Searchable abstracts of presentations at key conferences in endocrinology

ea0086mte8 | Metabolism, Obesity and Diabetes | SFEBES2022

Metabolic lessons from patients undergoing sex reassignment

den Heijer Martin

It is well known that cardiovascular risk differs between men and women and that this difference also changes over life. Sex hormones are thought to play a critical role in these differences, although it is difficult to distinguish between hormonal, chromosomal and environmental factors. Part of the effect of sex hormones can be explained by the effects of sex hormones on body composition, blood pressure, and lipid and glucose metabolism. Transgenders feel incongruence between...

ea0081rc8.5 | Rapid Communications 8: Calcium and Bone | ECE2022

Estradiol is the major sex steroid regulating bone marrow fat in both men and women: a study in transgender persons

Tebbens Marieke , Schutte Moya , Troelstra Marian , Nederveen Aart , den Heijer Martin , den Heijer Peter H

Background: Bone marrow fat is a unique fat depot that is regulated independently of other fat depots. Estradiol is an important regulator of bone marrow fat. This is illustrated by an increase in marrow fat fraction after menopause and a decrease following estradiol replacement. We hypothesize that estradiol is the major sex steroid that regulates bone marrow fat not only in women, but also in men.Methods: This is an open-label partly randomized interve...

ea0063oc14.2 | Sex Hormones | ECE2019

The effect of testosterone therapy on serum oestradiol levels in transgender men

Defreyne Justine , Aers Xavier-Philippe , Daphne Fisher Alessandra , Schreiner Thomas , Den Heijer Martin , T'Sjoen Guy

Background: Testosterone therapy in transgender men (TM) is aimed at achieving serum testosterone levels in the male reference range. It remains unknown if serum oestradiol levels in TM should be evaluated and/or adjusted. Although reported serum oestradiol levels in TM are variable in the current literature, these values may be affected through two possible mechanisms: serum oestradiol levels may increase through aromatization of exogenous testosterone, while the effects of e...

ea0041gp146 | Paediatric Endocrinology & Development | ECE2016

Breast development in male-to-female transgender patients after one year cross-sex hormonal treatment

de Blok Christel , Klaver Maartje , Nota Nienke , Dekker Marieke , den Heijer Martin

Background: In male to female transgender patients breast development is a key part in the process of feminization using cross sex hormone therapy. In the Endocrine Society’s clinical guideline ‘Endocrine treatment of transsexual persons’ the onset of breast growth is estimated as 3–6 months after starting cross sex hormone treatment. The maximum breast growth however is seen after 2–3 years. But how much growth, in centimeters or cup-sizes, we can exp...

ea0041ep397 | Developmental endocrinology | ECE2016

Cross-sex hormone therapy affects body fat distribution in transgender persons

Klaver Maartje , Dekker Marieke , Schreiner Thomas , Fisher Alessandra , T'sjoen Guy , den Heijer Martin

Introduction: Fat distribution is an important secondary sex characteristic, which is generally peripherally or pear-shaped (gynoid) in females and centrally or apple-shaped (android) in males. Total body fat increases in male-to-females (MtFs) and decreases in female-to-males (FtMs) during cross-sex hormone therapy (CSHT), approaching body fat amounts of the desired sex. However, changes in android or gynoid fat distribution might be a better measure for masculinization and f...

ea0041ep961 | Steroid metabolism + action | ECE2016

Increase in insuline-like growh factor levels during cross-sex hormone treatment in transgender persons

Nota Nienke , Dekker Marieke , Klaver Maartje , Wiepjes Chantal , Heijboer Annemieke , den Heijer Martin

Background: Sex steroids probably stimulate growth-hormone secretion during puberty, which in turn contributes to the development of gender specific body characteristics. Hypothetically, adequate growth hormone levels in transgender persons are also important to achieve the best therapeutic results. The influence of cross-sex hormone treatment (CHT) at growth-hormone production in adult transgender persons is not yet elucidated.Objective: To investigate ...

ea0037gp.10.05 | Calcium, Vitamin D and Bone | ECE2015

Effect of 1-year cross-sex hormonal treatment on bone mineral density of the lumbar spine in transgender patients

Vlot Mariska , Klaver Maartje , Lips Paul , de Jongh Renate , Heijboer Annemieke , den Heijer Martin

Background: Oestrogen can increase bone mineral density (BMD) by decreasing bone turnover, which is mainly seen in trabecular bone. Testosterone can increase bone size, but the effect on BMD is less clear. Cross-sex hormonal treatment (CSHT) in transsexuals can therefore affect the BMD. For example, in male-to-female individuals (MtFs) a lower BMD before start of CSHT has been described in comparison to healthy control men.Objectives: To investigate the ...

ea0037gp.11.08 | Calcium, Vitamin D and Bone (1) | ECE2015

Associations of visceral and hepatic fat with serum 25-hydroxyvitamin D concentrations

de Jongh Renate , de Mutsert Renee , Lips Paul , Rosendaal Frits , den Heijer Martin

Introduction: Obesity is associated with lower serum 25-hydroxyvitamin D (25(OH)D) concentrations. A major explanatory hypothesis is that vitamin D is sequestered by adipose tissue. Another hypothesis is a decreased hepatic activation by 25-hydroxylase in obese individuals. Because adipose tissue has different characteristics and functions in different parts of the body an important question is whether serum 25(OH)D is more strongly related to visceral (VAT), hepatic, or total...

ea0037ep130 | Steroids, development and paediatric endocrinology | ECE2015

Serum prolactin levels in transgender persons before and during cross-sex hormonal treatment

Nota Nienke , Klaver Maartje , den Heijer Martin , Dekker Marieke , Heijboer Annemieke

Introduction: Gender dysphoria refers to the incongruence between the subject’s experienced sex on the one hand and the assigned sex on the other hand. Several studies assume a relationship between oestrogen substitution therapy and serum prolactin levels.Aim: The aim of this study is to get more insight into the effect and time-course of changes in serum prolactin levels during cross-sex hormone therapy.Methods: This prospect...

ea0056oc3.5 | New insights in bone disorders | ECE2018

Change in bone mineral density during the first 10 years of gender affirming hormonal treatment in transwomen and transmen

Wiepjes Chantal , de Blok Christel , Vlot Mariska , de Jongh Renate , Lips Paul , den Heijer Martin

Background: Concerns about the effects of gender affirming hormonal treatment (HT) on bone mineral density (BMD) exists, particularly for transmen with decreasing estrogen levels. HT in transpersons affects BMD on short term, but long-term follow-up studies are lacking. Therefore this study aimed to investigate the change in BMD during the first 10 years of HT in adult transwomen and transmen, in order to determine whether it is necessary to assess BMD during HT.<p class="...