Abstract: Objective To evaluate the sleep quality and salivary cortisol level in children with postural tachycardia syndrome (POTS), and to analyze the correlation among salivary cortisol level, sleep quality and the severity of clinical symptoms. Methods This prospective study included 40 children with POTS (case group) from May 2018 to May 2019, and 20 healthy children who took health examination in the same period were selected as controls.Saliva samples were collected from two groups of children at six time points (awakening, 30 minutes after awakening, at 12:00 p.m., 4:00 p.m., and 8:00 p.m., and at bedtime), and the concentration of salivary cortisol was determined by enzyme-linked immunosorbent assay.The Pittsburgh Sleep Quality Index (PSQI) and POTS symptom scale were filled in to evaluate the sleep quality and the severity of clinical symptoms of POTS. Results The systolic blood pressure in supine position (t＝2.194), systolic blood pressure in upright position(t＝2.351), diastolic blood pressure in upright position (t＝2.227), stable heart rate in supine position(t＝2.117) in control group were significantly higher than those in POTS group, while the maximal heart rate in the upright position(t＝-3.88)and the difference in the resting and standing position (t＝-7.86) were significantly lower than those in POTS group(P＜0.05).The concentration of salivary cortisol in POTS group was significantly higher than that in the control group(P＜0.05) when waking up in the morning, 30 minutes after waking, at12:00, 4:00 pm and 8:00 pm.POTS group had poorer sleep quality (PSQI score) than control group[(7.2±3.0)vs.(1.35±1.39), t＝-10.370, P＜0.001], including sleep quality score, sleep time, sleep hours, sleep efficiency, sleep disorder, daytime dysfunction and overall comparison between groups.Symptom score and PSQI score were positively correlated with cortisol concentration in saliva after waking(r＝0.62, 0.60, P＜0.001).Moreover, symptom score and PSQI score were positively correlated(r=0.58,P＜0.001). Conclusionss Salivary cortisol concentration was positively correlated with the severity of clinical symptoms and PSQI score.To some extent, salivary cortisol concentration can reflect the sleep quality and clinical symptoms of children with POTS.

Key words: postural tachycardia syndrome, salivary cortisol, Pittsburgh Sleep Quality Index, severity of clinical symptoms

摘要： 目的 评估体位性心动过速综合征(POTS)患儿睡眠质量和唾液皮质醇水平,分析唾液皮质醇水平与睡眠质量、临床症状严重程度的相关性。方法 选择2018年5月-2019年5月在儿科确诊为POTS的患儿40例作为病例组,并纳入同期进行健康检查的儿童20例作为对照组。收集两组儿童6个时点(晨起清醒时、醒后30min、12:00、16:00、20:00以及晚间上床休息时)的唾液样品,利用酶联免疫吸附法测定唾液皮质醇浓度。通过匹兹堡睡眠质量指数(PSQI)量表及POTS症状评分表分别进行睡眠质量、POTS临床症状严重程度评估。结果 对照组平卧位收缩压(t＝2.194)、直立位收缩压(t＝2.351)、直立位舒张压(t＝2.227)、平卧位稳定心率(t＝2.117)高于POTS组;直立位最大心率(t＝-3.88)、卧立位心率差值(t＝-7.86)低于POTS组,差异均有统计学意义(P＜0.05)。POTS组唾液皮质醇浓度在晨起清醒时、醒后30 min、12:00、16:00及20:00均高于对照组,差异有统计学意义(P＜0.05);POTS组患者睡眠质量(PSQI评分)较对照组明显较差[(7.2±3.0) vs.(1.35±1.39),t＝-10.370,P＜0.001],其中睡眠质量、入睡时间、睡眠时间、睡眠效率、睡眠障碍、日间功能障碍和总分与对照组相比,差异均有统计学意义(P＜0.05);临床症状严重程度评分、PSQI评分与苏醒后唾液中皮质醇浓度呈正性相关(r＝0.62、0.60, P＜0.001);POTS症状评分与PSQI评分呈正相关(r=0.58, P＜0.001)。结论 唾液皮质醇浓度与POTS患儿临床症状的严重程度、PSQI评分呈正相关。POTS患儿的唾液皮质醇浓度在一定程度上可以反映其睡眠质量和临床症状严重程度。

关键词: 体位性心动过速综合征, 唾液皮质醇, 睡眠质量指数, 临床症状严重程度