Smoking's Connection to Genital Warts

Smokers are at a "moderately increased" risk of genital warts, according to the authors of a study who set out to assess the association between smoking and clinical diagnosis of genital warts.

A team of researchers administered a questionnaire on lifestyle and health to a sample of 58,094 women (ages 18 to 45) randomly drawn from the general population of Denmark, Iceland, Norway, and Sweden. Longitudinal data were reconstructed based on self-report of age-specific events. Women reporting having been clinically diagnosed with genital warts were followed up until the age at first diagnosis; women reporting never having been diagnosed with genital warts were censored at the age of the interview.

Included in the model as time-dependent covariates were age-specific smoking doses and ages at onset of smoking, sexual intercourse, condom use, hormonal contraceptive use, first pregnancy, and alcohol drinking. Lifetime number of coital partners and country of origin were included in the model as fixed covariates.

Compared to never-smokers, ever-smokers reported a lower age at first intercourse and more coital partners. In the adjusted model, sexual behavior strongly influenced the risk of diagnosis with genital warts, and smokers had an increased risk compared with nonsmokers. A modest additional dose-response effect was noted, with smokers experiencing a 0.6% increased risk of genital wart diagnosis for each additional cigarette smoked daily.

"Smokers experienced a moderately increased risk of being diagnosed with genital warts," the authors concluded. "This finding could be explained by the immunosuppressive effects of nicotine, or by confounding not accounted for the in the adjusted model."