Laboratory Monitoring in Transgender and Gender-Diverse Individuals

BACKGROUND

Increasing numbers of transgender and gender-diverse individuals are seeking initiation of gender-affirming hormone therapy. This aligns an individual's physical characteristics with their gender identity and improves psychological outcomes. Physical changes, including changes to muscle mass and body fat redistribution, can alter sex-specific laboratory reference ranges.

CONTENT

We review the impact of gender-affirming hormone therapy on laboratory parameters with sex-specific reference ranges, with a focus on hemoglobin/hematocrit, renal function, cardiac biomarkers, and prostate-specific antigen.

SUMMARY

Gender-affirming hormone therapy results in changes in laboratory parameters with sex-specific reference ranges. For individuals established on gender-affirming hormone therapy, reference ranges that align with an individual's gender identity should be used for hemoglobin/hematocrit, serum creatinine, and high-sensitivity cardiac troponin and N-terminal brain natriuretic peptide. Clinicians should interpret these biomarkers according to the reference range that aligns with one's affirmed gender.

Biochemical liver damage during gender affirming therapy in trans adults assigned female at birth: a meta-analysis

PURPOSE

To assess the effects of testosterone (T)-based gender affirming hormone therapy (GAHT) on liver blood tests (LBTs) in assigned female at birth adults, using a meta-analytic approach.

METHODS

Prospective and retrospective studies were selected that reported the prevalence of biochemical liver damage (BLD) and LBTs changes during T therapy. Data collected included pre-and-during therapy alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), gamma-glutamyl-transferase (GGT), and alkaline phosphatase (ALP) mean concentration values.

RESULTS

The prevalence of BLD in 14 studies on 1698 subjects was 1% (95% CI 0.00-3.00; I2 = 14.1%; p = 0.82). In 17 studies on 2758 subjects, GAHT was associated with a statistically (but not clinically) significant increase in AST, GGT and ALP at 12 months and ALT at 3-7 (MD: 1.19 IU/l; 95% CI 0.31, 2.08; I2: 0%), at 12 (MD: 2.31 IU/l; 95% CI 1.41, 3.21; I2: 29%), but with no more significant increase at 24 months (MD: 1.71 IU/l; 95% CI -0.02, 3.44; I2: 0%).

CONCLUSIONS

Analysis of aggregate estimates confirms a low risk of BLD and abnormalities in LBTs, transient in most cases, during T-based GAHT, thus suggesting a limited need for careful liver monitoring in AFAB people.

Cancer care for transgender and gender-diverse people: Practical, literature-driven recommendations from the Multinational Association of Supportive Care in Cancer

In the United States, over 2 million individuals openly identify with a gender that differs from their sex assigned at birth. A cancer diagnosis is physically and psychologically taxing-and, in some, traumatic. However, for transgender and gender-diverse (TGD) people, many of whom have experienced discrimination in myriad health care settings, the challenges may be even greater. These recommendations focus on how best to deliver quality cancer care to transgender men (individuals who identify as men but were assigned female sex at birth), transgender women (individuals who identify as women but were assigned male sex at birth), and people who identify somewhere beyond this gender spectrum as nonbinary or using other terms, based on the available, albeit sparse, literature. This review broaches: (1) the epidemiology of cancer in TGD individuals, including the incidence of cancer and cancer-related mortality; (2) cancer center practices that are welcoming and affirming to TGD patients; (3) the need for awareness and intentionality in the spaces of diagnosis and treatment for cancer; (4) the inevitable conclusion that gender differences exist but much more needs to be learned about the impact of gender-affirming therapy, consisting of gender-affirming surgeries and gender-affirming hormone therapy, on cancer therapy; and (5) the efficacy and perceived safety of antineoplastic therapy and gender-affirming hormone therapy.

Transgender people in clinical trials of drugs and biologics: An analysis of ClinicalTrials.gov from 2007 to 2023

AIMS

Transgender people have unmet health needs related to chronic conditions such as dementia, osteoporosis and hypertension. Community-driven advocacy increased transgender representation in phase III trials for pharmacological prevention of HIV, but the extent to which drug trials for other conditions have included transgender people is unknown. We investigated the extent to which trials of drugs and biologics represented transgender people across therapeutic areas on ClinicalTrials.gov.

METHODS

Cross-sectional analysis of trials of drugs and biologics registered on ClinicalTrials.gov from 2007-2023. We included efficacy and effectiveness trials (phase II-IV) with transgender-related terms (e.g. 'transgend*'). We labelled trials as Inclusive or Exclusive of transgender people using the trial eligibility criteria. We compared trials (therapeutic area, trial design, enrolment), summarized trials registered from 2008 onward and characterized participant enrolment for Inclusive trials with primary trial publications. We summarized continuous data using median (range), categorical data using frequencies and percentages and compared trial characteristics using Fisher's exact test.

