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Number in Blood Pressure Tells All
Excerpt
by Randy Dotinga,
HealthDay
To the befuddlement of patients everywhere,
blood pressure measurements come in two numbers -- one that's
bigger and one that's smaller, such as 120 over 80.
Now, new research confirms that
the first number is the more important of the two, and suggests
the difference between them -- the little-known "pulse pressure"
-- doesn't mean much at all.
"We believe that the number
to watch more closely is the higher blood pressure," says
study co-author Dr. Eliseo Guallar, a researcher at Johns Hopkins
School of Public Health. Why? Because it's a better indication
that a seemingly heart-healthy person will die of heart disease,
he explains.
Doctors and nurses routinely take
the blood pressure of patients by using cuffs to monitor the "push"
in the circulatory system. The top "systolic" number
measures the pressure when the heart pumps blood out, and the
bottom "diastolic" number measures the pressure between
the pumps. The pressure doesn't reverse itself between heartbeats,
but simply goes down a bit.
High blood pressure is a sign that
the heart is working extra hard to push blood through the body.
"Too much pressure is bad because it makes your heart overwork,
making it more prone to arrhythmias and heart failure," Guallar
says. "And as you're pumping blood with more force, you're
damaging your arteries."
Stressed-out arteries, in turn,
can lead to heart disease, stroke, vascular diseases, and kidney
disease.
Doctors have now realized the importance
of the systolic pressure after giving too much emphasis to the
diastolic pressure, says Dr. Daniel Jones, dean of the School
of Medicine at the University of Mississippi Medical Center and
spokesman for the American Heart Association.
In recent years, however, some
researchers have speculated that the pulse pressure could also
be a sign of heart trouble.
Guallar and his colleagues examined
the medical records of 7,830 white and black Americans -- both
men and women -- who were followed for 15 years. The subjects
were aged 30 to 74 and seemed to have no sign of heart disease.
The findings appear in the Nov.
4 issue of the Annals of Internal Medicine.
Those with higher systolic pressure
levels were more likely to die of heart disease. Diastolic pressure
appeared to possibly play a role in death rates in older patients,
as did unusually low blood pressure. But pulse pressure didn't
seem to be directly connected to mortality.
"From the scientific standpoint,
the really important information is that pulse pressure is not
going to be an easy tool for clinicians to use to make decisions
about patients," Jones says.
Patients are unlikely to worry
about -- or even know about -- their pulse pressures. But they
should continue to get their blood pressure checked in the traditional
way, Guallar says, "and keep a particular eye on the systolic
blood pressure and make sure it's not high."
Doctors say any systolic pressure
above 120 is cause for concern.
More information
To learn more about blood pressure,
visit the National
Heart, Lung, and Blood Institute or the American
Heart Association.
Reference
Source 101
For more information on how to prevent other diseases, use
PreventDisease.com's "Quick
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