TUESDAY, June 3 (HealthDay News) -- Your ability to kick the
smoking habit may have a lot to do with your genetic make-up, a new
study finds.
Researchers have found gene patterns that influence a smoker's
response to specific smoking-cessation treatments. The researchers
identified several genetic variations that appear to indicate the
likelihood of success or failure with nicotine replacement therapy
and the smoking-cessation drug bupropion (Zyban).
"There is a significant chunk of evidence that the ability to
quit smoking has inheritable components," said lead researcher Dr.
George R. Uhl, chief of the molecular neurobiology research branch
at the U.S. National Institute on Drug Abuse.
"There is no single gene that has variants related to smoking,"
Uhl said. "There is no gene that even has a large effect. But
nevertheless, we have identified a number of different genes that
are all contributors to the individual differences in the ability
to quit smoking."
The findings were published in the June issue of the
Archives of General Psychiatry.
For the study, Uhl's team analyzed the DNA of 550 smokers who
were part of smoking-cessation studies. These people had been
randomly assigned to receive either nicotine replacement therapy;
the antidepressant Zyban, which has been found to help people quit
smoking; or a placebo.
The researchers found 41 gene variants linked to smokers who
successfully quit using nicotine replacement therapy, and 26 genes
that were specific to successful quitting with Zyban.
Uhl said these genetic variants alone aren't enough to predict
successful treatment to quit smoking. And, the specific role these
genes play still isn't clear, he said.
But, the findings do explain why different people respond to
different smoking-cessation treatments, Uhl said.
"We are now trying to use this information, in new studies of
people who are trying to quit, to see if we can increase the power
of the approaches to smoking cessation," Uhl said. "We want to
target smokers with what would be the best way to help them
quit."
In the future, knowing which smokers are more likely to respond
to specific treatments would help tailor treatment to individual
needs, Uhl said.
The study was supported by the U.S. National Institutes of
Health, the tobacco company Philip Morris USA Inc., and the drug
maker GlaxoSmithKline.
Dr. Norman H. Edelman, scientific consultant to the American
Lung Association, said he thinks that using genetic information to
help people quit smoking is still far in the future.
"There are a lot of powerful tools now that let people go on
fishing expeditions for genetic linkages, and you're always going
to find something," he said. "The fact that they found the few
genes that correlate with whether you're successful in smoking
cessation is not surprising. Your ability to quit is going to
depend at least somewhat on your genetic background."
There may be value in being able to determine who will respond
best to individual treatments, Edelman said.
"I don't think this is going to be used clinically anytime soon,
but it's of some interest that they could make a distinction about
who responds to which treatments," he said.
More information
For more on how to stop smoking, visit the
American Cancer Society.
