Robert Sorge, PhD, on the Role of Gender Identity in HIV and Chronic Pain

Gender identity may influence pain sensation more than genetic sex among individuals with HIV and chronic pain, according to new findings published in the Journal of Pain Research.

These findings emerged from a preliminary study of 51 African American participants living with HIV and chronic pain. Of these participants, 24 were cisgender men, 20 were cisgender women, and 7 were transgender women. The researchers recorded data on genetic sex, gender identity, pain severity, pain interference, depression and anxiety, and pain-related stigma. A quantitative sensory testing battery was administered to all participants to evaluate their pain responses to noxious heat and mechanical stimuli.

The results of the study indicated that a greater magnitude of temporal summation for heat pain stimuli or mechanical stimuli was experienced by transgender women and cisgender women compared with cisgender men. Reports of greater severity of chronic pain were more common among transgender women and cisgender women compared with cisgender men. Reports of greater mechanical summation were more common among transgender women compared with cisgender men and cisgender women.

These findings provide further evidence that gender identity and genetic sex are distinct variables, and also that that treatment should take identity into account as opposed to only genetic sex, the authors of the study wrote.

Infectious Diseases Consultant discussed these findings and their implications further with corresponding author Robert Sorge, PhD, associate professor in the Department of Psychology, director of the PAIN Collective, and co-director of the Undergraduate Neuroscience Program at the University of Alabama at Birmingham.

Infectious Diseases Consultant: Could you discuss the significance of recognizing the difference between sex and gender identity when caring for patients?

Robert Sorge: In our work examining pain sensitivity, my collaborators and I have found that certain measures can be used to possibly predict whether a person has a higher likelihood of developing chronic pain. Our work suggests that gender identity may be an important factor in this, possibly even more important than genetic sex. Research has shown that gender roles may play a role in how sensitive people are to pain stimuli when tested in a laboratory setting. This is especially important for clinicians to recognize among people whose gender identity is different than their genetic sex.

ID CON: What prompted you to examine the impact of gender identity on pain responses among people living with HIV and chronic pain?

RS: I have been involved in a lot of animal research that has shown a pronounced sex difference in terms of the immune cells involved in mediating chronic pain. My colleagues and I have demonstrated this in mice and rats, and other researchers have replicated those effects. There are known sex differences in some instances among humans as well. In experimental pain tests, men tend to show a higher pain threshold or less sensitivity to these tests compared with women, who tend to demonstrate more sensitivity to pain stimuli. However, in many of these studies, gender and sex have been equated, and this is not representative of all patient populations.

My colleague, Burel Gooden, PhD, from the University of Alabama at Birmingham, was conducting a study of pain among HIV patients and serendipitously happened to enroll 7 transgender women. We thought it would be interesting to examine whether having a gender identity that differs from one’s genetic sex plays a role in sensitivity to pain.

ID CON: The results of your study indicated that transgender women appeared to experience a greater sensitivity to chronic pain compared with other groups. Could you elaborate on this finding and why you think this was the case?

RS: When it comes to performing pain tests like those we performed in our study, we are able to control the stimulus itself (ie, the temperature, pressure, etc, associated with the stimulus). When people are exposed to the exact same stimuli, the differences in how pain is perceived can be observed in their reaction to those stimuli. Our study showed that transgender women with chronic pain were more sensitive to painful stimuli than cisgender men with chronic pain. We found that there were not many differences in terms of the severity of their chronic pain among transgender women compared with cisgender men, but instead that the sensitivity to painful stimuli tended to align with their gender identity rather than their genetic sex. Because transgender women are a highly stigmatized minority group, it becomes very important to ensure that this is recognized.

ID CON: What key takeaways from this study do you hope to leave with infectious disease specialists and other clinicians who treat patients with HIV and chronic pain?

RS: It is important to know that is that there is a huge sex difference in terms of how pain is treated clinically. Women are much more likely to have their pain attributed to psychological causes, experience more dismissal of their pain, and are generally thought to be expressing higher levels of pain compared with men. However, evidence suggests that women actually are experiencing more pain than men, and they are more sensitive to pain stimuli than men.

If a transgender woman came into a clinic and was expected to experience the same amount of pain relative to their genetic sex, this would not coincide with their actual lived experiences. In the case of HIV and chronic pain, recognition of gender identity is a very important factor in understanding how much pain they may be experiencing. Evidence shows that individuals with HIV tend to experience more chronic pain compared with the general population. Individuals with HIV and multi-site pain also tend to demonstrate higher levels inflammatory molecules or higher levels of inflammation, which can increase pain. Thus, not only are individuals with HIV and chronic pain likely to be more sensitive to pain, but in this group of transgender women in our study, it appears that their sensitivity to the stimuli align with their gender identity rather than their genetic sex.

ID CON: How might health care practices or institutions generate greater awareness of the distinction between gender identity and genetic sex in clinical settings?

RS: On clinical intake forms, it is important to avoid limiting gender options to solely male and female. This primarily asks patients to indicate their sex, but allowing someone to select a gender separate from sex may give the physician more information about the patient.

ID CON: What is the next step in terms of future research in this area?

RS: In the future, we would like to extend this work to a much larger population, and hope to examine the effect of hormones among patients with HIV and chronic pain. In the animal studies that my colleagues and I have performed, we have observed that hormones are really important to the function of immune cells. Our future work will involve examining hormone levels in a more extensive sample of individuals. Our present sample only had transgender women, so in the future, we would like to examine pain sensitivity in transgender men as well.

—Christina Vogt

References:
Strath LJ, Sorge RE, Owens MA, et al. Sex and gender are not the same: why identity is important for people living with HIV and chronic pain. J Pain Res. 2020;13:829-835. doi:10.2147/JPR.S248424