WHAT DOES ELEVATED BLOOD PRESSURE MEAN?

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PEDIATRICS Vol. 64 No. 5 November 1979 693

COMMENTARIES

Hypertension

and

Sports

The article “Response of Hypertensive

Adoles-cents to Dynamic and Isometric Exercise Stress”

which appears in this issue of Pediatrics (p 579)

raises a number of interesting and practical

ques-tions for pediatricians. For example, What is

hyper-tension? What does hypertension mean to the child

or youth? Should the youth with hypertension be

allowed to participate in competitive athletics?

What is the role of exercise testing in the evaluation

of hypertension? What additional information does

it provide?

WHAT IS HYPERTENSION?

Blood pressure (BP) is the resultant of cardiac

output (CO), and systemic vascular resistance

(SVR). Because CO and SVR vary from one person

to another, it is not surprising that there is a wide

range of normal BP values. Londe’s early studies”2

awakened the pediatrician to the measurement of

blood pressure and his later studies3’4 documented

its relevance in pediatric practice. Londe has

sup-ported the concept that a blood pressure exceeding

the 95th percentile should be considered elevated

(if confirmed by three consecutive “abnormal”

mea-surements). Most pediatricians and epidemiologists

accept this as a loose working definition of

hyper-tension in children.

One third of youths diagnosed as hypertensive by

the above criterion, when followed for three to eight

years,3 will have their BPs return to normal.

Be-cause of the ominous connotation of hypertension,

I would like to use the terminology mildly elevated

blood pressure (rather than high blood pressure)

for the adolescent with a BP of <170/100 and no

underlying etiology ascertained. These are the

in-dividuals in whom BP is more likely to return to

normal. For the youth with a BP 170/100 or an

underlying etiology for the BP elevation,

hyperten-sion is an appropriate term.

WHAT DOES ELEVATED BLOOD PRESSURE MEAN?

This depends upon its cause and its severity. As

mentioned above one third of children with a BP

greater than the 95th percentile wifi return to a

normal value when followed for three to eight years.

Therefore, all youths diagnosed as “hypertensive”

may not carry the same long-term risks as adults

diagnosed to have hypertension. Two

generaliza-tions which may be made about long-term outlook

are: the younger the child when first diagnosed, and

the higher the blood pressure, the more likely is the

observation to be abnormal and related to an

un-denying etiology such as chronic renal disease. The

corollary of this is that mild elevation of BP is more

likely to be of unknown etiology (ie, primary).

Therefore, a means to predict accurately the youth

who will have persistent and progressive

hyperten-sion would be of value in determining which

mdi-viduals should be observed and counseled vs those

who require medical or surgical therapy. This

dis-tinction is critical because of the data presented by

Heyden et al5 on the long-term follow-up of 15- to

24-year-old persons with hypertension. Two of his

patients died of cerebrovascular accidents prior to

age 30. Because of the potential risk of strokes,

heart failure, and accelerated atherosclerosis most

pediatricians justifiably are concerned about their patients with elevated blood pressure. For the youth

with mildly elevated BP the medical concern should

be directed at life-style measures aimed at the

pre-vention

of hypertension and its chronic sequelae.

For the less frequent problem, ie, the youth with

moderate to severe hypertension often secondary

to an underlying problem, the concern is more

immediate with regard to etiology and initiation of

therapy. A reasonable regimen for evaluation and

therapy has recently been presented as a

supple-ment to Pediatrics.6

SHOULD YOUTHS WITH ELEVATED BLOOD PRESSURE BE RESTRICTED FROM

COMPETITIVE ATHLETICS?

If a preliminary evaluation does not detect an

underlying disease and BP is only mildly elevated

(as defined here), these youths may be readily

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694 PEDIATRICS Vol. 64 No. 5 November 1979

cleared for participation. The rationale for this

ap-proach is the fact that there is little or no evidence

to indicate that these youths are at increased risk

of morbidity or mortality from their blood pressure

level. As a matter of fact, some adult studies have

demonstrated a beneficial effect upon the blood

pressure by a physical training program. If this is

the case we certainly do not want to have our

athletic youngsters become sedentary by

recom-mending decreased activity. For the individual with

moderate to severe hypertension (ie, 170/100) or

secondary hypertension the picture is not as

clear-cut. Again, there are few or no data to support an

increased risk of athletic participation unless the

individual has an underlying problem such as

Mar-fan syndrome or Ehiers-Danlos syndrome.

