A population‐based study of age‐related associations between vaginal pH and the development of cervical intraepithelial neoplasia

Peng Teng,Min Hao

doi:10.1002/cam4.2845

Abstract

The association between vaginal pH and the risk of cervical intraepithelial neoplasia (CIN) is unclear. We evaluated the dose‐response relationship between vaginal pH and CIN risk, as well as the combined influence of vaginal pH and high‐risk human papillomavirus (hrHPV) on the risk of CIN and the mediation effects of hrHPV infection on vaginal pH level and the development of CIN. We investigated 2304 women in Shanxi, China. The dose‐response relationship between vaginal pH and CIN risk was assessed using categoric and spline analyses. We established interaction and mediation models to determine the correlation between pH and hrHPV in the development of CIN. After adjusting covariates, a positive association was observed between hrHPV infection and the development of CIN [OR (95% CI) = 4.75 (3.52‐6.40) for CIN2+; OR (95% CI) = 7.30 (4.10‐13.00) for CIN3+], while a negative correlation was showed between vaginal pH level and CIN3+ [OR (95% CI) = 1.04 (0.59‐1.84); high vs low: OR (95% CI) = 0.32 (0.15‐0.69), P = .002]. The highest risk of CIN (5.24 of CIN2+ and 5.80 of CIN3+) were observed when hrHPV infection was combined with middle vaginal pH (4.6‐5.0). A significant mediation effect of hrHPV infection was observed in the association between vaginal pH level with CIN2+ (P = .002) and CIN3+ (P = .004). In conclusion, abnormal vaginal pH significantly induced the risk of high‐stage CIN in Chinese women infected with hrHPV. Therefore, maintaining normal vaginal pH levels may reduce the risk of CIN.

Highlights

Cervical cancer is the second most common malignant tumor among women worldwide.[1]
Cervical intraepithelial neoplasia (CIN) is the precancerous lesion of the cervix, which is related to invasive cervical cancer, caused by persistent infection of high-risk human papillomavirus.[6,7]
A crossover model and a mediation model were respectively used to evaluate the interaction between vaginal pH level and high-risk human papillomavirus (hrHPV) infection, and whether vaginal pH has a mediating effect in CIN caused by hrHPV, both models were adjusted for age, education, occupation, yearly family income, smoking status, drinking status, and clean the vagina

Summary

Introduction

Cervical cancer is the second most common malignant tumor among women worldwide.[1] Contrary with the decreasing incidence trends in Western countries,[2] cervical cancer incidence has substantially increased in China.[3,4] About 132,000 cases of cervical cancer have occurred in China, accounting for 28% of the world's total cervical cancer burden. TENG and HAO incidence rates being 10 times higher than the national average.[5] Cervical intraepithelial neoplasia (CIN) is the precancerous lesion of the cervix, which is related to invasive cervical cancer, caused by persistent infection of high-risk human papillomavirus (hrHPV).[6,7] The progression from CIN to cervical cancer needs about 8-12 years, so cervical cancer is a preventable disease.[8] Risk prediction should be the first step in the prevention of cervical cancer. Risk factors for CIN and cervical cancer include socioeconomic status, race, smoking, younger age at first intercourse, high parity, and oral contraceptive use.[9,10,11] relatively little is known about nonbehavioral factors that influence the risk of CIN

Methods

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Discussion

Conclusion