Considerations of sex and gender differences in preclinical and clinical trials

Sex distribution in clinical trials of radiologic contrast agents: A 27-year review

PURPOSE

Clinical trials play a pivotal role in assessing the safety and efficacy of medical therapies. Addressing sex distribution among enrollees in clinical trials of radiologic contrast agents is essential for ensuring the generalizability of trial outcomes. Previous research has highlighted the influence of demographic factors, particularly sex, on treatment responses, emphasizing the need for equitable representation in clinical trials. Our study aim was to determine the sex distribution of enrollees in clinical trials of radiologic contrast agents.

METHODS

Our retrospective study included a total of 65 clinical trials conducted between 1990 and 2017 identified on clinicaltrials.gov after a comprehensive review including searching individually for all FDA approved contrast agents. Data collected included the year of FDA approval, the number of participants, sex distribution, trial location, trial phase, and study type. Inter-rater validation ensured data accuracy.

RESULTS

Our analysis revealed fluctuations in sex distribution of trial enrollees. Enrollment of males exceeded females in most years, with a shift towards a more equitable representation in recent trials. Trials conducted in the United States had a higher rate of enrollment by females. Phase I trials had the most balanced representation, whereas Phase IV trials had the highest sex disparity.

CONCLUSION

Across all trials, females made up 47.3 % of enrollees [3316 out of 7016 total enrollees]. Enrollment of males exceeded females in 44 of the 65 trials studied, females outnumbered males in 19 trials, and enrollment was equal between the sexes in 2 trials. While the sex distribution observed across all trials represents an equitable representation of enrollees, the wide variance of sex distribution at the level of individual trials has the potential to limit the generalizability of results.

Promoting equity in clinical research: The role of social determinants of health

OBJECTIVE

This study aims to investigate the association between social determinants of health (SDoH) and clinical research recruitment outcomes and recommends evidence-based strategies to enhance equity.

MATERIALS AND METHODS

Data were collected from the internal clinical study manager database, clinical data warehouse, and clinical research registry. Study characteristics (e.g., study phase) and sociodemographic information were extracted. Median neighborhood income, distance from the study location, and Area Deprivation Index (ADI) were calculated. Mixed effect generalized regression was used for clustering effects and false discovery rate adjustment for multiple testing. A stratified analysis was performed to examine the impact in distinct medical departments.

RESULTS

The study sample consisted of 3,962 individuals, with a mean age of 61.5 years, 53.6 % male, 54.2 % White, and 49.1 % non-Hispanic or Latino. Study characteristics revealed a variety of protocols across different departments, with cardiology having the highest percentage of participants (46.4 %). Industry funding was the most common (74.5 %), and digital advertising and personal outreach were the main recruitment methods (58.9 % and 90.8 %).

DISCUSSION

The analysis demonstrated significant associations between participant characteristics and research participation, including biological sex, age, ethnicity, and language. The stratified analysis revealed other significant associations for recruitment strategies. SDoH is crucial to clinical research recruitment, and this study presents evidence-based solutions for equity and inclusivity. Researchers can tailor recruitment strategies to overcome barriers and increase participant diversity by identifying participant characteristics and research involvement status.

CONCLUSION

The findings highlight the relevance of clinical research inequities and equitable representation of historically underrepresented populations. We need to improve recruitment strategies to promote diversity and inclusivity in research.

Women Have Tendons… and Tendinopathy: Gender Bias is a "Gender Void" in Sports Medicine with a Lack of Women Data on Patellar Tendinopathy-A Systematic Review

INTRODUCTION

Patellar tendinopathy is one of the most common musculoskeletal problems associated with sport. While commonly perceived as a predominantly male problem, recent epidemiological studies revealed that it also affects a large number of sport-active women. The aim of this systematic review was to understand how the available treatments apply to women affected by patellar tendinopathy.

METHODS

We analysed the available literature with a systematic review on three databases (PubMed, Cochrane, Web of Science) on February 2021, retrieving a total of 136 studies published from 1983.

RESULTS

The overall scientific field offers an astonishingly low number of data on treatment results referring to only 78 women (2%) in the entire literature. Only 5% of the retrieved articles considered focusing only or mostly on men to be a limitation.

CONCLUSIONS

Women represent only a minority of patients studied for this topic. The few documented cases are further fragmented by being related to different treatments, thus basically offering no solid evidence for results and limitations of any therapeutic approach in women. This literature analysis showed a greater gender gap than what is recognized in science and general medicine; it showed a gender blindness in sports medicine when investigating a common problem like patellar tendinopathy.

