Department of Paediatrics, Monash University, The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.
Department of Paediatrics, Monash University, The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia; Department of Paediatrics, Monash University, Melbourne Children's Sleep Centre, Monash Children's Hospital, Melbourne, Victoria, Australia.
Sleep Med. 2021 May;81:466-473. doi: 10.1016/j.sleep.2021.03.020. Epub 2021 Mar 24.
Children with Down syndrome (DS) are at increased risk for sleep disordered breathing (SDB), which can have adverse effects on the cardiovascular system. In adults with SDB, nocturnal dipping of heart rate (HR) and blood pressure (BP) is reduced, and this is associated with an increased risk of future cardiovascular events. We aimed to compare nocturnal dipping of HR and pulse transit time (PTT) (a surrogate inverse measure of BP change) in children with DS and SDB to those of typically developing (TD) children with and without SDB.
19 children with DS (3-18 years) were age and sex matched with 19 TD children without SDB (TD-) and with 19 TD children with matched severity of SDB (TD+). Nocturnal dipping was assessed as the percentage change in HR and PTT from wake before sleep onset to total sleep, N2, N3 and REM sleep across the night and to the first cycle of sleep.
Children with DS exhibited reduced nocturnal dipping of HR during total sleep, N2, N3 and REM sleep and increased PTT (reduced BP dipping) in N2 sleep. Fewer children with DS exhibited a greater than 10% fall in HR between wake and N2 or REM sleep compared to TD+ children.
Our findings demonstrate significantly reduced nocturnal dipping of HR in children with DS compared to TD children matched for SDB severity, suggesting SDB has a greater cardiovascular effect in these children. Further studies are required to fully understand the mechanisms involved and to assess if treatment of SDB improves nocturnal dipping.
唐氏综合征（DS）患儿发生睡眠呼吸障碍（SDB）的风险增加，这可能对心血管系统产生不良影响。在患有 SDB 的成年人中，夜间心率（HR）和血压（BP）的下降幅度减小，这与未来心血管事件的风险增加相关。我们旨在比较患有 SDB 的 DS 患儿与无 SDB 的典型发育（TD）患儿以及患有 SDB 但严重程度相匹配的 TD 患儿之间夜间 HR 和脉搏传输时间（PTT）（BP 变化的替代逆测量）的下降情况。
将 19 名年龄在 3-18 岁之间的 DS 患儿与 19 名无 SDB 的 TD 患儿（TD-）和 19 名 SDB 严重程度相匹配的 TD 患儿（TD+）进行年龄和性别匹配。夜间下降情况通过 HR 和 PTT（BP 变化的替代逆测量）从睡前觉醒到整个睡眠、N2、N3 和 REM 睡眠以及夜间第一周期睡眠的百分比变化来评估。
DS 患儿在整个睡眠、N2、N3 和 REM 睡眠期间的 HR 夜间下降幅度较小，并且在 N2 睡眠期间的 PTT（BP 下降幅度减小）较大。与 TD+ 患儿相比，较少的 DS 患儿在觉醒与 N2 或 REM 睡眠之间的 HR 下降超过 10%。
与 SDB 严重程度相匹配的 TD 患儿相比，DS 患儿的 HR 夜间下降幅度明显减小，这表明 SDB 对这些患儿的心血管系统有更大的影响。需要进一步的研究来全面了解涉及的机制，并评估治疗 SDB 是否可以改善夜间下降。
