Hypertensive crises exhibited a pronounced circadian pattern with a morning predominance (39% vs 32% afternoon and 28% night; p=0.012), but no significant seasonal variation (p=0.642).
Observational (n=119,147)
No
In a tropical setting, hypertensive crises demonstrate a pronounced morning predominance but lack the seasonal variation typically observed in temperate climates.
p-value: p=0.012
Objective: Circadian and seasonal patterns of blood pressure (BP) variation are well described in temperate climates, yet data from tropical regions—particularly regarding hypertensive crises—remain scarce. Understanding temporal patterns of hypertensive crises may inform emergency department (ED) preparedness, risk stratification, and preventive strategies. We aimed to investigate circadian and seasonal variations in the incidence of hypertensive crises in a tropical setting, comparing temporal patterns between hypertensive emergencies and non–organ-damage presentations. Design and method: We conducted a retrospective observational study including all adult ED visits to a tertiary cardiology center in São Paulo, Brazil, between 2021 and 2024. Hypertensive crises were defined by systolic BP >180 mmHg and/or diastolic BP >110 mmHg at triage. Cases were classified as hypertensive emergencies or non-emergency hypertensive crises based on ICD-10 diagnoses indicating acute target-organ damage. Circadian distribution was analyzed by time of presentation (morning, afternoon, night), and seasonal variation by meteorological season. Multivariable logistic regression was used to evaluate associations between temporal patterns and clinical presentation. Results: Among 119,147 ED visits, 7,439 (6.2%) met criteria for hypertensive crisis, including 2,931 (2.4%) hypertensive emergencies. A clear circadian pattern was observed, with the highest incidence of presentations occurring in the morning hours (39%), followed by afternoon (32%) and night (28%) (p=0.012). This circadian distribution was consistent across both emergency and non-emergency presentations. In contrast, no significant seasonal variation was observed, with a relatively uniform distribution across summer, autumn, winter, and spring (p=0.642). Temporal patterns were independent of age, sex, baseline BP values, and comorbidity burden. Hypertensive emergencies were associated with higher hospitalization and mortality rates but did not demonstrate distinct circadian or seasonal clustering compared with non-emergency presentations. Conclusions: Hypertensive crises exhibited a pronounced circadian pattern with a morning predominance, but no significant seasonal variation. Recognition of morning vulnerability may support targeted preventive strategies, optimized antihypertensive chronotherapy, and ED resource allocation.
Gonçalves et al. (Fri,) conducted a observational in Hypertensive crises (n=119,147). Circadian and seasonal time of presentation was evaluated on Circadian distribution of hypertensive crises presentations (p=0.012). Hypertensive crises exhibited a pronounced circadian pattern with a morning predominance (39% vs 32% afternoon and 28% night; p=0.012), but no significant seasonal variation (p=0.642).