A Systematic Review of the Historical Use of Sex and Gender in the American Journal of Physiology-Heart and Circulation

Females continue to be underrepresented in research despite the 1993 National Institute of Health (NIH) Revitalization Act and 2016 NIH mandate for inclusion of sex as a biological variable. Recently, the American Journal of Physiology-Cirulation and Heart (Am J Physiol Heart and Circ) issued a call and published several papers with the focus on sex as a biological variable in an effort to improve inclusion and representation of females in journal articles. To determine the progress Am J Physiol Heart and Circ has made in sex/gender reporting we conducted a systematic review of the first six months of each decade from 1980 to 2020 using PRISMA guidelines. METHODS: In the first six months of 1980 to 2020, 1,729 articles were published, of which 979 articles were reviewed. Articles were excluded if they did not include subjects, were editorials, methodology papers, or other special topics that did not include original research. RESULTS: From 1980 to 2020, human (H) studies increased and animal (A) studies decreased (1980: H=0.8%, A=89.3%; 1990: H=5.1%, A=81.7%; 2000: H=13.9%, A=69.9%; 2010: H=15.4%, A=68.4%; 2020: H=21.2%, A=58.7%). These studies (n=724, 74%) included 42,269 participants. In human studies, the number of males compared to females reported in the journal for each decade was consistently higher (1980: males n=5, females n=3; 1990: males n=199, females n=70; 2000: males n=355, females n=305; 2010: males n=472, females n=186; 2020: males n=1,222, females n=1,157). In animal studies, male animals were included consistently more than females (1980: males n=1,291, females n=58; 1990: males n=2,628, females n=447; 2000: males n=3,083, females n=590; 2010: males n=4,517, females n=663; 2020: males n=1,973, females n=1,372). CONCLUSIONS: While there has been improvement in the inclusion of female participants, this systematic review clearly demonstrates disparities in reporting sex as a biological variable in the Am J Physiol Heart and Circ. The underrepresentation of females in animal and human studies compromises our understanding of female physiology, directly impacting clinical care and outcomes. The call for using sex as a biological variable by the Am J Physiol Heart and Circ will likely contribute to closing the gap on this disparity and set new standards and expectations for the inclusion of females reported in research articles. Further, it is imperative that organizations such as the American Physiological Society and NIH ensure the use of sex as a biological variable as the norm instead of the exception. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.