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睾酮使跨性别男性的红细胞水平升高：10年内38%超过男性红细胞增多症阈值

大型使用睾酮的跨性别男性队列中的红细胞增多症：关于患病率、决定因素和暴露年限的长期随访研究

队列与登记研究跨性别激素
Authors
Milou Cecilia Madsen, Dennis van Dijk, Chantal M. Wiepjes, Elfi B. Conemans, Abel Thijs, Martin den Heijer
Journal
The Journal of Clinical Endocrinology & Metabolism
Year
2021
Source
https://doi.org/10.1210/clinem/dgab089

Summary

Testosterone makes the body produce more red blood cells. Blood that becomes too thick raises the risk of clots, heart attack and stroke. Amsterdam doctors reviewed blood tests from 1,073 trans men on testosterone over up to 20 years. About one in nine had repeatedly high levels by male standards. The chance of ever crossing the limit kept rising for years, reaching 38% after a decade, so someone stable for years can still develop it. Long-acting injections, smoking, higher weight, older age and lung disease raised the risk. The authors advise checking blood for as long as testosterone is used. More than half of the clinic's trans men were left out for missing data. Using the normal limits for women would label far more people as affected (26%, the authors said in a reply to a letter), so the true scale may be higher.

Key findings

  • 在1,073名使用睾酮的跨性别男性中，11%按男性标准在两次检查中血液过于浓稠（红细胞占血容量一半以上）；3.7%和0.5%超过了更高的标准。
  • 24%至少有一次血液检查高于男性标准。
  • 平均而言，红细胞占血液的比例从治疗前的39%升至一年后的45%，之后在20年间只略有上升。
  • 在有起始数据的776名男性中，曾经超过男性标准的几率在10年后达到38%，14年后达到50%。
  • 与凝胶相比，长效睾酮注射与血液过于浓稠的几率约为3倍有关；吸烟（几率约为两倍）、较高体重、较大的起始年龄和肺部疾病也增加风险。
  • 作者在对一封已发表信函的回复中说，如果改用女性的正常标准，26%会在两次检查中达到标准。
  • 该研究只测量了血液检查，没有测量血栓或心脏病发作等实际的健康事件。

Abstract

CONTEXT: Erythrocytosis is a known side effect of testosterone therapy that can increase the risk of thromboembolic events. OBJECTIVES: To study the prevalence and determinants in the development of erythrocytosis in trans men using testosterone. METHODS: A 20-year follow-up study in adult trans men who started testosterone therapy and had monitoring of hematocrit at our center (n = 1073). RESULTS: Erythrocytosis 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). CONCLUSION: Erythrocytosis 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.

Conclusion

Erythrocytosis 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. The authors add that regular hematocrit control seems warranted for as long as testosterone is used.