Androgen Receptor Genotype in Humans and Susceptibility to Endocrine Disruptors

Individualized medicine: Sex, hormones, genetics, and adverse drug reactions

Clinically relevant adverse drug reactions differ between men and women. The underlying physiological and pharmacological processes contributing to these differences are infrequently studied or reported. As gene expression, cellular regulatory pathways, and integrated physiological functions differ between females and males, aggregating data from combined groups of men and women obscures the ability to detect these differences. This paper summarizes how genetic sex, that is, the presence of sex chromosomes XY for male or XX for female, and the influence of sex hormones affect transporters, receptors, and enzymes involved in drug metabolism. Changing levels of sex steroids throughout life, including increases at puberty, changes with pregnancy, and decreases with age, may directly and indirectly affect drug absorption, distribution, metabolism, and elimination. The direct and indirect effects of sex steroids in the form of exogenous hormones such as those used in hormonal contraceptives, menopausal hormone treatments, transgender therapy, and over-the-counter performance enhancing drugs may interfere with metabolism of other pharmaceuticals, and these interactions may vary by dose, formulation, and mode of delivery (oral, injection, or transdermal) of the steroid hormones. Few drugs have sex-specific labeling or dosing recommendations. Furthermore, there is limited literature evaluating how the circulating levels of sex steroids impact drug efficacy or adverse reactions. Such research is needed in order to improve the understanding of the impact of sex hormones on pharmacological therapies, particularly as medicine moves toward individualizing treatments.

'Omics' and endocrine-disrupting chemicals - new paths forward

The emerging field of omics - large-scale data-rich biological measurements of the genome - provides new opportunities to advance and strengthen research into endocrine-disrupting chemicals (EDCs). Although some EDCs have been associated with adverse health effects in humans, our understanding of their impact remains incomplete. Progress in the field has been primarily limited by our inability to adequately estimate and characterize exposure and identify sensitive and measurable outcomes during windows of vulnerability. Evolving omics technologies in genomics, epigenomics and mitochondriomics have the potential to generate data that enhance exposure assessment to include the exposome - the totality of the lifetime exposure burden - and provide biology-based estimates of individual risks. Applying omics technologies to expand our knowledge of individual risk and susceptibility will augment biological data in the prediction of variability and response to disease, thereby further advancing EDC research. Together, refined exposure characterization and enhanced disease-risk prediction will help to bridge crucial gaps in EDC research and create opportunities to move the field towards a new vision - precision public health.