A recent article from Popular science explained how researchers experiment almost exclusively on male animal subjects (https://www.popsci.com/male-female-research-subjects). A study from 2011 showed that animals in medical research are up to five times more likely to be male than female. On top of that, when female subjects are included in studies, they tend to be tested when they're at their most "male-like". Meaning they're menopausal or in the period before ovulation and menstruation; researchers say this is to make the experiments simpler by cutting out hormonal cycles. This is a problem due to the fact that what happens in a male organisms body does not reflect what happens in a females body. The results from biomedical studies done using rodents as a test subject are already hard enough to "translate"; however, by leaving out females could make the results even more uncertain. There is no question that males and females have bodies that are different in many ways, we already know for certain that different diseases are more prevalent in human women than in men (and vise versa). A new study aims to quantify the differences between male and female subjects, known as sexual dimorphism. The study analyzed up to 234 physical characteristics in more than 60,000 mice- 14,250 wild type, along with 40,192 mutant mice from 2,186 single gene knockout lines. The knockout mice had one gene inactive to demonstrate what role it plays. The results showed that sex altered the mutation effects by 17.7 percent in quantitative traits, and 13.3 percent in qualitative traits. This just confirms that sex matters in biological studies, females and males metabolize drugs differently and can have drastically different responses to lots of different medical interventions. In fact, most medications are pulled off the market due to adverse reactions in women.
It infuriates me that we have known about this for so long and still have done nothing to change this. It has been 27 years since the National Institutes of Health created the Office of Research on Women's Health as a step to overcome the systemic exclusion of women from studies. They have had great success when it comes to clinical trials, the percent of women has increased from 9 to 41 percent from 1970-2006. Even though they are still underrepresented and should be 50 percent of the study it is much closer than how grossly underrepresented they are in animal studies. The researchers need to start being mindful in what they are doing, I am not positive on the entire logistics of how to setting up a biomedical study but they need to begin including females in equal numbers so there results can be more meaningful.