Change in Visceral Fat and Total Body Fat and the Effect on Cardiometabolic Risk Factors During Transgender Hormone Therapy

Abstract

Introduction Excess visceral fat increases the risk of type 2 diabetes and cardiovascular disease and is influenced by sex hormones. Our aim was to investigate changes in visceral fat and the ratio of visceral fat to total body fat (VAT/TBF) and their associations with changes in lipids and insulin resistance after 1 year of hormone therapy in trans persons. Methods In 179 trans women and 162 trans men, changes in total body and visceral fat estimated with dual-energy X-ray absorptiometry before and after 1 year of hormone therapy were related to lipids and insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR)] with linear regression analysis. Results In trans women, total body fat increased by 4.0 kg (95% CI 3.4, 4.7), while the amount of visceral fat did not change (−2 grams; 95% CI −15, 11), albeit with a large range from −318 to 281, resulting in a decrease in the VAT/TBF ratio of 17% (95% CI 15, 19). In trans men, total body fat decreased with 2.8 kg (95% CI 2.2, 3.5), while the amount of visceral fat did not change (3 g; 95% CI −10, 16; range −372, 311), increasing the VAT/TBF ratio by 14% (95% CI 10, 17). In both groups, VAT/TBF was not associated with changes in blood lipids or HOMA-IR. Conclusions Hormone therapy in trans women and trans men resulted in changes in VAT/TBF, mainly due to changes in total body fat and were unrelated to changes in cardiometabolic risk factors, which suggests that any unfavorable cardiometabolic effects of hormone therapy are not mediated by changes in visceral fat or VAT/TBF.

The Impact of Hormone Therapy on Cardiometabolic Risk Factors in Trans Persons: Implications and Future Perspectives

“…In agreement with these findings, recent data suggest that the long-term administration of cyproterone acetate, which was used in the present study by Klaver et al ( 6 ), in combination with estradiol reduces insulin sensitivity ( 7 ). Furthermore, Klaver et al ( 6 ) found that in trans men hormone therapy increased testosterone concentrations and induced a modest increase in estradiol, likely due to aromatization of testosterone to estradiol. TBF was decreased, while the amount of VAT did not change, thereby increasing the VAT/TBF ratio by 14% (95% CI: 10-17] in trans men.…”

“…I have read with great interest the article by Klaver et al ( 6 ), in which the authors report the results of an original study that builds upon previous findings of changes in body composition and cardiometabolic risk factors following hormone therapy in trans persons. More specifically, the team of investigators set out to investigate the impact of hormone therapy on the amount of visceral fat (VAT), total body fat (TBF) and the VAT/TBF ratio over approximately 1 year in 179 trans women and 162 trans men with gender dysphoria and examined the associations between changes in body fat mass/distribution and cardiometabolic risk factors.…”

“…Klaver et al ( 6 ) found that hormone therapy increased estradiol and decreased testosterone levels in trans women. This was accompanied by an increase in TBF, while the amount of VAT did not change, resulting in a decrease in the VAT/TBF ratio of 17% (95% CI: 15%-19%) in trans women.…”

“…This was accompanied by an increase in TBF, while the amount of VAT did not change, resulting in a decrease in the VAT/TBF ratio of 17% (95% CI: 15%-19%) in trans women. These changes were paralleled by reduced lean body mass, total cholesterol, high- and low-density lipoprotein cholesterol, and triglyceride concentrations, while homeostatic model assessment of insulin resistance (HOMA-IR) increased ( 6 ). In agreement with these findings, recent data suggest that the long-term administration of cyproterone acetate, which was used in the present study by Klaver et al ( 6 ), in combination with estradiol reduces insulin sensitivity ( 7 ).…”

“…These changes were paralleled by reduced lean body mass, total cholesterol, high- and low-density lipoprotein cholesterol, and triglyceride concentrations, while homeostatic model assessment of insulin resistance (HOMA-IR) increased ( 6 ). In agreement with these findings, recent data suggest that the long-term administration of cyproterone acetate, which was used in the present study by Klaver et al ( 6 ), in combination with estradiol reduces insulin sensitivity ( 7 ). Furthermore, Klaver et al ( 6 ) found that in trans men hormone therapy increased testosterone concentrations and induced a modest increase in estradiol, likely due to aromatization of testosterone to estradiol.…”