Decreased heart rate variability (HRV) is considered a common marker of autonomic dysfunction that contributes to poor health outcomes. While some studies have suggested that children with autism spectrum disorder (ASD) show reduced HRV, research is yet to consider whether this may be associated with medication use and symptom severity. This study examined the relationship between resting state HRV, medication use and symptom severity in children diagnosed with ASD. Children with ASD (N = 86), aged between 3 and 12 years (M = 8.09), were compared to 44 neurotypical children of similar age (M = 7.15). Laboratory assessment of HRV involved 5 min of non‐invasive baseline electrocardiogram assessments while participants viewed an age‐appropriate non‐verbal animated video. Time‐domain and frequency‐domain HRV measures were analyzed. ASD symptom severity was assessed using the Autism Diagnostic Observation Schedule‐Second Edition (ADOS‐2) and Social Responsiveness Scale (SRS‐2). Results indicated that children with ASD exhibited reduced resting HRV relative to neurotypical children. Subsequent analyses within the ASD group suggested that this group difference was greater in children who were taking psychotropic medication (N = 36). Our data also provides tentative evidence of a relationship between HRV and social impairment symptoms in children with ASD, with more severe repetitive behaviors (as measured by the ADOS‐2) associated with decreased resting HRV. Overall, these findings suggest that HRV may be atypical in children with ASD and suggest the importance of exploring HRV as a risk factor for cardiovascular health in this group.

中文翻译：

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自闭症谱系障碍患儿的心率变异性以及药物和症状严重程度的关联

心率变异性（HRV）降低被认为是自主神经功能障碍的常见标志，可导致健康状况不佳。尽管一些研究表明自闭症谱系障碍（ASD）儿童的HRV降低，但研究尚需考虑这是否与药物使用和症状严重程度有关。这项研究检查了患有ASD的儿童的静息状态HRV，用药与症状严重程度之间的关系。比较3到12岁（M = 8.09）的ASD儿童（N = 86）与44个年龄相似的神经型儿童（M= 7.15）。HRV的实验室评估包括5分钟的非侵入性心电图基线评估，而参与者观看了适合年龄的非言语动画视频。分析了时域和频域的HRV测度。使用自闭症诊断观察表第二版（ADOS-2）和社会反应量表（SRS-2）评估ASD症状的严重程度。结果表明，相对于神经型儿童，ASD儿童表现出较低的静息HRV。随后在ASD组内进行的分析表明，在服用精神药物的儿童中，该组差异更大（N= 36）。我们的数据还提供了ASD儿童HRV与社交障碍症状之间关系的初步证据，其中更严重的重复性行为（由ADOS-2衡量）与静息HRV降低有关。总体而言，这些发现表明，HRV在ASD患儿中可能是非典型的，并表明探索HRV作为该组心血管健康危险因素的重要性。