What is causing low levels of testosterone in men living with HIV?

A study, published in the journal AIDS, has shown that low testosterone levels are common in older men living with HIV despite modern effective antiretroviral treatment. The good news, according to the researchers, is that this problem is not linked to erectile dysfunction (ED) or osteoporosis. Unfortunately low levels of free testosterone may be linked to the use of certain HIV treatments.

Scientists from the Pasteur Institute in Paris enrolled 240 men living with HIV to participate in the study. The average age at enrolment was 43, 78% of whom identified as gay or bisexual. All participants had an undetectable viral load and had lived with HIV for an average of eight years. Of all participants 47% had used, or were using, a non-nucleoside reverse transcriptase inhibitor (NNRTI) based treatment - the remaining 53% were using treatments based on NRTIs, protease inhibitors and integrase inhibitors.

It was found that 9% of the participants had a clinically determined low level of free testosterone - that’s roughly twice the expected number when compared to HIV negative men of the same age.

Those 9% of participants were slightly older than the others, had extensive treatment experience, had experienced a wide range of HIV treatments and had a lower CD4 count than those with normal free testosterone levels.

The team noted that they didn’t find any difference in levels of erectile dysfunction, depression or quality of life when compared to those with normal free testosterone levels.

A number of factors were identified to be associated with lower free testosterone levels:

• Efavirenz use - men who took HIV treatment based on the NNRTI Efavirenz (also sold as Sistine and Stocrin) were four times more likely to experience testosterone problems.
• Older age
• Being overweight
• Low CD4 count

The study’s authors believe that the above factors, especially the use of Efavirenz, may cause hormonal problems for men living with HIV. They recommend that hormone, and specifically free testosterone, levels should be monitored regular as part of HIV care.