New guidelines for the management of hypertension have been published in 1999 by the World Health Organization (WHO) and the International Society of Hypertension (ISH). The WHO/ISH Committee has adopted in principle the definition and classification of hypertension provided by the JNC VI (1997). The new classification defines a blood pressure of 120/80 mm Hg as optimal and of 130/85 mm Hg as the limit between normal and high-normal blood pressure. It is unclear which self-measured home blood pressure values correspond to these office blood pressure limits. In this study we reevaluated data from our Dübendorf study to determine self-measured blood pressure values corresponding to optimal and normal office blood pressure using the percentiles of the (office and home) blood pressure distributions of 503 individuals (age, 20 to 90 years; mean age, 46.5 years; 265 men, 238 women). Self-measured blood pressure values corresponding to office values of 130/85 mm Hg and 120/80 mm Hg were 124.1/79.9 mm Hg and 114.3/75.1 mm Hg. Thus, we propose 125/80 mm Hg as a home blood pressure corresponding to an office blood pressure of 130/85 mm Hg (WHO 1999: normal) and 115/75 mm Hg corresponding to 120/80 mm Hg (optimal). Am J Hypertens 2000;13:940-943 © 2000 American Journal of Hypertension, Lt

Düsing, R.

Mengden, T.

Vetter, H.

Vetter, W.

Weisser, B.

