March 19, 2025
Why pain medication may not be as effective for women as it is for men
A new study led by 荔枝视频 professor Dr. , PhD, may help to explain why there is an over-representation of women experiencing chronic pain compared to men. In 2019, the Canadian Pain Task Force found chronic pain is more common among females of all ages, including children, when compared to males.
鈥淏oth males and females develop pain, but each sex develops it through different means,鈥 says Trang, a professor in the , and (CSM). 鈥This study identifies a very unique type of biological process through a specific immune cell that is distinctive to each sex.鈥
The , published in Neuron, focused on neuropathic pain, which is caused by injury to a nerve or the nervous system. A debilitating symptom of this is allodynia which is experienced when someone feels pain from a stimulus that does not typically cause pain. This condition can be very hard to treat; for instance, things like a light touch, temperature changes, and clothing against the skin can be agonizing. The study, conducted in rats and mice, found that in both sexes pain signals can be communicated by pannexin 1 (Panx1) channels but through different types of immune cells. In female rodents, however, activation of Panx1 releases leptin, a hormone which has been associated with heightened pain sensitivity.
Chronic pain treatment and the female factor
In female rodents, researchers found injury to a nerve releases leptin, a hormone which is associated with heightened pain sensitivity.
Fan et al., Neuron 2025
鈥Injury to a nerve can be debilitating,鈥 says Trang. 鈥淲e know that a lot of preclinical research has been in male subjects. Consequently, treatments were often developed from a male-based understanding and may not be very effective in females.鈥
Heightened levels of leptin in females experiencing chronic pain have been recorded in studies before. Trang notes that as far back as the 1980s, researchers who were working with human blood samples found that female patients experiencing chronic pain had higher levels of leptin in their blood than those who did not have chronic pain.
鈥淚n the clinic, we鈥檝e known for many years that women are more likely than men to suffer from chronic pain, and it鈥檚 often hard to know why some people respond to treatment and others don鈥檛,鈥 says Dr. , MD 鈥03, pain clinician and clinical associate professor at the CSM. 鈥淏oth sex and gender are important factors that need a lot more investigation, but this latest research might prove to be one of the ways that we can personalize treatment for patients so that it鈥檚 more likely to be effective.鈥
High-risk a path to high impact
Trang鈥檚 research is in a category of scientific exploration sometimes referred to as high-risk, high-reward. It means the research has the potential for a big impact, but it also means it could fail. Sourcing funding for this kind of fundamental science can also be difficult. Fortunately, a few years ago, Trang met 荔枝视频 philanthropists Donna and Rod Evans. The former business owners have a family member living with chronic pain and were fascinated by the work Trang was leading.
鈥淲e had our own company; we are very familiar with high-risk ventures,鈥 says Rod. 鈥淎fter talking to Tuan, and hearing about the research he was conducting we wanted to support him.鈥
鈥淚 did a lot of my own research. We were impressed with the projects underway at the Hotchkiss Brain Institute,鈥 adds Donna. 鈥淲e told them we were okay with higher-risk opportunities and committed eyes wide open. We鈥檙e very excited about Tuan鈥檚 results.鈥
In addition to supporting Trang鈥檚 research, the Evans have also supported dementia research at (HBI). Both Rod and Donna鈥檚 fathers were diagnosed with dementia, so that research is near and dear to their hearts.
The first authors of this paper are Churmy Y. Fan, PhD, 鈥20, Brendan B. McAllister BA 鈥11, MSc 鈥14, PhD 鈥19, and Sierra Stokes-Heck, MSc, 鈥23.
In addition to the philanthropic support of the Evans, Trang received grants from the Canadian Institutes of Health Research (CIHR) and Natural Sciences and Engineering Research Council of Canada. Fan was supported by a Spinal Cord, Nerve Injury, and Pain (SCNIP) award through the Hotchkiss Brain Institute (HBI), McAllister was supported HBI postdoctoral and CIHR fellowships. Additional acknowledgements can be found in the paper.
Tuan Trang is an associate dean and professor in the , and a professor in the at the Cumming School of Medicine (CSM). He is a member of and at the CSM.
Lori Montgomery sees patients in the 荔枝视频 Pain Program and is a clinical associate professor in the departments of and at the Cumming School of Medicine (CSM). She is a member of the Hotchkiss Brain Institute and the at the CSM, and is Community Integration Medical Lead for Alberta Health Services Community, Rural and Continuing Care.