ESPE Yearbook of Paediatric Endocrinology

mirwig@bidmc.harvard.edu Int J Obes (Lond). 2021 Dec;45(12):2562–2569. doi: 10.1038/s41366-021-00935-x. Epub 2021 Aug 16. PMID: 34400797. https://pubmed.ncbi.nlm.nih.gov/34400797/

Brief Summary: This retrospective chart review of 470 ethnically diverse transgender and gender diverse individuals (>=17 years) from two medical centres in Washington, DC, studied their weight trajectories during gender affirming hormone therapy (GAHT) over up to 57 months. The authors found an increase in body weight in trans-males receiving testosterone almost immediately after GAHT initiation (+3–4%). After that, BMI remained stable for 34 months. In trans-females, BMI first remained constant but increased after 22 months.

The baseline obesity rates of trans-males were 1.5-4x higher than in European studies [1–7] but comparable to US reference populations [8] and rose during GAHT up to 52%, while at baseline and throughout treatment, fewer trans-females individuals than cis-gender people were obese.

While other studies had shown weight increases for trans-males receiving testosterone during the initial year [1–7], data on weight effects of GAHT for trans-females were scarce and conflicting [1–3,7]. This study showed no direct effect during the first 21 months of treatment. Previous studies had shown that the initial weight gain in trans-males is primarily caused by a gain in lean mass while fat mass reduces [9]. As this study did not assess body composition, it is uncertain how much fat mass was gained during treatment. Also, as there was no control group, it is unclear how high the contribution of GAHT compares to other factors like aging, especially since the highest weight gain was observed in the youngest age group (17–29 years old).

Compared to previous reports, this study is the first to describe the time course of body weight changes during GAHT over more than 2 years and its effects on different weight categories and ethnic groups. It shows how vital weight management and obesity treatment are for transgender people who are already at an elevated risk for cardiovascular disease.

References: 1. Deutsch MB, Bhakri V, Kubicek K. Effects of cross-sex hormone treatment on transgender women and men. Obstet Gynecol. 2015 Mar;125(3):605–610. 2. Elbers JMH., Giltay EJ, Teerlink T, Scheffer PG, Asscheman H, Seidell JC, Gooren LJG. “Effects of Sex Steroids on Components of the Insulin Resistance Syndrome in Transsexual Subjects.” Clinical Endocrinology 58, no. 5 (May 2003): 562–71. 3. Fisher AD, Castellini G, Ristori J, Casale H, Cassioli E, Sensi C, Fanni E, et al. “Cross-Sex Hormone Treatment and Psychobiological Changes in Transsexual Persons: Two-Year Follow-Up Data.” The Journal of Clinical Endocrinology and Metabolism 101, no. 11 (November 2016): 4260–69. 4. Pelusi C, Costantino A, Martelli V, Lambertini M, Bazzocchi A, Ponti F, Battista G, Venturoli S, Meriggiola MC. “Effects of Three Different Testosterone Formulations in Female-to-Male Transsexual Persons.” The Journal of Sexual Medicine 11, no. 12 (December 2014): 3002–11. 5. Quirós,C, Patrascioiu I, Mora M, Aranda GB, Hanzu FA, Gómez-Gi El, Godás T, Halperin I. “Effect of Cross-Sex Hormone Treatment on Cardiovascular Risk Factors in Transsexual Individuals. Experience in a Specialized Unit in Catalonia.” Endocrinologia y Nutricion: Organo de La Sociedad Espanola de Endocrinologia y Nutricion 62, no. 5 (May 2015): 210–16. 6. Van Caenegem E, Wierckx K, Taes Y, Schreiner T, Vandewalle S, Toye K, Lapauw B, Kaufman JM, T’Sjoen G. “Body Composition, Bone Turnover, and Bone Mass in Trans Men during Testosterone Treatment: 1-Year Follow-up Data from a Prospective Case-Controlled Study (ENIGI).” Eur J Endocrinol 172, no. 2 (2015): 163–71. 7. Wierckx K, Van Caenegem E, Schreiner T, Haraldsen I, Fisher AD, Toye K, Kaufman JM, T’Sjoen G. “Cross-Sex Hormone Therapy in Trans Persons Is Safe and Effective at Short-Time Follow-up: Results from the European Network for the Investigation of Gender Incongruence.” The Journal of Sexual Medicine 11, no. 8 (August 2014): 1999–2011. 8. Hales CM, Carroll MD, Fryar CD, Ogden CL. Prevalence of Obesity and Severe Obesity Among Adults: United States, 2017–2018. NCHS Data Brief. 2020 Feb;(360):1–8. PMID: 32487284. 9. Klaver M, Dekker MJHJ, de Mutsert R, Twisk JWR, den Heijer M. “Cross-sex Hormone Therapy in Transgender Persons Affects Total Body Weight, Body Fat and Lean Body Mass: A Meta-analysis.” Andrologia 49, no. 5 (2017): e12660.