A new study has found that 80% of deaths connected to high blood
pressure now occur in the developing world [1]. Dr Carlene MM Lawes
(Clinical Trials Research Unit, University of Auckland, New Zealand)
and colleagues also found that much of the burden is borne by people
with prehypertension, so prevention and treatment strategies
targeted to those with hypertension will miss much BP-related
disease, they note in the Lancet.

"The take-home [message] from our research is the sheer staggering
size of the problem," senior author Dr Anthony Rodgers (Clinical
Trials Research Unit), told heartwire. "The other surprising thing
is just how much of the burden is borne by people not currently
targeted by current programs--most important, people at high risk in
low- and middle-income countries." Rodgers also highlights the lack
of response to this problem: "High blood pressure is a silent
killer, and I imagine that is relevant--otherwise how could there
not be more response to something that kills so many millions of
people?"

Experts penning a strongly worded, accompanying commentary are
somewhat harsher in their conclusions [2]. Dr Stephen MacMahon
(University of Sydney, Australia) and colleagues say this situation
with regard to high BP "was predicted a decade ago by the Global
Burden of Disease Project, but none of the major health-development
funds . . . have made any substantive or sustained effort to address
this issue. Similarly, none of the major international drug
companies have offered material assistance in this global health
crisis, despite gargantuan profits from the sales of BP-lowering
drugs in high-income countries."

Number of Deaths in Developing Nations Staggering

In their report, Lawes et al provide updated estimates of the global
burden of disease attributable to high BP (defined as 115 mm Hg
systolic or greater) by age and sex for adults and by World Bank
region for the year 2001. Data for systolic BP were obtained from
the Global Burden of Disease 2000 study and updated to include more
recent, country-level data, they note.

They show that 7.6 million premature deaths (about 13.5% of the
global total) and 92 million disability-adjusted life-years--around
6% of the global total--were attributed to high BP. Worldwide, 54%
of stroke and 47% of heart disease is due to high BP--about half of
this was in people with hypertension (systolic BP 140 mm Hg or
greater), while the remainder was in those with lesser degrees of
high BP.


And while the proportion of premature deaths due to high BP was
greater in high-income countries (17.6%) than in low- and middle-
income nations (12.9%), the actual number of deaths related to high
BP in richer countries was dwarfed by those in low- and middle-
income countries: 1.39 million deaths compared with 6.22 million
deaths.

Eastern Europe, Central Asia, East Asia, and the Pacific (including
China), followed by South Asia (including India), bore the brunt of
these high-BP¡Vrelated deaths. More than one-third of all deaths in
the lower-income countries of Europe and Central Asia region were
related to high BP, for example.

The figures also show that, in low- and middle-income regions, a
greater proportion of the burden of disease attributed to high BP
was in young age groups than it was in high-income countries.

"Most of the disease burden caused by high BP is borne by low-income
and middle-income countries, by people in middle age, and by people
with lesser degrees of high BP," say the researchers.

"Prevention and treatment strategies restricted to rich countries or
individuals with hypertension will miss much BP-related disease,"
they conclude.

How Big a Problem Does This Have to Be to Prompt Action?

In their editorial, MacMahon and colleagues wonder: "How big a
problem does this have to become before anyone with resources takes
meaningful action?"

Fortunately, reports from the World Health Organization and the
World Bank "provide some hope that real action may be imminent,"
they note.

Both highlight the importance of chronic disease as an obstacle to
economic development as well as a barrier to improved national-
health status and "recommend action to control the huge epidemics of
cardiovascular disease already affecting Asia and South America and
threatening other regions, including Africa, where stroke is rapidly
becoming a common cause of death and disability."

The risk of stroke is quickly reduced by BP-lowering drugs, and
large benefits can be achieved with generic antihypertensives
costing as little as $1 a year per person, say MacMahon et al. And
effective nondrug interventions can also be provided at low cost,
they note.

However, there is still a huge mountain to climb, they stress. For
example, "there is no single initiative on the whole African
continent to implement BP-control strategies systematically on a
populationwide scale, even to those at very high risk of death or
disability. For many such individuals, the first medically relevant
attention they receive is admission to the hospital after stroke."

Begin at the Beginning: Primary Care Must be Overhauled

The major obstacle to the control of BP-related diseases in low- and
middle-income countries is the absence of appropriate primary-
healthcare services, the editorialists point out. Such services must
be adapted to provide continuing care, not only for the management
of BP-related diseases but also for the management of other serious
chronic disorders, including HIV infection.

Unfortunately, however, research into healthcare delivery "is not
attractive to most international funding agencies," they note, "many
of which still prefer to believe that the world's leading health
problems will be resolved by the development of new treatments based
on technologies such as genomics, proteomics, or metabolomics." But
for much of the world's population, any new drugs, however
effective, "will have little relevance if there is no system in
place to deliver treatment to those in need.

"The failure of primary-care systems combined with a myopic view of
disease targets among those who set international health priorities
has contributed to the staggering inequality in access to BP-
lowering treatments. The antihypertensive care available for many
people is much as it was in the first half of the 20th century,
before the development of diuretics and beta blockers, where
malignant hypertension was a common cause of hospital admission and
death everywhere. This travesty cannot continue to be ignored by
those most able to bring about change," they conclude.

Rodgers has minority shares in Iusero, which is developing BP-
lowering implants, has several research grants in the area of BP
lowering, and has consulted for several companies that market BP-
lowering drugs.

Lawes CMM, Vander Hoorn S, Rodgers A, et al for the International
Society of Hypertension. Global burden of blood-pressure¡Vrelated
disease, 2001. Lancet 2008; 371:1513-1518.
MacMahon S, Alderman MH, Lindholm LH, et al. Blood-pressure¡Vrelated
disease is a global health priority. Lancet 2008; 371:1480-1482.