CarnalNation

The findings of two studies presented this week at the 2010 International Microbicides Conference in Pittsburgh indicate that using lubricants for anal sex may increase the receptive partner's risk for contracting sexually transmitted infections (STIs), including HIV. The authors of both studies say that their findings warrant further study of the association between lubricants and rectal infection with STIs and HIV.

The first study, led by Julie Russo of the University of Pittsburgh, examined six commonly used lubricants for their safety and impact on rectal tissue. The researchers studied five water-based products (Astroglide, Elbow Grease, ID Glide, KY Jelly, and PRÉ) and one condom-compatible silicone-based product (Wet Platinum). Five of these lubes were the most commonly used by the 6,300 respondents to the International Rectal Microbicides Advocates (IRMA) survey; the sixth product, PRÉ, was chosen by the researchers because its chemical make-up is most closely related to that of the cells lining the rectum. In other words, PRÉ is considered "isomolar" whereas the other five products are considered "hyperosmolar" because they contain higher concentrations of salts and sugars than the cells. The researchers analyzed the chemistry, pH, and slipperiness of each of the lubes and then determined their effects on different cell types, rectal and cervical tissue, and healthy rectal bacteria.

The researchers found that the five hyperosmolar products may have toxic effects on cells because of the higher amounts of sugars and salts contained in them. When cells come into contact with hyperosmolar substances, they seek to correct the chemical imbalance by expelling water, which leads to cell death. The toxicity and resulting cell damage from lubricants may make tissues more susceptible to infection. The results of the analysis indicate that PRÉ and Wet Platinum were the safest lubricants for use during anal sex. Astroglide was shown to be the most toxic to both cells and tissues while KY Jelly had the most deleterious effect on the bacteria necessary for good rectal health. Despite these findings, study author Dr. Charlene Dezzutti emphasizes that conclusions about STI and HIV transmission cannot be made from these data alone.

The second study, led by Pamina M. Gorbach of UCLA, looked at the rectal health, sexual behavior, and lubricant use of 302 men and women from Los Angeles and Baltimore who engage in receptive anal intercourse. The researchers tested the participants for gonorrhea and chlamydia and compared STI incidence against such factors as gender, ethnicity, HIV status, and type of lube used. Water-based lubes were used by 76% of participants. Silicone-based, oil-based, and numbing lubes were used by 28%, 17%, and 6%, respectively. White people (72%) used lube more often than African-Americans (38.5%) and Latinos (57%). HIV-positive participants were also more likely to use lube than HIV-negative participants. The researchers found that the study participants who used lubricants during receptive anal sex were three times more likely to have a rectal STI than those who did not use lube—11.7% compared to 5.1%, respectively. According to these results, rectal lubricants may increase vulnerability to sexually transmitted infections, including HIV. The researchers plan to conduct additional research in this area to determine the possible ways that lubrication may facilitate disease transmission.

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