Circadian rhythm of blood pressure and its correlations with short-term variability

Background. Arterial hypertension (AH) is the main risk factor for cardiovascular (CV) and cerebrovascular diseases. To effectively prevent damage to target organs and reduce morbidity and mortality, adequate control of blood pressure (BP), including its variability (VAR), is important. The latter includes circadian, short-term, and long-term components, and VAR is best documented with out-of-office BP monitoring methods such as ambulatory BP monitoring (ABPM). The morning rise (MR) of BP is one of the components of variability, its disturbances are associated with an increased risk of stroke and CV events, regardless of the level of BP. Purpose – the aim of the study was to study the relationship between the morning rise in blood pressure and the short-term blood pressure variability in patients with arterial hypertension. Materials and Methods. The study included 169 patients with hypertension aged 43 to 78 years. Based on the results of ABPM, an assessment of the morning dynamics and short-term BP VAR were carried out. To assess the morning dynamics of blood pressure, the speed and amplitude of MR of systolic BP (SBP) and diastolic BP (DBP) were studied. SBP and DBP VAR were evaluated separately for day, night, and 24-hour periods using the SD, SDcorr, and ARV indices. Results. In this open, non-randomized, cross-sectional study of patients with hypertension, a direct relationship between BP VAR and its morning dynamics was revealed – the increase in VAR was associated with greater amplitude and speed of BP MR. The established correlations were closer for MR amplitude than for MR speed, which allows to draw a conclusion about different pathogenesis mechanisms of their disorders and requires further study of this phenomenon. An increase in VAR SBP was associated not only with changes in the morning dynamics of SBP, but also with changes in the morning dynamics of DBP, and vice versa Conclusions. ABPM should be an essential part of the management of hypertensive patients with an individualized approach to pharmacotherapy to achieve not only optimal 24-hour BP control, but also correction of elevated BP and excessive morning rise for the best cardiovascular and cerebrovascular protection.