Diurnal variation in the diving bradycardia response in young men
Diurnal variation in the diving bradycardia response in young men
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DOI：
10.1007/s10286-016-0342-1
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发表时间：
2016-04-01
影响因子：
5.8
通讯作者：
Sakamoto, Shizuo
中科院分区：
文献类型：
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作者：
Konishi, Masayuki;Kawano, Hiroshi;Sakamoto, Shizuo
18名青年男性（年龄26 ± A2岁，身高174.2 ± A6.0 cm，体质量70.2 ± A8.1 kg，体脂18.0 ± A3.8%，平均± A标准差）参加了本研究。在每天0900、1300和1700小时测量口腔温度、5分钟心电图数据的心率变异性（HRV）和潜水心动过缓反应。所有参与者在坐姿下进行两次潜水反射测试，面部浸入冷水（1.9-3.1 A度C），在吸气中期呼吸暂停至少30秒，并尽可能长，连续顺序。口腔温度在上午（0900）低于下午（1300）和晚上（1700）。在心率变异性的频域参数中，早晨高频功率的自然频率高于晚上。所有受试者在两次潜水反射试验中都表现出心动过缓反应。在尽可能长的时间内和30 s内，R-R间期的峰值均为上午大于下午和晚上，说明在潜水反射试验中最大心动过缓的出现具有日变化，上午达到峰值，晚上逐渐降低。心率变异性指标也有同样的变化。
The present study aimed to examine diurnal variation of the diving bradycardia responses on the same day.Eighteen young men (age 26 +/- A 2 years; height 174.2 +/- A 6.0 cm; body mass 70.2 +/- A 8.1 kg; body fat 18.0 +/- A 3.8 %; mean +/- A standard deviation) participated in this study. Oral temperature, heart rate variability (HRV) from 5-min of electrocardiogram data, and diving bradycardia responses were measured at 0900, 1300, and 1700 hours daily. All participants performed diving reflex tests twice in the sitting position with the face immersed in cold water (1.9-3.1 A degrees C) and apnea at midinspiration for a minimum of 30 s and as long as possible, in consecutive order.Oral temperature was found to be less in the morning (0900) than in the afternoon (1300) and evening (1700). In the frequency domain parameters of heart rate variability, the natural logarithms of high-frequency power were higher in the morning than in the evening. All participants showed bradycardia response to the two diving reflex tests. The peak values of R-R interval during the diving reflex test both for as long as possible and 30 s were longer in the morning than in the afternoon and evening.Our results indicated that the maximal bradycardia during the diving reflex test exhibits a diurnal variation, with peak levels at morning and gradual decrease towards the evening. The HRV indexes show the same variation.