Prognosis in Relation to Blood Pressure VariabilityResponse to Prognosis in Relation to Blood Pressure Variability: Pro Side of the Argument
1163 i t is well known that cardiovascular events occur more frequently in the morning and that blood pressure (Bp) levels increase on waking in the morning (morning surge). 1, 2 in a previous study, we first defined morning Bp surge (MBps) by ambulatory Bp monitoring (ABpM), and the results demonstrated that MBps in elderly hypertensive patients is associated with silent cerebral infarcts defined by brain magnetic resonance imaging and future clinical stroke events independently of age or
... ge 24-hour Bp level. 3 We also stressed the importance of controlling morning hypertension in clinical practice. 1, 4, 5 Many studies indicate that MBps is a risk factor for cardiovascular disease, independently of 24-hour Bp levels in both hypertensive outpatients and community-dwelling subjects, 1, 6, 7 although a few studies have struck a discordant note. 8,9 in this debate article, i demonstrate the evidence that MBps and related Bp variability (Bpv) are risk factors for organ damage and cardiovascular events, and i discuss perspectives related to this issue. Evidence of Cardiovascular Events the major prospective studies on MBps in which the number of study subjects was >800 are summarized in table 1. JMU-ABPM Study the first prospective study was our Jichi Medical University school of Medicine (JMU)-ABpM study. 3 We first defined 2 MBpss by ABpM as follows: (1) a sleep-trough surge defined as morning Bp (2-hour average of 4 Bp readings taken at 30-minute intervals just after wake-up) minus the lowest nocturnal Bp (1-hour average of the 3 Bp readings centered on the lowest nighttime reading); and (2) a prewaking surge defined as morning Bp minus the prewaking Bp (2-hour average of 4 Bp readings just before wake-up). the exaggerated MBps group, defined as the top-tenth percentile of patients with a sleep-trough surge (≥55 mm Hg), exhibited a significantly increased stroke risk even after matching for age, 24-hour Bp, and nocturnal Bp dipping status. the prewaking surge tended to be associated with stroke risk, although the association was not significant (P=0.07). Among the 519 study subjects, only 5 acute myocardial infarctions (definitive) occurred during the same 42 months period (one in the sleep-trough surge ≥55 mm Hg group and 4 in the sleep-trough surge <55 mm Hg group). PIUMA Study in the progetto ipertensione Umbria Monitoraggio Ambulatoriale (piUMA) study of a cohort of 3012 initially untreated hypertensive patients, the top-tenth percentile of sleep-trough MBps was not associated with the cardiovascular prognosis. in addition, blunted MBps (the lowest quartile, the opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association.