Smoking is accompanied by a suppressed cervical nitric oxide release in women with high‐risk human papillomavirus infection

Objective Both smoking and the release of nitric oxide ( NO ) in the uterine cervix are determinants for high‐risk human papillomavirus (hr HPV ) infection. We compared the cervical NO release between smoking and non‐smoking women with and without hr HPV infection. Design Open clinical cohort study. Setting University Hospital in Finland. Population One hundred and twenty‐five smoking and 301 non‐smoking women, with ( n  = 244) and without ( n  = 182) hr HPV infection. In total, 264 women showed cytological and/or histological cervical epithelial changes. Methods The presence of hr HPV was tested by an HPV DNA test and the release of NO was assessed from NO metabolites in the cervical fluid by the Griess reaction. Main outcome measures The difference in cervical NO release between smoking and non‐smoking women with and without hr HPV . Results Infection with hr HPV in smokers (70%) was more frequent ( p  = 0.001) than in non‐smokers (52%). As a whole, smoking was accompanied by a 35% decrease ( p  = 0.04) in NO release in hr HPV ‐infected women (35.9 μmol/L, 95% confidence interval 27.0–44.2) compared with non‐smoking hr HPV ‐ infected women (48.3 μmol/L, 95% confidence interval 38.0–56.2). No difference in NO release between smokers and non‐smokers was seen in women with healthy cervical epithelium, but smoking was accompanied by a suppressed (26%) NO release ( p  = 0.03) in women with either cytological or histological changes. Conclusions Smoking may suppress NO release in the uterine cervix in women with hr HPV infection.