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Normal Values of Blood PressureSelf-Measurement in View of the 1999 WorldHealth Organization-International Society ofHypertension GuidelinesB. Weisser, T. Mengden, R. Du¨sing, H. Vetter, and W. VetterNew guidelines for the management ofhypertension have been published in 1999 by theWorld Health Organization (WHO) and theInternational Society of Hypertension (ISH). TheWHO/ISH Committee has adopted in principle thedefinition and classification of hypertensionprovided by the JNC VI (1997). The newclassification defines a blood pressure of 120/80mm Hg as optimal and of 130/85 mm Hg as thelimit between normal and high-normal bloodpressure. It is unclear which self-measured homeblood pressure values correspond to these officeblood pressure limits.In this study we reevaluated data from ourDu¨bendorf study to determine self-measured bloodpressure values corresponding to optimal andnormal office blood pressure using the percentilesof the (office and home) blood pressuredistributions of 503 individuals (age, 20 to 90 years;mean age, 46.5 years; 265 men, 238 women). Self-measured blood pressure values corresponding tooffice values of 130/85 mm Hg and 120/80 mm Hgwere 124.1/79.9 mm Hg and 114.3/75.1 mm Hg.Thus, we propose 125/80 mm Hg as a home bloodpressure corresponding to an office blood pressureof 130/85 mm Hg (WHO 1999: normal) and 115/75mm Hg corresponding to 120/80 mm Hg (optimal).Am J Hypertens 2000;13:940–943 © 2000 AmericanJournal of Hypertension, Ltd.KEY WORDS: World Health Organization,International Society of Hypertension, guidelines,self-measured blood pressure.Self-measurement provides valuable infor-mation on the long-term control of bloodpressure1–3 and increases the reproducibil-ity and precision of blood pressure mea-surement.4 However, definitions for high bloodpressure are generally based on casual, office bloodpressure values. Until recently, most of the epide-miologic and pharmacologic studies have used onlycasual blood pressure measurement. Various influ-ences that limit the accuracy and validity of casual(office) blood pressure measurement are well docu-mented.5 One of the problems of blood pressureself-measurement is that there is no universallyagreed-upon upper limit of normal self-measuredhome blood pressure. Several studies have adressedthis problem in the past. In the population-basedDu¨bendorf study6 we have proposed 133/86 mmHg as the upper limit of normal self-measuredblood pressure, corresponding to the 140/90 mmHg cutoff limit for casual blood pressure usingReceived August 9, 1999. Accepted January 13, 2000.From the Medizinische Poliklinik Universita¨t Bonn, Bonn, Ger-many; and Universita¨tsspital Zu¨rich, Medizinsche Poliklinik, Zu¨-rich, Switzerland.Address correspondence and reprint requests to B. Weisser,Medizinische Poliklinik Universita¨t Bonn, Wilhelmstrasse 35-37,D-53111 Bonn, Germany.AJH 2000;13:940–943© 2000 by the American Journal of Hypertension, Ltd. 0895-7061/00/$20.00Published by Elsevier Science, Inc. PII S0895-7061(00)00259-4percentiles of the distributions of self-measured andcasual blood pressure. Other groups have obtainedsimilar data to our original Du¨bendorf study con-cerning the normal values of self-measurement, in-dicating that using percentiles for determination ofnormative values might be an appropriate method.7We agree with the statement in the JNC VI 1997publication that self-measured blood pressure “val-ues of 135/85 mm Hg or greater should be consid-ered elevated,” provided that 140/90 mm Hg is thedefinition of hypertension using office blood pres-sure.8 Therefore, most of the international societiesof hypertension have until now used 135/85 mm Hgas the upper limit of normal for self-measured bloodpressure.In the contrast, the 1999 WHO/ISH guidelinespropose 125/80 mm Hg as home blood pressurecorresponding to an office blood pressure of 140/90mm Hg.9 We disagree with this proposal, which isin contrast with our original Du¨bendorf data andwith the JNC VI recommendations. The differencemight be explained by the fact that this proposal isbased on a single study using only two measure-ments on the same day an ambulatory blood pres-sure recording was performed.10 We believe thatonly the average of home blood pressures obtainedin the morning and in the evening for at least 7 days(better would be 14 days) might serve as a referencevalue.In the 1999 World Health Organization/Interna-tional Society of Hypertension Guidelines, an officeblood pressure less than 130/85 mm Hg is defined asnormal (130 to 139/85 to 89 mm Hg 5 “high normal”)and a blood pressure less than 120/80 mm Hg isdefined as optimal with respect to cardiovascularrisk.9 It is unclear how these newly defined officelimits can be compared to self-measured blood pres-sure values.MATERIALS AND METHODSIn this analysis, we have attempted to determine theself-measured blood pressure values corresponding tothese cutoff points of office blood pressure by usingpercentiles of the distributions of self-measured andcasual blood pressure from our Du¨bendorf database.In the Du¨bendorf study, 503 individuals were studied(age, 20 to 90 years; mean age, 46.5 years; 265 men, 238women). The subjects were not preselected accordingto their blood pressure levels. Only patients takingantihypertensive drugs were excluded.Office blood pressure was measured twice in thesitting position after a rest of at least 5 min before andafter a 2-week period of home blood pressure mea-surement. The patients were instructed on the tech-nique of blood pressure self-measurement during thefirst visit. Oscillometric semiautomatic devices (OM 1,Boehringer Mannheim, Switzerland) were used bothfor office and home blood pressure determination. Thesubjects were instructed to measure blood pressure athome once in the morning and once in the eveningover a period of 14 days. They were instructed to writedown the measurements and to report them duringtheir second office visit (a mean of 26.7 measurementswas obtained). The means of the first and second visit(two measurements per visit) were compared with themeans of self-measured home blood pressure bypaired two sided t test and values are given asmeans 6 standard deviation.RESULTSMean office blood pressure (130.0 6 16.5/82.1 6 11.1mm Hg) was significantly (P , .01) higher than meanself-measured blood pressure (123.1 6 14.6/77.6 610.7 mm Hg). There was no significant difference be-tween the first and second visit. Mean office bloodpressure was 129.8 6 17.6/82.5 6 12.2 mm Hg (firstvisit) and 130.2 6 18.0/81.7 6 11.9 mm Hg (secondvisit). However, the correlation coefficients betweenthe values were lower than those for the comparisonbetween morning and evening self-measured bloodpressures. This difference indicates that there was lessvariation in self-measured blood pressure comparedwith office blood pressure.The percentiles of an office blood pressure of 130/85mm Hg and 120/80 mm Hg were determined and theself-measured blood pressure values at these percen-tiles were calculated. The results are