We need to pay special attention on sleep postures and heart diseases in down syndrome with sleep disordered breathing

Abstract

Down syndrome (DS) is known to be often (30–50%) comorbid with sleep disordered breathing (SDB) for their facial anatomical deformation, muscular hypotonia. Daytime sleepiness resulted from SDB may relate to impaired cognitive function even in general public. In DS, congenital heart diseases (CHD) are also highly complicated (30–60%). Such CHD and SDB may cause a vicious cycle and early intervention to SDB in DS would contribute to their better intellectual and physical development. We reported that some of the DS slept in unusual postures. Thus, we studied the mutual relation among them in DS. We recruited 90 caregivers of the DS in Fukuoka. The questionnaires for the DS contained demographic descriptions including CHD, sleeping postures, Epworth sleepiness scale (ESS), and SDB symptoms (easiness of getting to sleep, snoring, arousal, witnessed apneic episodes, nocturnal urination, nap, hardness of awakening). We calculated individual Caup index (0–5 yo), Rhorer index (6–13 yo), and BMI (14-yo) for judging obesity. We analyzed the relation between SDB symptoms and these items using chi-square test. Seventy of 90 DS (34 men, 18 ± 10 yo) responded to the survey. Thirty-seven DS (53%, 15 men, 15 ± 9 yo) had CHD. Symptoms of SDB were as follows: “easiness of getting to sleep” in 90%, “snore” in 75%, “nocturnal arousal” in 52%, “witnessed apneic episodes” in 40%, “night urination” in 19%, “nap” in 41%, “hard to awaken” in 15%. There was significantly higher proportion of obese DS in “hard to awaken” than in “easy to awaken” (78% vs. 33%, P < 0.05), and tendency of higher proportion of unusual sleep postures in “easy to awaken” than “hard to awaken” (67% vs. 33%, P < 0.1). Furthermore, higher ESS was in “nocturnal arousal” and “night urination” than in “no arousal” and “no night urination” (38% and 55% vs. 4% and 13%, P < 0.01, respectively). Finally, there were tendencies of higher comorbidity of CHD in those with SDB symptoms. Preventing obesity seems to be useful to improve SDB also in DS. The complication of CHD in the DS with SDB suggested formation of the vicious cycle. The unusual sleeping postures in the DS seem to be self-defending behaviors to protect from SDB. In conclusion, we need not only to take general care of SDB like reducing weight but also to give attention to specific risk factors of SDB in DS. Our deepest appreciation goes to the members of the Fukuoka branch of Japan Down Syndrome Society.