Managing Pre-Hypertension - Reducing a Global Burden or
Preventing a Global Catastrophe?
What is 'pre-hypertension'? Is it a problem and if so what if anything can we do
about it? Given the changing definitions of hypertension I will not get tied down
by further arbitrary cut off points - but suffice to say that as blood pressures
track with age, those with pressures above the median of pressures in childhood
or early adult life have a high risk of having pressures over 140 systolic or 90
diastolic by middle life and a 50% or more chance of being hypertensive should they
survive to 70 years. However that is just the beginning of the problem. These estimates
are based on figures from the affluent nations in the 1980's from which extrapolations
to 2020 predicted an increasing contribution of hypertension to the global burden
of disease as infectious disease and malnutrition diminish in the developing world.
These are probably gross under estimates as they failed to predict the rapid increase
in rates of obesity worldwide with accompanying hypertension, diabetes and vascular
disease. The effects of increasing hypertension on cardiovascular morbidity and
mortality will be further exacerbated by continued high smoking rates in the developing
world and increasing rates in young women. Decreasing physical activity and increasing
use of junk foods with high saturated fat, sugar and salt are further increasing
blood pressure levels both directly and via obesity. These lifestyle patterns have
spread rapidly throughout all major continents and are reflected in epidemic-like
rates of hypertension and diabetes in South East Asia, in some former Eastern Block
nations and in economically disadvantaged indigenous populations such as those in
North America and Australasia. For example, in the Monica study middle aged men
in Poland had an alarming 57% prevalence rate for hypertension (140/90 or more)
compared with 32% for US surveys, with hypertensives having twice the overall mortality
rates of normotensives. Sedentary lifestyles and unhealthy eating patterns in the
developed world have tripled rates of obesity and diabetes in young and middle aged
adults in the last twenty years and will likely reverse the falling rates of heart
attack and stroke.
Although advances in drugs have made life far more tolerable for hypertensives,
over 75% of treated patients have inadequate blood pressure control. This is probably
at least in part because by the time treatment is started there are already irreversible
changes in large artery stiffness as a consequence of lifelong exposure to gradually
increasing pressures. This is especially likely to be the case in isolated systolic
hypertension where the problem is primarily one of reduced arterial compliance.
Add to these observations the fact that in most communities less than half the hypertensives
are receiving treatment gives little cause for complacency about current management
We know the main lifestyle or environmental factors that can keep blood pressures
normal and reverse pre- and mild hypertension. They include avoiding excess body
fat, regular physical activity in day to day life, dietary patterns typified by
the DASH study with several serves of fruit and vegetables, and substitution of
saturated fat products with low fat dairy foods. When these habits are coupled with
moderation of salt intake to around 5 g a day and avoidance of heavy alcohol consumption
few will develop hypertension or diabetes.
How can we achieve these changes in the face of major cultural shifts world wide
and globalisation of behavioural patterns based on urbanisation, cars, computers,
television, fast food, jumbo size portions and high calorie soft drinks. It presents
an enormous challenge and a call for action at many levels. If we just talk about
it we will be no more effective than King Canute sitting on the seashore telling
the tide to go back. Let's not mince words, we are talking about the need to prevent
hypertension, obesity, diabetes and related cardiovascular disease from becoming
a global health catastrophe. Action means putting nutrition and physical activity
along with smoking as priorities for governments, national and international bodies,
health professionals, public health personnel, the food industry, the media, town
planners, schools, parents and the public at large. Efforts need to include a major
focus on children and their families to encourage early lifelong healthier eating
and activity and to prevent childhood obesity. Pre-hypertension is endemic. Hypertension
and diabetes rates have already increased dramatically in the most heavily populated
nations. The causes are obvious. The solutions are not. They will require resolve,
concerted effort, ingenuity, education, substantial resources, not least to counter
the advertising and legal budgets of the food and tobacco industries, legislation
and above all both community and political will.
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