Many clinical trials are done on men, because those running them fear women’s hormonal cycles will confuse the results. Yet findings are taken as being valid for women on the assumption that such effects will not be large enough to make the drugs useless or unsafe. But some findings are increasingly challenging these somewhat contradictory beliefs, particularly the second part, and questioning whether there are dangers in ignoring the influence of sex chromosomes on medication.
“Right now, when you go to the doctor and you are given a prescription, it might not ever have been specifically tested in females,” said Professor Deborah J. Clegg of Cedars-Sinai Hospital, California, in a statement. “Almost all basic research – regardless of whether it involves rodent models, dogs, or humans – is predominately done in males. The majority of research is done with the assumption that men and women are biologically the same.”
The problem has been recognized for some time. Canada has adopted policies to encourage research that uses both male and female animals in research, leading to at least one scientific breakthrough that would probably not have occurred had they not. Nevertheless, it may be more serious than previously realized.
Clegg is senior author of a paper in Cell Metabolism exploring the ways failure to account for sex can distort scientific results. “While the sex of the subject in clinical studies is obviously important, so too is the sex of the cell, or the hormonal context in which in vitro studies incorporate sex in the model, important,” the paper argues. “Cells may exhibit differential variations upon exposure to sex hormones. Female and male cells respond differently to chemical and microbial stressors.”