Cardiomodulatory Effects of Gender-Affirming Hormone Therapy

The aim of this study is using a prospective and cross-sectional observational design, to assess the effect of initiation and effect of gender-affirming hormone therapy in trans men (female to male) and in trans women (male to female) on: * Cardiovascular risk factors, including blood pressure, body mass index, body composition, and blood lipids * Cardiovascular function, structure and anatomy as assessed by cardiovascular magnetic resonance (CMR) imaging and transthoracic echocardiography * Circulating cardiovascular and inflammatory biomarkers assessed by immunoassays and proteomic profiling * Self-reported health-related quality of life. The study will have one longitudinal group where 60 trans women and 60 trans men are followed from the start of treatment till 6-12 months after. An age-matched control group will go through the same assessments. The second part of the study will be cross-sectional, where the investigators aim to include 100 trans women and 100 trans men already on gender-affirming hormone therapy and being followed at Oslo University Hospital by an endocrinologist. In both these group, patients who both previously or currently are using Gonadotropin-releasing hormone agonists (GnRH-agonists), so called puberty blockers, will also be eligible for inclusion.