Effects of sex steroid hormones on regional fat depots as assessed by magnetic resonance imaging in transsexuals

Abstract

We investigated prospectively the effect of sex steroids on regional fat depots and thigh muscle mass in adult transsexuals. Ethinyl estradiol in combination with cyproterone acetate, a progestational antiandrogen, was given to 20 male-to-female (M-F) transsexuals, and parenteral testosterone esters were given to 17 female-to-male (F-M) transsexuals. Before and after 12 mo of cross-sex hormone administration, several anthropometric measurements (weight, skinfolds, body circumferences, and bioimpedance) were performed, and transverse magnetic resonance images were obtained at the level of the abdomen, hip, and thigh to quantify fat depots (subcutaneous and visceral) and muscle areas. We observed that treatment with ethinyl estradiol in M-F transsexuals induced a significant increase in all subcutaneous fat depots, with a lesser but proportional and significant increase in the visceral fat depot and a decrease in thigh muscle area. Testosterone administration in F-M transsexuals markedly increased thigh muscle area, reduced subcutaneous fat deposition at all levels measured, but slightly increased the visceral fat area. We conclude that sex steroid hormones are important determinants of the sex-specific localization of body fat.

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)

“…Bone turnover markers increased significantly during the first year of testosterone treatment in trans men. The increased muscle mass and loss of fat mass are consistent with previous research carried out in trans men using testosterone treatment (10,11,12,13) and confirm the anabolic effects of testosterone on skeletal muscle described in men (18).…”

“…We previously reported a substantially higher muscle mass and a larger periosteal and endosteal circumference, higher trabecular volumetric bone mineral density (vBMD) and lower cortical vBMD in a cross-sectional study using peripheral QCT (pQCT) in adult trans men after long-term testosterone treatment (10 years) and SRS compared with age-matched control women (9). This larger bone size was probably mostly explained by the higher androgen-induced muscle mass in trans men (10,11,12,13). In order to explore the direct and indirect (through increased muscle mass) influence of sex steroids on adult bone metabolism, mass, and size, we have set up a prospective controlled study in trans men, before any hormonal treatment compared with agematched healthy control women.…”

Testosterone, SHBG and cardiovascular health in postmenopausal women

“…[83][84][85] In obese postmenopausal women, a similar increase in visceral fat and decrease in subcutaneous fat have been reported after administration of a weak androgen (nandrolone decanoate). 86 Similarly, high doses of exogenous testosterone increase BMI and visceral fat mass in female cynomolgus monkeys.…”

A long-term follow-up study of mortality in transsexuals receiving treatment with cross-sex hormones

“…Several studies have looked at the effects of cross-sex hormone administration on laboratory variables related to cardiovascular risk in transsexuals, finding partially favorable and partially unfavorable effects (7)(8)(9)(10). The skewed sex ratio in cardiovascular disease favoring women at all ages and the increasing incidence of cardiovascular disease after menopause were previously interpreted to indicate that estrogens are cardioprotective.…”