyperactive and inattentive behavior but not academic success had significantly improved in children in whom HS had ceased.

CONCLUSIONS

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

Snoring, intermittent hypoxia and academic performance in primary school children

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.