RESULTS

Ninety-seven trials represented transgender people. Characteristics were similar between 85 Inclusive and 12 Exclusive trials. Among Inclusive trials, 58% focused on infectious diseases (e.g. treatment or prevention of HIV and COVID-19), 15% on mental health (e.g. post-traumatic stress disorder, substance use-related disorders), and the remainder focused on endocrine (9%), pain (5%), digestive system disorders (1%) and neoplasms (1%). Twenty (of 25) trials reported enrolment of transgender participants in primary trial publications or reported results.

CONCLUSION

Transgender-inclusive trials have increased since 2008. Most trials focused on infectious diseases and mental health. Investigators should increase opportunities to include of transgender people in trials of drugs and biologics for chronic diseases.

Reference Ranges for All: Implementing Reference Ranges for Transgender and Nonbinary Patients

OBJECTIVES

 This study aimed to highlight the necessity of developing and implementing appropriate reference ranges for transgender and nonbinary (TGNB) patient populations to minimize misinterpretation of laboratory results and ensure equitable health care.

CASE REPORT

 We describe a situation where a TGNB patient's abnormal laboratory values were not flagged due to undefined reference ranges for gender "X" in the Laboratory Information System (LIS). Implementation of additional reference ranges mapped to sex label "X" showed significant improvement in flagging abnormal lab results, utilizing sex-invariant reporting as an interim solution while monitoring developments on TGNB-specific reference ranges.

CONCLUSION

 Informatics professionals should assess their institution's policies for registration and lab reporting on TGNB patients as nonimplementation poses significant patient safety risks. Best practices include using TGNB-specific reference ranges emerging in the literature, reporting both male and female reference ranges for clinical interpretation and sex-invariant reporting.

Gender Reassignment and the Role of the Laboratory in Monitoring Gender-Affirming Hormone Therapy

Transgender people experience distress due to gender incongruence (i.e., a discrepancy between their gender identity and sex assigned at birth). Gender-affirming hormone treatment (GAHT) is a part of gender reassignment treatment. The therapeutic goals of the treatment are to develop the physical characteristics of the affirmed gender as far as possible. Guidelines have been developed for GAHT, which recommend dosage as well as different formulations of oestrogen and testosterone for treatment. Questions arise about the metabolic side effects of hormone treatment. Establishing reference ranges for common analytes in transgender individuals remains a task for laboratory medicine. It has been suggested once GAHT is commenced, the reference ranges for affirmed gender are reported for red blood cells, haemoglobin and haematocrit. For transgender assigned-female-at-birth (AFAB) people, testosterone concentrations are recommended to be within the reference interval established for cisgender men and for transgender assigned-male-at-birth (AMAB) people, estradiol concentrations are within the reference range for cisgender women. Sex-specific reference ranges are available for certain laboratory tests, and these may be organ (e.g., heart)-specific. Transgender-specific reference ranges may be a requirement for such tests. Laboratories may need to make decisions on how to report other tests in the transgender population, e.g., eGFR. Interpretation of further tests (e.g., reproductive hormones) can be individualized depending on clinical information. Electronic medical record systems require fields for gender identity/biological sex at birth so that laboratory results can be flagged appropriately. In this review, we aim to summarise the current position of the role of the laboratory in the clinical care of the transgender individual. Prior to the review, we will summarise the genetics of sex determination, the aetiology of gender incongruence, and the recommendations for GAHT and monitoring for the transgender population.

Impact of sex used for assignment of reference intervals in a population of patients taking gender-affirming hormones

Background

Gender-affirming hormone therapy with either estradiol or testosterone for transgender persons can significantly impact chemistry and hematology laboratory tests. The sex used for assignment of reference intervals (RIs) in the electronic health record (EHR) will influence normal/abnormal flagging of test results.

Objective

To analyze common non-hormonal laboratory tests with sex-specific RIs ordered in patients with sexual orientation/gender identify (SOGI) field differences (one or more differences between legal sex, sex assigned at birth, and gender identity) in the EHR at an academic medical center in midwestern United States.

Methods

We utilized a previously characterized data set of patients at our institution that included chart review information on gender identity and gender-affirming therapy. We focused on the subset of these patients that had orders for 18 common laboratory tests in calendar year 2021.

Results

A total of 1336 patients with SOGI field differences (1218 or 91.2% identifying as gender-expansive; 892 or 66.8% receiving estradiol or testosterone as gender-affirming therapy) had a total of 9374 orders for 18 laboratory tests with sex-specific RIs. Hemoglobin, creatinine, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and high-density lipoprotein were the most frequently ordered tests. For patients taking estradiol, 128 of 970 (13.2%) creatinine and 39 of 193 (20.2%) hemoglobin measurements were within the RI for one sex but not the other. For those taking testosterone, 119 of 531 (22.4%) creatinine and 49 of 120 (40.8%) hemoglobin measurements were within the RI for one sex but not the other. Values above the cisgender female RI but within the cisgender male RI were common for hemoglobin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase in patients taking testosterone.

Conclusions

Clinicians should be aware of the potential impact of gender-affirming therapy on laboratory tests and what sex/gender is being used in the EHR to assign RIs.

