ESPE Abstracts

Introduction: International guidelines recommend puberty blocking using GnRH analogs and subsequent association with estrogen therapy in transgender girls who require for medical treatment. They have been shown to have a bone mineral density calculated as standard deviation score (BMD-SDS) for their assigned sex lower than the mean at baseline, and there is a potential risk of impairing peak bone mass as treatment result.

Objective: To study the effects of double therapy in transgender girls based on anthropometric data and BMD. To compare the evolution of weight and BMD, calculated in SDS for assigned sex and SDS for affirmed gender.

Material and method: Retrospective study of 20 transgender girls (45% Tanner II-III) who were treated with triptorelin and subsequent estrogen therapy. Variables included age, weight/height (SDS for age and assigned sex) and BMD (LUNAR Densitometer, GE HealthCare; measurement of g/cm2, in L1L4 and total body excluding the head; SDS for age and assigned sex). Variables analyzed pre-treatment, one year after triptorelin therapy and 12 months after the associating of transdermal estradiol. We compared weight-SDS and BMD-SDS for assigned sex with those corresponding to SDS for affirmed gender.

Results: BMD g/cm2 increased during treatment but BMD-SDS/Assigned sex decreased as treatment progressed. The mean one year after estrogen therapy BMD-SDS is lower than pretreatment but this decline wasn´t observed using BMD-SDS/Affirmed gender scores. Similarly, weight-SDS/Assigned sex was lower than the mean pretreatment and decreased during therapy, however this wasn´t observed if we refer to the weight-SDS/Affirmed gender.

Conclusions: Over the two first year´s treatment in transgender girls, weight-SDS and BMD-SDS/Assigned sex have decreased although SDS values for the affirmed gender have maintained.