How-ever, common sense should indicate a cautious

ap-proach to the problem, especially if the

hyperten-sion is secondary to renal disease and the individual

wishes to participate in a contact or strenuous sport.

In this situation there is the threat of renal trauma

and a worsening of the disease. The youth with

moderate hypertension (unusual) should have more

extensive evaluation and stress testing should be

performed under careful scrutiny. If

antihyperten-sive medication is indicated, the patient should

have a stress test after the medication is begun in

order to assess BP responsiveness to therapy. The

individual with severe hypertension should be

thor-oughly evaluated and treated appropriately.

Com-petitive athletics are probably contraindicated

be-cause ofthe effect ofsevere blood pressure elevation

on the kidney, brain, and heart.

WHAT IS THE ROLE OF EXERCISE TESTING IN THE EVALUATION OF THE MILD OR MODERATE ELEVATIONS OF BLOOD

PRESSURE? WHAT INFORMATION DOES IT PROVIDE?

In order to evaluate such youths more objectively

we have been making them exercise to observe what

occurs to their BP with dynamic and isometric

exercise. The results of such testing are reported by

Fixler et al in this issue of Pediatrics. Fixler and

his colleagues have used the 95th percentile cut-off

for their adolescents, and their values are

substan-tially lower than most studies reported to date (the

majority of studies suggest a 140/85 as an

appro-priate cut-off point for adolescents). Presumably

the etiology of the blood pressure elevation in the

youth of Fixler et al was primary and mild since the

values and standard deviations for systolic and

di-astolic blood pressures were 134 ± 11 and 79 ± 9,

respectively. With these lower values which were

“norms” for the Dallas study it is not too surprising

to see the little difference between their

“hyperten-sive” group and control group since many of the

hypertensive group may have been classified as

upper limits normal in other regions. What Fixler

et al have very nicely demonstrated is that most

adolescents whose BP exceeded 200 mm Hg during

exercise had higher resting blood pressures. Our

own data in healthy black children7 suggest that

200 mm Hg is the top normal systolic BP response

to exercise (using the 95th percentile). It would

appear that the populations of Fixler et al separate

fairly well into a “mild elevation of BP group” and

a group which during exercise has an excessive BP

response. The major determinant of an “abnormal”

exercise BP response is systemic vascular resistance

if the premises (1) BP = CO x SRV and (2) cardiac

output at maximum exercise is relatively similar for

individuals oflike size and effort8 are correct.

There-fore, the greater than 200 mm Hg group of Fixler et

al might be predictive of individuals who are more

likely to have an abnormality of BP due to an

increased systemic vascular resistance.

The mechanisms responsible for the blood

pres-sure response to isometric exercise are not well

delineated. Diastolic blood pressure increases, but

total SVR does not increase. Isometric exercise is a

significant component of such activities as

wres-tling, gymnastics, football line blocking, mowing the

lawn, shoveling snow, and carrying groceries or

other loads. The youth with mild blood pressure

elevation probably is at no increased risk when

participating in such sports but individuals with

moderate hypertension or secondary hypertension

should be evaluated more critically before

compet-itive participation in contact and strenuous sports

is permitted. We have observed that 4 to 5% of

adolescent boys have an elevated BP (>140/90)

during their preparticipation football examination.

Those whose BP does not become normal during

the examination should have their BPs checked on

two or three more occasions. Parenthetically, some

athletes, especially football linemen may have very

large upper arms; when measuring their blood

pres-sure an appropriate size cuff should be used to avoid

misinterpretation.