shown in Table 1and are compared with our original results (officevalues, 140/90 mm Hg).Thus, the corresponding self-measured blood pres-sure to the recently defined upper limit of normality(130/85 mm Hg) was 124.1/79.9 mm Hg and optimaloffice blood pressure corresponds to a home bloodpressure of 114.3/75.1 mm Hg.TABLE 1. PERCENTILES OF THE DISTRIBUTIONOF OFFICE BLOOD PRESSURE AT 120/80 MM HG,130/85 MM HG, AND 140/90 MM HG AND THECORRESPONDING SELF-MEASURED BLOODPRESSURE VALUESOfficeBlood Pressure(mm Hg) PercentileSelf-MeasuredBlood Pressure(mm Hg)Systolic 140 76.3 132.6130 57.7 124.1120 34.8 114.3Diastolic 90 78.4 85.885 67.0 79.980 50.1 75.1AJH–AUGUST 2000–VOL. 13, NO. 8 1999 WHO-ISH GUIDELINES 941DISCUSSIONThe objective of identifying normal values is to defineblood pressure values associated with an increasedcardiovascular morbidity and mortality. The predic-tive value of blood pressure self-measurement seemsto be superior to office blood pressure.11In the present study, the self-measured blood pres-sure values were written down by the subjects. Wehave recently shown an observer bias in the individualpatient reporting self-measured blood pressure val-ues.12 This bias can be reduced by using devices suchas the Omron IC to record all measurements; it wasnot available at the time of the present study. How-ever, we have also demonstrated that observer biasdid not substantially affect group comparisons,12 andwe are confident that we have obtained valid data inthe present study.During the last decades, large and prospective stud-ies in untreated subjects have contributed to the defi-nition of normal office blood pressure values by show-ing that blood pressure values greater than 140/90mm Hg are associated with increased cardiovascularmorbidity and mortality. It will be very difficult toconduct such large studies investigating the prognos-tic significance of self-measured blood pressure in un-treated subjects.A more acceptable method is to determine thepercentile of the distribution of office blood pres-sures at 140/90 mm Hg. The corresponding bloodpressure level at the same percentile of the distribu-tion of self-measured values might serve as a refer-ence value for an upper limit of normality. Othermethods have been used for the determination ofnormal home blood pressure values. Mean bloodpressure 6 one or two standard variations or the95th percentile in normotensive subjects have beenproposed as upper limits, although these values arearbitrary cutoff points. In addition, regression anal-ysis has produced values similar to the results of theso-called “percentile-correspondence” method usedin this analysis. We think that every method can becriticized for some reason, but our original datafrom Du¨bendorf are in very good accordance withreference values for home blood pressure based onthe only prognostic study available.11For the definition of normal values it is not suffi-cient to introduce the mean differences betweenself- and office measurement as a correcting factor,as the office-home difference increases with higherlevels of blood pressure.13 In addition to the com-parison of office and home blood pressure, anotherimportant conclusion might be drawn from the datashown in Table 1. At an office blood pressure of140/90 mm Hg, the percentiles for systolic and di-astolic pressures are very similar (76.3% and 78.4%).However, using the lower blood pressure levels of130/85 and 120/80 mm Hg the percentiles for thesystolic blood pressure decrease more than thoseobtained for diastolic blood pressure. The optimalblood pressure corresponds to percentiles of 34.8%(distribution of systolic blood pressure) and 50.1%(distribution of diastolic blood pressure). Thus, thenew cutoff values might be more ambitious withrespect to the systolic blood pressure as comparedto diastolic blood pressure.In conclusion, if an upper limit of 130/85 mm Hgfor the normal office blood pressure is accepted, assuggested by the guidelines of the WHO and ISH(1999), we propose, for practical reasons, 125/80mm Hg as the corresponding self-measured bloodpressure.REFERENCES1. Kleinert HD, Harshfield GA, Pickering TG, DevereuxRB, Sullivan PA, Marion RM, Mallory WK, Laragh JH:What is the value of home blood pressure in patientswith mild hypertension? Hypertension 1984;6:574–578.2. Pickering T: Recommendations for the use of home(self) and ambulatory blood pressure monitoring. Am JHypertens 1996;9:1–11.3. Mengden T, Schwartzkopff B, Strauer BE: What is thevalue of home (self) blood pressure monitoring in pa-tients with hypertensive heart disease? Am J Hypertens1998;11:813–819.4. Mengden T, Ba¨ttig B, Vetter W: Self-measurement ofblood pressure improves the accuracy and reduces thenumber of subjects in clinical trials. J Hypertens 1991;9(suppl 6):336–337.5. Mancia G, Bertinieri G, Parati G, Pomidossi G, FerrariA, Gregorini L, Zanchetti A: Effects of blood pressuremeasurement by the doctor on patients’ blood pressureand heart rate. Lancet 1983;ii:695–698.6. Weisser B, Gru¨ne S, Burger R, Blickensdorfer H, Iseli J,Michelsen SH, Opravil R, Rageth S, Sturzenegger ER,Walker P, Widmer W, Vetter W: The Du¨bendorf study:a population-based investigation on normal values ofblood pressure self-measurement. J Hum Hypertension1994;8:227–231.7. Mejia AD, Julius S, Jones KA, Schork NJ, Kneisley J:The Tecumseh Blood Pressure Study. Normative dataon blood pressure self-determination. Arch Intern Med1990;150:1209–1213.8. The Joint National Committee on Prevention, Detec-tion, Evaluation, and Treatment of High Blood Pres-sure: The Sixth Report National High Blood PressureEducation Program, National, Lung, and Blood Insti-tute, National Institutes of Health. Arch Intern Med1997;157(21):2413–2446.9. Guidelines Subcommittee: 1999 World Health Organi-zation-International Society of Hypertension guide-lines for the management of hypertension. J Hypertens1999;17:151–184.10. Mancia G, Sega R, Bravi D, De Vito G, Valagussa F,Cesena G, Zanchetti A: Ambulatory blood pressureAJH–AUGUST 2000–VOL. 13, NO. 8942 WEISSER ET ALnormality: results from the PAMELA study. J Hyper-tens 1995;13:1377–1390.11. Kubo T, Imai Y, Tsuji I, Nagai K, Kato J, Kikuchi N,Nishiyama A, Aihara A, Sekino M, Kikuya M, Ito S,Satoh H, Hisamichi S: Home blood pressure measure-ment has a stronger predictive power for mortalitythan does screening blood pressure: a population-based observation in Ohasama, Japan. J Hypertens1998;16:971–975.12. Mengden T, Hernandez Medina RM, Beltran B, AlvarezE, Kraft K, Vetter H: Reliability of reporting self-mea-sured blood pressure values by hypertensive patients.Am J Hypertens 1998;11:1413–1417.13. Mengden T, Ba¨ttig B, Edmonds D, Jeck T, Huss R,Sachinidis A, Schubert M, Feltkamp H, Vetter W: Self-measured blood pressure at home and during consult-ing hours: are there any differences? 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Normal values of blood pressure self-measurement in view of the 1999 World Health Organization-International Society of Hypertension guidelines

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