Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. Sex differences in excess and reservoir arterial blood pressures as markers of phenotype Przemyslaw Guzik a , Agata Schneider a , Jaroslaw Piskorski b,c , Krzysztof Klimas a , Tomasz Krauze a , Ryszard Marciniak d , Andrzej Minczykowski a , Anastasia S. Mihailidou e,f,  , and Andrzej Wykretowicz a,  Objectives: Excess pressure and reservoir pressure are related to various clinical outcomes in cardiovascular diseases, but whether there are sex differences in healthy individuals remains uncertain. We compared phenotypes of excess pressure and reservoir pressure between healthy men and women. Methods: Different features of noninvasively recorded radial and reconstructed aortic pressure waveforms were measured in 435 healthy adults (257 women, 59%). In addition to SBP and DBP, we compared values of maximal excess pressure and reservoir pressure (RP MAX ), excess pressure and reservoir pressure time integrals, respectively, as well as relative contributions of excess pressure (EP REL ) and reservoir pressure to total blood pressure time integral, respectively, between men and women divided in two age categories, below 51 (82 women and 66 men) and greater than or equal to 51 years old (175 women and 112 men), corresponding to average age of menopause for women and acceleration of vascular ageing for all. Results: In both age categories, compared with men, women had significantly lower peripheral and aortic SBP and DBP. Analysis of covariance adjusted for BMI revealed that women who were greater than or equal to 51 years old had significantly higher excess pressure time integral, RP MAX , reservoir pressure time integral, EP REL , and relative contributions of reservoir pressure than men in the same age category. In the younger age category below 51 years old, EP REL and RP MAX were also significantly higher in women than men. Conclusion: Our study shows that healthy women have lower peripheral and aortic SBP and DBP compared with healthy men; however, their excess and reservoir pressures are higher, particularly after 51 years of age. Keywords: blood pressure, excess pressure, hemodynamics, reservoir pressure, sex differences Abbreviations: ANCOVA, analysis of covariance; DBP TI , pressure time integral of DBP; EP MAX , peak excess pressure; EP REL , relative contribution of excess pressure time integral to the time integral of the total pressure waveform; EP TI , time integral of excess pressure; HR, heart rate; MBP, mean blood pressure; np, not possible to calculate; PP, pulse pressure; RP MAX , peak reservoir pressure; RP REL , relative contribution of reservoir pressure time integral to the time integral of the total pressure waveform; RP TI , time integral of reservoir pressure; TBP TI , time integral of the total pressure waveform INTRODUCTION C ardiovascular disease differs between men and women in presentation and clinical outcomes [1– 4]. Men have earlier onset; however, heart disease is the primary cause of death for all women [5], with post- menopausal women having increased risk for left ventricu- lar (LV) dysfunction and death than men at the same age [3]. Elevated brachial blood pressure (BP) is an independent risk factor for heart disease in both men and women, whereas aortic BP indicates arterial stiffness and pulsatility which have predictive value for adverse clinical outcomes in different populations [6–12]. In particular, indices derived from aortic pressure such as the excess pressure and reservoir pressure are prognostic for mortality, cardiovascular events and target organ damage in patients with hypertension, heart failure, or acute coronary syndrome [8–14]. Physiologically, reservoir pressure is a measure of aortic ‘cushioning’ effect caused by the elastic properties of the aorta and arterial walls – it depends on aortic inflow, compliance, and resistance to outflow [13,15,16] measured as peak value [maximal reservoir pressure (RP MAX ) and the time integral (RP TI )] [15,16]. The excess pressure represents the blood flow at the aortic root and is proportional to the load and extra work of the LV to eject blood to the aorta Journal of Hypertension 2019, 37:2159–2167 a Department of Cardiology-Intensive Therapy, Poznan University of Medical Sciences, Poznan, b Division of Material and Medical Physics, Institute of Physics, c Faculty of Medicine and Health Sciences, University of Zielona Gora, Zielona Gora, d Department of Medical Education, Poznan University of Medical Sciences, Poznan, Poland, e Department of Cardiology and Kolling Institute, Royal North Shore Hospital and f Macquarie University, Sydney, New South Wales, Australia Correspondence to Przemyslaw Guzik, MD, PhD, FESC, ISHNE Fellow, Department of Cardiology-Intensive Therapy, Poznan University of Medical Sciences, 49 Przybyszew- skiego, 60-355 Poznan, Poland. Tel: +48 618691391; fax: +48 618691689; e-mail: pguzik@ptkardio.pl  Anastasia S. Mihailidou and Andrzej Wykretowicz are shared senior authors for the article. Received 15 November 2018 Revised 12 March 2019 Accepted 29 March 2019 J Hypertens 37:2159–2167 Copyright ß 2019 Wolters Kluwer Health, Inc. All rights reserved. DOI:10.1097/HJH.0000000000002135 Journal of Hypertension www.jhypertension.com 2159 Original Article