Despite growing evidence that sex and gender play a meaningful role in how Parkinson’s is experienced, diagnosed, and treated, this is not consistently reflected in clinical studies or in our understanding of the condition. This International Women’s Day, we invite both researchers and the Parkinson’s community to reflect on how we can address these gaps.
In the UK, it is estimated that 41% of people with Parkinson’s are women; however, the ratio of men to women in Parkinson’s clinical trials does not currently reflect this. As we seek to improve care and identify new treatments for people with Parkinson’s, it is vital to recognise how sex and gender can influence a person’s experience, from symptom onset to their response to a therapy.
What do we mean by sex and gender?
In medical research, sex is defined by a person’s biological and physiological characteristics, such as genes, reproductive organs, and hormones. Gender, however, is self-defined and based on how a person sees themselves within their society and culture. A person’s experience with conditions and treatments can be affected by both sex and gender.
Recently, we heard the results of the AZA-PD study – a phase 2 clinical trial of the immunosuppressive drug azathioprine. Although some participants reported improvements in their symptoms, the overall results did not show that azathioprine slowed Parkinson’s progression. When the researchers looked at sub-groups of participants, however, they found that azathioprine had a greater beneficial effect in women. Although further research is required to fully understand these results, without the gender-specific analysis, this finding may have been overlooked.
These results are only one example of the growing body of evidence to support that there are gender and sex-specific differences in people with Parkinson’s. Ensuring women are fully represented in studies is critical for improving the quality and accuracy of research and helping us to provide more targeted and personalised care.
How can researchers address this gap?
There are a number of initiatives around the world to improve the representation of women in Parkinson’s research. For example, last year, the Critical Path Institute for Parkinson’s (C-Path) launched the Global Evidence in Medicine for Parkinson’s Disease (GEM-PD) initiative. The goal of GEM-PD is to better understand how Parkinson’s affects women uniquely by using C-Path’s global database and digital tools.
We also encourage researchers to examine their own data through a gender and sex lens and to take advantage of existing resources. For instance, the Michael J. Fox Foundation (MJFF) is currently running an online survey through Fox Insight to understand the experiences of women with Parkinson’s around pregnancy and reproductive health before and after diagnosis. This survey was designed by a group of women with Parkinson’s, with support from Cure Parkinson’s, all of whom were diagnosed with young onset Parkinson’s and have medical and research experience. Through the Fox Den platform, researchers can access this and other anonymised data from people with Parkinson’s to conduct and inform their own research.
How can we make research more accessible?
Taking part in clinical trials is a large commitment. For example, participants often need to take time off work or be away from family to attend hospital visits and pick up prescriptions. Therefore, simply encouraging more women to take part in Parkinson’s research is not enough.
Recent trials are finding ways to improve this. This includes the ongoing Edmond J. Safra Accelerating Clinical Trials for Parkinson’s (EJS ACT-PD) trial, which offers options like digital hospital visits and delivering the drugs directly to participants’ homes. These changes are largely due to the inclusion of people with Parkinson’s when designing the trial. By involving a steering committee of people with Parkinson’s, we can help to ensure that a trial is as accessible as possible and provides meaningful results.
