Summary

To prepare its 2017 guideline on hormone treatment for trans people, the Endocrine Society (a body of hormone doctors) paid Mayo Clinic reviewers to gather all studies on cross-sex hormones and heart health. They found 29 studies. Almost all simply observed patients, and many had no comparison group. Testosterone in trans men worsened cholesterol, raising 'bad' cholesterol and blood fats and lowering 'good' cholesterol. Estrogen in trans women raised blood fats. Heart attacks, strokes, blood clots and deaths were too rarely reported to measure risk, though they were more common in trans women. The reviewers judged the evidence low quality. The review mainly shows how little was known about heart safety when the guideline was written. Larger studies published since (for example Getahun 2018 and Nota 2019) are not included.

Key findings

• La revisión la pagó la Endocrine Society para respaldar su guía de 2017 sobre el tratamiento de la disforia de género (malestar por el propio sexo) con hormonas.
• Incluyó 29 estudios con 3.231 mujeres trans y 1.500 hombres trans; solo 1 asignó el tratamiento al azar, 17 solo compararon a las personas antes y después, y solo 4 tenían un grupo de comparación.
• En los hombres trans, tras 2 o más años, la testosterona se asoció con más grasas en sangre (triglicéridos, +21,4 mg/dL), más colesterol 'malo' (+17,8 mg/dL) y menos colesterol 'bueno' (hasta −8,5 mg/dL).
• En las mujeres trans, las grasas en sangre eran mayores tras 2 o más años (+31,9 mg/dL), sin un cambio claro en el colesterol.
• Entre las mujeres trans, los estudios informaron de 56 coágulos de sangre en 1.767 personas, 14 infartos en 1.073, 8 ictus en 859 y 139 muertes en 1.486, incluidas 23 muertes relacionadas con el corazón y 26 suicidios.
• Entre los hombres trans, los estudios informaron de solo 1 coágulo en 771, 1 infarto en 478, ningún ictus en 340 y 13 muertes en 651.
• Los revisores calificaron la evidencia global de baja calidad, probablemente afectada por la información selectiva, con pocos datos sobre los hechos de salud que más importan a los pacientes.

Abstract

BACKGROUND: Transgender individuals receive cross-sex hormonal therapy to induce desired secondary sexual characteristics despite limited data regarding its effects on cardiovascular health. METHODS: A comprehensive search of several databases up to 7 April 2015 was conducted for studies evaluating the effect of sex steroid use on lipids, myocardial infarction, stroke, venous thromboembolism (VTE), and mortality in transgender individuals. Pairs of reviewers selected and appraised the studies. A random-effects model was used to pool weighted mean differences and 95% confidence intervals (CIs). RESULTS: We found 29 eligible studies with moderate risk of bias. In female-to-male (FTM) individuals, sex steroid therapy was associated with statistically significant increases in serum triglyceride (TG) levels at 3 to 6 months and at ≥24 months (21.4 mg/dL; 95% CI: 0.14 to 42.6) and in low-density lipoprotein cholesterol (LDL-C) levels at 12 months and ≥24 months (17.8 mg/dL; 95% CI: 3.5 to 32.1). High-density lipoprotein cholesterol (HDL-C) levels decreased significantly across all follow-up periods (highest at ≥24 months, -8.5 mg/dL; 95% CI: -13.0 to -3.9). In male-to-female (MTF) individuals, serum TG levels were significantly higher at ≥24 months (31.9 mg/dL; 95% CI: 3.9 to 59.9) without any changes in other parameters. Few myocardial infarction, stroke, VTE, and death events were reported (more frequently in MTF individuals). CONCLUSIONS: Low-quality evidence suggests that sex steroid therapy may increase LDL-C and TG levels and decrease HDL-C level in FTM individuals, whereas oral estrogens may increase TG levels in MTF individuals. Data about important patient outcomes remain sparse.

Conclusion

Low-quality evidence suggests that sex steroid therapy may increase LDL-C and TG levels and decrease HDL-C level in FTM individuals, whereas oral estrogens may increase TG levels in MTF individuals. Data about important patient outcomes remain sparse.