Researchers explored the incidence of erythrocytosis in the first 20 months of testosterone therapy among people receiving gender-affirming hormone therapy (GAHT). Specifically, they conducted a descriptive fixed cohort study of hematocrit and hemoglobin data from the charts of 282 people taking testosterone for GAHT. During the first 20 months of testosterone therapy, the cumulative incidence of hematocrit levels over 50.4% was 12.6%; hematocrit levels over 52% was 1.0%; and hematocrit levels over 54% was 0.6%. In adults, normal hematocrit levels for cisgender men range from 41%-50%. For cisgender women, the normal range is slightly lower: 36%-44%. All people were taking injectable testosterone cypionate, with a median dose of 100 mg weekly. The authors concluded that severe erythrocytosis, where hematocrit was over 54%, is a rare outcome of gender-affirming testosterone therapy. Considering this rarity, and the paucity of outcomes data on clinical consequences of erythrocytosis in this population, the authors recommend that doctors who make clinical recommendations for frequent erythrocytosis screening within the first year of testosterone therapy reconsider that need among patients who prefer to minimize lab draws.
What We Know: Family medicine physicians are well-positioned to provide GAHT within their scope of practice. Gender-affirming care may include the use of testosterone, which can increase hemoglobin and/or hematocrit concentrations and can theoretically lead to arterial or venous thromboses. Secondary erythrocytosis from testosterone therapy has not specifically been identified as a cause of thromboses. There are few longitudinal patient-oriented outcomes in generally healthy transgender and gender diverse populations receiving testosterone therapy.
What This Study Adds: Researchers concluded that severe erythrocytosis, where hematocrit is more than >54%, is a rare outcome of gender-affirming testosterone therapy. They assert that primary care doctors making clinical recommendations and medical organizations establishing clinical guidelines reconsider the need for frequent erythrocytosis screening within the first year of testosterone therapy for patients who prefer to minimize lab draws.
Erythrocytosis in Gender-Affirming Care With Testosterone
Alana Tova Porat, et al
Virginia Commonwealth University, Richmond, Virginia
Pre-embargo article link (Link expires at 5 p.m. EDT Sept. 25, 2023)
