blood pressure – lower targets, greater challenges
TRANSCRIPT
COMMENTARY
Blood pressure – lower targets, greater challenges
A. M. A. Shehab MBChB MMED MD MRCP and M. J. Kendall MBChB MD FRCP
Division of Medical Sciences, University of Birmingham, Birmingham, UK
The world health organization has estimated that
high blood pressure causes one in eight deaths
world wide making hypertension the third leading
killer in the world (1). The seventh joint national
committee (JNC-7) report was recently published
in the Journal of the American Medical Association (2)
and presents new guidelines for the prevention and
management of high blood pressure, based on a
review of all the latest scientific literature. The
guidelines were developed by the National High
Blood Pressure Education Program Coordinating
Committee, administered by the National Heart,
Lung, and Blood Institute. The report addresses
areas including blood pressure measurement and
classification, patient evaluation and testing, treat-
ment approaches and monitoring, and certain
special considerations (2).
The new guidelines categorize blood pressure as
normal (<120/80 mmHg), prehypertension (120/
80 to 139/89), stage 1 hypertension (140/90 to 159/
99), and stage 2 hypertension (‡160/100). The JNC-
7 report on hypertension takes a stronger view than
its predecessors (3), reclassifying ‘high normal’
blood pressure as ‘prehypertension’ and calling for
aggressive treatment, first by changing lifestyle and
then with drugs. The guidelines also emphasize the
importance of a systolic blood pressure of over
140 mmHg as an important cardiovascular risk
factor for people over 50 years of age. Cardiovas-
cular disease risk increases as the blood pressure
rises above 115/75 mmHg, increasing 2-fold for
each 20/10 mmHg increment. Lowering blood
pressure from 140/90 towards the new goal level of
120/80 mmHg will decrease heart attacks (20–
25%), heart failure (50%), stroke (35–40%), kidney
disease, and will save lives (2). The blood pressures
at which most doctors consider treatment may be
beneficial are in fact well above the level at which
blood pressure starts to cause harm.
JNC-7 emphasizes the importance of aging
which is the single most important factor associ-
ated with the development of hypertension (4).
Unless preventive steps are taken, stiffness and
other damage to arteries worsen with age and
make high blood pressure more and more difficult
to treat. The new prehypertension category reflects
this risk and will prompt people to take preventive
action early. Data from the Framingham Heart
Study suggests that individuals who are normo-
tensive at 55 years of age have a 90% lifetime risk
for developing hypertension. So the aim should be
to slow the adverse effects of aging and delay the
onset of hypertension. In practice lifestyle modifi-
cation is the only way, at present, to counteract the
effects of age and to try to prevent the development
of hypertension.
JNC-7 recommends that Governments and
others should modify working conditions to reduce
the excessive demands and time pressures on those
living in the developed countries of the world. In
addition they should also promote exercise, weight
reduction, the consumption of less alcohol and the
taking of less sodium in the diet. Specifically JNC-7
recommends change to the ‘DASH’ diet – high in
fruits and vegetables, potassium, and calcium – (5).
Most important smoking cessation should be
encouraged and children and young people should
be discouraged from starting to smoke.
The JNC-7 guidelines include new data on US
control, awareness, and treatment rates for high
blood pressure. According to a national survey,
70% of Americans are aware of their high blood
pressure, 59% are being treated for it, and 34% of
those with hypertension have it under control (6).
Those percentages represent a slight improvement
over rates for 10 years ago, when 68% of Ameri-
cans were aware of their high blood pressure, 54%
were being treated for it, and 27% of those with
hypertension had it under control (6). By contrast,
Received 9 September 2003, Accepted 19 September 2003
Correspondence: Dr A. M. A. Shehab, Clinical Investigation
Unit, Queen Elizabeth Hospital, Edgbaston, Birmingham B15
2TH, UK. Tel.: 0121 414 6874; fax: 0121 414 1344; e-mail:
Journal of Clinical Pharmacy and Therapeutics (2003) 28, 441–443
� 2003 Blackwell Publishing Ltd 441
about 25 years ago, 51% were aware of their high
blood pressure, 31% were being treated, and 10%
of those with hypertension had it under control (6)
(Table 1).
