Sex Differences in Medicine
Series edited by Barbara Stranger
Biological sex profoundly influences disease risk, pathogenesis, progression, and treatment, but there are persistent gaps in the study of sex differences that span all areas of medicine. Reviews in this series will examine sex as a biological variable in cancer, metabolism, cardiovascular disease, autoimmunity, and more and highlight the potential to leverage these sex differences to optimize therapies for all.
Articles in series
Abstract
Testosterone (T) and 17β-estradiol (E2) are produced in male and female humans and are potent metabolic regulators in both sexes. When E2 and T production stops or decreases during aging, metabolic dysfunction develops and promotes degenerative metabolic and vascular disease. Here, we discuss the shared benefits afforded by E2 and T for metabolic function human females and males. In females, E2 is central to bone and vascular health, subcutaneous adipose tissue distribution, skeletal muscle insulin sensitivity, antiinflammatory immune function, and mitochondrial health. However, T also plays a role in female skeletal, vascular, and metabolic health. In males, T’s conversion to E2 is fundamental to bone and vascular health, as well as prevention of excess visceral adiposity and the promotion of insulin sensitivity via activation of the estrogen receptors. However, T and its metabolite dihydrotestosterone also prevent excess visceral adiposity and promote skeletal muscle growth and insulin sensitivity via activation of the androgen receptor. In conclusion, T and E2 are produced in both sexes at sex-specific concentrations and provide similar and potent metabolic benefits. Optimizing levels of both hormones may be beneficial to protect patients from cardiometabolic disease and frailty during aging, which requires further study.
Authors
Franck Mauvais-Jarvis, Sarah H. Lindsey
Abstract
Cancer risk is modulated by hereditary and somatic mutations, exposures, age, sex, and gender. The mechanisms by which sex and gender work alone and in combination with other cancer risk factors remain underexplored. In general, cancers that occur in both the male and female sexes occur more commonly in XY compared with XX individuals, regardless of genetic ancestry, geographic location, and age. Moreover, XY individuals are less frequently cured of their cancers, highlighting the need for a greater understanding of sex and gender effects in oncology. This will be necessary for optimal laboratory and clinical cancer investigations. To that end, we review the epigenetics of sexual differentiation and its effect on cancer hallmark pathways throughout life. Specifically, we will touch on how sex differences in metabolism, immunity, pluripotency, and tumor suppressor functions are patterned through the epigenetic effects of imprinting, sex chromosome complement, X inactivation, genes escaping X inactivation, sex hormones, and life history.
Authors
Joshua B. Rubin, Tamara Abou-Antoun, Joseph E. Ippolito, Lorida Llaci, Camryn T. Marquez, Jason P. Wong, Lihua Yang
Abstract
Depression and multiple musculoskeletal disorders are overrepresented in women compared with men. Given that depression is a modifiable risk factor and improvement of depressive symptoms increases positive outcomes following orthopedic intervention, efforts to improve clinical recognition of depressive symptoms and increased action toward ameliorating depressive symptoms among orthopedic patients are positioned to reduce complications and positively affect patient-reported outcomes. Although psychosocial factors play a role in the manifestation and remittance of depression, it is also well appreciated that primary biochemical changes are capable of causing and perpetuating depression. Unique insight for novel treatments of depression may be facilitated by query of the bidirectional relationship between musculoskeletal health and depression. This Review aims to synthesize the diverse literature on sex, depression, and orthopedics and emphasize the potential for common underlying biological substrates. Given the overrepresentation of depression and musculoskeletal disorders among women, increased emphasis on the biological drivers of the co-occurrence of these disorders is positioned to improve women’s health.
Authors
Mackenzie Newman, Henry J. Donahue, Gretchen N. Neigh
Abstract
Biological sex is an important modifier of physiology and influences pathobiology in many diseases. While heart disease is the number one cause of death worldwide in both men and women, sex differences exist at the organ and cellular scales, affecting clinical presentation, diagnosis, and treatment. In this Review, we highlight baseline sex differences in cardiac structure, function, and cellular signaling and discuss the contribution of sex hormones and chromosomes to these characteristics. The heart is a remarkably plastic organ and rapidly responds to physiological and pathological cues by modifying form and function. The nature and extent of cardiac remodeling in response to these stimuli are often dependent on biological sex. We discuss organ- and molecular-level sex differences in adaptive physiological remodeling and pathological cardiac remodeling from pressure and volume overload, ischemia, and genetic heart disease. Finally, we offer a perspective on key future directions for research into cardiac sex differences.
Authors
Thomas G. Martin, Leslie A. Leinwand
Abstract
Globally, the majority of people living with HIV are women or girls, but they have been a minority of participants in clinical trials and observational studies of HIV. Despite this underrepresentation, differences in the pathogenesis of HIV have been observed between men and women, with contributions from both gender- and sex-based factors. These include differences in the risk of HIV acquisition, in viral load set point and immune activation in responses to viremia, and differences in HIV reservoir maintenance. These differences obligate adequate study in both males and females in order to optimize treatments, but also provide a powerful leverage point for delineating the mechanisms of HIV pathogenesis. The shifts in exposure to sex steroid hormones across a lifespan introduce additional complexity, which again can be used to focus on either genetic or hormonal influences as the driver of an outcome. In this Review, we discuss consistent and reproducible differences by sex across the spectrum of HIV, from acquisition through pathogenesis, treatment, and cure, and explore potential mechanisms and gaps in knowledge.
Authors
Erin Mihealsick, Anna Word, Eileen P. Scully
Abstract
Autoimmune diseases are a leading cause of disability worldwide. Most autoimmune diseases occur more often in women than men, with rheumatic autoimmune diseases being among those most highly expressed in women. Several key factors, identified mainly in animal models and cell culture experiments, are important in increasing autoimmune disease in females. These include sex hormones, immune genes including those found on the X chromosome, sex-specific epigenetic effects on genes by estrogen and the environment, and regulation of genes and messenger RNA by microRNAs found in extracellular vesicles. Evidence is also emerging that viruses as well as drugs or toxins that damage mitochondria may contribute to increased levels of autoantibodies against nuclear and mitochondrial antigens, which are common in many autoimmune diseases. The purpose of this Review is to summarize our current understanding of mechanisms that may determine sex differences in autoimmune disease.
Authors
DeLisa Fairweather, Danielle J. Beetler, Elizabeth J. McCabe, Scott M. Lieberman
Abstract
Half of adults in the United States have hypertension as defined by clinical practice guidelines. Interestingly, women are generally more likely to be aware of their hypertension and have their blood pressure controlled with treatment compared with men, yet hypertension-related mortality is greater in women. This may reflect the fact that the female sex remains underrepresented in clinical and basic science studies investigating the effectiveness of therapies and the mechanisms controlling blood pressure. This Review provides an overview of the impact of the way hypertension research has explored sex as a biological variable (SABV). Emphasis is placed on epidemiological studies, hypertension clinical trials, the genetics of hypertension, sex differences in immunology and gut microbiota in hypertension, and the effect of sex on the central control of blood pressure. The goal is to offer historical perspective on SABV in hypertension, highlight recent studies that include SABV, and identify key gaps in SABV inclusion and questions that remain in the field. Through continued awareness campaigns and engagement/education at the level of funding agencies, individual investigators, and in the editorial peer review system, investigation of SABV in the field of hypertension research will ultimately lead to improved clinical outcomes.
Authors
Michael J. Ryan, John S. Clemmer, Roy O. Mathew, Jessica L. Faulkner, Erin B. Taylor, Justine M. Abais-Battad, Fiona Hollis, Jennifer C. Sullivan
Copyright © 2024 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)