Tohoku University Graduate School of Medicine and Pharmaceutical Science, Sendai, Japan.
Clin Exp Hypertens. 2011;33(6):404-10. doi: 10.3109/10641963.2010.549269. Epub 2011 Jun 7.
We previously demonstrated that heart rate (HR) variability obtained by daytime ambulatory monitoring and that of daily home measurement associated differently with cardiovascular mortality risk; cardiovascular mortality was linked with decreased daytime ambulatory HR variability and increased day-by-day home HR variability. The aim of this study was to identify factors contributing to each variability, clarifying possible reasons for their different predictive values. We obtained daytime ambulatory HR and home HR in 538 individuals of a general Japanese population aged ≥55 years. Daytime ambulatory HR variability and day-by-day home HR variability were estimated as a standard deviation measured every 30 min by daytime ambulatory monitoring and day-by-day home measurements once in the morning for 4 weeks, respectively. There was only weak correlation between daytime ambulatory HR variability and day-by-day home HR variability (r = 0.08∼0.14). In a multiple regression model, daytime ambulatory HR variability was associated with daytime ambulatory HR (P < 0.0001), daytime ambulatory blood pressure (BP) variability (P < 0.0001), and male sex (P = 0.003), while negatively associated with daytime ambulatory systolic blood pressure (SBP) (P < 0.0001) and smoking (P = 0.038). Meanwhile, day-by-day home HR variability was positively associated with home HR (P < 0.0001), day-by-day home BP variability (P < 0.0001), and male sex (P = 0.018). Associated factors of daytime ambulatory HR variability and day-by-day home HR variability were different. Our findings suggest that HR variabilities by different intervals of measurements might be mediated by different mechanisms.
我们之前已经证明，通过日间动态监测获得的心率（HR）变异性和日常家庭测量的 HR 变异性与心血管死亡率风险相关联的方式不同；心血管死亡率与日间动态监测 HR 变异性降低和日常家庭 HR 变异性增加有关。本研究的目的是确定导致每种变异性的因素，阐明其不同预测价值的可能原因。我们在一个年龄≥55 岁的普通日本人群中获得了 538 个人的日间动态 HR 和家庭 HR。日间动态 HR 变异性和日常家庭 HR 变异性分别通过日间动态监测每 30 分钟测量一次和每天早晨在家测量一次 4 周来估计，其标准差分别为 0.08∼0.14。日间动态 HR 变异性与日常家庭 HR 变异性之间只有微弱的相关性（r = 0.08∼0.14）。在多元回归模型中，日间动态 HR 变异性与日间动态 HR（P < 0.0001）、日间动态血压（BP）变异性（P < 0.0001）和男性（P = 0.003）相关，而与日间动态收缩压（SBP）（P < 0.0001）和吸烟（P = 0.038）呈负相关。同时，日常家庭 HR 变异性与家庭 HR（P < 0.0001）、日常家庭 BP 变异性（P < 0.0001）和男性（P = 0.018）呈正相关。日间动态 HR 变异性和日常家庭 HR 变异性的相关因素不同。我们的研究结果表明，不同测量间隔的 HR 变异性可能由不同的机制介导。
