Health Alert: Salt gene study

NATIONAL (NBC) - Patients with high blood pressure are often told to cut back on salt. Even if your blood pressure is normal, you may need to keep a close eye on the sodium in your diet. There's a new test you can't take with a grain of salt.

Gretchen Kelly wants to keep her blood pressure at a healthy level.

"A number of people in my immediate family, both sides, have died from strokes," she explains.

She takes drugs to help lower her blood pressure. A new study suggests she also needs to watch her diet.

"I did learn that I am salt sensitive," said Kelly.

People who are salt sensitive have a dangerous spike in blood pressure after a high-salt meal. Untreated, the problem can lead to stroke, heart attack and kidney failure. Even people with 'normal' blood pressure can be affected.

Robin Felder says, "Salt sensitivity is a hidden disease. You really can't find out if you're salt sensitive with a blood pressure cuff."

University of Virginia researchers are now working on a first-of-it's-kind genetic test to predict salt sensitivity.

"We would like to essentially develop our genetic test for salt sensitivity and high blood pressure so we could tell individuals whether they're going to have this, either have it or going to have these issues so then you can be proactive about lowering your salt at a time when it's easy to do and avoid those issues later in life."

In the study, participants eat a controlled diet for two weeks. Then researchers check tissue samples for changes in blood pressure genes.

The findings show the more genetic changes there are, the higher the risk for salt-induced high blood pressure.

"I have three of the five types that are associated with hypertension," said Kelly.

For salt-sensitive people like Gretchen, cutting back on salt isn't just healthier, it's life-saving.

So far in the study, the genetic test has a 94-percent accuracy rate in predicting salt-sensitivity among people with three or more variations in blood pressure genes.

Similar studies are being held at Georgetown and Vanderbilt universities.