Even mild stress can raise blood pressure

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Even mild stress can raise blood pressure

By Faith Reidenbach

NEW YORK, Feb 04 (Reuters Health) - It's been clear for some time that

psychological stress is linked to high blood pressure, or hypertension,

but the reason is unknown.

And until recently, investigations of a stress-hypertension link have

been conducted in laboratories, using staged activities such as public

speaking and mental arithmetic to " stress out " participants.

Now, in a " real-world " setting, a research team in Italy has confirmed

that mild stress can increase blood pressure and impair the

cardiovascular system's ability to regulate itself.

" These changes...might contribute, in susceptible individuals, to the

link between psychological stress and increased cardiovascular risk of

hypertension, " the team suggests in the January issue of Hypertension:

Journal of the American Heart Association.

The scientists detected the changes using a technique called autonomic

assessment, which measures alterations in the autonomic nervous system,

senior researcher Dr. Massimo Pagani told Reuters Health. The autonomic

nervous system controls blood pressure, the heart's rhythm and its

ability to contract, and other important bodily functions.

Changes in autonomic function can be detected by " computerized analysis

of beat-by-beat cardiovascular variability " on an electrocardiogram,

Pagani explained.

Pagani, an internal medicine specialist at the University of Milan, and

colleagues used electrocardiography and blood pressure measurements to

evaluate 30 medical students on two occasions: 30 to 60 minutes before

they took an examination and again 3 months later while they were on

break from classes.

They confirmed that the students were indeed stressed on the exam day,

based on their responses to psychological questionnaires, their saliva

levels of the stress hormone cortisol, and their saliva levels of

cytokines, proteins the immune system releases when the body is

stressed.

The students' blood pressure and heart rate were markedly higher on the

exam day than on the vacation day, the researchers determined. Other

autonomic measures, such as heart rate variability, a measure of the

heart's ability to handle stress, were also elevated on exam day.

" Our goal was to find a technique to assess the stress level acting in

any patient, " Pagani told Reuters Health, so that eventually therapy for

high blood pressure can be " individually planned with tailored lifestyle

changes. " In some cases, these would include non-drug therapies such as

" exercise, food reprogramming and relaxation, " he said.

In other cases, medication would be needed, and autonomic assessment of

patients could help physicians choose the drug, Pagani added.

For example, he pointed out, beta-blockers and ACE inhibitors inhibit an

important component of the autonomic nervous system, called the

sympathetic nervous system. Conversely, calcium-channel blockers, a

different class of antihypertensive drugs, boost the sympathetic nervous

system. Autonomic assessment could make it clear whether a patient's

sympathetic nervous system is adequate or needs to be enhanced or

suppressed.

" The main message, " Pagani said, " is that autonomic research might help

empower patients, who will be progressively in charge of their own

well-being, and fight against cardiovascular risk. "

SOURCE: Hypertension 2002;139:184-188.