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.

Reference Intervals for Clinical Chemistry Analytes for Transgender Men and Women on Stable Hormone Therapy.

BACKGROUND: Gender-affirming hormone therapy with either estradiol or testosterone is commonly prescribed for transgender individuals. Masculinizing or feminizing hormone therapy may impact clinical chemistry analytes, but there is currently a lack of published reference intervals for the transgender population. METHODS: Healthy transgender and nonbinary individuals who had been prescribed either estradiol (n = 93) or testosterone (n = 82) for at least 12 months were recruited from primary care and internal medicine clinics specializing in transgender medical care. Electrolytes, creatinine, urea nitrogen, enzymes (alkaline phosphatase, ALK; alanine aminotransferase, ALT; aspartate aminotransferase, AST; gamma-glutamyltransferase, GGT), hemoglobin A1c, lipids [total cholesterol, high-density lipoprotein (HDL), triglycerides], and high-sensitivity C-reactive protein (hsCRP) were measured on 2 clinical chemistry platforms. Reference intervals (central 95%) were calculated according to Clinical Laboratory Standards Institute guidelines. RESULTS: There was minimal impact of gender-affirming hormone therapy on electrolytes, urea nitrogen, hemoglobin A1c, and hsCRP. In general, the enzymes studied shifted toward affirmed gender. Creatinine values for both transgender cohorts overlaid the reference interval for cisgender men, with no shift toward affirmed gender for the estradiol cohort. The effects on lipids were complex, but with a clear shift to lower HDL values in the testosterone cohort relative to cisgender women. CONCLUSIONS: Transgender individuals receiving either masculinizing or feminizing hormone therapy showed significant changes in some analytes that have sex-specific variation in the cisgender population. The clearest shifts toward affirmed gender were seen with enzymes for the estradiol and testosterone cohorts and with creatinine and HDL in the testosterone cohort.

Oral estrogen leads to falsely low concentrations of estradiol in a common immunoassay.

Objectives: Recently, an estradiol immunoassay manufacturer (Beckman Coulter, USA) issued an 'important product notice' alerting clinical laboratories that their assay (Access Sensitive Estradiol) was not indicated for patients undergoing exogenous estradiol treatment. The objective of this analysis was to evaluate immunoassay bias relative to liquid chromatography tandem mass spectrometry (LC-MS/MS) in transgender women and to examine the influence of unconjugated estrone on measurements. Design: Cross-sectional secondary analysis. Methods: Estradiol concentrations from 89 transgender women were determined by 3 immunoassays (Access Sensitive Estradiol ('New BC') and Access Estradiol assays ('Old BC'), Beckman Coulter; Estradiol III assay ('Roche'), Roche Diagnostics) and LC-MS/MS. Bias was evaluated with and without adjustment for estrone concentrations. The number of participants who shifted between three estradiol concentration ranges for each immunoassay vs LC-MS/MS (>300 pg/mL, 70-300 pg/mL, and <70 pg/mL) was calculated. Results: The New BC assay had the largest magnitude overall bias (median: -34%) and was -40%, -22%, and -10%, among participants receiving tablet, patch, or injection preparations, respectively. Overall bias was -12% and +17% for the Roche and Old BC assays, respectively. When measured with the New BC assay, 18 participants shifted to a lower estradiol concentration range (vs 9 and 10 participants based on Roche or Old BC assays, respectively). Adjustment for estrone did not minimize bias. Conclusions: Immunoassay measurement of estradiol in transgender women may lead to falsely decreased concentrations that have the potential to affect management. A multidisciplinary health care approach is needed to ensure if appropriate analytical methods are available.

Sublingual Estradiol Is Associated with Higher Estrone Concentrations than Transdermal or Injectable Preparations in Transgender Women and Gender Nonbinary Adults.

