Repeated ambulatory monitoring reveals an evening rise in blood pressure in a Japanese population

Appropriate Circadian-Circasemidian Coupling Protects Blood Pressure from Morning Surge and Promotes Human Resilience and Wellbeing

Background

Blood pressure (BP) variability is involved in the appraisal of threat and safety, and can serve as a potential marker of psychological resilience against stress. The relationship between biological rhythms of BP and resilience was cross-sectionally assessed by 7-day/24-hour chronobiologic screening in a rural Japanese community (Tosa), with focus on the 12-hour component and the "circadian-circasemidian coupling" of systolic (S) BP.

Subjects and Methods

Tosa residents (N = 239, 147 women, 23-74 years), free of anti-hypertensive medication, completed 7-day/24-hour ambulatory BP monitoring. The circadian-circasemidian coupling was determined individually by computing the difference between the circadian phase and the circasemidian morning-phase of SBP. Participants were classified into three groups: those with a short coupling interval of about 4.5 hours (Group A), those with an intermediate coupling interval of about 6.0 hours (Group B), and those with a long coupling interval of about 8.0 hours (Group C).

Results

Residents of Group B who showed optimal circadian-circasemidian coordination had less pronounced morning and evening SBP surges, as compared to residents of Group A (10.82 vs 14.29 mmHg, P < 0.0001) and Group C (11.86 vs 15.21 mmHg, P < 0.0001), respectively. The incidence of morning or evening SBP surge was less in Group B than in Group A (P < 0.0001) or Group C (P < 0.0001). Group B residents showed highest measures of wellbeing and psychological resilience, assessed by good relation with friends (P < 0.05), life satisfaction (P < 0.05), and subjective happiness (P < 0.05). A disturbed circadian-circasemidian coupling was associated with elevated BP, dyslipidemia, arteriosclerosis and a depressive mood.

Conclusion

The circadian-circasemidian coupling of SBP could serve as a new biomarker in clinical practice to guide precision medicine interventions aimed at achieving properly timed rhythms, and thereby resilience and wellbeing.

Repeated ambulatory monitoring reveals an evening rise in blood pressure in a Japanese population

Recent studies have revealed 2 peaks in the onset of cardiovascular events, 1 in the morning and another in the evening. We evaluated whether blood pressure (BP) also rises in the morning/evening and identified the determinants of evening BP rise using 24-hour ambulatory BP monitoring for 7 consecutive days. We identified 2 BP peaks, 1 in the morning (0-3 hours after waking) and 1 in the evening (9-12 hours after waking). Subjects were subclassified according to the extent of evening BP rise: those in the top quartile (≥6.45 mm Hg, n = 34; ER group) vs all others. After adjustment for age, sex, and 24-hour systolic BP, evening BP rise was associated with the use of antihypertensive medications [odds ratio (OR), 3.57; 95% confidence interval (CI), 1.46-8.74; P = .01] and estimated glomerular filtration rate (OR, 0.96; 95% CI, 0.93-0.99; P = .04), confirming its association with antihypertensive medication use and renal dysfunction.