YOU ARE HERE: LAT HomeCollections

BOOSTER SHOTS: Oddities, musings and news from the
health world

Genetic tests: No anxiety, no gain?

January 12, 2011|By Eryn Brown, Los Angeles Times
  • Daphne Chen, a research associate at Affymetrix, views information from a scanned DNA sample refined from saliva at the company's lab in West Sacramento in April 2008. The information from the scan is used by client Navigenics to link traits and disease predispositions.
Daphne Chen, a research associate at Affymetrix, views information from… (Steve Yeater )

Ever since the 2007 introduction of direct-to-consumer genome-wide tests — assays that scan a patient’s DNA and report his genetic risk of developing 20 to 40 common diseases — observers have wondered if telling regular folks they’re more likely to develop illnesses such as diabetes, heart disease or cancer would trigger extreme anxiety, or would result in increased use of unnecessary and expensive tests.

Apparently it does not, according to researchers at Scripps Health in La Jolla.

But knowing more about potential risk for disease doesn’t seem to push patients to make significant lifestyle changes, either — suggesting that hopes that genome tests would inspire people to take better care of themselves might be overblown.

“People handled [getting their test results] very well. We don’t give consumers enough credit for what they can process,” said Dr. Eric J. Topol, the chief academic officer of Scripps Health and a member of the research team.

But, he said, “the lack of lifestyle improvements was disappointing.”

The Scripps team’s survey was the first to assess how the gene tests affect consumer behavior, experts said. It was published Wednesday in the New England Journal of Medicine.

Researchers recruited 3,639 subjects from San Diego-area health and technology companies. The patients purchased the Navigenics Health Compass, a direct-to-consumer genome test, at a discounted rate, and provided saliva samples at a local collection center.

They filled out an online survey to establish their baseline anxiety and health behaviors, received their test results, and then took another Web survey five months later to report their levels of anxiety and distress, what new health screenings they were planning to get or had received, and what changes, if any, they planned to make or had made in their lifestyles. The surveys were completed by 2,037 subjects, and more than 90% of them demonstrated no test-related distress, the study reported.

People who had higher risk for disease did say they would get a greater number of screening tests in the future to monitor their health. But the team “observed no significant differences in the level of anxiety, dietary fat intake or exercise behavior between baseline and follow-up for the same as a whole,” they wrote.

Topol said the medical establishment remained skeptical about genome-wide tests, and that the results should assuage some fears about the technology. “We’ve shown that at least those people who are curious are not hurt, and they may benefit from the results,” he said.

Other experts were not as convinced of the study’s value.

Dr. Colleen McBride, a researcher at the National Human Genome Research Institution of the National Institutes of Health, said the study was an important “first step,” asking questions about a burgeoning field about which very little is known.

But she said that the results would have been stronger if the subjects hadn’t been self-selected — that they were relatively highly educated, wealthy and motivated compared with the general population.  The team could have taken rigorous measurements of the behaviors subjects reported — hooking patients up to accelerometers, charting their weight and BMI, conducting rigorous dietary assessments, studying health records — instead of depending on Web survey responses.

“If they were going to find behavior change, they should have in this study,” McBride said. “Most of the rhetoric out there is inflated. This is not going to get people to change their behaviors.”

Knowing that you have, say, a doubled chance of having a heart attack one day might not change your doctor’s advice, either. Genetic results or no, you’ll still need to exercise and watch your diet.

“They’re not telling you anything you didn’t already know,” said Michelle Fox, a genetic counselor at UCLA who, like McBride, was not involved in the research. “Is there little anxiety because there’s little information? I’ve long argued that if people sat down and talked through family health histories [more thoroughly] they’d have just as much info as they get from these tests.”

Topol agreed that the test subjects were not representative of the general population. But they were the kinds of people who purchase direct-to-consumer tests today, he said.

“Where do you start?” he asked.

Today’s tests only offer a “gene peek,” he said, but tests in future years will screen more of the genome, providing more definitive information that might more precisely guide clinical care.

“This appears to be a much smarter way to do screening moving forward, especially as we get the genomic data filled in,” he said.

“The explosion of information is remarkable, and it will continue,” UCLA’s Fox said. “This is the future. But it’s not a here-and-now.”

Los Angeles Times Articles