Abstract
Psychological stress and physical activity contribute to blood pressure (BP) variability, which is a significant and independent risk factor for cardiovascular events. We examined the effects of physical activity level in the 5 min before each BP measurement and psychological stress on ambulatory BP and pulse rate variability in daily life. During a 24 h monitoring period, BP and pulse rate were measured by a multisensor ABPM device (TM-2441; A&D Co.) at 30 min intervals, and physical activity was continuously recorded by an actigraph built into the ABPM device. Psychological stress was assessed from negative emotions or worksite location in the participants' situational information at each BP measurement, which was self-reported on a paper pad immediately (or as soon as possible) after the measurement. A total of 642 ABPM readings with corresponding situational information were obtained from 50 high-risk patients and showed that BP and pulse rate were significantly associated with actigraph-recorded physical activity (increase against the physical-activity-above-walking level: 4.2 ± 2.0 mmHg, p = 0.036 for SBP; 5.4 ± 1.1 bpm, p < 0.001 for pulse rate). When self-reported situational factors were additionally included in the analysis model as variables, negative emotions (7.4 ± 2.5 mmHg, p = 0.003 for SBP) and worksite location (5.8 ± 2.1 mmHg, p = 0.005 for SBP) were significantly associated with BP increase, while the association between BP and physical activity was weakened (p > 0.05). The pulse rate increased against the physical-activity-above-walking level but did not change for negative emotions. In conclusion, the effect of negative emotions on BP was greater than that of physical activity, whereas no similar effect on pulse rate was found. Simultaneous monitoring of BP, pulse rate, and actigraph-recorded physical activity could detect psychological stress-induced BP elevation.