Epidemiologic determinants of vaginal pH.
OBJECTIVE
This study was undertaken to evaluate the relationship between vaginal pH and factors related to cervical cancer.


METHODS
In a population-based sample of 9161 women from Guanacaste Province in Costa Rica women were categorized into 2 groups, those with vaginal pH in the reference range (4.0-4.5) and those with elevated vaginal pH (5.0-5.5). Odds ratios were used to estimate the relationship between elevated pH and its potential determinants.


RESULTS
Aging was strongly associated with increasing vaginal pH, starting at around 45 years of age and continuing into old age. Menopause was responsible for an additional 1.7-fold increase in the odds of having an elevated pH (odds ratio 1.7, 95% confidence interval 1.4-2.0). Human papillomavirus infection and cervical intraepithelial neoplasia were not associated with changes in pH.


CONCLUSIONS
Our data indicate that vaginal pH is strongly related to age and to menopausal status and thus could be a marker of age-related hormonal changes. Elevated pH does not appear to be associated with risk of high-grade intraepithelial neoplasia among women infected with human papillomavirus.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D003364:Costa Rica; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008593:Menopause; D008598:Menstruation; D008875:Middle Aged; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000378:metabolism; D012016:Reference Values; D014412:Tumor Virus Infections / Q000378:metabolism; D014621:Vagina / Q000737:chemistry*; D002578:Uterine Cervical Dysplasia / Q000378:metabolism