New Beginnings for Sex and Gender Analysis in Neurodegenerative Research
The risk of Alzheimer’s disease affects women to a higher degree than men; but, men are at greater risk of Parkinson’s disease.
“We also know that while diseases such as ALS are more clinically prevalent in men, in a recent study, we found that the most common genetic mutation that causes ALS is more prominent in females than males,” says Dr. Mary Tierney, professor and clinician-scientist at the Department of Family and Community Medicine at the University of Toronto.
“Some mechanisms are protecting women from ALS and rendering men more vulnerable. Why? We need more research for that.”
And yet many research studies in neurodegeneration have combined male and female results without separating them by sex. The practice is changing with the help of the Canadian Consortium on Neurodegeneration in Aging (CCNA). One of its goals is to encourage and support Canadian researchers in including sex and gender differences in their studies of neurodegenerative diseases.
Sex and gender are not the same things. Sex differences refer to differences between males and females based on their sex chromosomes. Gender, on the other hand, refers to social roles, relationships, behaviours and other traits used to describe masculinity and femininity. Male and female traits, like nurturance or aggressiveness, are tied to sex differences in procreation or the influence of sex hormones on behaviour, but their expression depends on the societal context and can vary with time and across cultures.
The CCNA is made up of 20 content-oriented research teams that work on various aspects of degenerative diseases such as Lewy Body Dementia, Driving and Dementia, Caregiving, Nutrition and Lifestyle, Mobility and Exercise. Dr. Tierney leads the Women, Gender, Sex and Dementia (WGSD), a cross-cutting program which oversees the integration of sex and gender into research in all 20 teams.
“At the CCNA, the WGSD provides infrastructure and support to researchers to ensure that relevant sex and gender research questions are studied in all of the CCNA teams using both human and animal model studies. We scrutinize and monitor these projects and we provide feedback and incentives to make them think about sex and gender in their research.”
In the last four years, the WGSD developed an approach and best practice model which Dr. Tierney says could be applied to a wide range of research disciplines and topics.
“We developed six principles that we follow internally to facilitate the integration of sex and gender research when reviewing studies. I serve at the executive level and actively advocate for sex and gender consideration in guidelines, policy, and protocol development, publications and knowledge translation. Through our Women, Gender, Sex and Dementia cross-cutting program, we consider whether sex and gender are relevant to the work at hand, how it may affect their finding, and collect information that will permit the exploration of sex and gender on neurodegeneration in aging.”
Internally, the program has also developed online resources that provide information regarding various online training tools for sex and gender research. They provide input into preliminary research design stages and evidence-based sex and gender research questions. They even synthesize new research ideas regarding sex and gender differences.
Since its inception in 2014, the proportion of studies that incorporate sex and gender into their research projects has substantially increased. Future research plans that include sex and gender have also increased relative to the active projects.
When speaking with researchers, Dr. Tierney acknowledges that the most significant barrier to sex and gender integration in both pre-clinical and human studies is the lack of funding. However, she is optimistic about the advancement currently being seen through this new initiative.
Much of this optimism stems from the support of medical research agencies such as the Canadian Institutes of Health Research and the National Institutes of Health in the United States, which have both implemented a policy requiring sex and gender analysis to be considered in all funded studies. Additionally, the Women’s Brain Health Initiative, one of WGSD’s partners, provides funding and support to the CCNA.