Improving clinical outcomes through attention to sex and hormones in research

Biological sex, fluctuations in sex steroid hormones throughout life and gender as a social construct all influence every aspect of health and disease. Yet, for decades, most basic and clinical studies have included only male individuals. As modern health care moves towards personalized medicine, it is clear that considering sex and hormonal status in basic and clinical studies will bring precision to the development of novel therapeutics and treatment paradigms. To this end, funding, regulatory and policy agencies now require inclusion of female animals and women in basic and clinical studies. However, inclusion of female animals and women often does not mean that information regarding potential hormonal interactions with pharmacological treatments or clinical outcomes is available. All sex steroid hormones can interact with receptors for drug targets, metabolism and transport. Genetic variation in receptors or in enzymatic function might contribute to sex differences in therapeutic efficacy and adverse drug reactions. Outcomes from clinical trials are often not reported by sex, and, if the data are available, they are not translated into clinical practice guidelines. This Review will provide a historical perspective for the current state of research related to hormone trials and provide concrete strategies that, if implemented, will improve the health of all people.

Leveraging the Genetic Diversity of Human Stem Cells in Therapeutic Approaches

Since their discovery 15 years ago, human pluripotent stem cell (hPSC) technologies have begun to revolutionize science and medicine, rapidly expanding beyond investigative research to drug discovery and development. Efforts to leverage hPSCs over the last decade have focused on increasing both the complexity and in vivo fidelity of human cellular models through enhanced differentiation methods. While these evolutions have fostered novel insights into disease mechanisms and influenced clinical drug discovery and development, there are still several considerations that limit the utility of hPSC models. In this review, we highlight important, yet underexplored avenues to broaden their reach. We focus on (i) the importance of diversifying existing hPSC collections, and their utilization to investigate therapeutic strategies in individuals from different genetic backgrounds, ancestry and sex; (ii) considerations for the selection of therapeutically relevant hPSC-based models; (iii) strategies to adequately increase the scale of cell-based studies; and (iv) the advances and constraints of clinical trials in a dish. Moreover, we advocate for harnessing the translational capabilities of hPSC models along with the use of innovative, scalable approaches for understanding genetic biases and the impact of sex and ancestry on disease mechanisms and drug efficacy and response. The next decade of hPSC innovation is poised to provide vast insights into the genetic basis of human disease and enable rapid advances to develop, repurpose, and ensure the safety of the next generation of disease therapies across diverse human populations.

Sex and gender differences and biases in artificial intelligence for biomedicine and healthcare

Precision Medicine implies a deep understanding of inter-individual differences in health and disease that are due to genetic and environmental factors. To acquire such understanding there is a need for the implementation of different types of technologies based on artificial intelligence (AI) that enable the identification of biomedically relevant patterns, facilitating progress towards individually tailored preventative and therapeutic interventions. Despite the significant scientific advances achieved so far, most of the currently used biomedical AI technologies do not account for bias detection. Furthermore, the design of the majority of algorithms ignore the sex and gender dimension and its contribution to health and disease differences among individuals. Failure in accounting for these differences will generate sub-optimal results and produce mistakes as well as discriminatory outcomes. In this review we examine the current sex and gender gaps in a subset of biomedical technologies used in relation to Precision Medicine. In addition, we provide recommendations to optimize their utilization to improve the global health and disease landscape and decrease inequalities.

Sex differences in text-mined possible adverse drug events associated with drugs for psychosis

BACKGROUND

Understanding sex differences in adverse drug reactions to drugs for psychosis could potentially guide clinicians in optimal drug choices.

AIMS

By applying a text-mining approach, this study aimed to investigate the relationship between drugs for psychosis and biological sex differences in frequencies and co-occurrences of potential adverse drug events (ADEs).

METHODS

Electronic patient records of a psychiatric population (1427 men and 727 women) were text mined for potential ADEs. The relative risk of experiencing specific ADEs and co-occurrence of ADEs were calculated for each sex.

RESULTS

Findings included 55 potential ADEs with significantly different frequencies between the two sexes. Of these, 20 were more frequent in men, with relative risks of 1.10-7.64, and 35 were more frequent in women, with relative risks of 1.19-21.58. Frequent potential ADEs were psychiatric symptoms, including sexual dysfunction and disturbances in men, and gastrointestinal symptoms, suicidal and self-injurious behaviour and hyperprolactinemia-related events in women. Mention of different hyperprolactinemia-related ADEs often co-occurred in female patients but not in male patients.