The purpose of exercise testing in the youth with

elevated BP is to determine his or her BP response

under conditions which are like those which occur

in athletics. Unfortunately, a stress test is not the

same as competitive athletics and a direct

compar-ison cannot be made. Where readily available I

would recommend that youths whose BP remains

elevated have a stress test to evaluate their response

to dynamic and isometric exercise. This latter test

may not be essential, but I continue to recommend

it in our community in order to gather data which

may help us better delineate this problem for the

future, especially with regard to the youth more

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COMMENTARIES 695

likely to have persistent hypertension, the group

upon whom we can focus our preventive techniques.

A word of caution before we become too zealous

in pursuit and “care” of the young athlete with

elevated blood pressure. Of all sudden deaths in the

sports arenas few have ever been traced to a

hyper-tensive crisis. Although we have a nice instrument

to evaluate the response of blood pressure to

dy-namic and isometric exercise, let us exert caution in

our interpretation of its results. Longitudinal

obser-vations are going to be very important and the

paper by Fixier et al has served as a nice stimulus.

WILLIAM B. STRONG, MD

Medical College of Georgia

Augusta

REFERENCES

1. Londe 5: Blood pressure in children as determined under office conditions. Clin Pediatr 5:71, 1966

2. Londe 5: Blood pressure standard for normal children: As determined under office conditions. Clin Pediatr 7:400, 1968

3. Londe 5, Bourgoignie JJ, Robson AM, et al: Hypertension

in apparently normal children. J Pediatr 78:569, 1971

4. Londe 5, Goldring D: High blood pressure in children;

prob-lems and guidelines for evaluation and treatment. Am J Cardiol 37:650, 1976

5. Heyden S, Bartel AG, Hames CG, et al: Elevated blood pressure levels in adolescents, Evans County, Georgia.

JAMA 209:1683, 1969

6. Report of the Task Force on Blood Pressure Control in

Children. Pediatrics 59(suppl):797-820, 1977

7, Strong WB, Miller MD, Striplin M, et a!: Blood pressure

response to isometric and dynamic exercise in healthy black children. Am J Dis Child 132:587, 1978

8. Sproule BJ, Mitchell JH, Miller WF: Cardiopulmonary

phys-iological responses to heavy exercise in patients with anemia.

J Clin Invest 39:378, 1960

“Felicitas

Liberorum

Suprema

Lex”

(IYC

in Poland

and

the

World)

The year 1979, the 20th anniversary of the

Dec-laration of the Rights of Children, formulated by the United Nations, is declared an International

Year of the Child (IYC).

During this year each nation is focusing on the

problems and needs of its own children, and

at-tempting to share its resources with needy children

of the world. An International Secretariat of

UNI-CEF is coordinating world activities of the IYC.

In the United States a National Commission of

the IYC was established with Mrs. Jean Young as

chairperson. The National Institutes of Health

launched an exhibit entitled “NIH Research:

Help-ing Children Grow into Healthy Adults.” The

American Academy of Pediatrics sponsored

through its 16,000 pediatricians an educational sb-gan “Speak up for Children.”

A very unique commemoration of the IYC is

taking place in Poland near Warsaw where a Child

Health Center, a Hospital Monument, is being built,

Figure. Child Health Center (Centrum Zdrowia Dziecka), Warsaw, Poland.

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1979;64;693

Pediatrics

William B. Strong

Hypertension and Sports

Services

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(5)

WHAT DOES ELEVATED BLOOD PRESSURE MEAN?

COMMENTARIES

Hypertension

and

Sports

pre-vention

“Felicitas

Liberorum

Suprema

Lex”

(IYC

in Poland

and

the

World)

1979;64;693

Pediatrics

William B. Strong

Hypertension and Sports

Services

Updated Information &

http://pediatrics.aappublications.org/content/64/5/693

including high resolution figures, can be found at:

Permissions & Licensing

http://www.aappublications.org/site/misc/Permissions.xhtml

entirety can be found online at:

Information about reproducing this article in parts (figures, tables) or in its

Reprints

http://www.aappublications.org/site/misc/reprints.xhtml

Information about ordering reprints can be found online:

1979;64;693

Pediatrics

William B. Strong

Hypertension and Sports

http://pediatrics.aappublications.org/content/64/5/693

the World Wide Web at:

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