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.

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.

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.

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.