Purpose: Serum hormone profiles among different feminizing gender-affirming hormone therapies (GAHT) are poorly characterized. To address this gap, we described the serum estrogen profiles of three 17ß-estradiol preparations, taken with or without an antiandrogen, using a novel liquid chromatography-mass spectrometry (LC-MS/MS) assay in adults taking feminizing GAHT. Methods: This was a secondary analysis of 93 healthy transgender women and gender nonbinary adults taking feminizing GAHT in a prospective cross-sectional study. Eligible participants took 17ß-estradiol (sublingual tablet, transdermal patch, or intramuscular/subcutaneous injection) with or without oral spironolactone for ≥12 months before study entry. We determined serum estrone and estradiol concentrations for each hormone preparation and described the association between estrone and (1) clinically relevant estradiol concentration ranges (≤200 and >200 pg/mL) and (2) antiandrogen use. To achieve our objectives, we described our protocol for developing an LC-MS/MS assay to measure estrone and estradiol concentrations. Results: Estrone concentrations were higher among participants taking sublingual 17ß-estradiol tablets compared with transdermal or injectable preparations (p < 0.0001). Estradiol concentrations were higher for injectable versus transdermal preparations (p = 0.0201), but both were similar to sublingual tablet concentrations (p > 0.05). Estradiol >200 pg/mL (vs. ≤200 pg/mL) was associated with higher estrone concentrations among participants taking sublingual 17ß-estradiol, but not transdermal or injectable 17ß-estradiol. We observed no association between spironolactone and estrone concentrations (p > 0.5). Conclusion: Estrone concentrations were higher among transgender women and gender nonbinary adults taking sublingual 17ß-estradiol compared with transdermal or injectable preparations. The role of estrone in clinical monitoring and the influence of other antiandrogens (e.g., cyproterone acetate) on the estrogen profile remain to be determined.

Reproductive Endocrinology Reference Intervals for Transgender Women on Stable Hormone Therapy.

BACKGROUND: Transgender women and nonbinary people seeking feminizing therapy are often prescribed estrogen as a gender-affirming hormone, which will alter their reproductive hormone axis. Testosterone, estradiol, and other reproductive hormones are commonly evaluated to assess therapy, but reference intervals specific to transgender women have not been established. The objective of this study was to derive reference intervals for commonly measured analytes related to reproductive endocrinology in a cohort of healthy gender nonconforming individuals on stable feminizing hormone therapy. METHODS: Healthy transgender individuals who had been prescribed estrogen (n = 93) for at least a year were recruited from internal medicine and primary care clinics that specialize in transgender medical care. Total testosterone and estradiol were measured using immunoassay and mass spectrometry; LH, FSH, sex hormone binding globulin, prolactin, progesterone, anti-mullerian hormone (AMH), and dehydroepiandrosterone sulfate (DHEAS) were measured using immunoassay; free testosterone was calculated. Reference intervals (central 95%) were calculated according to Clinical Laboratory Standards Institute guidelines. RESULTS: The distribution of results for transgender women was different than what would be expected from cisgender men or women across all measurements. Use of spironolactone was associated with changes in the result distribution of AMH, FSH, LH, and progesterone. Compared to liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS), immunoassay was sufficient for the majority of estradiol and total testosterone measurements; free testosterone added little clinical value beyond total testosterone. CONCLUSION: Reference intervals specific to transgender women should be applied when evaluating reproductive endocrine analytes. Spironolactone is a significant variable for result interpretation of some tests.

Reproductive Endocrinology Reference Intervals for Transgender Men on Stable Hormone Therapy.

