ArticleThe Journal of clinical endocrinology and metabolism2021
Erythrocytosis in a Large Cohort of Trans Men Using Testosterone: A Long-Term Follow-Up Study on Prevalence, Determinants, and Exposure Years.
Article in The Journal of clinical endocrinology and metabolism, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 44 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
44 citing papers in PubMed, 3 syntheses or guidelines pooled it, 81 citations in OpenAlex.
- Endocrine Management of Transgender and Gender-Diverse Adolescents: Expert Opinion of the ESPE Working Group on Gender Incongruence and the Endo-ERN Main Thematic Group on Sexual Development and Maturation.Hormone research in paediatrics · 2026Guideline
- Body mass index and body composition changes in transgender people undergoing gender-affirming hormone therapy: a systematic review and meta-analysis.Reviews in endocrine & metabolic disorders · 2025Pooled it
- Diagnosis, management, and outcomes of drug-induced erythrocytosis: a systematic review.Blood advances · 2025Pooled it
- Cardiometabolic diseases in transgender populations.Cardiovascular diabetology. Endocrinology reports · 2026Review
- Therapeutic Issues Associated with Gender-Affirming Hormone Therapy in Transgender Individuals: A Systematic Review Relevant to Community Pharmacy Practice.Pharmacy (Basel, Switzerland) · 2026Review
- Transgender persons receiving gender-affirming hormone therapy: risk of acute cardiovascular events in a Dutch cohort study.European heart journal · 2026Article
- Cerebral Venous Sinus Thrombosis Associated With Testosterone Use as Gender-Affirming Hormone Therapy in a Transgender Patient: Case Report and Literature Review.Clinical case reports · 2026Article
- Testosterone Replacement Therapy in Women Is Associated with Improved Symptom Burden and Favorable Biomarker Changes: A Retrospective Observational Study.Journal of personalized medicine · 2026Article
- Exogenous Testosterone Use Increases the Risk of Central Serous Chorioretinopathy.American journal of ophthalmology · 2026Observational
- Easing the burden: exploring the role of long-acting testosterone formulations in gender-affirming care.Frontiers in public health · 2026Article
- Impact of testosterone-based gender-affirming hormone therapy on toll-like receptor transcript levels and peripheral blood leukocyte counts in transmasculine individuals.Frontiers in immunology · 2026Observational
- Kidney Health and Gender-Affirming Hormone Therapy for Transgender and Gender Diverse Individuals.Clinical journal of the American Society of Nephrology : CJASN · 2026Review
- The Utility of Serum Free Testosterone Concentrations in Monitoring Gender-Affirming Testosterone Therapy in Transmasculine Youth with Obesity.Transgender health · 2025Article
- The safety and efficacy of finasteride for transgender men with androgenetic alopecia: a case series.Journal of medical case reports · 2025Article
- Endocrine issues in critically ill transgender patients: A narrative review.World journal of critical care medicine · 2025Review
- Frequency, Timing, and Management of Erythrocytosis in Adolescents Receiving Gender-Affirming Testosterone Therapy-A Retrospective Study.Transgender health · 2025Article
- Gender-Affirming Care and Health Outcomes Among Transgender and Gender Expansive Youth: Research Advances and Future Priorities.Transgender health · 2025Article
- Testosterone-induced erythrocytosis: addressing the challenge of metabolic syndrome and widely prescribed SGLT2-inhibitor drugs.Endocrine connections · 2025Review
- Testosterone affects female CD4+ T cells in healthy individuals and autoimmune liver diseases.JCI insight · 2025Article
- Comparison of different testosterone formulations discontinuation and dose spacing on hematocrit and testosterone levels in transgender individuals with erythrocytosis.Revista brasileira de ginecologia e obstetricia : revista da Federacao Brasileira das Sociedades de Ginecologia e Obstetricia · 2025Article
Corrections and comments
- Commented on by
- Commented on by
- Commented on by
Authors and funding
6 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
contextErythrocytosis is a known side effect of testosterone therapy that can increase the risk of thromboembolic events.
objectivesTo study the prevalence and determinants in the development of erythrocytosis in trans men using testosterone.
methodsA 20-year follow-up study in adult trans men who started testosterone therapy and had monitoring of hematocrit at our center (n = 1073).
resultsErythrocytosis occurred in 11% (hematocrit > 0.50 L/L), 3.7% (hematocrit > 0.52 L/L), and 0.5% (hematocrit > 0.54 L/L) of trans men. Tobacco use (odds ratio [OR] 2.2; 95% CI, 1.6-3.3), long-acting undecanoate injections (OR 2.9; 95% CI, 1.7-5.0), age at initiation of hormone therapy (OR 5.9; 95% CI, 2.8-12.3), body mass index (BMI) (OR 3.7; 95% CI, 2.2-6.2), and pulmonary conditions associated with erythrocytosis and polycythemia vera (OR 2.5; 95% CI, 1.4-4.4) were associated with hematocrit > 0.50 L/L. In the first year of testosterone therapy hematocrit increased most: 0.39 L/L at baseline to 0.45 L/L after 1 year. Although there was only a slight continuation of this increase in the following 20 years, the probability of developing erythrocytosis still increased (10% after 1 year, 38% after 10 years).
conclusionErythrocytosis occurs in trans men using testosterone. The largest increase in hematocrit was seen in the first year, but also after the first years a substantial number of people present with hematocrit > 0.50 L/L. A reasonable first step in the care for trans men with erythrocytosis while on testosterone is to advise them to quit smoking, to switch to a transdermal administration route, and if BMI is high, to lose weight.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.