CONCLUSION

Several known sex-related ADEs were identified, as well as some previously not reported. When considering the risk-benefit profile of drugs for psychosis, the patient's sex should be considered.

Influences of Sex and Estrogen in Arterial and Valvular Calcification

Vascular and cardiac valvular calcification was once considered to be a degenerative and end stage product in aging cardiovascular tissues. Over the past two decades, however, a critical mass of data has shown that cardiovascular calcification can be an active and highly regulated process. While the incidence of calcification in the coronary arteries and cardiac valves is higher in men than in age-matched women, a high index of calcification associates with increased morbidity, and mortality in both sexes. Despite the ubiquitous portending of poor outcomes in both sexes, our understanding of mechanisms of calcification under the dramatically different biological contexts of sex and hormonal milieu remains rudimentary. Understanding how the critical context of these variables inform our understanding of mechanisms of calcification-as well as innovative strategies to target it therapeutically-is essential to advancing the fields of both cardiovascular disease and fundamental mechanisms of aging. This review will explore potential sex and sex-steroid differences in the basic biological pathways associated with vascular and cardiac valvular tissue calcification, and potential strategies of pharmacological therapy to reduce or slow these processes.

Approaches to considering sex and gender in continuous professional development for health and social care professionals: An emerging paradigm

Consideration of sex and gender in research and clinical practice is necessary to redress health inequities and reduce knowledge gaps. As all health professionals must maintain and update their skills throughout their career, developing innovative continuing professional education programs that integrate sex and gender issues holds great promise for reducing these gaps. This article proposes new approaches to partnership, team development, pedagogical theory, content development, evaluation and data management that will advance the integration of sex and gender in continuing professional development (CPD). Our perspectives build on an intersectoral and interprofessional research team that includes several perspectives, including those of CPD, health systems, knowledge translation and sex and gender.

HIV Persistence on Antiretroviral Therapy and Barriers to a Cure

HIV persists within the body despite successful suppression of virus replication with antiretroviral therapy (ART). HIV lurks in latent and active reservoirs, leading to rebound of virus spread if ART is interrupted. The latent HIV reservoir is a natural consequence of the life cycle of HIV, with integration of HIV into the genomes of cells that are or later enter the resting state, resulting in transcriptionally quiescent provirus. Resting CD4 T cells comprise the majority of the latent reservoir, although new evidence points to additional, smaller cellular reservoirs of latent HIV. An alternate, so-called active reservoir of HIV also exists within cells such as those found the B cell follicle of lymph nodes, where expression of HIV RNA can be found, again despite the full suppression of viremia and viral replication. Multiple factors such as the degree of virus exposure, timing of ART, and host factors can influence the size and characteristics of the HIV reservoir. Constructing effective strategies for HIV eradication and measuring their impact will require a sophisticated knowledge of the HIV reservoir.

Sex differences in acupuncture effectiveness in animal models of Parkinson's disease: a systematic review

Background

Many animal experimental studies have been performed to investigate the efficacy of acupuncture in Parkinson’s disease (PD). Sex differences are a major issue in all diseases including PD. However, to our knowledge, there have been no reviews investigating sex differences on the effectiveness of acupuncture treatment for animal PD models. The current study aimed to summarize and analyze past studies in order to evaluate these possible differences.

Method

Each of 7 databases (MEDLINE, EMBASE, the Cochrane Library, 3 Korean medical databases, and the China National Knowledge Infrastructure) was searched from its inception through March 2015 without language restrictions.

Results

We included studies of the use of acupuncture treatment in animal models of PD. A total of 810 potentially relevant articles were identified, 57 of which met our inclusion criteria. C57/BL6 mice were used most frequently (42 %) in animal PD models. Most of the studies were carried out using only male animals (67 %); only 1 study (2 %) was performed using solely females. The further 31 % of the studies used a male/female mix or did not specify the sex.

Conclusions

The results of our review suggest that acupuncture is an effective treatment for animal PD models, but there is insufficient evidence to determine whether sex differences exist. Future studies of acupuncture treatment for PD should use female animal models because they reflect the physiological characteristics of both males and females to fully evaluate the effect and the safety of the treatment for each sex.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1405-5) contains supplementary material, which is available to authorized users.

