Long-Term Hormone Therapy May Affect Metabolic Health of Transgender Individuals: Study Finds - Video

New research from Karolinska Institute shows that long-term sex hormone treatment in transgender individuals can lead to significant changes in body composition and risk factors for cardiovascular disease, particularly in transgender men. The study is published in the Journal of Internal Medicine.

The researchers followed 17 adult transgender men and 16 transgender women who were prescribed treatment with

testosterone and oestrogen, respectively. They used magnetic resonance imaging (MRI) to map body composition and measured metabolic risk factors via blood tests, blood pressure and vascular stiffness. The scans were conducted before the start of hormone therapy, after one year and after five to six years.

The results show that long-term hormone therapy leads to several major changes in both body composition and metabolic risk factors, particularly in transgender men. The changes in fat volumes continued over time, while the greatest changes in muscle mass and strength occurred after just one year of treatment.

In transgender women receiving oestrogen treatment, the changes were not as pronounced. Their muscle volume decreased by an average of seven percent after five years of treatment, whereas muscle strength remained unchanged. The transgender women increased their total fat volume but gained less abdominal fat.

Tissue samples from muscle, fat and skin were also taken as part of the study. The next step is to analyse these tissue samples to understand the interaction between genetic sex and sex hormones. The researchers are investigating, among other things, how hormone treatment affects skeletal muscle gene expression and the mechanisms behind changes in adipose tissue.

Reference: “Longitudinal changes in regional fat and muscle composition and cardiometabolic biomarkers over 5 years of hormone therapy in transgender individuals”, Tommy R Lundberg, Andrea Tryfonos, Lisa MJ Eriksson, Helene Rundqvist, Eric Rullman, Mats Holmberg, Salwan Maqdasy, Jennifer Linge, Olof Dahlqvist Leinhard, Stefan Arver, Daniel P Andersson, Anna Wiik, Thomas Gustafsson, Journal of Internal Medicine, online 28 November 2024, doi: 10.1111/joim.20039.