An excess morning blood pressure surge (MBPS) may portend an increased cardiovascular risk, but the mechanisms thereof have been little investigated. The link between MBPS, short-term blood pressure (BP) variability, and arterial stiffness has not been entirely defined.
In 602 consecutive untreated hypertensive patients (48 ± 12 years, 61% men, office BP 149/93 ± 17/10 mmHg), we measured carotid–femoral pulse wave velocity (cf-PWV, SphygmoCor) and 24-h ambulatory BP. Using self-reported sleep and wake times, MBPS was defined as sleep-trough (ST-MBPS), prewaking, rising. Short-term BP variability was calculated as weighted 24-h SBP SD and average real variability of 24-h SBP (ARV), that is, average of absolute differences between consecutive SBP readings.
ST-MBPS (r = 0.16, P < 0.001) and rising MBPS (r = 0.12, P = 0.003) showed a direct correlation with cf-PWV, whereas prewaking MBPS had no such relation (r = 0.06, P = 0.14). Only ST-MBPS was independently associated with cf-PWV (t = 1.96, P = 0.04) after adjustment for age, sex, height, office mean arterial pressure, heart rate, and renal function. This association was lost after further adjustment for weighted 24-h SBP SD (P = 0.13) or ARV (P = 0.24). ARV was a significant mediator of the relationship between ST-MBPS and cf-PWV (P = 0.003).
In untreated hypertension, ST-MBPS has a direct relation with aortic stiffness, which is mediated by an increased ARV. The adverse effects of MBPS may be partly explained by its link with arterial stiffness, mediated by short-term SBP variability.
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aDipartimento di Medicina, Università di Perugia, Perugia
bStruttura Complessa di Medicina Interna, Azienda Ospedaliero-Universitaria di Terni, Terni, Italy
Correspondence to Professor Giuseppe Schillaci, MD, Dipartimento di Medicina, Università degli Studi di Perugia, Struttura Complessa di Medicina Interna, Azienda Ospedaliero-Universitaria di Terni, Piazzale Tristano di Joannuccio, 1, IT-05100 Terni, Italy. Tel: +39 0744 205201; fax: +39 0744 205201; e-mail: firstname.lastname@example.org
Abbreviations: ARV, average real variability of 24-h SBP; BP, blood pressure; BPV, blood pressure variability; cf-PWV, carotid–femoral pulse wave velocity; eGFR, estimated glomerular filtration rate; MAP, mean arterial pressure; MBPS, morning blood pressure surge; PW-MBPS, prewaking morning blood pressure surge; RB-MBPS, rising morning blood pressure surge; ST-MBPS, sleep-trough morning blood pressure surge; wSD-24 h, weighted 24-h SBP SD
Received 30 June, 2016
Revised 10 August, 2016
Accepted 16 September, 2016
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