Background: It is well established that central aortic to peripheral pulse pressure amplification (PPA) decreases with heart rate (HR). In 24-hour blood pressure (BP) monitoring, it has been shown that central aortic BP and PPA follow a similar nocturnal dipping pattern to brachial BP and HR, respectively. However, whether the reduction in PPA during night-time is solely due to HR reduction is unknown. Aim: To investigate whether nocturnal dipping in PPA is associated with factors beyond HR. Methods: 24-hour BP readings were obtained in 29 participants (15 males, aged 66±15 years, mean±SD). Daytime and night-time brachial (b) and central (c) aortic systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and PPA were calculated, with PPA defined as the ratio bPP/cPP. Clinic BP and arterial stiffness by way of carotid-femoral pulse wave velocity (PWV) were also measured. Multiple linear regression was performed to determine associations between nocturnal change in PPA and HR, PWV, and other known factors of PPA. Results: Daytime and night-time differences in bSBP (9±10 mmHg), cSBP (7±9 mmHg), bDBP (8±6 mmHg), cDBP (8±6 mmHg), HR (7±6 bpm), and PPA (0.070±0.077) were significantly different (P<0.001 for all), but not central aortic PP (-1±5 mmHg; P=0.22) nor brachial PP (1±6 mmHg; P=0.42). Simple linear regression showed a 0.01 reduction in PPA with every 1 bpm reduction in HR (P<0.001; R2=0.53). When age, gender, height, weight, clinic bSBP and PWV were included in the model, only HR change (P<0.001) and height (P=0.02) were significantly associated with PPA change (model P<0.001; adjusted R2=0.57). Conclusions: As expected, nocturnal dipping in HR and PPA are closely associated, but HR change only explained half the variance observed in this cohort. Further studies in a larger cohort is warranted to understand the mechanisms that lead to nocturnal reduction of PPA beyond HR changes.
|Publication status||Published - 2020|
|Event||Annual Scientific Meeting of the High Blood Pressure Research Council of Australia 2020 - Virtual, Australia|
Duration: 1 Dec 2020 → 4 Dec 2020
|Conference||Annual Scientific Meeting of the High Blood Pressure Research Council of Australia 2020|
|Period||1/12/20 → 4/12/20|