Sex distribution of study samples reported in American Society of Biomechanics annual meeting abstracts

Background

Study samples should be appropriately selected to maximize generalizability of results. Excluding one sex from studies of conditions that affect both sexes is problematic and has received attention as a public policy issue in the United States, resulting in legislation and recommendations made by the National Institutes of Health to address this deficiency of study designs. It is unknown to what extent biomechanical studies have inappropriately excluded one sex. The objective of this study was to provide objective data on this question.

Methods

A retrospective review of random samples of abstracts presented at American Society of Biomechanics annual meetings from 1983 to 2013 was conducted to assess reporting of sex of study samples and whether the study samples were approximately balanced with respect to sex.

Findings

We did not find a statistically significant increasing trend in the percentage of abstracts reporting sex over time. However, increasing trends were noted in the percentage of abstracts including both sexes (p < 0.05) and percentage of abstracts having an “approximately balanced” study sample containing 50 ± 20% females (p > 0.05). In 2013 the percentage of abstracts reporting studies having approximately balanced study samples was only 28%, far from the ideal level of 100%.

Interpretation

While there has been modest change since 1983, there remains significant room for improvement in the reporting and composition of experimental studies reported at American Society of Biomechanics annual meetings.

Effects of treatment with zofenopril in men and women with acute myocardial infarction: gender analysis of the SMILE Program

Background

the SMILE studies proved the prognostic benefit of zofenopril vs. placebo or other ACE-inhibitors (ACEIs) in post-acute myocardial infarction (AMI). In this retrospective pooled analysis of these studies we assessed whether the zofenopril effect is influenced by gender.

Methods

the four double-blind, randomized, parallel-group SMILE studies, compared the efficacy and safety of 6–48 week treatment with zofenopril 60 mg/day with that of placebo, lisinopril 10 mg/day or ramipril 10 mg/day in 3630 AMI patients. This pooled analysis compared treatment efficacy (1-year combined occurrence of death or hospitalization for CV causes) in 2733 men and 897 women.

Results

women were older than men, had a higher prevalence of diabetes and of other major CV risk factors. The risk of a major CV event was significantly larger for women (23% vs. 17% men, p<0.001). Between-gender risk difference was more marked for people living in Southern (+54%) than in Northern Europe (+12%). In both genders zofenopril similarly reduced the 1-year risk of CV morbidity and mortality vs. placebo (−39% men, p = 0.0001; −40% women, p = 0.005). The risk reduction was more marked with zofenopril than with the other ACEIs, particularly in men (−27%, p = 0.012; women: −14%, p = 0.479). The drug safety profile was similar between genders in zofenopril-treated patients, while it was worse in women treated with other ACEIs.

Conclusions

post-AMI women are at higher risk of CV complications than men, particularly when living in Mediterranean countries. Their response to ACE-inhibition varies according to the type of drug and is usually better in men.

Pharmacogenomics, pharmacokinetics and pharmacodynamics: interaction with biological differences between men and women

Pharmacological response depends on multiple factors and one of them is sex-gender. Data on the specific effects of sex-gender on pharmacokinetics, as well as the safety and efficacy of numerous medications, are beginning to emerge. Nevertheless, the recruitment of women for clinical research is inadequate, especially during the first phases. In general, pharmacokinetic differences between males and females are more numerous and consistent than disparities in pharmacodynamics. However, sex-gender pharmacodynamic differences are now increasingly being identified at the molecular level. It is now even becoming apparent that sex-gender influences pharmacogenomics and pharmacogenetics. Sex-related differences have been reported for several parameters, and it is consistently shown that women have a worse safety profile, with drug adverse reactions being more frequent and severe in women than in men. Overall, the pharmacological status of women is less well studied than that of men and deserves much more attention. The design of clinical and preclinical studies should have a sex-gender-based approach with the aim of tailoring therapies to an individual's needs and concerns.

Should there be sex-specific criteria for the diagnosis and treatment of heart failure?

All-cause mortality from cardiovascular disease is declining in the USA. However, there remains a significant difference in risk factors for disease and in mortality between men and women. For example, prevalence and outcomes for heart failure with preserved ejection fraction differ between men and women. The reasons for these differences are multifactorial, but reflect, in part, an incomplete understanding of sex differences in the etiology of cardiovascular diseases and a failure to account for sex differences in pre-clinical studies including those designed to develop new diagnostic and treatment modalities. This review focuses on the underlying physiology of these sex differences and provides evidence that inclusion of female animals in pre-clinical studies of heart failure and in development of imaging modalities to assess cardiac function might provide new information from which one could develop sex-specific diagnostic criteria and approaches to treatment.