The association of nutritional status and other lifestyle factors on human papillomavirus viral load

Abstract

Infection with mucosotropic human papillomavirus (HPV) is necessary but not sufficient for development of cervical intraepithelial lesions and its ultimate stage cervical cancer. The majority of HPV infections are transient and only a minor proportion of infections persist and progress to more advanced stages of cervical dysplasia. This suggests that other factors are involved in the pathogenesis of cervical cancer. Previous studies have determined an increased risk of cervical cancer associated with high HPV viral load. Other host factors such as nutritional status may be associated with HPV infection persistence and higher risk of developing neoplasia. In this study, we have developed a real-time polymerase chain reaction assay to quantitate viral burden of eight HPV types most frequently found associated with cervical cancer. This methodology was used to study the association between viral load and risk of cervical dysplasia. Our results indicate a strong association of high HPV viral load with increased risk of low-grade and high-grade cervical intraepithelial neoplasia (OR = 47.7, 95% CI = 17.04-133.58; and OR = 58.05, 95% CI = 18.43-182.89, respectively). Findings from this study suggest a linear increase of HPV viral load with cytological grade. In addition, we studied the association of HPV viral load with the concentration of circulating antioxidant nutrients and nutrients involved in DNA methylation previously associated with cervical carcinogenesis. Our viral load-nutrient study identified an inverse association of viral burden and circulating trans-lycopene (p, 0.0375), β-cryptoxanthin (p, 0.0494), trans-β-carotene (p, 0.0105), and a possible protective association with cis-lycopene (p, 0.0544) and lutein (p, 0.0977). A direct association with total viral load was observed for α-carotene (p, 0.0038), α-tocopherol (p, 0.0207), γ-tocopherol (p, 0.0288), and δ-tocopherol (p, 0.0446). Findings from this study suggest a role of circulating nutrients in HPV viral load. Overall, HPV viral load may be useful as a surrogate biomarker for HPV persistence.