Sex/Gender Differences in Metabolism and Behavior: Influence of Sex Chromosomes and Hormones

Mammalians, including mice, rats, pigs, and dogs, used in scientific research are often males. Such bias is evident because researchers avoid using female animals as they are concerned that their reproductive cycles and hormone fluctuations may confound the results of their studies, which may lead to some disparity observed between preclinical studies and clinical trials. The National Institutes of Health (NIH) in the United States has been directing basic and clinical scientists to consider potential sex differences and perform their studies using cells and tissues derived from both males and females and using both male and female subjects since 2014. We expect an increase in research attention on study of sex differences during the upcoming era.