P22 CIRCADIAN VARIATIONS IN THE CARDIOVASCULAR SYSTEM

• Main Authors: Thomas Weber, Siegfried Wasserheurer, Arno Schmidt-Trucksäss, Enrique Rodilla Sala, Piotr Jankowski, Maria Lorenza Muisan, Cristina Giannatasio, Ian Wilkinson, Joerg Kellermair, Bernhard Hametner, Jose Maria Pascual, Robert Zweiker, Danuta Czarnecka, Anna Paini, Massimo Salvetti, Allessandro Maloberti, Peter Fitscha, Kai Mortensen, Elisabeth Wagner, Carmel McEniery, Cornelia Ablasser
• Format: Article
• Language: English
• Published: Atlantis Press 2017-12-01
• Series: Artery Research
• Online Access: https://www.atlantis-press.com/article/125930334/view

Background: Comprehensive information on 24-hour profiles of pulsatile as well as steady-state hemodynamics in humans is not available yet. Methods: In 693 healthy individuals (352 men) free from antihypertensive drugs, we performed 24-hour blood pressure (BP) monitoring with a validated oscillometric brachial cuff (mobilograph, i.e.m., Stolberg, Germany). Brachial waveforms were acquired and processed with ARCSolver algorithms to derive information on central pressures, wave reflections, stroke volume and systemic vascular resistance. Nighttime/daytime difference (N/D) was defined as nighttime (01.00–06.00) minus daytime (09.00–21.00) values / daytime values. Patients were categorized as young (Y: 15–40 years; n = 187), middle-aged (M: 41–70 years; n = 446), and old (O: 71–94 years; n = 60). Results: Averaged 24-hour brachial BP was 123/78 (Y), 127/82 (M), and 126/74 (O) mm Hg. N/D for brachial SBP was −13% (Y), −12% (M), and −5% (O). N/D for heart rate was – 20% (Y), −17% (M), and −15% (O). N/D for central SBP was less pronounced: −4% (Y), −6% (M), and −0% (O). Brachial pulse pressure (PP) displayed small circadian variations, whereas central PP was higher at nighttime: N/D was 25% (Y), 14% (M), and 17% (O). Consequently, PP amplification was higher at daytime (N/D was −21% (Y), −16% (M), and −12% (O)), and was related to heart rate, age, and gender. Measures of wave reflections were higher at nighttime, with N/D related to age, heart rate, mean pressure, systemic vascular resistance and stroke volume. Conclusion: The circadian profiles we provide may serve as reference for cardiovascular diseases and drug studies.