Effects of 12 Months' Treatment with Testosterone Undecanoate on Markers for Erythropoietic Activity and Safety Aspects in Transgender and Cisgender Hypogonadal Men

BACKGROUND

To investigate the erythropoietic activity and safety aspects of testosterone undecanoate (TU) injections in transgender men, assigned female at birth.

METHODS

Twenty-three men (13 hypogonadal cisgender men and 10 transgender men) who initiated TU at the study start (naïve) and 15 men (10 hypogonadal cisgender men and 5 transgender men) on steady-state treatment with TU (non-naïve) were included in this prospective 1-year observational study. A control group of 32 eugonadal cisgender men was investigated once at baseline. Complete blood count, testosterone in serum and saliva, and plasma lipids, and liver enzymes were assessed.

RESULTS

For naïve transgender men, a significant increase in hemoglobin concentration was noted (mean (SD)), 141 (8) g/L to 151 (13) g/L, while no increase was seen in naïve hypogonadal cisgender men. At the end of the study, naïve transgender men exhibited comparable levels of hemoglobin, hematocrit, and testosterone levels in serum and saliva to hypogonadal cisgender men, as well as to the eugonadal cisgender men. During the study, HDL-cholesterol decreased significantly in naïve transgender men, 1.4 (0.4) mmol/L to 1.2 (0.4) mmol/L, P = 0.03, whereas no significant change was noted in naïve hypogonadal cisgender men. Liver enzymes remained unchanged in all groups.

CONCLUSIONS

After 12 months of treatment with TU in naïve transgender men, hemoglobin and hematocrit increased to levels within the cisgender male reference range. A slight decrease in HDL-cholesterol was seen in naïve transgender men but liver enzymes remained unchanged.

Reference intervals: past, present, and future

Clinical laboratory test results alone are of little value in diagnosing, treating, and monitoring health conditions; as such, a clinically actionable cutoff or reference interval is required to provide context for result interpretation. Healthcare practitioners base their diagnoses, follow-up treatments, and subsequent testing on these reference points. However, they may not be aware of inherent limitations related to the definition and derivation of reference intervals. Laboratorians are responsible for providing the reference intervals they report with results. Yet, the establishment and verification of reference intervals using conventional direct methods are complicated by resource constraints or unique patient demographics. To facilitate standardized reference interval best practices, multiple global scientific societies are actively drafting guidelines and seeking funding to promote these initiatives. Numerous national and international multicenter collaborations demonstrate the ability to leverage combined resources to conduct large reference interval studies by direct methods. However, not all demographics are equally accessible. Novel indirect methods are attractive solutions that utilize computational methods to define reference distributions and reference intervals from mixed data sets of pathologic and non-pathologic patient test results. In an effort to make reference intervals more accurate and personalized, individual-based reference intervals are shown to be more useful than population-based reference intervals in detecting clinically significant analyte changes in a patient that might otherwise go unrecognized when using wider, population-based reference intervals. Additionally, continuous reference intervals can provide more accurate ranges as compared to age-based partitions for individuals that are near the ends of the age partition. The advantages and disadvantages of different reference interval approaches as well as the advancement of non-conventional reference interval studies are discussed in this review.

Distribution of High-Sensitivity Cardiac Troponin and N-Terminal Pro-Brain Natriuretic Peptide in Healthy Transgender People

Importance

Sex-specific differences in the commonly used cardiac biomarkers high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are apparent. There is an absence of medical literature delineating the concentration differences for these biomarkers in transgender individuals without cardiac disease.

Objective

To determine the distribution of hs-cTn and NT-proBNP in healthy transgender people.

Design, Setting, and Participants

In this cross-sectional prospective study, healthy transgender individuals prescribed testosterone or estradiol for 12 months or more were recruited from internal medicine and primary care clinics that specialize in transgender medical care between November 1, 2017, and July 1, 2018.

Exposures

Testosterone or estradiol for 12 months.

Main Outcomes and Measures

Concentrations for hs-cTnI (troponin I), hs-cTnT (troponin T), and NT-proBNP were measured.

Results

Transgender people prescribed testosterone (n = 79; mean [SD] age, 28.8 [7.8] years) or estrogen (n = 93; mean [SD] age, 35.1 [11.7] years) were recruited. The concentration of hs-cTn was significantly higher in transgender men relative to transgender women. For Abbott hs-cTnI levels, the median (IQR) concentration observed in transgender men and women was 0.9 (0.6-1.7) ng/L and 0.6 (0.3-1.0) ng/L, respectively. Results were similar across 2 additional hs-cTn assays. In contrast, NT-proBNP level was higher in transgender women. The median (IQR) NT-proBNP concentration was significantly higher in transgender women ( 49 [32-86] ng/L) than in transgender men (17 [13-27] ng/L).

Conclusions and Relevance

Findings of this cross-sectional study suggest that the differences in concentration for hs-cTn and NT-proBNP between transgender men and women were similar to what is observed between cisgender men and women. Sex hormones, rather than sex assigned at birth, may be a stronger driver of the observed concentration differences between healthy men and women for biomarkers of cardiac disease.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.