Akbay Ertan, Akinci Sinan
Department of Cardiology, Baskent University Hospital, Alanya Medical and Research Center, Alanya, Turkey.
Blood Press Monit. 2023 Apr 1;28(2):79-85. doi: 10.1097/MBP.0000000000000634. Epub 2022 Dec 23.
Morning blood pressure (BP) surge (MS) is associated with cardiovascular events. The autonomic nervous system plays an active role in the regulation of BP and its function can be evaluated by heart rate variability (HRV) analysis. This study aimed to evaluate autonomic nervous system functions in patients with increased MS.
Patients who underwent ambulatory BP monitoring (ABPM) and 24-h rhythm Holter in our hospital during the same period between 2017 and 2022 were evaluated. HRV parameters were obtained from 24-h rhythm Holter recordings. MS values of the patients were calculated from ABPM records and patients were divided into four groups according to the MS quartiles. HRV parameters and other parameters were compared between the groups.
A total of 129 patients were included in the study. The mean age of the patients was 57.2 ± 18.2 years, and 63 (48.8%) were male. HF, the square root of the mean squared differences of successive normal-to-normal intervals (rMSSD), and the proportion of adjacent RR intervals differing by >50 ms in the 24-h recording (pNN50) were statistically significant between the groups ( P = 0.039, P = 0.013, P = 0.011, respectively). In univariate regression analysis, low-frequency/high-frequency ratio was positively associated with MS and HF, SDNNi, rMSSD, and pNN50 were negatively associated ( β = 0.207, P = 0.019; β = -0.272, P = 0.002; β = -0.201, P = 0.022; β = -0.265, P = 0.002; β = -0.278, P = 0.001, respectively). Multiple linear regression analysis showed an independent association between HF, low-frequency/high-frequency ratio, rMSSD, pNN50, and MS ( β = -0.247, P = 0.005; β=0.206, P = 0.017; β = -0.209, P = 0.005; β = -0.227, P = 0.008, respectively).
We found an independent association between HRV parameters associated with vagal tone and MS. The findings of our study suggest that the increased sympathetic activity detected in patients with high MS in previous studies may be due to a decrease in basal vagal tone.
晨起血压激增（MS）与心血管事件相关。自主神经系统在血压调节中起积极作用，其功能可通过心率变异性（HRV）分析进行评估。本研究旨在评估MS增加患者的自主神经系统功能。
对2017年至2022年同期在我院接受动态血压监测（ABPM）和24小时节律动态心电图监测的患者进行评估。HRV参数从24小时节律动态心电图记录中获取。根据ABPM记录计算患者的MS值，并根据MS四分位数将患者分为四组。比较各组之间的HRV参数和其他参数。
本研究共纳入129例患者。患者的平均年龄为57.2±18.2岁，男性63例（48.8%）。各组之间高频（HF）、相邻正常RR间期差值的均方根（rMSSD）以及24小时记录中相邻RR间期差值>50ms的比例（pNN50）具有统计学意义（P分别为0.039、0.013、0.011）。在单因素回归分析中，低频/高频比值与MS呈正相关，HF、SDNNi、rMSSD和pNN50与MS呈负相关（β分别为0.207，P = 0.019；β = -0.272，P = 0.002；β = -0.201，P = 0.022；β = -0.265，P = 0.002；β = -0.278，P = 0.001）。多元线性回归分析显示HF、低频/高频比值、rMSSD、pNN50与MS之间存在独立关联（β分别为-0.247，P = 0.005；β = 0.206，P = 0.017；β = -0.209，P = 0.005；β = -0.227，P = 0.008）。
我们发现与迷走神经张力相关的HRV参数与MS之间存在独立关联。我们的研究结果表明，先前研究中在高MS患者中检测到的交感神经活动增加可能是由于基础迷走神经张力降低所致。
