RT Journal A1 Dyken M, Lin-Dyken DC, Poulton S, Zimmerman M, Sedars E T1 PRospective polysomnographic analysis of obstructive sleep apnea in down syndrome JF Archives of Pediatrics & Adolescent Medicine JO Archives of Pediatrics & Adolescent Medicine YR 2003 FD July 1 VO 157 IS 7 SP 655 OP 660 DO 10.1001/archpedi.157.7.655 UL http://dx.doi.org/10.1001/archpedi.157.7.655 AB Objectives  To investigate obstructive sleep apnea (OSA) in a consecutively encountered, nonselected population of young patients with Down syndrome using standard overnight polysomnography and to determine the effects of therapy.Methods  In a population of patients seen for routine developmental evaluations, 9 boys and 10 girls were studied using standard overnight polysomnography.Results  Using pediatric standards, OSA was found in 79% of the subjects (95% confidence interval, 54%-94%), with a median apnea index of 3 events per hour (interquartile range, 2-5), a median apnea-hypopnea index of 6 events per hour (interquartile range, 3-8), and a median arterial oxygen saturation (SaO2) low point of 88% (interquartile range, 84%-90%). Higher body mass index was significantly associated with a higher apnea index and a lower SaO2 level, and there was a significant inverse relationship between age and the lowest SaO2 value as well as a possible association between sleep-related symptoms at the time of diagnosis and the lowest SaO2 value. In addition, patients with OSA had a significantly higher movement arousal index than those without OSA.Conclusions  Using rigid polysomnographic standards, this pilot study revealed OSA in a high percentage of young subjects with Down syndrome and an association between OSA and obesity, age, and poor sleep quality. These findings justify larger and more detailed population studies to further define clinical factors that are concomitant with OSA in Down syndrome and to improve therapy.