Annotated abstract☆

2. Bass, J. L., Corwin, M., Gozal, D., Moore, C., Nishida, H., Parker, S., et al. (2004). The effect of chronic or intermittent hypoxia on cognition in childhood: a review of the evidence. Pediatrics, 114 805-816 

This is an excellent research article based upon a structured Medline search of the literature from 1966 to 2000 that reviewed and analyzed studies investigating the impact of chronic and intermittent subclinical hypoxia on cognition in children. A total of 788 literature citations were studied, with 55 research studies accepted to be included in the study as their findings met the criteria of providing direct evidence related to the variables of interest. Causes of hypoxia were divided into categories of congenital heart disease (CHD), sleep-disordered breathing (SDB), asthma, chronic ventilatory impairment, and respiratory instability in infants. There were 42 studies that included the categories of CHD and SDB that met the criteria of Evidence-Based Pediatrics and Child Health Criteria for association and causality as to the variables of interest. Nineteen of the 42 studies included specific arterial oxygen saturation data. Not surprisingly, in this research analysis of prior studies, chronic or intermittent hypoxia due to CHD or SDB was associated with adverse impact on cognition. Bass et al. noted that well-designed studies have consistently demonstrated that hypoxia adversely effects development, behavior, and academic achievement. In addition, adverse effects of hypoxia were noted in every age group from newborns through age 14 years.

Comments: The authors of this article identified various limitations in their work and noted that the evidenced-based studies accepted for review were not sufficiently homogeneous to undergo meta-analysis. However, their meticulous review of data from 42 previous well-designed studies gives food for thought and ideas for further research about this topic. With the increased incidence of overweight and obesity in the pediatric population, which is also linked to obstructive sleep apnea and snoring, I cannot help but think that these children would be an excellent group to study as to whether they experience intermittent hypoxia during sleep and its effect on their cognition.