Friday, November 19, 2010

Treatment zaps high blood pressure at the source

Treatment zaps high blood pressure at the source

By Julie Steenhuysen Julie Steenhuysen – Wed Nov 17, 12:18 pm ET

CHICAGO (Reuters) – A device that destroys nerves leading to the kidney safely lowered blood pressure in people with treatment-resistant hypertension, potentially offering a new option for millions of people who struggle to keep their disease in check, researchers said on Wednesday.

The device, made by privately held Ardian Inc of Mountain View, California, lowered the top blood pressure reading by an average of 32 points after six months, compared with no change in patients who took the best available medicines.

"There are a lot of questions, but it is very exciting," said Dr. Suzanne Oparil of the University of Alabama at Birmingham, who reviewed the findings presented at the American Heart Association meeting in Chicago.

The one-time treatment works by silencing nerves leading into and out of the kidney, which play a central role in the sympathetic nervous system, the body's "fight or flight" response that can increase heart rate and blood pressure.

Procedures that surgically disrupt these nerves had been shown to lower high blood pressure decades ago, but were abandoned with the advent of drugs that target the renin-angiotensin system, which regulates blood pressure and fluid retention.

"Those drugs are good but not perfect," said Dr Murray Esler of the Baker IDI Heart and Diabetes Institute in Melbourne, Australia, whose findings were released online by the Lancet.

"We can see that because of their failure in the patients on this trial. They are all on drugs of this type."

BLOOD PRESSURE READING FELL BY 32 POINTS

High blood pressure, or too much force exerted by blood as it moves against vessel walls, is the leading risk factor for premature death worldwide.

Nearly half of Europeans have hypertension, and in the United States, about 75 million Americans do -- and only two-thirds of those people are treated. Among those who are, half do not get their blood pressure under control.

Normal blood pressure is considered to be 120 over 80 or lower. A top reading of over 140 is considered high blood pressure.

[...]

After six months, blood pressure among those who got the treatment fell by 32 points on the top reading and 12 points on the bottom reading, pushing some into the near-normal range. There was no change in the control group.

"It was a big effect," Esler said. "The main pressure in the group after denervation was 145, and in 39 percent of them, it was 140 systolic."

"It's a much bigger effect than you would anticipate in a drug trial, particularly in these people, who are resistant to drugs anyway," Esler said.

Very, very interesting. Especially the part about the kidneys and the sympathetic nervous system being a controlling element of hypertension. I was able to dig up other info on the kidney-hypertension link, and it's pretty solid. Low carb and/or fasting is a more natural treatment option. The low carb route also helps the other parts of metabolic syndrome (low HDL, high Triglcyerides, abdominal obesity, high blood sugar, and hypertension), whereas this treatment only affects one. I'm curious why it doesn't seem to affect the other factors, and also wonder if it has any effect on mortality. In other words, does a treat a symptom of metabolic disorder, but not improve the underlying problem?

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