Vaccine could one day treat high blood pressure

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Vaccine could one day treat high blood pressure

Updated Thu. Mar. 6 2008 6:30 PM ET

CTV.ca News Staff

Treating high blood pressure could one day be as simple as going for a

vaccination.

A new study published in The Lancet finds that immunization against a hormone

called angiotensin II appears to lower the blood pressure of patients with

hypertension and could eventually replace traditional medications for the

common, and sometimes life-threatening, condition.

People with high blood pressure are typically treated with ACE inhibitors, which

stands for angiotensin-converting enzyme inhibitors, as well as with angiotensin

receptor blockers (ARBs).

While the drugs are effective, patients often stop taking them because they

don't like their side effects, such as dizziness or headache, or think they

don't need them because they are not noticing the symptoms of their high blood

pressure.

In fact, it's estimated that only about a third of patients with hypertension in

the U.S. have their blood pressure under control.

Immunization to suppress the action of angiotensin could simplify treatment,

since it would require only a few injections a year, rather than daily

pill-popping. But previous attempts to immunize against angiotensin I have shown

poor results.

In this study, researchers had better success by targeting angiotensin II, a

potent blood chemical that causes the muscles surrounding blood vessels to

contract, thereby narrowing the vessels and causing high blood pressure.

Dr. Bachmann of Cytos Biotechnology in Schlieren, Switzerland, tested the

vaccine on 72 patients with mild-to-moderate hypertension. The patients received

either 100 micrograms of the vaccine; 300 micrograms of the vaccine (24

patients); or placebo.

Their blood pressures were then taken 14 weeks later.

The researchers found that the 300 microgram group were able to lower their

average daytime blood pressure by -9.0/-4.0 mm Hg compared with placebo. They

also saw their early morning blood-pressure surge drop -25/-13 mm Hg compared

with placebo.

" The drop in blood pressure was especially pronounced in the early morning, when

the renin-angiotensin-aldosterone system is most active and when most

cardiovascular events occur, " the authors note.

In an accompanying editorial, Dr Ola sson and Dr Han Herlitz of the

department of nephrology at Sahgrenska University Hospital in Gothenberg,

Sweden, say: " The results of this new biotherapy for hypertension are intriguing

and promising, and vaccination for hypertension may turn out to be very useful

in many patients. "

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