Effects of Cross-sex Hormone Therapy on Eating Behavior, Metabolism, Energy Balance and Cardiovascular System

Current study aims to characterize five highly interconnected physiological systems in patients undergoing cross-sex hormone therapy - namely glucose and lipid metabolism, energy balance, eating behavior, functional brain networks involved in the regulation of eating behavior and the cardiovascular system - to gain novel insights into the effects of sex hormones on the human body. Gathered information will help to identify pathophysiological mechanisms for the development of overeating/obesity, insulin resistance, and cardiovascular disease. Secondarily, the relationships between the gut and oral microbiomes and metabolomes and circulating bacterial signatures will be investigated in relation to the other pervasive physiological systems. Current study is an observational study. The decision if the patient's request for cross-sex hormone therapy can complied with (i.e., if cross-sex hormone therapy is medically indicated) is made prior to the first contact with the study center and with the outpatients clinic for Endocrinology at the University Hospital in Leipzig. Decision ifor treatment is made according to national and international guidelines. Treatment of study participants with testosterone and estradiol/antiandrogens is not affected by the study. During the course of the study no invasive interventions are being performed.