ORIGINAL ARTICLE Pulsatile and steady 24-h blood pressure components as determinants of left ventricular mass in young and middle-aged essential hypertensives G Mule `, E Nardi, G Andronico, S Cottone, MR Federico, G Piazza, V Volpe, D Ferrara and G Cerasola Dipartimento di Medicina Interna, Malattie Cardiovascolari e Nefrourologiche, Cattedra di Medicina Interna e Centro Ipertensione, University of Palermo, Italy In order to explore the relations between left ventricular mass (LVM) and the pulsatile (pulse pressure) and steady (mean pressure) components of the blood pressure (BP) curve, 304 young and middle-aged essential hypertensive patients were studied by means of 24-h ambulatory BP monitoring and echocardio- graphy. In the overall study population, both the BP components showed significant correlations with LVM. These correlations were unevenly distributed in the subgroups of subjects younger and in those older than 50 years. While in this latter subgroup, in multivariate analysis, both 24-h mean BP (24-MBP) (b ¼ 0.27; P ¼ 0.008) and 24-h pulse pressure (24-h PP) (b ¼ 0.23; P ¼ 0.02) were associated with LVM, in the subset of younger hypertensives only 24-h MBP (b ¼ 0.21; P ¼ 0.009) was related to LVM, independent of other covariates. The relations observed between 24-h PP and LVM in the entire study population and in the patients older than 50 years lost statistical significance when the effect of 24-h systolic blood pressure (24-h SBP) was taken into account, in a multiple regression model in which 24-h MBP was replaced by 24-h SBP. Our findings seem to suggest that the association of PP with LVM in middle-aged hypertensives may partially explain the increased cardiovascular risk, documented in subjects with high PP. However, this relation is not independent, but is mediated by SBP. Journal of Human Hypertension (2003) 17, 231–238. doi:10.1038/sj.jhh.1001542 Keywords: pulse pressure; mean blood pressure; ambulatory blood pressure; left ventricular mass Introduction The relation between blood pressure (BP) and cardiovascular risk arises from studies using con- ventional sphygmomanometry and, more recently, indirect ambulatory blood pressure monitoring (ABPM). Both techiques provide two measures of BP (systolic (SBP) and diastolic (DBP)), which represent the extreme values of the sinusoidal waveform of arterial pressure. However, BP curve is more precisely described as consisting of a pulsatile component (pulse pressure (PP), which estimates the amplitude of the cyclic oscillations around the mean) and a steady component (mean pressure). The former depends on ventricular ejec- tion, arterial stiffness, and the timing of wave reflections, whereas cardiac output and peripheral vascular resistance are the major determinants of mean pressure. 1,2 Several studies in last years showed that PP is a powerful independent predictor of total and cardio- vascular mortality, especially in elderly subjects. 1–8 There is an increasing amount of evidence that ambulatory BP may improve definition of individual cardiovascular risk. 9 In the PIUMA study, cardio- vascular events were better predicted by ambulatory than by clinic PP. 8 In hypertensive patients, relations between PP and cardiovascular complications may be partially mediated by preclinical cardiovascular disease such as left ventricular hypertrophy. Contrasting data exist about the relations between PP and left ventricular mass (LVM) in young and middle-aged hypertensive subjects. 10–17 The purpose of our study was to analyse the relations of 24-h pulse pressure (24-h PP) and 24-h mean pressure (24-h MBP) to LVM indexed for body surface area (LVMI) in 304 essential hyper- tensive patients, aged 18–65 years, and to assess the Received 18 August 2002; revised 21 November 2002; accepted 15 December 2002 Correspondence: Dr G Mule `, Via Monte San Calogero, 29, 90146 Palermo, Italy. E-mail: giusemme@email.it Journal of Human Hypertension (2003) 17, 231–238 & 2003 Nature Publishing Group All rights reserved 0950-9240/03 $25.00 www.nature.com/jhh