doi: 10.1161/01.CIR.0000060887.83850.46
(Circulation. 2003;107:1347.)
© 2003 American Heart Association, Inc.
Editorial |
Morning Surge in Blood Pressure
From the University of Texas Southwestern Medical Center at Dallas, Dallas.
Correspondence to Norman M. Kaplan, MD, Department of Internal Medicine, Hypertension, University of Texas, Southwestern Medical Center, 5323 Harry Hines Blvd, CS 8.102, Dallas, TX 75390-8899.
Key Words: Key Words: • Editorials • blood pressure • stroke • sleep
Some days it just doesn’t pay to get out of bed. As long recognized, there is an increased risk for heart attack, stroke, and sudden death in the first few hours of the morning.1,2 In this issue of Circulation, Kario and colleagues have shown that, as for strokes, this risk is associated with a morning surge in blood pressure.3 Among the 519 elderly hypertensives in this study, the risk of stroke identified by brain MRI was 2.7-fold greater among the 55 who were in the top decile of the degree of morning surge of systolic blood pressure compared with the remaining subjects.
See p 1401
For their prospective study, blood pressures were measured by 24-hour ambulatory monitoring and the morning surge was defined as the difference between the mean systolic blood pressure during the 2 hours after waking and arising minus the mean systolic blood pressure during the hour that included the lowest blood pressure during sleep. This definition of the morning surge provided better discrimination than other definitions, including the difference between post-waking and preawakening levels as used by others.4 This definition should be used because the major component of the morning surge occurs only after arising from sleep and not during the time between awakening and arising.5
The risk of this morning surge has been seen by others,6 but the study by Kario et al3 is the largest and most definitive. The risk also has been noted after arising from afternoon siesta7 so it seems likely that a sudden rise in pressure poses a risk whenever it occurs.
Mechanism Responsible
Sudden activation of the sympathetic nervous system is the primary mediator of the morning surge. Increased 
-mediated sympathetic vasoconstriction has been found in normal subjects.8 Whereas arousal from sleep is associated with a slight rise in plasma epinephrine, arising induces a significant rise both in epinephrine and norepinephrine.9
Recognition of the Morning Surge
Automatic measurements of blood pressure by ambulatory monitoring are required to closely examine the sleep/awake differences. Unfortunately, ambulatory monitoring is unavailable to most practitioners and patients in the United States, although it is utilized more in other countries. Now that a small beginning in third-party reimbursement for ambulatory monitoring has been made in the United States, the procedure may become more generally available.
In the meantime, much of the clinically relevant information can be utilized by simply having patients measure their blood pressure in the early morning, soon after arising.6 Such reading are elevated in most patients, whether their office readings are <140/90 mm Hg or not.10 If they are elevated, the need for more effective, long-acting antihypertensive therapy is established. Moreover, the potential additional cardiovascular risk of heavy physical activity in the early morning can be avoided.4
In the study by Kario et al,3 the danger of an early morning surge was lessened among those who remained on one or another antihypertensive medication during the 4-year follow-up. Unfortunately, there are virtually no data documenting the ability of such therapy in general or of specific types of therapy in particular on the increased risks of cardiovascular catastrophes in the early morning. Such information should be obtained in all therapeutic trials measuring cardiovascular outcomes.
In the meantime, the clinical inferences of the data by Kario et al are clear: (1) patients who experience surges of blood pressure after arising are at risk for stroke and likely other cardiovascular events; (2) the presence of such surges can be strongly inferred by home blood pressure measurements; 3) if the early morning blood pressure is >140/90 mm Hg, additional antihypertensive therapy is indicated, logically to include formulations that provide 24-hour or longer efficacy. Even if such formulations are used, early morning home blood pressure measurements should be checked to ensure maximal cardiovascular protection.
Footnotes
The opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association.
References
1. Muller JE, Stone PH, Turi ZG, et al, and the MILIS Study Group. Circadian variation in the frequency of onset of acute myocardial infarction. N Engl J Med. 1985; 313: 1315–1322.[Abstract]
2. Muller JE. Circadian variation in cardiovascular events. Am J Hypertens. 1999; 12: 35S–42S.[CrossRef][Medline] [Order article via Infotrieve]
3. Kario K, Pickering TG, Umeda Y, et al. Morning surge in blood pressure as a predictor of silent and clinical cerebrovascular disease in elderly hypertensives: a prospective study. Circulation. 2003; 107: 1401–1405.
4. Leary AC, Struthers AD, Donnan PT, et al. The morning surge in blood pressure and heart rate is dependent on levels of physical activity after waking. J Hypertens. 2002; 20: 865–870.[CrossRef][Medline] [Order article via Infotrieve]
5. Khoury AF, Sunderajan P, Kaplan NM. The early morning rise in blood pressure is related mainly to ambulation. Am J Hypertens. 1992; 5: 339–344.[Medline] [Order article via Infotrieve]
6. Gosse P, Cipriano C, Bemurat L, et al. Prognostic significance of blood pressure measured on rising. J Human Hypertens. 2001; 15: 413–417.[Medline] [Order article via Infotrieve]
7. Bursztyn M, Ginsberg G, Hammerman-Rozenberg R, et al. The siesta in the elderly: risk factor for mortality? Arch Intern Med. 1999; 159: 1582–1586.
8. Panza JA, Epstein SE, Quyyumi AA. Circadian variation in vascular tone and its relation to -sympathetic vasoconstrictor activity. N Engl J Med. 1991; 325: 986–990.[Abstract]
9. Dodt C, Breckling U, Derad I, et al. Plasma epinephrine and norepinephrine concentrations of healthy humans associated with nighttime sleep and morning arousal. Hypertension. 1997; 30: 71–76.
10. Redón J, Roca-Cusachs A, Mora-Maciá J, on behalf of the ACAMPA investigators. Uncontrolled early morning blood pressure in medicated patients: the ACAMPA study. Blood Press Monit. 2002; 7: 111–116.[CrossRef][Medline] [Order article via Infotrieve]
Related Article:
Circulation 2003 107: 1401-1406.
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  H. Jones, G. Atkinson, A. Leary, K. George, M. Murphy, and J. Waterhouse Reactivity of Ambulatory Blood Pressure to Physical Activity Varies With Time of Day Hypertension, April 1, 2006; 47(4): 778 - 784. [Abstract] [Full Text] [PDF]
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 M. Bursztyn, T. Mengden, S. Uen, H. Vetter, R. Marfella, K. Esposito, P. Gualdiero, D. Guigliano, K. Kario, Y. Umeda, et al. Morning Blood Pressure Surge and the Risk of Stroke * Response Circulation, October 14, 2003; 108 (15): e110 - e111. [Full Text] [PDF]
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