Metabolic syndrome increases mortality risk in women with high-risk HPV

Using large-scale U.S. data following patients for more than a decade, York University Faculty of Health researchers found that women with both metabolic syndrome and high-risk strains of human papillomavirus (HPV) are at a 2.6 times higher risk for mortality than women without either condition, suggesting a need to look at chronic disease comorbidity when it comes to HPV-related cancers.

"While it has been known for some time that metabolic conditions can contribute to lingering HPV, this study extends previous work by examining the associations with mortality risk," says School of Nursing Assistant Professor Catriona Buick, also an Oncology Nurse Clinician Scientist at Sunnybrook Health Sciences Centre.

Buick, an expert in HPV, women's health and cancer care, teamed up with School of Kinesiology and Health Science PhD student Parmis Mirzadeh, whose research looks at obesity and metabolic illness, to take a closer look at the association.

Data for the study, published yesterday in PLOS ONE, was obtained by the United States National Health and Nutrition Examination Survey with a final sample of 5,101 individuals (3,274 women). The researchers found more than a quarter of the women with metabolic syndrome had high-risk HPV.

Their study didn't suggest increased mortality for HPV status alone, which the researchers say could be attributed to the fact that the data only allowed for a snapshot of whether a woman had HPV or not, and could not speak to the persistence.

HPV is the most prevalent sextually transmitted infection and has been referred to as the common flu of STIs. In most cases, the body will clear HPV fairly quickly, but lingering cases of high-risk HPV can develop into precancerous changes in the cervix and in some cases over many years cervical cancer."

Catriona Buick, Assistant Professor and Oncology Nurse Clinician Scientist, Sunnybrook Health Sciences Centre

While most of the 200 known strains do not present a serious problem, a handful are responsible for nearly all cases of cervical cancer, which represents 4.5 per cent of all cancers worldwide.

Metabolic syndrome refers to a cluster of conditions that increase the risk of heart disease, stroke and type 2 diabetes, which can include excess fat around the waist, high fasting blood sugar levels and high blood pressure. While not looked at directly in this study, individuals with metabolic syndrome are about 65 per cent more likely to develop cardiovascular disease and are 25 per cent more likely to die from "any" cause. It is not clear how metabolic syndrome could affect HPV.

"It likely has something to do with a weakened immune response and chronic inflammation, but the research looking at a direct physiological pathway still needs to be done," said Mirzadeh.

One in five Canadian adults have metabolic syndrome and those numbers are rising, and both Buick and Mirzadeh underline the importance of a healthy lifestyle, participating in routine cancer screening and getting vaccinated for HPV.

Jurisdictions in Canada and around the world are moving away from Pap smears and towards HPV testing, which Buick says can alert health practitioners to potential issues earlier and don't need to be done as frequently. While HPV vaccinations are very helpful, they only help protect against a handful of the most common of the 40 known cancer-causing HPV strains, says Buick.

"Regardless of vaccination status, everyone with a cervix still needs to get screened."