Obesity and excessive daytime sleepiness in prepubertal children with obstructive sleep apnea.

INTRODUCTION: The epidemic of childhood obesity has prompted remarkable changes in the relative proportions of symptomatic overweight or obese children being referred for evaluation of habitual snoring. However, it remains unclear whether obesity modifies the relative frequency of daytime symptoms such as excessive daytime sleepiness.
METHODS: Fifty consecutive, nonobese, habitually snoring, otherwise-healthy children (age range: 6-9 years) and 50 age-, gender-, and ethnicity-matched obese children (BMI z score: >1.67) underwent an overnight polysomnographic evaluation, followed by a multiple sleep latency test the following day.
RESULTS: The mean obstructive apnea/hypopnea index values for the 2 groups were similar (nonobese: 12.0 +/- 1.7 episodes per hour of total sleep time; obese: 10.9 +/- 1.5 episodes per hour of total sleep time). However, the mean sleep latency for obese children was significantly shorter (12.9 +/- 0.9 minutes) than that for nonobese children (17.9 +/- 0.7 minutes). Furthermore, 21 obese children had mean sleep latencies of < or =12.0 minutes, compared with only 5 nonobese children. Although significant associations emerged between mean sleep latency, obstructive apnea/hypopnea index, proportion of total sleep time with oxygen saturation of <95%, and respiratory arousal index for the whole cohort, the slopes and intersects of the linear correlation of mean sleep latency with any of these polygraphic measures were consistently greater in the obese cohort.
CONCLUSIONS: The likelihood of excessive daytime sleepiness for obese children is greater than that for nonobese children at any given level of obstructive sleep apnea severity and is strikingly reminiscent of excessive daytime sleepiness patterns in adults with obstructive sleep apnea.