BACKGROUND: Gender-affirming therapy with testosterone is commonly prescribed to aid in the masculinization of transgender men. Sex-hormone concentrations are routinely measured, but interpretation of results can be difficult due to the lack of published reference intervals. METHODS: Healthy transgender individuals who had been prescribed testosterone (n = 82) for at least a year were recruited from internal medicine and primary care clinics that specialize in transgender medical care. Total testosterone and estradiol were measured using immunoassay and mass spectrometry; LH, FSH, SHBG, prolactin, progesterone, anti-Müllerian hormone (AMH), and dehydroepiandrosterone sulfate (DHEAS) were measured using immunoassay; free testosterone was calculated. Reference intervals (central 95%) were calculated according to Clinical Laboratory Standards Institute guidelines. RESULTS: When evaluating general endocrine laboratory tests in people using masculinizing hormones, reference intervals for cisgender men can be applied for total and free testosterone and SHBG and reference intervals for cisgender women can be applied for prolactin. Reference intervals for estradiol, LH, FSH, AMH, and DHEAS differ from those used for cisgender men and cisgender women, and therefore should be interpreted using intervals specific to the transmasculine population. For testosterone and estradiol, results from immunoassays were clinically equivalent to mass spectrometry. CONCLUSION: Masculinizing hormones will alter the concentrations of commonly evaluated endocrine hormones. Providers and laboratories should use appropriate reference intervals to interpret the results of these tests.

Hematology reference intervals for transgender adults on stable hormone therapy.

BACKGROUND: The complete blood count (CBC) is a cornerstone of patient care. Several of the normal values for the components of the CBC differ by sex and, therefore, male-specific and female-specific reference intervals are required to interpret these laboratory results. Transgender individuals are often prescribed hormone therapy to affirm their gender, with resulting serum hormone concentrations similar to those of cisgender individuals. Gender-specific reference intervals for transgender men and women have not been established for any laboratory measurements, including hematology. We established clinically relevant hematological reference intervals for transgender individuals receiving stable hormone therapy. METHODS: Healthy transgender individuals prescribed testosterone (n = 79) or estrogen (n = 93) for ≥12 months were recruited from internal medicine and primary care clinics that specialize in transgender medical care. Concentrations for hemoglobin, hematocrit, MCV, MCHC, and RDWCV, as well as counts for red cells, white cells, and platelets, were evaluated. Results were interpreted in reference to the overall distribution of values and relative to serum estradiol and total testosterone concentrations. Calculated reference intervals were compared to established cisgender reference intervals. RESULTS: Regardless of serum hormone concentration, individuals prescribed testosterone or estrogen had hematology parameters that were not clinically different from cisgender males and females, respectively. CONCLUSION: The hematology parameters for transgender men and women receiving stable hormone therapy should be evaluated against the cisgender male and cisgender female reference ranges, respectively and does not require concurrent sex hormone analysis. Care providers can utilize this observation to aid in interpretation of hematology laboratory values for transgender people.

The Vaginal Microbiome of Transgender Men.

BACKGROUND: Hormonal changes influence the composition of vaginal flora, which is directly related to the health of an individual. Transgender men prescribed testosterone experience a vaginal hormone composition that differs from cisgender women. To the author's knowledge, there are no clinical studies evaluating the influence that testosterone administration has on the vaginal microbiome. METHODS: Vaginal swabs were self-collected by a cohort of self-identified healthy transgender men prescribed testosterone for at least 1 year (n = 28) and from cisgender women who were used as the comparator (n = 8). Participants completed a questionnaire to indicate the mode and dose of testosterone administration, sexual history, and vaginal health. Serum was collected for hormone analysis. Bacterial community profiles were assessed with broad-range PCR primers targeting the V3-V4 hypervariable region of the 16S bacterial rRNA, next-generation sequencing, and analysis by phylogenetic placement. RESULTS: Compared to cisgender women, the vaginal floras of transgender men were less likely to have Lactobacillus as their primary genus. Intravaginal estrogen administration was positively associated with the presence of Lactobacillus in transgender men (P = 0.045). Transgender men had a significantly increased relative abundance of >30 species and a significantly higher α diversity (P = 0.0003). The presence of Lactobacillus was significantly associated with a lower α diversity index (P = 0.017). CONCLUSIONS: The vaginal microbiome of transgender men who were assigned a female sex at birth and use testosterone may differ from that of cisgender women. Intravaginal estrogen administration may reduce these differences by promoting colonization with Lactobacillus species and decreasing α diversity.