PS-C07-7: EFFECTS OF PSYCHOLOGICAL STRESS AND PHYSICAL ACTIVITY ON AMBULATORY BLOOD PRESSURE AND PULSE RATE VARIABILITY

Abstract

Objectives: Physical activity and psychological stress during daily life contribute to ambulatory blood pressure (BP) variability. This study aims to investigate the effects of physical activity and psychological stress on daytime BPs measured by ABPM. Methods: This study is a post-hoc analysis using ABPM data from a comparison study of ambulatory BP measured by a wrist watch-type wearable BP monitoring device and an ABPM device. ABPM was performed at 30-min intervals for 24 h using a TM-2441 device (A&D Co., Tokyo), an oscillometric device with an upper-arm BP-cuff. This device is also equipped with a high-sensitivity actigraph that can detect fine-scale physical movements of the wearer in three directions. Physical activity was calculated as the sum of the actigraphically measured physical activity over the 5 min before each ABPM measurement. Study participants were asked to write a self-report diary of their general situation (i.e., location, emotion, and body position) corresponding to each BP measurement at least 10 times while awake. Results: From 50 outpatients (mean age 66.1 ± 10.8 years, 60.0% male, 98.0% hypertensive patients), 1580 daytime BP readings were taken by ABPM. Of these, 642 BP readings had corresponding diary information. In the mixed effect model analysis including physical activity, significant systolic BP (SBP) elevation associated with physical activity was observed in both a dataset of 1580 BP readings (2.9 ± 0.9 mmHg, P = 0.001 for light physical activity; and 2.9 ± 1.4 mmHg, P = 0.045 for moderate physical activity) and a dataset of 642 BP readings (2.5 ± 1.2 mmHg, P = 0.043 for light physical activity; and 4.2 ± 2.0 mmHg, P = 0.036 for moderate physical activity). In the analysis of 642 BP readings using the model including physical activity and situational factors from diary information, SBP was significantly higher during negative emotions than during positive emotions (7.4 ± 2.5 mmHg, p = 0.003), while the SBP change to physical activity decreased and was not statistically significant. On the other hand, pulse rate was unchanged by negative emotions, but was increased for physical activity. Conclusions: Daytime BP measured by ABPM was elevated to a greater extent by psychological stress than by physical activity. BP elevation without corresponding pulse rate increase might be influenced by psychological stress. Simultaneous monitoring of BP and physical activity might detect BP elevation caused by psychological stress.