While receptive anal sex is a known risk factor for anal human papillomavirus (HPV) infection and squamous cell carcinoma of the anus (SCCA), people with anal HPV infection and SCCA frequently report no lifetime receptive anal sex, implying that other factors may also increase the risk for anal HPV infection and persistence. Researchers predicted that body mass index (BMI) was related to HPV infection because of potential connections between obesity and diseases that may produce perianal or anal canal lesions. Anal canal specimens from men aged 18–70 from Brazil, Mexico, and the United States were genotyped for 36 HPV types. Eligibility requirements included a lack of a history of genital warts or HIV. Evaluable specimens were obtained from 328 men who had sex with men (MSM) and 1348 men who had sex with women (MSW) who had no lifetime receptive anal intercourse. In addition to adjusted prevalence ratios for the relationship between BMI and HPV infection, the prevalence of anal HPV infection and six-month persistence by BMI was calculated. Obese men showed a greater prevalence of HPV-16 in the anal canal than normal-weight men, albeit the 95 percent CI overlapped. HPV prevalence decreased with increased BMI among MSM. For persistence, a similar pattern was seen. After controlling for covariates, obese MSW had 2.4 times the risk of HPV-16 as normal-weight men.

BMI may be favorably linked with anal HPV among MSW and negatively associated with anal HPV among MSM, indicating that universal HPV vaccination programs should be maintained.

Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2019.1593083