Chen Chieh-Wen, Kuo Terry B J, Chen Chun-Yu, Yang Cheryl C H
aInstitute of Brain Science bSleep Research Center cBrain Research Center, National Yang-Ming University dDepartment of Education and Research, Taipei City Hospital eNeurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
J Hypertens. 2017 Mar;35(3):558-570. doi: 10.1097/HJH.0000000000001205.
Ambulatory blood pressure (BP) monitoring with a lack of nocturnal BP fall (BP nondipping) has been reported to be more prevalent among hypertensive populations and is a risk factor for cardiovascular disease than in patients with dipping pattern. However, its underlying mechanism is not fully understood. This study hypothesized that spontaneously hypertensive rats (SHRs) with a nondipping profile have an exaggerated disruption of both autonomic functioning and sleep compared with Wistar-Kyoto rats (WKYs) with a nondipping profile.
Continuous power spectral analysis of electroencephalogram, electromyogram, and cardiovascular variability was performed in WKYs and SHRs over 24 h. BP dipping was assessed as the percentage decline in SBP from dark active waking to light quiet sleep (lQS). According to the human definition of BP dipping (10%), we divided WKYs and SHRs into dipper and nondipper groups individually.
Of the four groups, both parasympathetic activity and baroreflex sensitivity in sleep were the lowest in the SHR nondippers. Compared with the WKY nondippers, the SHR nondippers spent more time awake and less time asleep during the light period and the opposite during the dark period. Moreover, they showed more interruptions and a lower delta power percentage of lQS. Correlation analysis revealed that baroreflex sensitivity during lQS was correlated with the BP dipping percentage in SHRs.
SHR nondippers exhibit poor sleep quality and impaired autonomic functioning to a greater degree than do SHR dippers and WKY nondippers, which may account for a higher cardiovascular risk in this population.
据报道，动态血压监测显示夜间血压无下降（血压非勺型）在高血压人群中更为普遍，并且与勺型模式的患者相比，是心血管疾病的一个危险因素。然而，其潜在机制尚未完全了解。本研究假设，与具有非勺型模式的Wistar-Kyoto大鼠（WKY）相比，具有非勺型模式的自发性高血压大鼠（SHR）在自主神经功能和睡眠方面的破坏更为严重。
对WKY和SHR进行24小时的脑电图、肌电图和心血管变异性的连续功率谱分析。血压勺型通过收缩压从黑暗活跃清醒到明亮安静睡眠（lQS）的下降百分比来评估。根据人类对血压勺型的定义（10%），我们分别将WKY和SHR分为勺型和非勺型组。
在四组中，SHR非勺型组睡眠中的副交感神经活动和压力反射敏感性均最低。与WKY非勺型组相比，SHR非勺型组在光照期清醒时间更长，睡眠时间更短，而在黑暗期则相反。此外，他们表现出更多的中断，并且lQS的δ功率百分比更低。相关分析显示，lQS期间的压力反射敏感性与SHR的血压勺型百分比相关。
SHR非勺型组比SHR勺型组和WKY非勺型组表现出更差的睡眠质量和受损的自主神经功能，这可能解释了该人群中更高的心血管风险。