JNC-7 commented ‘though improved, the treat-
ment and control rates are still too low’. The new
guidelines zero in on this problem, identifying fac-
tors that often lead to inadequate control, such as not
prescribing sufficient medication. The guidelines
also stress that most patients will need more than
one drug to control their hypertension and that
lifestyle measures are a crucial part of treatment.
In addition, the JNC 7 report reinforces several
other messages. The thiazide-type diuretics are
strongly recommended. They are the least expen-
sive antihypertensive drugs and are among the
most effective for patients who do not have a
compelling need for more expensive medications.
However many patients will require one or two
additional antihypertensive drugs to achieve goal
blood pressure. Particularly those whose blood
pressure is more than 20/10 mmHg over target
levels. Certain high risk conditions are compelling
indications for other drug classes (Table 2).
The guidelines also emphasize that no drug
regimen will be effective unless the medication is
taken and this requires effective patient motivation.
This is greatly enhanced when the patient has
positive experience with, and trust in, the physician
and can observe beneficial impact of the treatment
on their blood pressure.
The JNC 7 report is about more than hyperten-
sion. For many, high blood pressure is just one
manifestation of what may be termed the lifestyle
syndrome (7), which is a cluster of conditions and
diseases that result from consuming too many
calories; ingesting too much saturated fat, sodium,
and alcohol; not expending enough calories; and
smoking or being exposed to tobacco smoke. In
addition to hypertension, manifestations of the
lifestyle syndrome include the metabolic syn-
drome, obesity, dyslipidaemia, cardiovascular dis-
ease, cancer, osteoarthritis, depression, sexual
dysfunction, and type 2 diabetes mellitus. If the
stakeholders in hypertension control – clinicians,
patients, health services organizations, and the
purchasers of health care services – act and are
organized to use the tools described in the JNC 7
report to prevent hypertension, the mortality and
morbidity attributable to the lifestyle syndrome
will also be decreased. This requires a compre-
hensive programme of lifestyle, environmental and
clinical intervention (8, 9). Actions that lead to
control of hypertension and reduce the burden of
disease must be the criteria for success.
Table 1. Trends in awareness, treatment, and control of
high blood pressure in adults ages 18–74a (6)
National Health and Nutrition
Examination Survey (%)
1976–80 1988–91 1991–94 1999–2000
Awareness 51 73 68 70
Treatment 31 55 54 59
Controlb 10 29 27 34
aHigh blood pressure is systolic blood pressure (SBP) ‡140 mmHg or diastolic blood pressure (DBP) ‡ 90 mmHg or
taking antihypertensive medication.bSBP < 140 mmHg and DBP < 90 mmHg.
Table 2. Compelling indications
for individual drug classesCompelling indication Initial therapy
Heart failure Thiazide, B.blocker, ACEi, ARB, Aldosterone
antagonist
Post-myocardial infarction B.blocker, ACEi, Aldosterone antagonist
High coronary artery risk Thiazide, B.blocker, ACEi
Diabetes Thiazide, calcium antagonist, B.blocker,
ACEi, ARB
Chronic kidney disease ACEi, ARB
Recurrent stroke
preventions
Thiazide, ACEi
ACEi, angiotensin converting enzyme inhibitor; ARB, angiotensin receptor blocker;
B.blocker, beta blocker.
� 2003 Blackwell Publishing Ltd, Journal of Clinical Pharmacy and Therapeutics, 28, 441–443
442 A. M. A. Shehab and M. J. Kendall
JNC-7 is the latest set of guidelines from the USA.
They are authoritive and evidence-based. If they are
followed millions more patients will be treated and
the overall impact on mortality and morbidity from
cardiovascular disease could be enormous. How-
ever this could only be achieved if the health care
resources and the money for the necessary antihy-
pertensive drugs can be made available.
REFERENCES
1. The World Health Report (2002) Reducing risks,
promoting healthy life. Geneva, Switzerland: World
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5. Sacks FM, Svetkey LP, Vollmer WM et al. (2001)
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� 2003 Blackwell Publishing Ltd, Journal of Clinical Pharmacy and Therapeutics, 28, 441–443
Blood pressure – lower targets, greater challenges 443