OPEN Research Support

Jan Frystyk
Department of Endocrinology, Odense University Hospital

Projekt styring
Projekt status    Sampling ongoing
Data indsamlingsdatoer
Start 01.07.2018  
Slut 01.09.2044  

Testosterone treatment in transgender men and non-binary persons BODY IDENTITY CLINIC

Short summary

A 10 year prospective study of transgender men treated with testosterone regarding cardiovaskular risk factors, body composition, respiratory function and quality of life. 


Gender dysphoria is a distressed state arising from conflict between a person's gender identity and the sex assigned at birth. The term transgender is used to describe individuals, whose gender identity differs from the assigned sex at birth. Transgender men are persons assigned female at birth, but who self-identify as male. When a person's identity matches the gender assigned at birth, the term cisgender is used. Non-binary persons are persons, who consider themselves as both male and female or alternatively, as neither male nor female. Indeed, there is a growing awareness regarding non-binarity, which is often referred to as gender fluidity.

The number of transgender individuals in Denmark is estimated to be approximately 6,000, but this number may be far too low. Recent European studies reported that 0.6-0.8% of people assigned female at birth and 0.7- 1.1% of people assigned male at birth reported an incongruent gender identity. This would correspond to approximately 50.000 Danish individuals. At present, around 600 persons are referred annually to the clinics in Copenhagen and Aalborg (around 300/center/year), but the number of transgender persons attending health care facilities is increasing, most likely due to increasing awareness.

Transgender men want to use testosterone to change body shape from feminine to masculine and to increase strength.Testosterone treatment in transgender men has been reported to be overall safe regarding short term morbidity, however long term studies are warranted regarding  the prevalence of adverse events, complications, and reference values of blood samples, cardiovascular function and respiratory function.

The aim of this study is to follow a cohort of 200 transgender men on testosterone for 10 years, regarding cardiovascular risk factors, body composition, respiratory function, maximal oxygen consumption and quality of life .

Description of the cohort

Persons assigned female at birth (+18 years) that either use or want to use testosterone with the purpose of undergoing gender transformation.

Data and biological material




CT heart and body


Lung function

Mamimal oxygen consumption 

Body Dxa scans


Collaborating researchers and departments

Study group

Department of Endocrinology, Odense University Hospital 

  • Professor and Head of Research Jan Frystyk PhD DmSci
  • Professor Marianne Skovsager Andersen PhD DmSci
  • Head Consultant Jeppe Gram PhD
  • Louise Lehmann Christensen PhD
  • Consultant Dorte Glintborg PhD DmSci


Gender Identity Centre, Aalborg University Hospital  

Gender Identity Centre, Rigshospitalet, Copenhagen

Department of Endocrinology, Ghent University Hospital, Belgium

Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark 

Research Unit of Muscle Physiology and Clinical Biomechanics, University of Southern Denmark

Department of Clinical Biochemistry, Pharmacology and Genetics, Odense University Hospital

Elite Research Center for Individualized Medicine in Arterial Disease, Odense University Hospital (CIMA)

Center of Clinical Proteomic, Odense University Hospital (CCP)

The Clinical Cardiovascular Centre of Centre of Excellence (CAVAC), Odense University Hospital

Department of Clinical Physiology and Nuclear Medicine, Odense University Hospital 

Department of Psychology, University of Southern Denmark

The Molecular Endocrinology & Stem Cell Research Unit (KMEB), Odense University Hospital & University of Southern Denmark