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 “We know from other research that most people who have HPV clear
that infection after about a year,” said Gypsyamber D’Souza, the
report’s senior author from Johns Hopkins Bloomberg School of Public
Health.
Some people may be more likely to get the infection or have trouble
fighting it off, however. Tobacco users may be among that group,
D’Souza said by phone.
D’Souza and her coauthors used data on 6,887 adults age 18 to 59 who
had been tested for HPV infection, reported their recent nicotine
use and had given blood and urine samples to be tested for nicotine
and tobacco markers as part of a national survey conducted from 2009
to 2012.
Almost 30% were current tobacco users, who were more likely than
nonusers to be male, younger, less educated and to have a higher
number of lifetime oral sexual partners.
Two percent of current tobacco users had the infection, compared to
less than one percent of never or former tobacco users.
Based on the blood tests, with every additional three cigarettes
smoked per day, the risk for HPV-16 infection increased by 31%.
“We saw a very strong association between higher levels of tobacco
use and increased oral HPV prevalence across each of the biomarkers
we evaluated and even at low levels of tobacco use, which would
represent casual use or secondhand smoke,” D’Souza said.
Using biomarkers took away the uncertainty inherent in self-reported
tobacco use, she noted.
Oral HPV-16 infection is not common in the population and testing
positive for the infection does not mean those people went on to
develop cancer, but a 30% increase in risk represents an important
difference, D’Souza said.
Tobacco may suppress the immune system and make it harder for the
body to fight off the infection, she and her colleagues write.
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“It’s not known why (HPV-16) persists in some people,” D’Souza said.
“This suggests that tobacco may have a role in why they might be
unlucky enough not to have cleared the infection.”
Dr. Carole Fakhry, who worked with D’Souza on the study at the Johns
Hopkins University School of Medicine, said the infection is rare.
“The associated cancer is also rare, but increasing in the United
States and abroad,” she said.
Smokers tend to have more sexual partners and risky sexual practices
than nonsmokers, said Xavier Bosch, a public health and cancer
epidemiology expert at the Catalan Institute of Oncology in
Barcelona. He was not part of the new study.
There was still a link between tobacco and HPV infection even when
sexual behavior was accounted for, D’Souza said. That suggests that
riskier sexual behavior doesn’t fully explain the connection.
SOURCE: http://bit.ly/1uXQS02
JAMA 2014.
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reserved.] Copyright 2014 Reuters. All rights reserved. This material may not be published,
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